Choosing Silicone Grade by Application: Food, Resin, Candle & Soap

Not all silicone is interchangeable. Choosing the wrong grade - tin-cure for gummies, overly soft platinum for deep resin pours - yields sticky cavities, cure inhibition, or failed audits. Choosing silicone grade by application is a specification task buyers should own before RFQ. RUUIPON matches grade to use case on every MOQ 50 order; prototype 3-7 days; quote ~24 hours.

Quick Answer: Grade Selection Matrix

Application	Cure type	Certification	Typical shore A
Chocolate / gummy / baking	Platinum only	FDA / LFGB on request	30-40
Resin / epoxy art	Platinum preferred	N/A (non-food)	20-35
Candle / wax	Platinum	Heat rating critical	25-40
Soap (CP/MP)	Platinum	Skin contact optional	30-45
Prototype / budget craft	Tin possible	Not food-safe	Variable

Platinum vs Tin Cure: Non-Negotiable Rules

Platinum (addition cure): stable, low shrink, food grades available, resists many chemicals.
Tin (condensation cure): cheaper, shorter library life for production, inhibited by sulfur/clay/amines - not food-safe.

Deep dive: platinum vs tin cure guide. If you sell to consumers, assume platinum-only.

Food & Confectionery Grades

For chocolate, gummy, baking, ice:

• Request platinum food-contact compound with test report.
• Specify max continuous temp ( baking ) vs ambient ( chocolate release ).
• LFGB for EU retail; FDA 21 CFR for US - cert comparison.
• Shore A 30-40 balances flex demold and cavity stability on multi-cavity trays.

Solution hub: Food & Confectionery.

Resin & Craft Grades

Resin molds prioritize detail transfer and release:

• Platinum RTV with hardness matched to depth - soft for deep undercuts, firmer for thin webs.
• Inhibition check if master contains sulfur ( some clays, latex ).
• Post-cure optional for maximum library life.

Crafts bundle: Crafts & Resin solutions.

Candle, Wax & Soap Grades

Hot pour wax (60-90°C) demands heat-stable platinum, not hobby tin. Candle molds and soap molds:

Process	Grade note
Pillar candle	Firmer shore A, vertical wall stability
Wax melt clamshell insert	Flex for snap; see wax melt molds
Cold process soap	Platinum resists lye exposure short-term; expect matte finish over time
Melt & pour soap	Lower thermal stress; softer OK

Home fragrance programs: Candle & Soap. Related: wax melt molds.

Shore Hardness Pairing by Geometry

Grade selection includes durometer:

• Deep draw / undercuts: softer (shore A 20-30)
• Multi-cavity tray stability: medium (30-40)
• Flat bars with logo only: can use firmer (40-50)

Full chart: Shore hardness guide. Specify on RFQ to [email protected] or WhatsApp +86 135 3006 2969.

Batch traceability: store material lot number with each PO. If a cert is questioned two years later, you retrieve the matching compound batch - not a generic supplier letter.

Do not specify "FDA silicone" without application temperature. High-heat baking grades differ from ambient chocolate release grades even within platinum families.

Resin brands using alcohol inks or heavy pigment loads should still use platinum RTV molds - tin cure may interact with long-term library storage in warm warehouses.

Candle makers blending paraffin and soy see different shrink; grade selection stays platinum, but shrink offsets differ - prototype both wax types if SKUs split.

Soap makers: long-term lye exposure etches matte finish - acceptable if cosmetic finish is not critical. For mirror-finish guest soaps, plan shorter mold life or firmer shore with thicker webs.

When in doubt, ask factory to pour test plaque in proposed grade before full tray commit - negligible cost vs wrong-grade MOQ 50 remake.

Importer of record responsibilities: food-contact grade must match declared cert at border - random sampling failures trace to compound lot, not mold shape.

Dual-market SKUs (US + EU) often specify LFGB-grade platinum even for US-only launch - avoids re-tooling when EU expansion hits year two.

Hardness and grade interact: softer food molds demold delicate pralines cleanly; firmer grades chip thin chocolate ears on bunny molds - prototype both if unsure.

Supplier switching mid-SKU: request compound name on outgoing PO and match on incoming - "platinum food grade" alone is not interchangeable between vendors.

RoHS and REACH declarations sometimes requested for EU non-food craft molds sold as children's craft kits - clarify if silicone grade documentation covers those frameworks.

Shelf life of uncured vs cured mold: cured production mold library life is years; do not confuse with tin-cure kit pot life in buyer education content.

Colorant in silicone (pigmented mold body) is aesthetic only - does not replace food-grade compound certification for contact surfaces.

Request SDS for silicone compound in same email as cert - retailers increasingly ask both; having bundle ready speeds vendor onboarding portal upload.

Application mistake matrix on wall: food = platinum + cert; resin = platinum preferred; candle = heat-rated platinum; never tin for food - poster prevents night-shift mix-up if you run multiple lines.

When launching both US and EU from day one, specify strictest grade (LFGB-tested compound) single sourcing - simplifies SKU count and inventory.

Material change notification clause in contract - if compound lot changes, factory sends updated cert before production ship; prevents surprise audit failure.

Non-food resin molds still benefit from platinum for library life - tin-cure savings pennies per mold while limiting reorder interval.

Grade selection workshop with RUUIPON: send three application photos, receive recommended shore and cert path in quote - no charge line item on RFQ response.

Compound shelf life at factory: platinum base stored correctly before pour - ask about FIFO inventory if audit trail matters for medical-adjacent cosmetic molds.

Switching grade mid-SKU life requires new cert package and consumer packaging update if material callout printed on box - plan grade freeze before print run.

Heat-rise test for candle grade: pour wax at max process temp on prototype, measure cavity surface stickiness after 50 cycles - validates grade pairing.

Document grade on mold flange laser mark: "FG-PLT-32A" shorthand helps operators return mold to correct storage bin in multi-SKU facilities.

Frequently Asked Questions

Can one grade cover food and resin?
Technically possible with food-grade platinum, but uneconomical - resin molds do not need LFGB testing cost.

Does grade affect shrink?
Slightly; material offsets matter more. Tolerance guide.

How do I verify supplier grade?
Request batch cert matching compound name on invoice - not generic "food safe" sticker.

UV resin vs epoxy - different mold grade?
Both work on platinum RTV; inhibition rare with clean masters.

MOQ 50 with mixed grades?
Yes - per-SKU grade on same PO OK.

Choosing grade for private label OEM?
OEM guide

Get application-specific quote?
Contact RUUIPON