Keys Still Matter on Open-Back Glove Molds | RUUIPON

An open-back glove has no shut on the cavity face — you peel it off a flat-backed master like a sock. Keys still show up the moment a mother mold, a second skin, or a pour lid has to find that glove every cycle. Those keys belong in the jacket interface or as molded bosses on the *back* of the skin, not as steel pins through a chocolate well. If the glove can rotate 15° on the mother, a wet plaster dump balloons off-center and a logo walks. If the keys sit in thin 10A rubber, they tear on open and the next dump has no register at all. Food open-backs (bars, gummy sheets) often skip keys because there is no jacket shut; the day you add a carrier board, you spec keys.

RUUIPON cuts that interface in Bao'an since 2018. Prototype 3–7 business days after CAD lock. MOQ 20 pieces per design. USD $50 when CAD scope applies. [email protected] · +86 135 3006 2969. LSR *parts* with leader pins: wydsilicone.com.

Does not apply when you already have a designed two-part block with keys on the parting land (that's the split-mold page), when the tool is a steel press, or when a tiny soap sample peels twice and never sees a jacket. Don't drop drill blanks through a food tray.

Where keys live on a glove

Back-face bosses into jacket pockets. The cavity stays clean. The operator seats the glove on the mother the same way every time. Fillets on the bosses; sharp pips tear.

Fence on the jacket, glove drops in. Faster on a production bench. The fence has to be unique so the glove cannot sit 180° off.

No keys, friction only. Fine for a shallow chocolate bar on a flat board if sag stays in the 0.5–1.5 mm band. Not fine for a wet concrete glove or a vac-cast PU.

Run the RUUIPON Mold Structure Decision: flat back → open-back. Else deep undercuts that will not peel → two-part / plug / core (now you *do* have a shut, and keys move to that land). Large wet dump → mother mold, and that is when glove keys earn their keep.

We would not spec metal pins through a platinum food well. Pins belong in a rigid jacket, never touching the dump. Food cavities: no grease, no tin, no pin lube.

What tears and what flashes

Glove keys fail by tearing out of 10A–20A skins, not by the steel-tool problem of leader-pin wear. Confirm: torn boss still in the jacket pocket, hole in the glove back, cavity face maybe still perfect. Fix: enlarge the boss, add fillet, or move the register entirely into the jacket so the skin is a smooth sock.

Flash on an open-back is usually overflow at a pour lip, not a walking shut. If you added a lid for pressure-cast and the lid walks, that *is* a shut — treat it like a two-part and put keys in the lid/jacket, not in the chocolate face.

flowchart TD
  A[Open-back glove] --> B{Jacket, lid, or second skin?}
  B -->|no shallow food tray| C[Keys optional; watch sag 0.5–1.5 mm]
  B -->|yes| D{Keys in thin rubber bosses?}
  D -->|they tear| E[Move register into jacket fence / pockets]
  D -->|they hold| F[Unique so 180 off is impossible]
  C --> G[Food: dry well, no pins, no tin]
  E --> H[Witness seat, then MOQ 20]
  F --> H

The photo that would prove register: glove seated on the mother with a unique pip visible on the back, plus a 180°-wrong attempt that will not drop in. A pretty cavity selfie is not that photo.

Typical shop values

Caption: Typical shop values.

Food trays versus craft gloves on the same "open-back" word

A chocolate bar sheet on a board is open-back because the master was flat. Keys would only print into the next stacked tray in storage. A concrete glove is open-back because you peeled a sock, then you *must* register that sock to a mother or the dump walks. Using one RFQ checkbox for both is how pins end up through a gummy well. We would not. Cabinets stay split; food stays dry and tin-free.

Worked example (anonymized)

Open-back PU planter glove, platinum ~15A, plaster mother. No keys. Operators seated it by eye; wet dump walked 8 mm and the logo landed on the jacket seam. We recast the skin with three filleted back bosses and matching pockets in a new plaster mother. CAD $50 because the boss layout was new. Food was never on this PO. Witness seat, then MOQ 20.

One procurement mix-up

"Open-back means no keys, two-part means keys" as a checkbox. Keys follow the *interface that must repeat*, not the marketing name of the mold. Tooling charge is not unrestricted ownership of a jacket you then drill pins through a chocolate face.

We would not recommend

We would not recommend steel pins through a food cavity.

We would not recommend sharp unfilleted pips in 10A skins.

We would not recommend skipping keys on a wet-dump glove because the master was flat-backed.

We would not recommend greasing keys "so they seat." Food wells stay dry; craft keys get a named dust only if we say so.

What to ask when you're buying

• Is there a jacket, lid, or carrier that must find the glove?
• Keys in the rubber back or in the jacket fence?
• Food tray — do we even need keys, or is sag the real spec?
• Who replaces a torn boss — recast skin or recast mother?
• Unique pip so 180° off is impossible?

RFQ copy-pack

Send to [email protected] · +86 135 3006 2969 · Xinhe Blvd, Shajing, Bao'an.

RUUIPON open-back glove key RFQ Dump: food / PU / plaster / concrete Jacket or lid? yes / no; material Keys today: none / rubber bosses / jacket fence / pins (we would not through food) Torn keys? photo of back and pocket Qty: witness / MOQ 20 CAD: locked / $50 3D if boss layout new

Matched next step: say whether a jacket or lid must find this glove. We put filleted keys on the back or in the mother. We will not pin a chocolate well. Prototype 3–7 business days after CAD lock. MOQ 20 per design.

Related: glove vs block, registration keys on two-piece molds, when you need a mother mold, contact.

FAQ

My chocolate bar tray has no jacket. Do I still need keys? Usually no. Watch edge sag. The day you add a lid or a depositor carrier, spec register then — not pins through the wells.

Can I glue torn glove keys with silicone caulk? We would not on a production or food skin. Recast the glove against the unsanded master. Craft flange nicks are a different page.

Why did the glove seat fine dry and walk when wet? Hydrostatic head. Dry fit is not the dump. Keys plus a mother that takes the load.

Do two matching gloves on one jacket need mirrored keys? They need unique keys so glove A cannot sit in B's pockets. Color-tint the skins if it helps operators. Don't pigment the food dump through the well.

Is a $50 CAD required to add bosses to an existing glove? If we must model the boss layout, that CAD scope applies. A recast from a locked master with bosses already on the pattern does not.