PC VS ABS

PC VS ABS Plastic is a comparative guide with helpful info. It shows the suitability of each material for different uses. This guide lets you get the information you might need to improve your business strategies.

Plastic is handy, but it also poses environmental issues. However, if you are aware, you can reduce these risks and create a better world.

The first synthetic plastic was discovered in 1907. Since then, people have used plastics instead of metals or wood. Plastics are everywhere, from household items to car parts. We need plastics in electronics items, packaging, and even consumable items. So, you have many product options to create for your customers. However, the issue is choosing the suitable plastic material for them. ABS and PC are two popular plastics used in our modern world.

plastic injection molding material

What is ABS Polycarbonate?

ABS and Polycarbonate, or PC, are two different plastics. They can be combined or used as separate materials but are most commonly found in individual forms.

When you compare these materials (ABS VS PC), you must thoroughly know their properties. Also, you must know how to use them in various products. Once you have ideas for all these, you can choose the best option for your project. If you still have questions, feel free to contact us.

What is PC Plastic?

PC stands for Polycarbonate. People mainly like PC plastics because they are impact-resistant and easy to mold. It’s a type of thermoplastic.

PC plastic was first discovered in 1953, and now, it is one of the most used plastic materials in the industry. Most of the industries prefer PC plastic over ABS plastic.

Polycarbonate has a combination of BPA and phosgene. The process of making PC plastic is known as condensation polymerization.

In the factory, an operator first prepares raw materials. Then, he mixes the BPA in a solvent. During the mixing, the machine introduces the phosgene gas into the mixture. The process is fully automated, so the amount required for the reaction remains stable. Finally, this process will end by creating the polycarbonate resin.

Next, the operator melts the polycarbonate resin and puts it in an extruder. The machine then produces long strands of PC profiles through the extrusion process. The operator cools the strands and cuts them into small pallets. These pallets are the raw PC plastics you need to create various PC injection molding plastic products.

Properties of PC Plastics

The combination of BPA and phosgene improves the behavior of PC plastic. Because of this, polycarbonate pallets are trendy for many plastic products.

(1)  The most important benefit that we can get from PC plastic is its toughness. It is almost unbreakable. It can smoothly work in temperatures between -20°C and 140°C.

(2) PC plastic has high impact strength. Note that its density is between 1.2 and 1.22. Because of this, this polymer can resist high impact and fracture. For safety and comfort, PC plastic is an excellent choice.

(3) PC plastic is transparent. According to various scientists, it can transmit light more than 90% of the time. Various manufacturers customize this transparency based on customer needs.

(4) PC plastic is exceptionally lightweight, not lighter than ABS. It typically weighs only 1.19 grams per cubic centimeter. Since it offers excellent transparency, you can use it to create many OEM products, saving significant costs.

(5) PC plastic is entirely UV resistant. This means it can block ultraviolet radiation up to 100%.

(6) This thermoplastic is also chemically resistant. It is excellent against many hydrocarbons, alcohols, and mild acids. However, it shows fair resistance to petroleum. Also, for alkalis and HH, PC plastic breaks easily.

(7) Finally, PC plastic works great under high heat. It remains 100% stable even at 135°C. if you wan to know more high heat materials, please go to high temperature plastic material page to know more.

Business Opportunities of PC Plastics

Because of the above seven benefits, PC plastics are prevalent in various applications. There are great opportunities for businesses to enter this vast market.

PC plastic is better than other plastic materials in many ways. It is resistant to impact and high heat. It also offers transparency up to 94%. Due to these benefits, PC plastic is in high demand in the plastic products market.

The following table showcases the trendy PC plastic products in the niche market. You can also get a similar product made of different alternative materials. Alternative materials might be cheap for specific parts. Therefore, knowing the properties of the materials for plastic parts is crucial when choosing them.

Category Popular Products/Opportunities Alternative Materials
Electronic Devices Power system parts, telecom hardware, high-stable capacitors ABS, PET, and PVC
Building Materials Dome lights, glazing, roofing sheets, and sound walls Glass, acrylic, and PVC
3D printing Prototypes, OEM parts, plastic tools PLA, ABS, and Nylon
Data Storage Kits Discs, signage sheets, or films ABS, Acrylic, and PET
Vehicle Parts Headlamp lenses, bezels, reflectors, and bullet-proof window glass Glass, Acrylic, and ABS
Aerospace & Military Cockpit canopies, riot shields, safety goggles Glass, Acrylic
Optical Devices Eyewear lenses, camera lenses, sunglass lenses Glass, Acrylic
Mobile Devices Smartphone cases, coves, screen protectors Glass, Metal, ABS
Medical tools Sterilize equipment, biocompatible materials ABS, PEEK, SS
Niche Use Luggage, MP3 player cases, toys, hobby parts, UV-resistant outdoor items ABS, Nylon, and metal

PC VS ABS

What is ABS Plastic?

ABS stands for Acrylonitrile Butadiene Styrene. People prefer ABS plastic due to its durability, impact resistance, and ease of molding. It is also a type of thermoplastic.

ABS Plastic was first discovered in 1948 before PC plastic. It is mainly prevalent due to its cost-effectiveness and ease of manufacture.

ABS plastic comprises three raw materials: Acrylonitrile, Butadiene, and Styrene. In the factory, an operator prepares these monomers and then moves them to the polymerization chamber.

In the polymerization chamber, the operator mixes the monomers in water with surfactants. This mixing gradually creates tiny droplets. Finally, the reactor produces ABS copolymer.

Later, he mixes the monomers in the reactor again, but he won’t add water this time. This process is fully controlled so the operator can ensure a uniform distribution of the monomers. The result of this process is molten ABS.

After cooling the molten ABS, the operator cuts it into pallets. The plastic product factory mainly uses these pallets to shape them into various ABS products. Go to ABS injection molding page and is ABS plastic safe page to know more about ABS.

Properties of ABS Plastic

The polymer chain of ABS plastic offers many unique benefits. Although ABS is not superior to PC, it is still trendy in the plastic market due to its cost-effective nature and ease of processing.

(1) ABS plastic is also excellent for impact resistance. It can absorb any physical shock.

(2) ABS plastic is strong and long-lasting. Its hardness ranges from  68 to 118. Also, its tensile strength ranges from 22.1 – 74.0 MPa, a significant amount.

(3) This plastic material can remain stable under fair loads. For high loads, it may not be as suitable as PC plastic. However, ABS plastic is still prevalent in many structural applications.

(4) ABS plastic can typically withstand temperatures from -20 to 80 degrees Celsius (-20 to 176 F). However, you can improve its heat resistance ability during molding.

(5) ABS plastic is resistant to mild acids, alkalis, and oils. Unlike PC plastic, it can withstand alkalis and oils. However, it swallows when it comes in contact with some other chemicals. Glacial acetic acid, carbon tetrachloride, and aromatic HC easily break ABS plastic.

