Replacement and Reorder RTV Silicone Molds
The safest replacement reference is the original approved CAD, master, or finished part, not a mold that has already stretched, torn, or taken a set. If you're reordering, send the revision letter and the golden sample note. If you're replacing a failure, send photos of the tear, yellowing, or distortion and say whether we may improve the structure. Copying a worn cavity as the new nominal is how the next lot is born wrong.
RUUIPON recasts RTV skins in Bao'an against a living master and jacket. A recast is not a new steel tool. If the master was sanded to clean it up or lost, you're back to CAM. High-volume HCR/LSR parts replacements are an HTV product or mold RFQ here, or ask us if you need a high-volume LSR cold-runner tool quote, not this page.
Duplicate what, exactly?
| Source you send | What we should do | Risk if we copy blindly |
|---|---|---|
| Locked CAD plus golden sample | Recast the skin, same Shore, same keys | Low, if compound is unchanged |
| Original master, still true | Recast against it | Low, if the pattern wasn't cleaned |
| Approved finished casting | Reverse the part, then cut a new master | Scale/shrink must be named |
| Worn RTV mold only | Reconstruct, don't duplicate the stretch | High: distortion becomes nominal |
| Photos of a lost mold | Same as from-photos plus a measured part if you have one | High without a millimetre datum |
First order equals NRE/master/prototype plus production molds plus pack/freight. Unchanged reorder equals recurring mold cost plus QC/pack/freight. If geometry, Shore, master, or structure changes, some NRE reopens. That's the commercial reason to keep a design record.
Common mix-up: waiting for catastrophic failure, then rushing a copy
Molds tell you they're dying: a tear starting at a thin shut, keys that walk, yellow sticky from the dump chemistry, edge sag that moved grams. Order the recast when the first production CTQ drifts, not when the tray is in two pieces on Friday. A rush copy of a stretched tool will not save the weekend.
If the same corner tears on every reorder, the structure is wrong. Raising Shore A or pouring a thicker skin is usually a dodge. Move the split, add a plug, add a jacket.
Typical shop values
| Item | Typical shop value |
|---|---|
| Recast vs new NRE | Recast if master plus keys still register; new NRE if pattern is lost or cleaned |
| Cavity Shore (typical food skin) | Same 10A–20A as the golden sample unless you approve a change |
| Platinum shrink | ~0.1–0.3%; tin-cure old molds may have kept moving |
| Prototype on an unchanged recast | Often a functional check vs golden sample, not a full 3–7 day new design |
| New geometry / improved split | 3–7 days after the new CAD lock; MOQ 20 |
| Outer-row weight drift | 3–6% heavy vs center is a classic sag/set symptom |
Reference values only. Confirm material-specific limits against the supplier’s technical data and agree project acceptance criteria before production.
Failure: new molds, same tear, heavier edge
Symptom: Reorder arrives, fails in the same week at the same serif; grams don't match the golden sample; color/Shore close enough; CAD revision unknown.
Confirm: Overlay new dump vs approved part. Check master for sanding. Check compound vs the original lot pack. Photograph the tear origin.
Fix: Reconstruct from CAD or the approved part. Change the structure if the tear is geometric. Don't copy the old mold and don't silently change Shore.
Worked example: torn 12-up bear, master still in Bao'an
A co-packer sent a tray torn at the ear undercut, 14 months after approval. We still had master Rev B and the jacket. Recast the platinum skin, same 10A–20A, same keys. We did not pour against the torn tray. We also offered a slightly thicker ear fillet as a paid revision; they declined, so the recast stayed Rev B. Copying the stretched ear would have locked in the grams error that had already started.
What to ask when you're buying
- What is the reference: CAD revision, master, approved part, or the old mold?
- May we improve the known tear geometry, or must this be a duplicate?
- Is the compound still the golden-sample grade, including food-doc path?
- Who still has the master and jacket, and may the shop keep a copy?
- How many replacements now, and what's the wear trigger for the next recast?
When this page is the wrong route
A brand-new shape is not a reorder. Start at master options and prototype validation. If you're replacing thousands of molded silicone articles, that's HCR/LSR as an HTV product RFQ here, or ask us for a high-volume LSR tool. A tiny undamaged stamp that you lost in a drawer is a duplicate job, but still needs the CAD or a measured sample. Geometry can override: one improved split is worth more than ten identical doomed recasts.
Related: quality control, cost, manufacturer, contact.
RFQ: replacement pack
Copy this.
- Original CAD/master revision if you have it
- Approved finished part or golden-sample photos
- Old mold photos and the failure (tear, yellow, set, lost)
- Duplicate vs allowed DFM improvement
- Quantity of replacements and expected dumps per month
- Compound / Shore / food-doc path must match: yes/no
- Who holds the master today
Send the old mold photos, the approved part, and the revision if you have it. We will say recast, reconstruct, or improve, before anyone copies a stretched cavity. [email protected] · +86 135 3006 2969.
We would not recommend copying a stretched mold as the new nominal
We would not recommend waiting until the tray is in two pieces. We would not recommend changing Shore on a repeat without a new first article. We would not sand the master to clean it and then expect the recast to match Rev B.
RUUIPON Mold Structure Decision:
- Reference still true: CAD / master / approved part? - yes -> Same tear as last time?
- Same tear as last time? - yes -> Improve split / plug / jacket, then recast
- Same tear as last time? - no -> Recast skin on the living master
FAQ
Can you recast if I only have the old mold? We can try to reconstruct, but we will not treat a stretched cavity as nominal. Send an approved part or CAD if you have either. Expect some NRE.
Is a reorder cheaper than the first PO? Usually, because master/DFM/prototype NRE doesn't repeat when nothing changed. Pack and freight still do. A structure change reopens NRE.
The same corner tears every time. Can you just use tougher rubber? Sometimes tear strength helps. If the undercut will not peel, tougher rubber delays the funeral. Fix the split, plug, or fillet.
Do I need a prototype on a recast? If master, Shore, and structure are unchanged, a check against the golden sample is the usual shop path. If we change anything, treat it as a new prototype.
Who owns the master on a reorder? Whatever the first PO said. Paying for molds does not automatically move the pattern. Write custody if you need it.