A second material moulded over a first: grips, seals, two-colour parts. No assembly step.
In short: overmoulding bonds a second material over a moulded substrate: soft-touch grips, seals and two-colour parts with no separate assembly step. Carmo runs it in-house, in one 2K cycle or in two stages, with medical-grade material pairs, under the ISO 13485 QMS.
Overmoulding moulds a second material over a part that has already been moulded: a soft grip over a rigid handle, a seal over a housing, a second colour or texture over a base. At Carmo we run overmoulding in-house, in 2K (both shots in one tool) or in two stages, as part of our injection moulding of plastic components.
Overmoulding is usually plastic over plastic. It can be done two ways:
The bond is chemical where the material pair is compatible, or mechanical (keyed features) where the materials won’t bond on their own.
Common overmould pairs combine a rigid engineering thermoplastic (PC, PA, ABS or POM) with a soft TPE or TPU. Carmo runs the same medical-grade and technical-grade thermoplastics here as in series production, including proprietary Carmo PVC recipes refined over decades.
The pair you choose also decides how the part ends its life: an overmoulded part needs separating before its polymers can be recycled, and the pairing and bonding decisions made at design stage make that easier or harder. Can multi-material components be recycled?
They overlap, but the difference is the first part. Overmoulding moulds over a part that was itself moulded first (usually plastic); insert moulding moulds around a pre-made component (often metal) loaded into the tool; 2K is overmoulding done in one tool, in one cycle. Which of the three fits your part is typically settled as part of a design for manufacturing (DFM) review. Read more: Overmoulding vs insert moulding and 2K moulding.
Whichever technique fits your part, it is produced in-house under Carmo’s ISO 13485-certified quality management system, documented and traceable like every component we make.
Tell us the part, the material pair and the volume. We'll propose 2K or two-stage overmoulding, and the tooling route that fits.
Nine functional medical components in a medical-grade material: months taken out of a timeline that had already run long.
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Functional prototypes in the production material in 1–2 days, where a conventional mould tool takes up to six weeks.
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The buoyancy lock that holds the life jacket together: co-developed over two years for equipment that has to save lives.
Read the caseOvermoulding moulds a second material over a part that was already moulded, in one shot (2K) or in two stages. It is how soft-touch grips, seals and two-colour parts are made in one piece, without a separate assembly step.
Typically a rigid engineering thermoplastic (PC, PA, ABS or POM) with a soft TPE or TPU. Compatible pairs bond chemically; others are keyed mechanically. Carmo scopes the pairing as part of the design engagement.
2K (two-shot) is one way to overmould: both materials in one tool, in one cycle. Overmoulding can also be done in two stages with two tools, which can lower tooling cost at lower volumes.
Yes. Overmoulding runs in-house at Carmo under the ISO 13485-certified quality management system, whether the part is moulded in one 2K cycle or in two stages. Documentation and traceability for every component are covered under quality assurance at Carmo.
More than 80 years of continuous private ownership: one team from prototype to volume, no handover.
ISO 13485-certified quality management and an ISO Class 8 cleanroom environment: components with the documentation your audit asks for.
You bring the problem; we bring the know-how to solve it. We don’t walk away from the hard ones. Hear it from our customers.