(6) ABS plastic is highly flammable at high temperatures. It has a fire resistance of up to 31%. However, heating it above the range may produce hot flames. However, it is good that it doesn’t make any pollutants.

(7) You can 100% recycle ABS plastic. Various factories or small workshops accept old ABS to create toys, appliances, or casings.

Business Opportunities of ABS Plastic

ABS plastic is also in high demand in the plastic market. It is durable and cost-effective. You can use it to create various gadgets, car parts, and household items.

According to Grand View Research, the ABS market will grow at a CAGR rate of 4.6% from 2022 to 2030. So, investing in ABS plastic is undoubtedly profitable. All you need is to know the proper way of investing.

The following table showcases the most popular ABS plastic products in the market. This table can give you some ideas on various ABS products and show the alternative materials used. Note that alternative materials may be cheaper and have lower standards.

Category Popular Products/Opportunities Alternative Materials
Gardening Tools Mini shovels, plastic rakes, plastic hoes, plastic claws, and hand equipment PP, PE, metal
Toys Varieties of plastic toys, colorful toys PE, PVC
Musical Instruments Recorders, harmonicas, flutes, bugles, drums and rhythms Wood, metal, PC
Electronic Devices PC keyboards, enclosures for various gadgets, printer parts, phone case PC, PP
Car Parts Car dashboard components, door liners, pillar trim, panels for various equipment, mirror housings, seat backs, and belts PP, PC plastic
Medical Devices Nebulizers, disposable syringes, housings for various medical equipment PC, PE
Household items Vacuum cleaners, kitchen items, coffee makers, toasters, and more PC, stainless steel
Pipes and fittings Tools for liquid and gas delivery systems, outdoor and underground use Metal, PVC, PE
3D printing OEM parts, additive manufacturing, molds PLA, Nylon, PC

High temperature plastic material

Acrylonitrile Butadiene Styrene vs Polycarbonate (ABS VS PC): What’s the Difference?

The above two sections explain what ABS and Polycarbonate are. You have already learned about their making process, popular products, and properties. Now the question is, which one is better? ABS or Polycarbonate? Suddenly, you can not make the decision. However, you will need some comparison to get the best option from PC VS ABS.

First, thoroughly research your project needs. What specific application will the plastic part be used for? Does it need high-impact resistance? Is transparency necessary? You can also determine parameters like mechanical stress, temperature, and moisture.

Second, consider the environment in which your plastic part will be used. Is there any exposure to UV radiation? Does the material need to be fire-resistant? Is there any chemical or solvent exposure?

Third, consider the cost of your whole project. In this case, you should balance the price with the product’s overall performance. You can use cheaper plastics, but the material properties must meet the project’s needs.

For example, your project may involve both impact resistance and temperature. You might be making a mistake if you choose ABS instead of PC. ABS’s max temperature rating is only 80, while PC plastic offers up to 140. So, for the temperature-involved job, PC plastic is suitable. Always take safety factors into account.

After thoroughly researching the project needs, compare the materials (ABS VS PC) and choose the best option. Here, we will use six primary factors to compare these two plastics.

PC VS ABS Plastic: Material Properties

When you compare both plastics (PC VS ABS), the material properties come first. Both plastics have unique advantages and limitations.

When you think of strength, PC offers more impact resistance. The values are in the table below. As you can see, PC has more density and less elongation to break. This means the PC is more rigid and suitable for heavy-duty applications.

Moreover, PC plastic offers high-temperature resistance. It remains stable and does not deform even in high heat. PC also prevents water absorption and has excellent transparency. You can use this transparency feature to create a wide range of plastic products, like lenses, phone screens, and more.

On the other hand, ABS is one step ahead of PC plastic in terms of UV resistance and electric insulation. It also has an excellent capability, up to 31% of flame retardancy. For other materials, ABS shows average standards.

 PC VS ABS Plastic: Material Properties Summary Table

Property Polycarbonate (PC) Acrylonitrile Butadiene Styrene (ABS)
Density 1.25 g/cm3 1.01 to 1.20 g/cm3
Hardness 114 – 124 Rockwell R 68 to 118 Rockwell R
Tensile Strength 28.0 – 75.0 MPa 22.1 – 74.0 MPa
Impact Strength 10 – 90 Kj/m² 8.00 – 48.0 kJ/m²
Elongation to break 6.10% to 138% 3.00 – 150 %
Temperature Rating −40 °C to 130 °C (−40 °F to –266 °F) (-20° C to 80° C (-20° F to 176° F)
Melting Point 220 – 320 °C 180 – 240 °C
Transparency 0.000 – 94.0 % 0.000 – 91.0 %
UV Resistance Excellent, but you must add a UV stabilizer Excellent
Chemical Resistance Excellent, except for alkalis and HH Excellent, except for Glacial acetic acid, carbon tetrachloride, and aromatic HC
Electric Insulation 1000 to 1017 ohm-cm 109 to 1017 ohm-cm
Fire resistance 25% ( can add fire resistant element) 0.5% to 31.2% ( can add fire resistant element)
Water absorption 0.0200 – 0.350 % 0.0500 – 1.00 %
Weather resistance Good with UV stabilizers Poor; more prone to degradation without protection
Surface Finish Glossy and Smooth Matte, slightly rougher texture

Injection molding service

PC VS ABS Plastic: Ways of Processing

There are various ways of processing plastics. Some standard processing techniques are injection plastic mold, extrusion, thermoforming, blow molding, and machining.

ABS plastic is easy to process because it has a low melting point. In injection molding, the process temperature for ABS is 210 to 260 degrees Celsius. On the other hand, the process temperature for PC plastic is 260 to 320 degrees Celsius.

ABS is also easy to process in extrusion. Since it has a lower viscosity, you can create smooth plastic profiles. On the other hand, PC plastic is more rigid, and your extruder will need more pressure to make the profiles.

When you compare them (PC VS ABS), the ease of processing only matters regarding production cost. However, if you consider the product’s outcome, PC plastic will give you the best service.

PC injection molding

PC VS ABS Plastic: Filament for 3D Printing

3D printing is trendy in our modern world. You can create 3D objects with a 3D printer. The working principle is the same as the typical printer but on a 3D surface. The printer typically builds the object layer by layer. Various types of materials are used to do this. ABS and polycarbonate plastics are two popular ones.

Each plays a crucial role in 3D printing, comparing both (PC VS ABS) plastics. Each type has its unique benefits and limitations.

ABS filament is typically a durable and flexible plastic. It is mainly used for its strength and impact resistance, making it ideal for various functional parts and household items. ABS filament is easy to print and a cost-effective method. However, it produces fumes that may make you feel uncomfortable. Besides, it may warp if you don’t print on a heated bed.

On the other hand, PC plastic is also strong, transparent, and highly temperature-resistant. These two benefits can be used to create a wide range of 3D objects. However, what makes PC plastic less familiar is its high melting point. It is also more expensive than ABS plastic.

