Isocyanates and polyols are basic constituents along with chain extenders and catalyst which ultimately form the TPU. In addition to elasticity TPU also shows resistance to the followings.
- Abrasion and wear
- Oils
- Greases.
When the question that thermoplastic polyurethane is safe or not arises, it is considered safe to be utilized for numerous applications. The basic reason of TPU being safe is because of its chemical structure and characteristics. Thermoplastic polyurethane finds its application in numerous sectors including following areas.
- Sportswear manufacturing industry
- Auto industry and
- Medical sector
In its raw form Diisocyanates can be hazardous so this risk is eliminated by ensuring the complete reaction during the production process. So the production process of thermoplastic polyurethane is very controlled and it ultimately provides the safe usage of TPU. The evaluation of TPU by the regulatory authorities proved it to be safe to be utilized even for the food and medical applications. However, manufactures are required to adhere, follow and implement the regulations and standards devised by these regulatory bodies.
Definition of TPU
TPU is composed of polyols and diisocyanates chemicals. These are present in thermoplastic polyurethane in the form of alternate soft and hard segments. The properties and characteristics of TPU are the combination of the following.
- Elastomers
- Conventional thermoplastics.
TPU is considered very suitable to be utilized in many important sectors because it maintains its structural integrity at elevated temperatures and in harsh environments. These sectors include medical sector, food industry, electronics industry and automotive industry. Go to TPU injection molding to know more.
The manufacturers always try to find cost effective solutions from business point of view, yet at the same time they require quality to be maintained. This tough scenario is resolved by the standard thermoplastic processing techniques. These techniques are adopted due to following reasons.
- Less cost and
- Better performance
- Ability of thermoplastic polyurethane to be processed by these techniques
Generally, there are three major techniques which are adopted for processing of TPU. These methods are as follows
- Blow molding,
- Injection molding
- Extrusion.
Thermoplastic polyurethane is extensively utilized in protective cases, footwear and apparel because of flexibility and transparency it offers. These products require good looks and durability which Thermoplastic polyurethane provides. Moreover, there are certain applications like toys for children, which include direct human touch. Moreover, thermoplastic polyurethane has been declared safe to be utilized for these applications by regulatory bodies as well.
Properties of TPU
The major characteristics of TPU are the followings.
- Biocompatibility
- Process ability
- Over molding
- Cost effectiveness
- Recyclability
- Versatility in applications
- Weather ability
- Strength and durability
- Elastic properties
TPU bears the properties of elasticity and flexibility. The property of being flexible allows TPU to be utilized in harsh environments covering a wide range of temperature.
Safety Concerns Related to TPU
There are numerous safety concerns regarding the safe utilization of thermoplastic polyurethane. This is because of the chemical composition and characteristics of the TPU. The safety concerns which are of significant importance are discussed below.
- The production and processing of TPU must be very controlled. This is important to for two reasons.
- To achieve the required properties
- To ensure the complete reaction of isocyanates (This will prevent the reaction of un-reacted isocyanates with other chemicals)
- TPU can also cause the sensitivity of respiratory system or irritation of respiratory system. This is mainly because of the inhalation of thermoplastic polyurethane fumes or dust. Moreover, allergic reaction related to skin can also be caused by TPU if a sensitive skin is exposed.
- TPU bears the inherent property of being flammable. So in order to avoid fire related risks and hazards, handling of TPU must be carried out carefully. The safety measures need to be adopted and implemented to prevent any fire incident.
- Disposal of TPU is another important parameter which is related to the safety concerns of TPU. Because if TPU is not disposed off properly it can affect the environment adversely. TPU shows slow degradation and also there is risk of chemicals leaching. However, the compatibility of TPU with other chemicals can resolve this issue. Moreover, burning of TPU results in the release of harmful and toxic gases. These dangerous gases include the followings.
- Hydrogen cyanide
- Carbon monoxide.
- It is pertinent to mention that adhering to safety standards and regulations devised by regulatory bodies is of significant importance to prevent risks and hazards. The production and processing of TPU must be carried out in an environment which has proper ventilation. The utilization of personal protective equipment is mandatory to avoid any health risks. Moreover, the health of the workers performing duties in TPU exposed environment need to be regularly monitored. This practice is essential to identify health issues at early stage which can be subsequently treated.
- TPU is not easy to be recycled because it has mixed polymer nature. Chemical additives are also present in TPU which affects its biodegradability. Sustainable practices need to be adopted at all levels so that risks and hazards posed by TPU on the environment can be eliminated.
Answering The Question, Is TPU Safe?
TPU is considered safe to be utilized in numerous applications because of the following reasons.
Biocompatibility
TPU possesses the characteristic of biocompatibility. It means TPU will not pose any harm to living tissues and can be tolerated without getting any adverse affects. This characteristic is of significant importance in the scenarios including direct or indirect human touching. This mainly includes the following applications.
- Textiles
- Medical devices
- Wearable technology
Non-Toxic nature
TPU is generally manufactured by utilizing raw material of non toxic nature. This is of important significance keeping in view the final utilization of TPU product. The usage of non toxic raw material in production process ensured that there will be no leaching of hazardous chemicals or dangerous substances. Subsequently, there will be no health risk of the end product user. Moreover, TPU production complies with safety related regulatory standards which are implemented in numerous sensitive industries such as medical sector and consumer goods.
