Almost every day, manufacturers are developing new TPE Materials. This is for many reasons; manufacturers offering several modern technologies, growing preferences of customers, and the new regulation of the government. You may already know if you need an SBC compound or a TPV based on your application or end-use environment, but how do you determine the proper grade?
TPE manufacturers custom-formulate it to meet a wide range of performance criteria, making it difficult even for experts to choose the right one.
TPE material suppliers always start with a high-level description of the application’s requirements before translating them into material specifications. Use this checklist and guide to help you through the process.
TPE Selection Intent: Material Replacement or New Grade
It is important to know what materials are already being used, such as PVC or silicone rubber, or perhaps another TPE, where improvements are needed or if a pricing target exists.
If you are using a TPE for the first time, make a list of any functional or performance requirements.
Formulating For Process Ability In The Manufacturing Process
Think about how the part you will make and assemble the part. Manufacturers customize the TPE formulas for:
- Injection molding
- Extrusion
- Blow molding
All these depend on how you treat the materials.
For complex parts with thin and thick sections or severe undercuts, specialty high-flow TPEs have been developed.
It is vital to know the material of the substrate if the TPE will be co-extruded or over-molded. A TPE material that links best to nylon may not adhere to polycarbonate.
Target Of Cost: Balancing The Performance And Price:
There are several targets of costs involved in the selection of material. This is defined either in the cost per pound or the cost per part. Having a complete estimate in mind will also help make the right decision.
Considerations Of Environmental Conditions: Exposure And Usage
Will you use the product indoor, outdoor, or both? Know at what temperature you will expose it. Also, if it requires chemical resistance? For instance, if you use TPE in a seal, know will it be under load or flexed repeatedly.
To determine if you require special ingredients or additives, consider the following end-use conditions:
Requirements Of Temperature:
Check the constant use of temperature at maximum and minimum. Also, evaluate the time exposed to extreme temperatures.
UV Conditions:
Exposure to extreme weather or UV conditions.
Exposure To Chemicals:
Do you require the splash resistance or will the part be submerged? What will be the temperature during the exposure? Types of chemicals include:
- Acid
- Base
- Cleaning solution
- Oil, and more
Usage Of TPE Material:
Know if the part is under load, or it will be repeatedly extended or flexed?
Concerns On Monitoring: Market And Industry:
Some standards and regulations apply depending on the sector and world region, whether you are building a medical gadget or a pipe seal. Certifications or further testing may be necessary, which could influence the TPE’s ingredient selection.
You must consider the following things:
Electrical/ Cable and Wire:
You may require UL certification or listing and REACH SVHC compliance.
Automotive:
This is the approval of the specification of OEM material.
Products Of Customers, Housewares, and Toys:
Food contact regulations in the United States, or European directives on food contact and toy safety: 2009/48/EC and EN-71-3
Healthcare And Medical:
Biocompatibility recipes that comply with ISO 10993-5
Construction And Building:
NSF 51 and NSF 61 certification for usage with potable water in the construction industry.
Surface Appearance And Aesthetics: Determine How You Want To Look And Feel
TPE manufacturers define this material by their feel, finish, and color, and they can also modify it to satisfy specific aesthetic requirements:
- Feel of the Surface/Haptics: High surface friction or “grippy” feeling – Dry or silicone-enjoy feeling
- Surface Finish: silky-smooth or lubricious
- Shiny (able to mimic high gloss levels of PVC)
- Matte finish (low gross, rubber-like look & feel)
- Color: TPEs can be clear, translucent, or opaque in their natural state, depending on the formula. TPEs can also be bespoke in colors or you can dye them online during processing. Some TPEs are more color-tolerant than others.
Material Performance: Prioritization Of Properties
The composition and manufacturing method of a TPE has a direct impact on its physical and thermal qualities. If you require specific qualities, such as hardness or performance, and tear strength, you must address these in the material selection process.
To Begin, Consider The Following Factors:
Hardness:
You can measure TPE on the Shore OO, A, or D scales. And can range from a highly soft gel (think shoe inserts) to a hard plastic like polypropylene.
Stretch and bounce-back:
You can stretch TPE material twice its original length and then return it to its original shape. Tensile and extension qualities reveal how a TPE stretches and bounces back.
Set of Compression:
Will the TPE part be subject to a load or will it require seal maintenance for an extended length of time? What are the conditions: high or low temperatures? The type of compression set required will determine the TPE family to use.
Abrasion Resistance or Wear Resistance:
Is this a disposable product or something that needs to withstand repeated use over a long length of time? Is this a disposable product or something that needs to withstand repeated use over a long time? The chemistry of TPE determines its toughness.
TPR material suppliers also provide materials that are resistant to abrasion.
Tear Resistance or Puncture Resistance:
Think about how you will use the product; for example, for infant items, you’ll want a TPE that can withstand biting and tearing. TPEs are customizable for optimal tear and puncture resistance by measuring tear strength.
Bending Resistance:
Will the TPE be bent or flexed while in use? This could cause a flexural modulus requirement, which is a measurement of the TPE’s ability to bend.
Adhesion To Other Materials:
Will the TPE be over-molded onto a stiff material such as polycarbonate, as in a power tool handle? Will a hard/soft seal be there by co-extruding it with polypropylene? When choosing the right TPE, consider the substrate material.
Special Requirements:
Think about any unique traits or characteristics that the TPE may require. Here are several examples:
- Acoustic dampening energy absorption
- Content that has been recycled
- Anti-microbial for hot, wet situations
- Mineral reinforced