PC VS ABS Plastic: Recyclability

ABS and polycarbonate plastics are both recyclable, but their process may differ. For ABS plastic, people often use the shredding method, sometimes chemically. On the other hand, you can recycle PC plastic in two ways: shredding and melting.

Recycling polycarbonate is more complex than recycling ABS plastics. One reason for this is its composition.

PC VS ABS Plastic: Costs

The manufacturing cost of ABS plastic is lower than that of PC plastic. Also, the melting point of ABS is lower than that of PC plastic. Also, the viscosity of molten ABS is lower than PC. Combining all these properties, you will find that processing ABS plastic is also cost-effective.

You can decide on the right option based on just costs. However, you must also compare performance. PC plastic offers more performance quality than ABS plastic. It even comes with a smooth and glossy finish.

PC VS ABS Plastic: Applications

ABS plastic is widely used in car parts, consumer goods, and electric casings. It is strong and easy to process, so ABS plastic is preferred in these three industries.

Polycarbonate, on the other hand, is favored for safety equipment. Safety gear, optics discs, and medical gadgets are all popular items. You can check the respective tables described above for each item.

Make Your Decision: Which is Better?

When to choose ABS plastic?

If you need a cost-effective material, ABS is the best option. It’s ideal for products that don’t need high-temperature resistance. ABS is generally easy to process. Moreover, ABS plastics are lighter than PC plastic. Therefore, you can use this material to create toys and many weight-sensitive products, and lots of PC materials used in over mold or insert molding process as substrate.

When to choose PC plastic?

Polycarbonate thermoplastic gives you everything you need. It is strong, durable, and high-temperature resistant. Although it is not as cheap as ABS plastic, PC products are stable for a long time. A PC plastic is the right choice if your project demands improved performance and toughness.

You can also create a hybrid version, combining ABS and PC. ABS/PC typically combines the properties of both ABS and PC.

Compared to PC (PC VS PC/ABS ), PC/ABS provides better impact resistance and lower shrinkage. Unlike PC, PC/ABS is easy to process. On the other hand, compared to ABS (ABS/PC VS ABS), ABS/PC provides more heat resistance.

The choice mainly depends on your specific use, budget, and requirements. Therefore, always assess your target before choosing the right material. It not only saves your time but also your valuable investment.

Frequently Asked Questions

Is PC lighter than ABS?

No, ABS is typically lighter than PC or Polycarbonate. Its density generally starts at 1 gram per cubic centimeter, while PC is up to 1.20. Therefore, ABS plastics are lighter than PC plastic. If weight is a critical factor in your project, ABS may be the better choice over a PC.

Is PC filament stronger than ABS?

Yes, the PC filament is stronger than ABS. The hardness level of PC plastic is 114 to 124 Rockwell. It also has higher impact resistance so that it can withstand greater force. Polycarbonate offers high heat resistance.

What is the ratio of ABS to PC?

The ratio of ABS to PC in a blend typically is 60:40. The custom ratio may also include 50:50 or 70:30. The ratio may differ based on specific project needs.

Which is better, ABS or PC or PP luggage?

PC or Polycarbonate is typically the more robust plastic. This plastic is also durable, making it the most suitable material for luggage. However, people also use PP or polypropylene for luggage manufacturing. Note that PP also offers high strength and durability, if you want to know more plastic materials, you could go to how to choose the best plastic injection molding materials page to know more material selection tips.

Is PC-ABS expensive?

The PC/ABS is more expensive than the typical ABS. The combination of PC and ABS typically increases this price. Although the cost is higher, you can get added benefits.

injection molding phone case

What is PC/ABS material?

PC/ABS material, also known as polycarbonate-ABS, similar to ABS but is strong than ABS injection molding, it is a thermoplastic blend that combines the properties of both polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS). This unique combination results in a material that is strong, durable, and heat-resistant, making it ideal for a wide range of manufacturing applications.

PC/ABS injection molding processing

The processing temperature for PC/ABS injection molding typically ranges between 365-410°F (185-210°C). However, it’s important to note that the exact processing temperature will vary depending on the specific grade of PC-ABS being used and the conditions of the molding process.

It is important to note that the correct processing temperature is crucial for achieving optimal results when using PC-ABS injection moulding. If the temperature is too low, the material may not fully melt or may not fill the mould properly, resulting in weak, welding line, or sink marks. On the other hand, if the temperature is too high, the material may degrade or burn, resulting in poor surface finish or discoloration.

To ensure the best results, it is important to follow the recommended processing temperature range provided by the PC ABS material manufacturer. Additionally, it is also important to keep the mold temperature at the appropriate temperature and to properly vent the mold to avoid trapping gases and ensuring a good flow of the material.

It is also important to consider the gate size, shape and location, and the injection speed and pressure, these are all factors that can have an impact on the final product quality and the process itself.

Advantages of PC/ABS injection molding

One of the main advantages of PC/ABS injection molding is its strength and durability. The combination of PC and ABS results in a material that is much stronger and more impact-resistant than either material alone. This makes it ideal for manufacturing parts that will be subject to heavy use or exposure to the elements. Additionally, PC ABS is also heat-resistant, making it suitable for use in high-temperature environments.

PC/ABS injection molding

Body Infrared thermometer

Disadvantages of PC/ABS injection molding

Despite its many advantages, there are also some disadvantages to using PC/ABS injection molding. One of the main downsides is its relatively high cost compared to other materials. Additionally, PC-ABS is not as flexible as some other plastics, which can make it less suitable for certain applications. Finally, it is also more difficult to recycle than some other thermoplastics.

Despite these disadvantages, PC+ABS injection molding is still a popular choice for a wide range of manufacturing applications. It is often used to produce parts for automobiles, consumer electronics, and other consumer goods. Additionally, it is also commonly used in the medical, aerospace, and industrial sectors.

When deciding whether to use PC/ABS injection molding for a particular application, it is important to consider the specific properties and requirements of the part. If strength, durability, and heat-resistance are important factors, then PC+ABS may be the ideal choice. However, if cost and flexibility are more important, then other materials may be more suitable.

Overall, PC/ABS injection molding is a strong and durable material that is well-suited for a wide range of manufacturing applications. Its combination of properties makes it ideal for parts that will be subject to heavy use or exposure to the elements, while its heat-resistance makes it suitable for use in high-temperature environments.

However, its relatively high cost and lack of flexibility may make it less suitable for certain applications. When deciding whether to use PC+ABS plastic molding, it is important to consider the specific properties and requirements of the part.

Sincere Tech offers custom injection molding service for various of plastic resin, those materials include ABS+PC, PA66+GF, PA66, PPS, PPSU, PP, ABS, PE, ASA and among others, if you need custom plastic mold and injection molding service, welcome to contact us.

ABS plastic

A Detailed Guide On ABS Injection Molding

ABS injection molding process is a procedure where molten ABS plastic is injected into a mold at high pressures and temperatures. The process helps replicate multiple types of prototype designs for many industrial applications because ABS plastic is an engineering-grade plastic. It’s machined by industries including automotive, consumer products, and construction, to name a few.

