By: Mr Anil Gupta, Managing Director, KAPL (Krishna Antioxidant Pvt. Ltd.)
Thermoplastic elastomers (TPE) are a class of copolymers, contemporary constructional polymers, which are physically cross-linked materials made up of thermoplastics and elastomers. Essentially, a mix of plastic and rubber, bearing thermoplastic as well as elastomeric properties. This copolymer exhibits elasticity similar to that of rubber and plastic materials and is therefore used where standard plastics or conventional elastomers fail to impart the physical properties needed in the end product.
The viscosity of thermoplastic elastomers is significantly lower than the viscosities of traditional rubber elastomers, which offers many processing advantages for thermoplastic elastomers as compared with natural rubbers. Today, they are used in many applications, like adhesives, footwear, medical devices, automobile parts, household goods, etc., where they offer elasticity benefits over a wide temperature range.
Thermoplastic elastomers are one of the most versatile polymers in today’s market. TPE is referred to as “third-generation rubber“ owing to the high elasticity of thermoset vulcanised rubber at room temperature and the good processability of thermoplastic at high temperatures. TPE is composed of two dissimilar phases: a soft phase which represents the rubber segment and provides elastic properties, and a hard phase which represents the thermoplastic segment and provides both processing ease and full recyclability to the material. Thermoplastic Elastomers can be modelled into desired shapes by employing the classic processing technologies.
Given their versatility, almost 40% of thermoplastic elastomers are used globally in vehicle manufacturing as they have numerous variants with diverse attributes, their applications are widespread ranging from coatings to bumpers, upholstery and sealing components. Today, roughly a third of the about 30,000 parts in cars are made of plastics.
Some of the top TPEs used in the sector are:
PP (Polypropylene) – It is chemically resistant and provides improved strength, stiffness, and higher temperature capabilities. It is mainly used in the making of chemical tanks, automotive bumpers and battery boxes.
PUR (Polyurethane) – Is one of the most versatile polymers that has demonstrated its applications over a wide range. They appear flexible and soft or rigid and hard in the automotive industry. The material is abrasion resistant with superior hardness. Rigid PU foam imparts better load-bearing properties, superior substrate adhesion and excellent insulation.
PA (Polyamide) – Is material is water absorbent and is essentially used for applications under the engine hood of the vehicle.
PE (Polyethylene) – Used for car bodies and electrical insulation due to its high impact and moisture resistance.
ABS (Acrylonitrile-butadiene-styrene copolymer) – This is an impervious material which is used to improve toughness, heat and impact resistance in vehicle interiors.
The automotive industry faces multiple challenges in manufacturing which include: lowering noise, reducing fuel consumption and emissions, increasing product and user safety, improving performance, reducing weight and improving comfort.
These along with other TPEs have gained popularity, as they find diverse applications in the automotive sector owing to a wide range of physical attributes that benefit the sector:
1. Their ability to be elongated and return to their original state ensures physical durability, extending product life. KAPL has developed a range of antioxidants which are specially designed to maximise the product lifetime by developing properties including heat, colour and processing stability when the product is subjected to extreme conditions and high temperatures.
2. As TPEs are very light in weight, their manufacturing requires very less energy which means – lower fuel consumption, lower CO2 emissions and lightweight automobiles.
3. They can be easily coloured using any dye. They offer enormous freedom in designing interior and exterior parts as they are durable, abrasion and vibration-resistant
4. They provide maximum passenger safety in case of a collision as they are shock absorbent and can be moulded into upholstery, enhancing comfort and vehicle handling.
5. TPE products also have the potential to be recycled since they possess attributes of plastics which can be moulded and reused.
6. TPE is durable and can weather tough conditions. This makes them ideal for many internal mechanisms of cars and trucks, such as car locks.
7. They ensure better vehicle strength-to-weight ratio results in greater fuel economy (lower fuel costs), which in turn translates to lower emissions (reduced carbon dioxide in the atmosphere).
These factors not only influence the productivity and economic benefits of using thermoplastics but also lower environmental impact and help make driving safe and comfortable. The rise of electric vehicles has increased the demand for new components, for example, the demand for long-term heat-resistant plastics has increased.
The use of TPE has witnessed exponential growth and is expected to grow further because of its huge applications in daily life. Encapsulation and moulding are the most widely used applications of TPE materials. About 85% of plastic products in the modern world are made up of TPE materials. The competitive price-performance as compared to other natural rubber products is one of the major reasons. Thermal characteristics of thermoplastics are important in the design and selection of automobile parts and components.
Disclaimer: The views and opinions expressed in this article are solely those of the original author. These views and opinions do not represent those of The Indian Express Group or its employees.