Question 1: Both squeeze, stretch, and bounce back — what actually separates silicone squishy from TPR?

Answer: One sentence: silicone is a thermoset platinum-cured elastomer with nothing to migrate out; TPR is a thermoplastic rubber (SEBS/SBS plus mineral oil and plasticizer) that is cheap, fast to mold, and can slowly bleed its oil.

MY LSR 3100N is a food-grade two-component platinum-catalyzed liquid silicone: 400–600 cps, 1:1 ratio, cures 2–3 h at 25 °C, elongation >500%, dry non-tacky hand-feel, and a compression ratio over 30× for that "air-like" squish. TPR is injection-molded in seconds from a thermoplastic compound and is recyclable and far cheaper per piece — but it softens with heat, smells of oil, and its plasticizer can migrate. Selection rule: child-contact, mouth-contact, or premium hand-feel → silicone; high-volume promotional giveaways on tight budget → TPR.

Question 2: How big is the real gap in safety, durability, and processing? Can they substitute for each other?

Answer: Let's look scenario by scenario (based on measured parameters of commercially available grades):

Conclusion: They are not interchangeable — a TPR part cannot be made food-grade by goodwill, and a silicone part cannot match TPR's per-unit cost at million-piece runs. Practical guidance: ① for anything a child may mouth, bite, or sleep against, specify platinum-cured food-grade silicone and demand a migration/heavy-metal report, not just an "environmentally friendly" claim; ② for adult stress-relief novelties and promotional items, TPR is legitimate and cost-effective — just avoid oil-heavy formulations that stain packaging and desktops; ③ note that silicone's self-defoaming behavior lets small studios pour molds without vacuum gear, which makes it practical for short runs where TPR tooling cost is prohibitive. Two caveats before switching either way: ① if you previously ran condensation-cure silicone in the same mold, clean it with white spirit or the platinum compound will not cure (sticky surface); ② cure time should be validated against your actual mold thickness and ambient temperature — 25 °C cure is typically 3× the working time. Verify final feel, hardness, and compliance reports against your target market's toy-safety standard.

High Temperature Resistance Silicone Rubber(300℃), plz check MY HTV 328 series