This article comprehends ABS molding from definition to applications, processes, and techniques. So read on!

ABS Injection Molding Overview: 

ABS (Acrylonitrile Butadiene Styrene) injection molding is a popular technique for the production of ABS plastic products with exact specifications. From engineering terms, ABS is a rigid and durable thermoplastic polymer, famous for its ease of manufacturing or fabrication. The molding techniques are applied to inject the molten abs into the mold die, after which the part cools down and is then ejected upon solidification. This method is fastidious and efficient and can produce a wide variety of ABS products, which makes it a cheap solution for bulk volumes.

How to precisely machine ABS?

The ABS plastic molding process is quite similar to the process of injection molding, like many other thermoplastic molding techniques. It begins by supplying ABS resin plastic pellets into a hopper, where these are subsequently melted and injected into a mold under highly controlled pressure up to 700–1400 bar. Then cooling and hardening phases stratify, and the injection-molded part is ejected, and the cycle starts again in a repetitive manner to form multiple parts from a single tool die.

ABS plastic injection molding is famous for its simplicity and efficiency; hence, it’s notably considered an ideal process for large-scale batch parts to effectively bring to market with minimal turnaround. When it comes to ABS, it has good dimensional stability and post-molding workability, which means it’s relatively easy to machine, drill, bore, and mill it to the needed parts’ specifications.

ABS injection molding

Why ABS Molding is The Right Choice?

ABS is a material of choice for injection molding because of its advantageous properties. These are the features that make its use indispensable; for instance, a good material has high strength, a low melting point, recyclability, and excellent resistance to chemicals and heat. Its plasticity is a main reason for its easy processing and shaping into several shapes and sizes. Thus, ABS is widely applicable in fields that require strength and durable components, like interior automotive parts, household appliances, tools, and medical devices. Its versatility and reliability answer the question, ‘Why is ABS the best option for injection molding projects?”.

Characteristics of ABS Plastic

ABS injection molding

ABS injection molding

Let’s discuss its peculiar characteristics:

  • Chemical formula: The ABS plastic is made up of (C8H8) x· (C4H6) y· (C3H3N) z.
  • Heat and Chemical Resistance: ABS are not easily affected by heat or chemical reactions.
  • Impact, abrasion, and stain resistance: ABS is famous for its durability, resistance to abrasion and staining, and ability to withstand impact.
  • Typical temperature range: The normal working temperature for ABS is 204–238 °C.
  • Liquefying temperature: The ABS has a liquefying temperature of 105 °C.
  • Tensile strength: The abs have a tensile strength of 46 MPa (6600 PSI).
  • Specific gravity: The particular gravity of ABS is 1.06.
  • Shrink Rate: The abs have a shrink rate of 0.5-0.7%.

Advantages of ABS Injection Molding

Here are the key benefits of abs molding:

  1. Energy Efficiency: 

The equipment used in ABS molding delivers efficient performance during thermoplastic processing. The strength and dynamics of their operations guarantee steady and regular production performance by reducing energy demand and the overall cycle times.

  1. Versatile Applications:

ABS plastic molding allows for the production of a great number of applications, which can be applied to ABS resins of different sizes with uniform integration capabilities. Thus, the adaptability of the process ensures the production of complicated components for various industrial applications.

  1. Accurate Reproducibility:

It’s notably the best choice for the production of detailed and complex feature parts, for instance, interior and exterior parts, which is why it’s superior to other molding processes. Besides, ABS plastics sustain their properties and performance even in extreme temperature situations or conditions. That’s the main reason for their use in aerospace and electronics applications.

Disadvantages of ABS Injection Molding

Despite benefits, ABS plastic machining entails limitations too; let’s discuss each in brief details.

  1. Poor UV resistance:

ABS plastic has poor resistance to ultraviolet (UV) rays from the sun; hence, it degrades when it’s exposed for a long time. In order to mitigate this issue, the ABS components are usually covered with UV-resistant materials to make them more protected and sustainable.

  1. High Smoke Evolution:

Although abs are normally considered non-toxic thermoplastics to humans, Because it can produce harmful smoke during the injection molding process. Thus, it can affect the health of personnel in charge designated for molding abs. Strong safety protocols are needed for its operators, along with technical expertise.

  1. Poor fatigue resistance:

The ABS plastic may not be good for applications that require high stress or strain because of its limited fatigue resistance. The prolonged exposure of ABS to stressors usually results in degradation and decreased durability of the part or product over time. If you need more high-stress, then PC ABS injection molding will be a better solution.

Considerations in the ABS Plastic Injection Molding Process

There are some key aspects to consider for machining ABS. These necessary factors include;

  1. ABS Plastic Parts Design:

Before you initiate the ABS plastic injection molding process, you have to consider the technicalities of the parts’ design. Try to split designs to uniform wall thickness to avoid stress, with a 25% variation of the wall thickness as per a rule of thumb. The inclusion of more ribs or radii can increase strength and avoid snapping issues.

  1. Wall Thickness and Radius Ratio:

The ratio of radius to wall thickness should not be less than 0.3.  Because the larger radii will be the stress buster. Nevertheless, avoid considering small radii because they can cause shrinkage problems in products during the injection molding process. The design of ABS plastic parts should be kept in balance so that they are both strong and don’t shrink under strain or stress.

ABS injection moulding

Precautions in the ABS Plastic Injection Molding Process: 

For optimal prototype development projects, from small to large-scale batches, here are a few considerations to count on.

1. Drying ABS Material Before Processing:

ABS plastic is very moisture-absorbing. Problems during processing are likely to occur. The material should be completely dried initially before injection molding to prevent issues related to the increased cost of the project, the extension in machining time, and the production of parts with a cloudy or rougher surface finish. Although ABS resins may absorb moisture from the atmosphere naturally in a range of 0.4% to 2%, Therefore, it’s important to lower the moisture content to 0.5% or less than the maximum limit to avoid any problems. This way, the process of drying is usually carried out at temperatures of 80–95 °C for around 3–4 hours.

2. Molding Temperature Control:

Molding temperature control is crucial in ABS injection molding to avoid thermal decomposition. These issues lead to the formation of brown granules on the molded parts. The process of ABS plastic overheating can cause chemical bond breakage. Although high temperatures are essential for glossy and matte abs parts, it’s important not to damage the material. The ideal temperature range for ABS injection molding is between 180 and 230 °C, and shorter exposure times at higher temperatures are recommended to avoid degradation over time.

3. Injection Pressure and Speed in ABS Injection Molding:

ABS plastic has a higher injection pressure than other materials, for example, PP injection molding. The reason isthat it iss highly viscous plastic. Although that’s not required for products that are simple or thick, excessive pressure can lead to severe consequences, like the parts sticking together. In addition, the increased friction ultimately raises production costs. On the other hand, low pressure can cause mold shrinkage and components of inferior quality.

