A consumer electronics brand developing its next‑generation flagship TWS earbuds required a robust waterproof seal, all within an extremely compact design and at high production volumes. Traditional pre‑formed silicone gaskets with manual assembly proved inadequate, as the complex geometries of the charging case hinge, acoustic chamber, and Type‑C port pushed conventional methods to their limits, causing inconsistent sealing and low assembly yields.

Our engineering team collaborated closely with the client’s design departments. After extensive mold‑flow analysis and process validation, we delivered a customized micro‑LSR overmoulding solution built around our high‑precision vertical injection machine. Equipped with an advanced micro‑shot dosing unit, our system reliably handles extremely small shot weights while maintaining exceptional shot‑to‑shot consistency.

The closed‑loop controlled metering pump ensures near‑perfect A/B component ratio accuracy, eliminating material degradation and curing defects. Our cold‑runner needle‑valve technology virtually eliminates runner waste, and the coordinated mold temperature control maintains uniform thermal distribution, enabling rapid, complete curing of micro‑seals in short cycle times. In mass production, this solution delivered outstanding dimensional stability, dramatically improved first‑pass yield rates, and substantially reduced manual intervention through automated assembly integration, all while lowering per‑unit production costs.

Most importantly, the finished seals maintained their waterproof integrity even after repeated use cycles. The success of this project has led the client to adopt our LSR technology across their entire waterproof product portfolio and has cemented a long‑term strategic partnership with our company. This project clearly demonstrates that our precision micro‑moulding equipment can transform demanding waterproof specifications into a stable, high‑output manufacturing reality.