The Challenge
The brand’s incumbent ear tips varied noticeably in softness between production batches, and fine flash on the dome seam caused scratchy in-ear feel — the top driver of returns. For their retail expansion they required: skin-contact-safe platinum LSR, Shore 00 hardness held within ±2 across all three sizes, flash below 0.05 mm at the parting line, acoustic-transparent dome geometry, and 8 colorways with lot-to-lot color consistency.
Our Solution
We built a 16-cavity LSR mold with cold-runner feed to eliminate runner waste and hold durometer uniformity, tuned cure curves per cavity with in-mold pressure sensors, applied tear-trim deflashing plus 100% automated edge inspection, and validated ISO 10993-10 skin sensitization for prolonged ear contact.
Results
- ✅ Shore 00 hardness held within ±2 across S/M/L and all lots
- ✅ Flash below 0.05 mm; automated edge inspection on 100% of parts
- ✅ ISO 10993-10 skin sensitization passed for ear contact
- ✅ Scaled to 10M units/year across 8 colorways with 99.5% pass rate
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