The injection speed is another key factor in the production of high-quality final products. Too high a speed can lead to plastic burning or thermal decomposition. Besides this, there are problems of poor glossiness, weld lines, and discoloration. Also, the lack of mold filling can be seen at slow injection speeds. The injection speed is a critical aspect of material processing for ensuring efficiency and minimal waste of material. The ABS plastic usually needs a smaller shot size than other plastics, which means that the material usage is reduced but the molding techniques are not affected.

Applications of ABS Plastic Molding:

ABS plastic is widely adopted by many industries because of its versatility and advantages. Some key applications of ABS plastic molding include:Some key applications of ABS plastic molding include:

1. Automotive Industry:

ABS plastic is widely used in the automotive industry for producing lightweight components, which are substitutes for metals like aluminum. A few examples include door liners, instrument panels, dashboard components, pillar trim, handles, and seat belt parts.

2. Commercial Applications:

ABS plastic is a popular material for its use in many household products. These are examples of the products that are consumed in daily life: refrigerator liners, vacuum cleaners, control panels, and food processors.

3. Electrical Industry:

The ABS-molded products are used in the electrical industry in the production of electronic enclosures and computer keyboards.

4. Building and Construction Industry:

ABS plastic is notably one of the best materials in the construction industry for its high impact resistance and the ability to bear chemical and physical changes. For these reasons, its use is usual for pipes and fittings.

ABS injection molding parts

Other Aesthetic Applications:

ABS plastic is heavily employed in various other applications for shaping products for manufacturing and musical instruments.

For example, the manufacturing of sports equipment and facilities involves the use of ABS injection molding. Furthermore, medical products such as compressors and nebulizers and disposable syringes or one-use products can also be made from ABS plastic because of its stringent strength.

ABS machining techniques

Here are some key techniques commonly used:Here are some key techniques commonly used:

1. Thin-Walled Parts:

ABS has a higher viscosity, so it requires higher injection pressures for thin-walled parts. Therefore, molds must be made to be able to cope with these high pressures. Usually, steel-made molds are used for fabricating thin-walled products.

2. Large Hollow Parts:

Water-assisted or gas-assisted injection molding is the one that is useful for fabricating large, thin, or hollow parts. The high-pressure water or gas causes the molten or lava plastic to be pressed against the sides of molds. Therefore, it must be ensured that the thickness of the ABS material sheet is uniform and the internal volumes are smooth.

3. Thick-Walled Parts:

The normal injection molding for thick-walled components can cause sink marks on the parts’ surface. The compression injection molding uses a definite quantity of the molten plastic to lower the sink marks and internal stresses. On the other side, thinner or more uniform mold walls can be used to avoid the sink mark problem.

4. Multi-material components:

Techniques like insert molding and overmolding are used for multi-material components. ABS overmolding usually uses highly durable plastics to enhance the functionality of a product or part. For instance, in industrial tooling applications like cordless drills, These methods help replicate ABS parts to be more efficient and effective for design specifications.

Compatible Materials for ABS Molding

Injection ABS molding can be processed with many types of materials, from thermosets to thermoplastics. Among these, thermoplastics use reinforcing additives like glass or carbon fiber fillers. Besides, it’s also possible to inject exotic metals like aluminum, titanium, and zinc, but this usually involves the combination of the metals with a plastic filler material to make the flow uniform through the mold.

Summary

To sum up, ABS plastic molding is a well-known technique that heavily uses a bunch of materials for injection molding. Its heat-resistant feature and durability make it extremely useful for various industrial parts fabrication. The ABS plastic injection molding process is a cheap way of manufacturing various automobile and aircraft parts for manufacturing projects. If you are in need of a dependable and cost-efficient solution for plastic injection molding, ABS plastic molding is a go-to choice.

Polypropylene Injection Molding

Polypropylene injection molding or PP injection molding, is a molding manufacturing technique using polypropylene, which is a type of thermoplastic polymer material that is exposed to heat until it turns to melt. The process forces the low viscosity molten polymer to flow into specially designed molds. On cooling, the liquid turns into a solid plastic and assumes the mold’s shape. This technique is most effective when used on the polymer in its processed form. This technique enables the creation of geometries that would otherwise be challenging to achieve. Curious about polypropylene itself? Now, let’s explore more about polypropylene and its uses, along with the reasons for its popularity in injection molding.

In this article, we will give you a comprehensive description of injection molding polypropylene and discuss the strengths of PP material as well by considering its applications across manufacturing sectors.

Polypropylene injection molding

Types of Polypropylene Used In Molding Applications

The most common types of propylene employed in molding applications include;

1. Homopolypropylene (PP-H)

PP-H, or homopolypropylene is the most used type of polypropylene, characterized by high rigidity and strength as a result of crystalline structure. It is commonly employed in uses where the material will be exposed to a lot of force, as it is with containers, auto parts, and more. PP-H has good chemical and heat resistance hence; it is used in products such as buckets and other household utensils. However, it is less flexible and therefore not as effective in more flexible applications.

2. Random Copolymer Polypropylene (PP-R)

PP-R is a random copolymer polypropylene that contains only a small amount of ethylene, which increases its flexibility and impact strength. This makes PP-R suitable for use in piping systems, automotive parts, and any other consumer goods that are expected to have a long life cycle. Due to these properties, it is commonly used in hot and cold water pipes and containers where strength and flexibility are a requirement.

3. Block Copolymer Polypropylene (PP-B)

PP-B is a block copolymer polypropylene that has a block structure with ethylene thus making it have better impact strength and elasticity compared to PP-A. This type is applied in the automobile industry, in the manufacturing of shockproof packaging material and other heavy-duty consumer products. The automotive sector and protective packaging industries are ideal for PP-B because of its flexibility and damping properties in stressed applications.

Polypropylene Injection Molding: How Does it Work? 

PP Plastic Injection molding provides an advantage of mass production of identical plastic parts. High volumes- from a thousand to millions of identical parts can be produced at one time. Because the intended mold is reused several times in the part’s manufacturing process. This makes polypropylene injection molding another suitable option to meet the large demand and ensure that the products produced are of equal quality, simultaneously.

Process Conditions For Propylene Injection Molding

Table 1: Operational Parameters for pp plastic injection molding.

Parameter  

Specification

Drying Requirement Dry at 80-90°C (176-194°F) for 2 hours; moisture level must be under 0.1%.
Melting Temperature Range 220-280°C (428-536°F)
Mold Temperature Range 20-80°C (68-176°F)
Heat Deflection Temperature (HDT) 100°C (212°F) at 0.46 MPa (66 PSI)
Injection Temperature 32-66°C (90-150°F)
Tensile Strength 32 MPa (4700 PSI)
Flexural Strength 41 MPa (6000 PSI)
Density 0.91 g/cm³
Injection Molding Pressure Up to 180 MPa
Shrinkage Rate 1.5-2.0%

Comparison of Polypropylene Grades for Injection Molding

Let’s compare, different injection molded polypropylene grades for the molding process.

