The short answer
Choose silicone when the part has to work hot, from about −55 to 200°C / −67 to 392°F, or needs a grade with a long medical or food-contact record. Choose TPV when the part stays below about 125°C / 257°F and you want lower material cost, lower weight, better tear and abrasion resistance, thermoplastic cycle times and reusable scrap. Both resist UV and ozone very well.
Silicone (LSR or HCR) and TPV are often compared for seals, gaskets and soft parts in appliances, kitchenware and devices. They overlap less than it seems: temperature and documentation usually decide it. For the wider field, see TPV vs. other elastomers.
TPV vs. silicone side by side
| Property | TPV (EPDM/PP) | Silicone (LSR, HCR) |
|---|---|---|
| Hardness range | About 35A to 50D | About 10A to 80A; gels softer |
| Service temperature | About −40 to 125°C / −40 to 257°F | About −55 to 200°C / −67 to 392°F; special grades higher |
| Compression set | Good at moderate heat; rises as heat goes up | Very good over a wide temperature range |
| Oil and fluid resistance | Fair; swells noticeably in hot oil | Fair; swells in fuels and many oils. Good in water |
| UV and ozone | Very good | Excellent |
| Density, g/cm³ | About 0.9–1.0 unfilled | About 1.1–1.2 (LSR); filled grades higher |
| Tear and abrasion | Good | Standard grades low; high-tear grades better |
| Processing | Injection, extrusion into a cool mold; no cure | LSR: two-part injection into a hot mold. HCR: compression, transfer or extrusion; post-cure common |
| Drying | About 80°C / 176°F, 3 h (4 h with regrind), to 0.08% or less | Not applicable |
| Scrap | Same-grade regrind goes back in | Cured scrap cannot be remelted |
| Typical parts | Seals, grommets, boots, grips, appliance gaskets | Medical tubing and parts, baby and kitchen products, high-heat seals, keypads |
Typical ranges. Silicone properties depend on the polymer, filler and cure system; TPV properties on hardness and grade. Confirm on the data sheet for the exact grade.
Temperature range
This is silicone’s clearest advantage. Silicone stays flexible well below freezing and keeps working at about 200°C / 392°F, with some grades rated higher for intermittent use, and its compression set stays low across that range. TPV is limited by its polypropylene matrix, which melts at about 160–165°C / 320–329°F, so most grades are used up to about 125°C / 257°F, and compression set climbs as the part nears that limit. Oven, cooktop, lighting and engine-adjacent seals usually stay in silicone.
Biocompatibility and food contact
Silicone has a long history in medical tubing, device parts, baby products and bakeware, and many silicone grades are offered with medical or food-contact documentation. TPV is also offered in medical-style and food-contact grades, though the selection is narrower. In both families these claims are grade-specific: a grade may be tested to ISO 10993 or USP Class VI, or the producer may issue an FDA letter for certain food uses, while other grades in the same family have none. Ask for the documents for the exact grade and color, and check them against your use. See our TPE / TPV page for grade types.
Cost
Silicone is generally a higher-cost material per pound than TPV, and it is denser (about 1.1–1.2 vs. 0.9–1.0 g/cm³), so a pound of TPV makes more parts. LSR offsets some of that with highly automated, flashless molding and short cures in thin parts, so for small high-volume parts compare cost per finished part, not per pound. HCR parts made by compression molding usually carry more labor for loading and deflashing.
Processing
LSR is a two-part liquid metered, mixed and injected through a cold runner into a hot mold, commonly about 180–200°C / 356–392°F, where it cures. Its very low viscosity needs tight shutoffs to avoid flash. HCR is a gum compounded with a cure system and compression, transfer or extrusion molded; many parts are post-cured in an oven. Cured scrap cannot be remelted.
TPV is dried at about 80°C / 176°F for 3 hours (4 hours with regrind) to 0.08% or less, melted at about 175–230°C / 347–446°F and injected into a cool mold at about 10–66°C / 50–151°F. Regrind goes back in, and TPV bonds to PP in two-shot molding. See processing parameters and the drying guide.
Tear strength and wear
Standard silicones have low tear strength: once nicked, they tear easily, which matters for thin flaps, valves and parts pulled over edges. High-tear silicone grades improve this. TPV generally resists tearing and abrasion better at a similar hardness, which suits boots, grommets pushed through panels and parts handled often. Where abrasion is the main failure, look at TPU too; see TPE vs. TPU and TPU.
When to choose TPV, and when to choose silicone
When to choose TPV
- Service below about 125°C / 257°F
- Parts that see tearing, abrasion or repeated handling
- High volumes where thermoplastic cycles and regrind lower part cost
- Two-shot parts on a PP substrate
- Weight or material cost matters
When to choose silicone
- Continuous heat above about 125°C / 257°F, or very low temperatures
- Medical or food uses that need a grade with the right documentation and track record
- Very soft parts below about 30A, or translucent soft parts
- Seals that must keep low compression set when hot
What to send us
- The silicone or TPV grade you use now, and the hardness
- Service temperature range and any steam, oil or cleaners
- Medical or food-contact requirements, and the documents your customer needs
- Whether the part is overmolded, and on what
- Quantity and ship-to city
We can source either one: TPV and other thermoplastic elastomers as pellets, and silicone rubber grades. Tell us which you run now, or send both options and we will quote them side by side. A polymer chemist reviews every request and checks the grade against your part, process and documents before we quote. Every lot ships with a COA. We aim to send your quote within one to three business days.
Common questions
Is TPV a substitute for silicone?
In some parts. Where the part runs below about 125°C / 257°F and does not need silicone’s medical or food-contact history, TPV can mold faster, weigh less and tear less easily. Above that temperature, or in long-term implant or skin-contact uses, silicone remains the usual choice.
Which handles higher temperature, TPV or silicone?
Silicone, by a wide margin. Typical silicone grades work to about 200°C / 392°F, while most TPV grades stop around 125°C / 257°F because the PP matrix softens.
Is silicone biocompatible and TPV not?
Neither family is biocompatible as a family. Individual grades of both are tested for medical uses, for example to ISO 10993 or USP Class VI. Ask for the documentation of the exact grade for your use.
Why does silicone tear so easily?
Standard silicone rubbers have low tear strength, so a nick spreads easily. High-tear grades help. TPV generally resists tearing and abrasion better at a similar hardness.
Is TPV cheaper than silicone?
TPV is usually lower in material cost per pound, and its lower density gives more parts per pound. LSR can still be competitive per part in high-volume automated molding, so compare finished part cost.
Can I mold TPV in an LSR tool?
Usually not. LSR tools run hot to cure the part, while TPV needs a cool mold, a different runner system and different shrinkage allowances. A switch means a new tool.
Tell us about the silicone or TPV part
A polymer chemist reviews every request, then matches your grade or finds a qualified equivalent and prices it.
What to send for an accurate quote
- The grade name, from any supplier, or a data sheet
- Color (natural, black or a custom match)
- Fill type and percentage, if any
- Melt flow, if you know it
- Quantity for this order and what you use in a year
- Ship-to city and state or province