What is TPE Material? | The Definitive Guide

What is TPE Material?

TPE Material (Thermoplastics Elastomers) is also known as thermoplastic rubbers. It belongs to the family of thermoplastic rubber materials with TPR, TPU, and TPV. It has most characteristics similar to thermoplastics and thus is used in several applications. Like other thermoplastic rubbers, TPE is also considered a successful blend between plastics and rubber.

When heated, TPE becomes free-flowing, and that flowing tendency is increased when sheer force is applied to it. When cooled down, it regains its original shape and structure(A prime characteristic found in traditional thermoplastics).

TPE material goes through physical cross-linking, which can be altered by the additional application of heat. That feature and its elastomeric component make it easy to recycle and re-use the production waste.

Thermoplastic elastomers are soft in nature that makes molding or extruding other thermoplastic material very easy. TPE is also quite popular in applications like automotive, wires & cables, home appliances, etc.

The popular grades of TPE material are supplied by teknor apex. They are produced and supplied under 6 different trade names representing different applications and technologies – di- and tri-block hydrogenated styrene block copolymers (Tekron, Elexar, and Monprene), thermoplastic vulcanizates (Uniprene), thermoplastic polyolefin blends (Telcar), Tekbond are a few of them.

TPE Plastic: Key Properties – 

The shore scale can measure the softness of the material. The usual softness comes at 20 Shore OO up to 90 Shore A.

Manufacturers highly prefer TPE material due to significant cost savings and its easy processability. Any conventional rubber is a thermosetting material, which means it must go through a chemical cross-linking reaction during molding, usually called vulcanization. The reaction makes it possible for it to be processed in traditional thermoplastic machinery.

The vulcanization reaction takes around 1 minute to several hours to complete(though various factors are responsible for infusing the time). On the other hand, thermoplastic molding for TPEs omits the cross-linking process and makes the cycle times much faster, which can be as little as 30 seconds.

1. TPE products are recyclable, the production waste and scarp can be re-processed. At the same time, most thermosetting elastomers end up in the landfill.
2. Fantastic resistance to most chemicals(oils, alcohols, greases, aromatic and aliphatic hydrocarbons, dilute alkalis) and weathering.
3. Excellent flexural fatigue resistance
4. Good colorability
5. Low specific gravity
6. Decent electrical properties
7. Great wear and tear resistance

Advantages – 

1. TPE plastic is an engineering marvel, combining the looks and flexibility of thermosetting rubber with the processing prowess of plastics.
2. It has high elasticity and encompasses a wide range of compression sets, durometers, and excellent elongation.
3. The excellent processability makes it compatible with bulk manufacturing with injection molding or extrusion. The reclaiming and recycling benefit is the cherry on top of the cake.
4. Thermoplastic elastomer products have excellent thermal properties and show good stability when exposed to a broad range of environmental effects.
5. Reduction in detrimental pollution is another crucial benefit over traditional thermoplastics as TPEs consume less energy while production and can be easily recycled.
6. TPE polymer is an inexpensive alternative to silicone, latex, and PVC compounds – It can be used for tuning applications mostly influenced by thermoplastics
7. It can be colored easily with most dyes.
8. It has improved consistency in terms of both raw materisl and finished products. The materials require no-reinforcing agents, little or no compounding, and cure systems, making them super-efficient without any dissimilarities within batches.

Disadvantages – 

1. Drying might be required before processing.
2. The number of low-hardness products manufactured by TPE is quite low
3. Softens at high temperatures

Engaging Read – Top 10 Injection Molding Defects (And How To Prevent Them)

What Are The Most Popular TPE Material Grades? –

1. Thermoplastic Polyolefins (TPE-O or TPO) 
2. Styrenic Block Copolymers (TPE-S)
3. Thermoplastic polyurethanes
4. Melt processable rubber (MPR)
5. Thermoplastic polyether block amides

1. Thermoplastic Polyolefins (TPE-O or TPO):

This variation of TPE polymer is a blend between polypropylene and un-crosslinked EPDM rubber. In exceptional cases, a low degree of crosslinking is deliberately made to improve heat resistance and compression set properties. The blend is mostly used in applications with high toughness, such as automotive bumpers and dashboards.

The properties align with the high hardness scale – that is,>80 Shore A and meagre elastomeric properties.

2. Styrenic Block Copolymers (TPE-S):

Source: Thermoplastic Elastomers, Edited by Prof. Adel El-Sonbati

The TPE-S polymer consists of two-phase block copolymers with hard and soft fragments – Styrene blocks and butadiene blocks. Styrene blocks are responsible for thermoplastic pro[pertios and butadiene blocks are responsible for flexural properties.

SBS has a high value in production, used in applications like low-level seals and grips, bitumen modification, footwear, adhesives where chemical resistance and ageing are not required.