Table 2: Technical Specifications of different injection molding polypropylene plastic Grades.

Polypropylene Type Tensile Strength Elongation at Break Flexural Rigidity Heat Resistance Notable Features
Pro-fax 6323 4,930 psi 11% 210,000 psi 199.0 °F General-purpose, resists stress cracks
Pro-fax SG702 2,900 psi 6% 150,000 psi 180.0 °F Impact-resistant, suitable for automotive use
Pro-fax 6523 4,790 psi 12% 200,000 psi 190.0 °F Stiffness, ideal for food packaging
Pro-fax PD702 4,500 psi 12% 170,000 psi 190.0 °F Maintains dimensions well, easy to process
FHR P5M6K-048 3,900 psi 11% 153,000 psi 183.0 °F Clarity-enhanced, visually appealing

Polypropylene Injection Molding

Design Guidelines for Polypropylene Injection Molding Parts

Molding of polypropylene is easy, but to get the best result, one has to follow certain design principles. This section focuses on the practical recommendations that are necessary to produce long-lasting and high-performance polypropylene components.

Living Hinges Key Factors

When designing living hinges in polypropylene, it is good to work at a thickness of between 0.2 mm to 0.51 mm. For optimum performance, the radii should be wide and the hinge should have a flat shoulder. This design approach provides flexibility and strength to withstand the usage of the hinge when used several times.

Guidelines for Wall Thickness

In the case of polypropylene parts, the thickness of the walls of the product must not exceed 0.635 mm to 3.81 mm thickness. Thick parts should also have smooth changes in thickness from one level to another to avoid defects such as sink marks. Moreover, ribs should preferably be less than half the thickness of the adjoining walls to provide strength and prevent the formation of structural voids.

Radii in design

Radii in the mold design also assists in reducing stress concentrations. So, it significantly impacts the life cycle of the part. The suggested radius should be at least twenty-five percent of the wall thickness. The radius of curvature should be 75% of the thickness of the wall which gives both the strength and the fine surface finish.

Draft Angle Recommendations

Polypropylene can take very small angles of drafting, as small as one degree, which is adequate for most parts. But if your part has textured surfaces, it’s recommended to increase the draft angle up to five degrees depending on the depth of the texture. In the case of filled polypropylene materials, it may be necessary to have a draft angle of up to ten degrees to facilitate easy ejection of the part and to improve the quality of the final part.

Setting Part Tolerances 

Requirements for tolerance of polypropylene parts can be classified into commercial tolerance or fine tolerance. Commercial tolerances are relatively larger and cheaper as compared to fine tolerances which are precise but expensive. For instance, a commercial tolerance for a 20 mm part will be in the region of ± 0.125 mm, while the fine tolerance for the same part is about 0.075 mm. Thus, it’s crucial to understand that if tighter tolerances are desired they can have a large impact on the production cost.

Polypropylene Material Processing

Polypropylene has a melting point within the range of 160-170°C and this means that correct temperature control is required while processing the material. Additionally, it is crucial to dry the polypropylene pellets for the injection molding process. For optimal outcomes and splay-free parts, the moisture must be kept below 0.02%.

Injection Molding

The PP injection molding temperature is needed around 220°C and 280°C while the mold temperature is between 30°C and 80°C. These conditions are as follows to have proper flow and solidification. Cycle time is another critical consideration. Usually, it refers to the time taken to complete a cycle and it should be reduced to avoid warping, and efficient cooling is important. In addition, cooling channels must be designed in such a manner that allows equal distribution of heat all over the surface.

Extrusion Processing

Extrusion is carried out by melting Polypropylene at a temperature of 210°C to 250°C. Temperature control and cooling rate are two critical factors that need to be well controlled to allow the formation of the desired product properties.

The extrusion die is a critical component in the process. It has to be designed to not allow the die to swell and control the flow of the material that is being extruded to achieve the desired quality of the final product.

Blow Molding

The blow molding process involves heating polypropylene and then forming it into a parison and blowing it in a mold. Temperature and inflation pressure should be strictly maintained to produce the desired shape of the product. Ejection Part cooling is required to retain the part shape and dimensions. The cooling rate should be dependent on the size and complexity of the part in question.

PP injection molding

Quality Inspection:

The two areas that are of particular importance include;

  • Sanitary and Storage Procedural Measures The Purity of polypropylene depends on handling and storage procedures and clean equipment.
  • Quality Control Periodical examination during processing helps to ensure that the material and the final products are of the right quality and standard and meet the requirements.

What are The Benefits of Propylene Injection Molding?

The following are the benefits of polypropylene injection molding:

  • Affordability: Polypropylene injection molding is relatively cheap and more so for productions that will require large quantities. The process has a low material cost and little wastage since the material that is in excess can be reused in the system. This efficiency means that large production volumes are offered at cheaper unit prices than would be in the case of smaller production volumes.
  • Short Cycle Time: The injection molding process can produce high volumes of parts in the shortest time possible. Polypropylene has good thermal properties and hence the molds can be filled and cooled quickly enhancing the production rates and lead times.
  • Superior Chemical Resistant: Polypropylene is highly resistant to a vast number of chemicals such as acids, alkalis, and organic solvents. This property makes it suitable for use in applications in extreme conditions including car parts and chemical vesse.
  • Least Impact: Polypropylene has less impact strength as compared to HDPE, however, copolymer polypropylene has good impact strength. This makes it a preferred choice for products that require mechanical strength and resistance to impact, for example, automotive and durable consumer goods.
  • Dimensional Stability: Once it has been cooled, polypropylene has high dimensional stability. This stability is very essential to guarantee that the molded parts are fitting correctly and performing their intended tasks without requiring further modification.
  • Low Moisture Absorption: Polypropylene has little or no capability to absorb moisture and therefore the strength and dimensions of the material do not change when exposed to different humidity levels. This property makes this property suitable for use in applications where the material is exposed to moisture most of the time.
  • Flow Characteristics: Due to the favorable flow characteristics it is easier to process polypropylene and this makes the molding process easier. It makes it possible to produce large quantities of molded products and also helps overcome the typical problems with molding, such as warping or lack of filling.

What are the Limitations of Propylene Injection Molding?

Some of the demerits of Polypropylene Injection Molding include the following;

  • High Thermal Conductivity: Polypropylene has a low heat resistance and thus it cannot be used in high-temperature areas. Polypropylene has poor thermal stability and the parts made from it may deform or lose their strength at temperatures above 100°C (212°F).
  • UV Stability Polypropylene is not very resistant to UV light and when exposed to UV light for long, it undergoes degradation by fading to an undesirable color, becoming brittle, and exhibiting low mechanical properties. This limitation makes it necessary to use UV stabilizers or coatings especially when the product is to be used outside.
  • High Shrinkage Rate: As much as 1.5% to 2.0% of polypropylene shrinks, the parts made from this material may warp or undergo dimensional changes if not well controlled. This can also influence the quality of the final product because the performance of the product can be compromised where precision is required.
  • Not Suitable for High Stress Application: Although polypropylene has good impact strength it does not offer high strength and stiffness. In applications where high tensile or flexural loads are applied on the part, PP may not offer sufficient strength.
  • Limited Ability to Produce Small Features: While polypropylene has many uses, it is not easy to produce very small features and intricate details. The flow characteristics of the material and the cooling properties may reduce the level of detail in very fine designs.
  • Less number of colors available: Polypropylene has fewer choices of colors as compared to other plastics in the market. Striking specific or even desired shades may be possible only with the help of colorants or other kinds of treatments.