Resistance to Chemicals
Thermoplastic polyurethane tends to resist the followings.
- Solvents
- Oils
- Greases
- Synthetic chemicals
This important property plays an important role in safe utilization of TPU. When thermoplastic polyurethane is exposed to common environmental parameters the chemical resistance property of TPU ensures that it does not release any dangerous or hazardous substances. In addition to that this characteristic also increases the lifespan and durability of thermoplastic polyurethane.
Flexibility and Durability (Utilization without breakage)
Thermoplastic polyurethane is considered very suitable for many applications in which repeated stretching and bending is carried out. This is because good mechanical properties that TPU possess. The safe utilization of Thermoplastic polyurethane is achieved because excellent toughness, elasticity and flexibility prevent the breakage of TPU. The major usage of TPU in this context is in following areas.
- Coatings for fabrics
- Sports equipment
- Cases (flexible) for electronic devices
Resistance to Heat
There are numerous applications which require thermal stability because products or items are exposed to high temperatures in those applications. Thermoplastic polyurethane provides thermal stability at high temperatures without degrading thus providing safe usage. Consequently TPU finds its utilization in such applications including the followings.
- Industrial seals
- Automotive parts
- Footwear
Environmental Safety
Thermoplastic polyurethane is considered safe to be utilized keeping in view its impact on overall environmental safety.TPU has the ability to be recycled and can be reused for numerous applications.TPU differs from others materials in recycling process due to followings.
- TPU can be melted and reshaped without significant loss of characteristics
- TPU is eco friendly
- TPU does not release toxic substances
Regulatory Compliance
There are certain regulations and standards devised by the regulatory bodies related to following parameters.
- Occupational health
- Consumer safety
- Environmental impact
Manufacturers which are producing TPU comply with the standards and regulations to provide the requirements of above mentioned parameters. There are two major standards which are adhered by the manufacturers to ensure the safety of TPU.
- FDA (Food and Drug Administration) regulations, European Union
- REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals), United States
Raw Materials of TPU and Their Safe Processing
The production of thermoplastic polyurethane involves various raw materials. These raw materials ultimately form TPU after undergoing chemical reactions. It is important to handle these raw materials in a proper way during the production process because these raw materials can be hazardous if their handling is not carried out carefully.So, in production process a tight controlling and close monitoring of these raw materials is ensured. Subsequently, this results in the production of safe and non toxic thermoplastic polyurethane.
Following parameters related to raw materials need to be considered during the production of TPU.
Isocyanates
These are vital components in manufacturing of TPU. Isocyanates and polyols are basic constituents along with chain extenders and catalyst which ultimately form the TPU. It is important to note that isocyanates are toxic in raw form and can be the cause of respiratory sensitization and respiratory irritation due to followings.
- In un-reacted form if inhaled
- If Saturation is exceeded than the exposure limits
These risks and hazardous are eliminated and prevented by completely reacting the isocyanates with polyols during the manufacturing process to obtain the polyurethane polymer.
Polyols
These chemicals are another important raw materials in manufacturing of TPU. These materials are non toxic and safe to be utilized in the raw form as well. The chemistry of these chemicals shows that these are the polyethers or polyethers with hydroxyl groups. These chemicals undergo chemical reaction with isocyanates to provide polyurethane polymer.
Chain Extenders
In order to adjust the characteristics and properties of final polymer, chain extenders are utilized in the production of TPU. These chain extenders generally include the followings.
- Diamines
- Glycols
It is pertinent to mention that these materials are safe and non toxic providing that they are handling properly and are ensured to be completely reacted during the polymerization process.
Catalysts and Additives
In addition to above mentioned raw materials certain catalysts and additives are also added during the production process of TPU. These catalysts and additives are added to enhance the following properties.
- Processing characteristics
- UV resistance
- Flame retardancy
These catalysts and additives are generally considered safe to be utilized in the production process of TPU .However, selection of these materials is carefully carried out by the manufacturers to ensure the followings.
- These materials comply with the safety regulations
- These materials does not pose any hazard in the final product
Conclusion
Thermoplastic polyurethane is considered a safe material to be utilized in many renowned applications and sectors. Although there are some raw materials such as isocyanates which can be hazardous in un-reacted form if not handled properly but controlled production process and compliance to regulation standards ensures its completion reaction. The final product TPU is inert and safe and finds its applications in automotive industry, medical sector and consumer products because of its bio compatibility, on toxic nature and enhanced mechanical properties. There are numerous international bodies that devise the regulations and standards related to safe usage of TPU.
These bodies such as US based FDA (Food and Drug Administration) and the European union based Chemicals Agency (ECHA) has approved that the utilization of TPU is safe. This approval is based on numerous tests and data sheets related to the safety of TPU. This approval provides the authority that TPU is safe to be utilized because its production and processing is in compliance with the devised health and safety standards and regulation. The final products of TPU also underwent extensive testing to ensure their safe usage before they are launched into the market.
If you want to know more simialr injection molding materials, please go to is TPE safe page to know about TPE plastics.