When SBS is mixed with hydrogen, it becomes SEBS, eliminating the C=C bond in the butadiene component. As a result, the SEBS grade has improved performance, heat resistance, mechanical properties, and chemical resistance.

3. Thermoplastic polyurethanes:

Source: Thermoplastic Elastomers, Edited by Prof. Adel El-Sonbati

These materials are based on polyester or polyether urethane types. They are used in applications needing flawless wear and tear resistance. Prime examples are industrial belting, footwear, wires, and cables, etc.

A Detailed Guide on Thermoplastic Polyurethenes

4. Melt processable rubber (MPR):

MPR is designed for particular applications that require high-end chemical resistance. As a result, MPR is often replaced with nitrile rubber. It has identical properties to vulcanized rubber in noise-dampening applications and has similar stress relaxation properties.

Major applications include handgrips and weather grips for automobiles, coated fabrics and sheet goods, window and door weatherstripping. These applications demand a good bond with thermoplastics like ABS and polycarbonate; MPR does it perfectly.

Due to high compression set values, MPR lags behind its peers in market share in the high-performance sealing market.

5. Thermoplastic polyether block amides:

These polymers are known for their good chemical resistance and strong bonding with polyamide engineering plastics. The main applications are aerospace components and wires, and cables.

Bio-based Thermoplastic Elastomers – 

Bio-based TPE polymer types have been developed to combat the dependence on non-renewable resources such as petroleum. Bio-based materials are the need of the hour. These elastomers are made from biomass monomers derived from natural sources like corn, wheat, vegetable oils, starch, castor, canola oil, corn and soybean oil, etc.

Below are the most popular bio-based TPE plastic grades:

Applications – 

TPE plastic is considered for a job when flexibility is a top priority. It proves to be more beneficial than thermoset rubbers and traditional thermoplastics with reduced costs, consistent production of higher quality products, better safety while delivering on par performance.

Let’s go through with application detail:

Processability: TPE Material

TPE polymer can be processed seamlessly in traditional machinery like injection molding, extrusion, thermoforming, blow molding, calendering, and new-age 3D printing methods.

Asa mentioned at the beginning of the post, TPE material needs little or no compounding, the addition of reinforcing agents, stabilizers, or cure systems.

Injection Molding:

Injection molding, without any doubt, is the most popular method for TPE processing, thanks to its high productivity rates and less waste generation. The most common applications include finished parts, tubes, foams, etc. The processing capability of TPE is fine, and it sits in the hot runner without creating any problems.

1. Mold Temperature – 25-50°C
2. Melt temperature – 160-200°C
3. Compression ratio: 2:1 to 3:1
4. Screw ratio L/D: 20-24

All the numbers are ideal recommendations from our side. You can modify them depending on your need.

Extrusion:

The use of single screw extruders is highly recommended, equipped with three-section or barrier screws. The extrusion method is used for manufacturing foams and tubes.

1. Melt temperature: 180-190°C
2. L/D ratio of 24
3. The compression ratio of 2.5:1 to 3.5:1

3D Printing:

TPE polymer is compatible with 3D printing methods like FDM and SLS. The method is utilized to produce flexible parts with complex geometries. The most popular applications include phone covers, belts, springs, stoppers, etc.

The Difference Between TPE and TPV – 

FAQs – 

1. Does TPE material need drying?

Ans. TPE material doesn’t necessarily need drying. However, if needed, it can be stored in a cool and dry environment for upto two years if maintained well in its original packaging and sealed well against moisture, heat and other impurities.

2. Is TPE safe for Kids?

Ans. TPE is absolutely safe for kids as it contains a meagre amount of extractable compounds that migrate from the surface of an infant care product. That’s a significant factor assuming whatever babies touch, they put it in their mouths.

3. Is TPE better than PVC?

Ans. Both TPE and PVC have their pros and cons. They are known for their excellent flexibility and high strength making them suitable for various applications; however, one factor at which TPE fares better is its resistance towards different chemicals such as oils, greases. Diluted acids and diluted alkalis.

4. Is TPE better than Latex?

Ans. It completely depends on the application for which are being used. An example of bands made from latex is much more durable than those made from TPE or the combination of TPE and latex; however, as TPE has embedded properties of plastics, its fares significantly in terms of other mechanical and physical properties and also have substantially more applications.

5. Is TPE an FDA approved material?

Ans. There are specific TPE grades that are FDA compliant. For example, Elastocon 2850PE and 2865PE grades of thermoplastic elastomers with Shore A hardnesses of 50 and 65 are FDA compliant and odorless.

Final Thoughts –

Thermoplastic elastomers are a fantastic choice for your production needs. Its properties, applicability, and processing conditions are suitable enough for any manufacturer for creating quality products with intricate designs.

Thus, were my thoughts on TPE material. I hope you would find this post helpful. Kindly comment on your reviews in the comment box.

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Peace Out 🙂