Common Parts Manufactured by Polypropylene Injection Molding

Propylene injection molding commonly produces the following parts:

  • Dashboard Panels
  • Glove Compartments
  • Mirror Housings
  • Plastic Containers
  • Kitchen Utensils
  • Food Containers
  • Crates and Pallets
  • Medical Device Housings: Lots of medical injection molding parts made from PP material.
  • Plumbing Pipes
  • Toys: Many of plastic injection molding toys made by ABS and PP materials.

Gates and runners in polypropylene injection molding tool

In polypropylene injection molding, gates and runners constitute some of the most important features that control the flow of the molten material into the mold cavity. The design of these elements should enable proper filling, and the quality of the finished parts should be very high.

Polypropylene injection molding shop

Sprue Design

The sprue serves as a conduit for molten polypropylene, connecting the injection molding machine to the mold cavity. This is a cylindrical design with a spherical part at the end that fits properly into the machine nozzle. This is critical to prevent leaks and ensure a smooth flow of materials through the system and equipment.

Runner System

Molten polypropylene travels through runners from the sprue to the mold cavity. Molds with multiple cavities design their runners with branches to evenly distribute the material. We suggest employing cold slugs at junctions to prevent early stiffening and ensure free flow. The runner diameters range from 4 to 7 mm to ensure that there is optimal flow and cooling for the mold. 

Gate Functionality

Gates are the last opening through which molten polypropylene is allowed to flow into the mold cavity. The dimensions and the kind of gate determine how the material is transported throughout the manufacturing process and the quality of the last part. They are pin gates and edge gates and they are chosen depending on the type of mold that is to be made. The gate should allow for easy flow of materials into the mold while at the same time reducing the formation of surface defects.

Gate Sizing and Placement

Small gates are normally used to minimize friction and prevent the wear out of the material. The thickness of the gate land is the part of the gate that joins the cavity should be as thin as possible so that it can be easily filled. Gate location is important, usually located at the thickest section of the mold to achieve an even spread of material and minimize defects.

Design Considerations

Some of the common problems such as sink marks and poor filling can be solved through proper gating and runner systems. To improve production efficiency and part quality, updating the designs at some intervals based on the best practices and feedback on the process is effective.

Industry Applications of Propylene Injection Molding

PP injection molding often finds its applications across various manufacturing sectors;

Food Packaging

Polypropylene is widely used in food packaging since it is safe and has a longer lifespan. Take-out containers and food storage products such as cups and containers are made from PP foam for thermal insulation and protection. PP material is used in making plastic cups and bottles for beverages and food products since the material does not react with moisture or chemical substances.

Consumer Goods

In the consumer goods industry, polypropylene is preferred for its strength and the ability to be molded. PP is used in small appliances like blenders and hairdryers because it offers impact strength and ease of molding. Polypropylene is safe and durable and it is used often in injection molding toys. Furthermore, polypropylene’s durability is also used in household products such as bins for storage and utensils in the kitchen.

Automotive

The automotive industry is one of the major users of polypropylene as the material is light in weight and has a high degree of strength. PP is utilized in interior trim parts such as dash and panels due to the material’s versatility in terms of appearance and durability. There are also polypropylene glove compartments and mirror housings to give the needed strength and impact protection.

Textiles

It is common knowledge that polypropylene fibers are essential in different textile areas because of their strength and resistance to stains. PP fiber carpets are capable of withstanding wear and stain. PP is used for furniture and automotive interiors since it does not wear out easily and is easy to clean. Due to its excellent characteristics, polypropylene fibers are used in the production of clothing that wicks moisture, providing comfort and performance.

Packaging Films

One of the most important types of packaging films is polypropylene films because of the strength and flexibility that they offer. The applications of BOPP (Biaxially Oriented Polypropylene) films are in packaging due to their high clarity, excellent mechanical properties, and moisture and oxygen barrier properties. CPP (Cast Polypropylene) films are used for heat sealability in flexible packaging applications for a variety of products.

Pipes and Fittings

Polypropylene pipes are used in plumbing and industrial practices since they are chemically inert and can be easily installed. PP plumbing pipes are used for both hot and cold water because of their strength and resistance to corrosion. In industrial applications, the use of polypropylene pipes is in chemical and waste handling systems, and the material is well endowed with the strength and capability of withstanding aggressive conditions.

Summary

This article gives more information about polypropylene (PP) as an engineering plastic, including the different types available, the properties of the PP, and the complexities of the injection molding process. It also examines the challenges associated with selecting the right equipment, addressing issues related to product design, and discussing the fundamentals of mold design. In the same vein, the article discusses some of the major defects that are likely to occur during production and how to correct them.

OEM contact manufacturer

To ensure the best PP material and injection molding production, it is wise to seek advice from an experienced supplier. An experienced provider can provide recommendations on the most suitable PP plastic injection moldings for your product’s functional requirements and the final product’s appearance, ensuring a successful project.

FAQs – Polypropylene Injection Molding

Q1. What are the major categories of polypropylene Pallets for injection molding?

They include Homopolypropylene (PP-H) for rigidity, Random Copolymer Polypropylene (PP-R) for flexibility, and Block Copolymer Polypropylene (PP-B) for impact resistance.

Q2. What should be done to polypropylene before molding?

Polypropylene has to be dried at 80-90°C for not less than 2 hours to bring the moisture content to below 0.1% reduction in molding quality is achieved to avoid the formation of poor-quality products.

Q3. What are some of the problems that may occur in polypropylene injection molding?

Some of the most common imperfections are sink marks, flowlines, venting issues, warping, and incomplete filling. These problems can be solved by adjusting the thickness of the wall, increasing venting groove, the temperature of the mold, and the pressure of injection.

 

 

injection molding wall thickness

Information about PA6/PA66 (Nylon) Injection Molding

Basically, there are PA6 AND PA66(Nylon 6 or Nylon 66), Nylon has tenacious and wearable,  self-lubricious and smooth characteristics with non-toxic and antibiosis and high water absorbability. In addition, its tensile strength and stiffness will be sharply decreased with the moisture-absorbing. Then, the size of finished pieces changes greatly. If in the high-temperature environment for a long time, it will be resolved.

It will not soften gradually with increasing high temperature until closing to the extent of melting-point. Once reaching the proper temperature, it will flow. It is soluble in many chemicals. However, gas, lubricating oil, developer, detergent and grease have no effect on nylon.

