Post-Cure Before First Food-Contact Pour | RUUIPON

Wash a new platinum food-contact RTV mold, then post-cure it, then dump the first chocolate, gummy, ice, or batter. Do not treat the shipping bag as a kitchen-ready cavity. Fresh addition-cure rubber can hold leftover volatiles and handling film from the box. A documented oven post-cure (time and temperature from the grade's processing notes, not a guess from a blog) plus a hot-water wash and a full dry is the sequence we want before food touches the face.

RUUIPON pours those platinum tools in Bao'an since 2018. Mix is 1:1 or 10:1 by weight, vacuum degassed. Prototype 3–7 business days after CAD lock. Production MOQ 20 pieces per design. USD $50 CAD when that modeling scope applies. If the RFQ says food-contact, the post-cure line belongs on the PO, not in a later complaint about smell.

Does not apply when the mold is craft resin, plaster, or concrete with no food claim. A tin hobby kit you already own is also outside this bake schedule — and we would not spec tin for a food cavity anyway (platinum vs tin). LSR kitchen *parts* post-cure in a different cell; that is wydsilicone.com.

Why the first dump is not out of the bag

Platinum RTV cures in the box. That cure is not the same as a food-contact post-cure. Shops bake to drive off residuals the TDS cares about, and to stabilize the skin before you park fatty chocolate or hot batter in the pocket. Skip it and you get:

• A new-mold smell that transfers on the first two pours
• A slightly tacky face that grabs pectin
• A buyer who thinks the rubber is "not food-grade" when the compound was fine and the bake was missing

Wash is the other half. Powder from demold, fingerprints, and box dust sit in micro-texture. We wash, we do not oil. Dry cavity-up until the face is matte. A wet pocket is a stick complaint waiting for chocolate release physics.

If the cavity face is tacky and the jacket back is fully cured, stop. That is inhibition from the master, not a post-cure you can bake away. Remake from a sealed master. Baking a sticky inhibited face and then pouring chocolate is how you invent a documentation problem.

Wash, then heat, then food — in that order

1. Inspect. Cavity vs jacket. Keys seated. No uncured patches.

2. Wash. Warm water, mild detergent if the PO allows it, rinse until the water sheets. No abrasive pads on a logo well. No butter, no spray.

3. Dry. Cavity-up, room air until matte. Trapped water in a serif becomes steam in the oven and a blister conversation.

4. Post-cure. Oven on a support so the skin does not sag (unsupported loaded sag in use is already 0.5–1.5 mm; a floppy bake makes it worse). Time and temperature follow the platinum grade, not "as hot as the kitchen goes." Jacket on if the tray will warp.

5. Cool, wash again if the RFQ asks for a second rinse, dry, then first food dump. Keep that first dump as the witness, not a social-media pour.

Commercial dishwashers are not a substitute post-cure. They add detergent film and mechanical wear. If the production spec is hand-wash, do not "sanitize" the new tool in a pit washer before the bake. Food-doc packing list: food-grade molds.

Typical shop values

Caption: typical shop values. Not a lot-specific bake log.

Write the post-cure schedule on the PO as "per grade processing notes" plus who owns the oven (our shop vs your kitchen). We would not invent a Celsius number here as a fake shop measurement.

Common mix-up: boiling overnight as post-cure

A lot of first-use blogs say boil the mold for hours. Boiling is a wash variant. It is not a documented oven post-cure, it will not fix inhibition, and it can warp a jacket-less 20A tray. If your QA needs a recorded bake, put oven time and support on the PO. If you only need a clean cavity for a home test dump, wash and dry thoroughly and still do not skip the shop bake when the listing is food-contact production.

Worked example (anonymized)

A 24-cavity pectin tray, platinum ~25A, jacketed. Buyer wanted first gummies the day the courier arrived. We had already post-cured the lot per the grade notes after the pour, but the buyer re-washed in a dishwasher with rinse aid and dumped while the pockets were still cold-wet. First row stuck. Second dump, hand-rinsed and matte-dry, released. We did not recast. The RFQ for the next design now says: shop post-cure, hand-wash spec, first dump on a dry tray, dishwasher not used as the bake. Prototype still 3–7 business days after CAD lock; the bake is inside that sample, not an extra mystery week, when you ask for it at lock.

Who runs the oven, and what we write on the packing list

If the bake happens in Bao'an, the packing list can say the lot was post-cured per the grade processing notes and washed. If you run the oven, we still ship a clean, dry cavity and we still want that bake on *your* SOP before the first retail dump. Do not split the lot — baking three trays and skipping the other seventeen is how a later carton smells different. Platinum shrink (0.1–0.3%) is already in the master; the oven is not a second shrink compensation, and a warped bake is a jacket problem, not a reason to recut CAD. 21 CFR 177.2600 remains extraction of the finished article. A bake log is not that extraction, and an extraction PDF is not a bake log.

We would not recommend

We would not recommend first food contact out of the polyethylene bag.

We would not recommend using a kitchen broiler or a "max oven" guess in place of the grade's post-cure notes.

We would not recommend baking a tacky inhibited cavity and hoping it becomes food-ready.

We would not recommend oiling the cavity so the first chocolate slides. Dry platinum is the release face.

flowchart TD
  A[New platinum food mold arrives] --> B{Cavity face tacky, jacket cured?}
  B -->|Yes| C[Stop — inhibition, remake]
  B -->|No| D[Wash, no oil]
  D --> E[Dry cavity-up until matte]
  E --> F[Oven post-cure per grade, skin supported]
  F --> G[Cool, optional second rinse, dry]
  G --> H[First food dump = witness]

What to ask when you're buying

• Is post-cure included on the food PO, and who runs the oven?
• Hand-wash or dishwasher after that bake?
• Do you want the first dump done in Bao'an as the witness, or shipped clean for your kitchen?
• 177.2600 / LFGB pack on this compound, not a factory stamp?
• Prototype after CAD lock, then MOQ 20 of the baked lot?

RFQ copy-pack (first food contact)

To [email protected]:

• Dump and temperature (chocolate / pectin / batter / ice)
• Market and which reports must ship
• Post-cure: shop bake per grade, yes/no on the PO
• Wash spec for production
• CAD lock state; $50 if we still model
• Prototype 3–7 business days after lock, then MOQ 20 / design

Matched next step: put wash + post-cure on the RFQ so the sample you approve is the sample you will dump. Phone +86 135 3006 2969. contact. Validation path: prototype validation.

FAQ

Do I have to post-cure a new food-grade silicone mold? For production food contact, yes — wash, documented bake per the grade, dry, then dump. Skipping it is how new-mold smell becomes a "bad silicone" ticket.

Can I just boil it? Boil is not the oven schedule. It can clean. It can also warp a floppy tray. Use it only as a wash variant, not as the PO bake.

Why does a new mold smell if it is platinum? Fresh rubber and box film. Wash and post-cure knock that down. A leftover tin smell is a different chemistry and not our food spec.

Will post-cure fix a sticky cavity? Not if the face is inhibited. Sticky-against-the-master is scrap. Remake.

Does every tray in an MOQ 20 lot get the same bake? That is the point of putting it on the PO. Do not bake only the courier sample and skip the rest of the lot.