Overmolding & injection
Overmolding & Injection Molding for Cable Assemblies
Strain relief, sealed boots, integrated branding and insert retention formed in one shot — in PVC, TPE, TPU, PP, PA and PUR.
Three problems solved in one shot, or none of them.
Overmolding solves three problems at once: it locks the connector to the cable, it controls where the cable bends, and it is the only realistic way to make an interface survive a wet, oily or high-vibration environment. Done badly it does none of these, and adds a failure point where there was none.
Material selection.
| Material | Where it fits | Trade-off |
|---|---|---|
| PVC | General indoor, cost-sensitive, wide colour range | Stiffens in cold; limited flex life |
| TPE | Handheld devices, flexible strain relief, soft-touch | Lower chemical resistance than TPU |
| TPU | Drag chain, abrasion, oil exposure, robotics | Higher material and processing cost |
| PP / PA | Structural bodies, higher temperature, chemical resistance | Bonding to cable jacket needs specific design |
| PUR | Abrasion and hydrolysis resistance, outdoor and marine | Process window is narrower than PVC |
| Silicone | High-temperature and medical-adjacent builds | Requires dedicated process control |
Bonding is a design decision, not a hope. We confirm jacket material and surface condition before tooling, because an overmold that looks fine at T1 can delaminate at month six if the two materials were never meant to bond.
What we control, and what goes wrong when nobody does.
- Insert movement
- Connector shifting during injection causes pin misalignment. Controlled by holder design and injection sequence.
- Flash at the parting line
- Controlled by tool fit, clamp tonnage and shot parameters; checked at first-piece and in process.
- Short shots at the cable exit
- Usually a gating or venting issue. Resolved at mold concept stage rather than by raising temperature.
- Delamination from the jacket
- A material compatibility and surface-preparation issue — confirmed before tooling, not after.
- Sink marks on thick sections
- Controlled by wall-thickness uniformity in the mold concept, not by packing pressure alone.
- Stress cracking at the strain relief
- Geometry and radius design, validated by bend and pull checks before release.
Options available.
- Exit geometry — straight, right-angle or custom exit angle
- Colour — Pantone or sample match
- Identification — molded-in logo or part number
- Strain control — integrated strain relief and bend limiter
- Sealing — sealed boots and gasket paths to IP65 / IP67 / IP68 / IP69K design targets
- Low-pressure molding — for delicate inserts and thin-wall connectors
- Integration — overmold-to-panel or overmold-to-bracket geometry
Tell us the connector, the jacket and the environment.
Those three facts decide the material, the exit geometry and the sealing path. Everything else follows from them.