Nylon injection molding

Advantages Nylon Injection Molding :

It has high mechanical strength, good tenacity and high press resistance and strength of extension. Its strength of extension is close to yielding strength, which is twice stronger than ABS injection molding parts.

Nylon Injection molding parts have excellent fatigue durability with the smooth surface and minor friction coefficient and good wear resistance. It also has corrosion resistance and remarkable resistance to alkali (acid) and most of the salt solution, non-toxic, presenting inertia to biological erosion and good anti-mildew ability, heat resistance and excellent electrical features.

Its product has a lightweight and is easy to dye and molding.

Disadvantages of PA injection molding:

It is easy to absorb water and has poor light resistance. It requires more strict plastic molding technology. It can absorb water and becomes swelling in alcohol but has no resistance to strong acid and oxidizer.

Therefore, it cannot be used as acid-resisting material.

Nylon Injection Molding process:

We should exactly control the injection molding process to prevent problems like flashing. Meanwhile, as the faster speed of condensation quick releasing for melt, we should keep off the insufficient production caused by material blocking in orifice runner and gate (temperature and pressure increase liquidity firstly).

As the poor thermal stability, the temperature should not be too high so as not to cause yellowing of material.

The proper injection pressure can be judged by the appearance of the products. If it has higher injection pressure, products will appear the problems such as flashing; the too low temperature will bring about defects like a ripple, flow mark, weld line or insufficient producing. Therefore, the higher holding pressure should be avoided in order to prevent increasing the internal stress for products generally.

It is advisable that injection should be done with speed so as to avoid problems such as ripple or insufficient mold filling caused by the rapid cooling rate.

PA Nylon injection molding Technique

1, Preparation of Original Materials
PA (polyamides) absorbs humidity easily, which has an effect on the course of working, like decreasing viscosity of the melt and appearing bubbles and crazing on the surface, etc. And force property of product will also decrease obviously. Therefore, the drying process must be done before shaping up. Besides, PA is easily oxidized and color changed as well as decomposition under hot temperature, so it will be better with vacuum drying. But if there is no vacuum drying condition, atmospheric hot air drying can also be adopted.

The temperature of vacuum drying is 85-95 Celsius degrees and the lasting time is 4-6H; while the temperature of hot air drying is 90-100 Celsius degrees and the lasting time is 8-10H. PA materials after being dried are not fit for locating in the air (not more than 1-3H).

2, Melting Temperature
The choice of the machine barrel is mainly based on the melting point of PA Material. At the same time, it is also related to the type of injection molding machine, type of product and size. Generally, under 220-320 Celsius degrees, PA6: 220-300 Celsius degrees; PA66: 260-320 Celsius degrees, as the processing temperature of PA is narrow, so the temperature of machine barrel must be controlled strictly, in order to avoid decomposition of melt thus to make the product go bad. The setting of the machine barrel has a large effect on plasticizing and speed of melt.

The temperature of the middle section of the machine barrel should be higher than the melting point of 20–40 Celsius degrees and lower than the decomposition of 20-30 Celsius degrees. The temperature of the front section is lower than the middle section of 5-10 Celsius degrees. The temperature of back-end (loading section) is lower than the middle section of 20-50 Celsius degrees. Cooling of the charging hole must be effective. If the temperature of the middle section is too low and the screw changes its speed too fast, then jamming phenomenon will appear. If the temperature of the posterior section is too high, then the delivering capacity will be affected. A lower speed of screw will affect production efficiency.

3, Injection Pressure
Injection pressure has a small effect on the force of PA. Choosing of injection pressure mainly depends on the type of injection molding machine, machine barrel temperature, type and size of the product, and mold structure. And there are also some factors like injection speed, injection time and injection time, etc.

4, Injection Speed
Choosing of injection speed is related to the thickness of the product, the temperature of the melt, the size of the gate, etc. The injection speed cannot be so fast. Otherwise, the excess temperature will be caused due to over cutting thus to create decomposition, causing color changing of product and decrease of force property. Too fast injection speed will also create defects like bubble and scorching, etc.

5, Revolving Speed of Screw
Intermediate speed should be adopted. The too-fast speed may cause decomposition of plastic due to excessive cutting, causing color changing and decrease of property and too slow of revolving speed, which may affect the quality of melt and production efficiency due to a long period of melting.

6, Back-pressure
On the premise to guarantee the quality of the product that the lower of the back-pressure is the better. High back-pressure may decompose due to the excessive cutting of melting.

hdpe injection molding

7, Mold temperature for PA injection molding

The high temperature of mold improves hardness, density, tensile strength and modulus of elasticity of the product. Mold temperature is related to the property of the product. As to those thin products which require elongation and good transparency, it will be better with lower mold temperature; while as to those thick molds which require high strength, good abrasion resistance and transformation less, and then higher temperature of mold temperature is better. The specific is as follows.

The thickness of product temperature of mold: Less than 3mm, mold temperature use 50 -70 Celsius degrees, 3-6mm, mold temperature use 70-90 Celsius degrees, 6-10mm, mold temperature use 80-100 Celsius degrees, and wall thickness is more than 10mm, 100 Celsius degrees Mold temperature has a big effect on contractibility rate of product. The higher of the mold temperature, the bigger of the contractibility, otherwise, the smaller of the contractibility rate.

8, Molding Cycle
It mainly depends on the thickness of the product. As to thin wall product, the injection time, pressure maintaining time and cooling time can all be shorter; while as for thick wall product, in order to avoid the appearance like shrinkage transformation, sink mark and bubbles, etc., then injection time and pressure maintaining time should be lengthened and high mold temperature should be adopted. The cooling time should be longer.

9, Post-processing of Product
Crystallization of the process of molecular orientation and cooling process while in the process of cooling creates some internal stress in the product. The size and shape of the product will change while in the future storage and using process. Therefore, annealing and humidifying processing are required.

10, Annealing
It adopts a product that is 80 Celsius degrees higher of the temperature and accurate precision. The product is taken out after being demoulded, putting in oil or paraffin for annealing. The temperature of annealing is higher than the usage temperature of 10-20 Celsius degrees and time is 10-60 minutes. (Depending on the thickness of product)

11, Humidifying
While in the process of shaping up, a product that is used in humanity or aqueous solution must be put into boiling water or potassium acetate solution for 1-2 days after taken out.

12, Residence Time
While in the process of manufacturing, if the temperature of glue is above 300 Celsius degrees, then the long residence time of melting in the machine barrel must be avoided (20 minutes), otherwise decomposition will be caused due to overheating, causing the color change of product or brittleness. If a temporary stoppage for more than 20 minutes is required, then the temperature of the machine barrel can be lowered to 200 Celsius degrees. When in a long time of residence, polymer with higher viscosity must be used to clean the machine barrel. For example, HDPE or PP can be used for cleaning.

Contact us to get a price for your PA injection molding (PA6, PA66, PA12) or any other custom injection molding projects.