Precision silicone overmolding · drawing review → sampling → volume
Teat cup liners, pulsation tubing and claw gaskets, moulded in food-contact silicone and matched to your shell size and vacuum level. This page sets out how a liner is specified, which dimensions must be fixed before tooling, and what the four common field failures actually point at.
Three product lines
A milking cluster is replaced as a set: the liner sets milking performance and teat health, the pulsation tube sets whether the vacuum curve stays true, the gasket decides whether the cluster leaks air. Distributors usually ask for the whole set in one enquiry.
The flexible part that touches teat and milk, alternating vacuum and pulsation to open and massage. Food-contact silicone, low extractables, resistant to repeated washing.
The path the vacuum pulse travels. Only a tube that resists kinking and keeps its rebound delivers an undistorted pulsation curve; hardening or internal cracking changes the milking rhythm directly.
Small parts between lid, claw and tube connectors — but they decide whether the system holds vacuum at all.
Specification
A liner is not "close enough to fit": 1 mm of diameter or a few Shore A of hardness changes milking performance and teat condition. Dimensions below are confirmed against your drawing or cluster model — we do not assume a universal size.
| Item | Why it matters | How it is confirmed |
|---|---|---|
| Shell diameter and barrel length | Sets the sealing line and the stroke; a loose fit loses vacuum | Measured from the liner in use, or from the shell drawing |
| Hardness and wall thickness | Too hard compresses the teat, too soft leaves milk behind; wall drives rebound and life | Set against the vacuum level and milking duration of the cluster |
| Cattle vs small ruminant system | Teat size and vacuum settings differ; one tool cannot serve both | Separate tooling per species and cluster size |
| Material and washing route | Food-contact silicone has to survive acid and alkaline wash cycles | Grade chosen from the cleaning process and disinfection temperature |
| Marking and packaging | Private-label buyers need batch, brand and size marking | In-mould marking or secondary printing, per brand requirement |
Field failures
Usually cleaning resistance or an over-strength wash: check chemical dosing and soak time first, then consider a different grade.
A surface and compound cleanliness issue — tool polishing and compound filtration. Once the wall is rough it will not clean up; the part has to be replaced.
Check cluster seals and pulsation tubing for ageing and leaks first, then whether liner diameter and hardness suit that cluster.
Normally hardness too high or vacuum too strong — a specification issue, not an operator issue.
For the general method of reading interface and material failures, see eight failure modes in silicone overmoulding; for food-contact compliance framing and test scope, see R&D and testing.
Working models
Brands and distributors usually take one of three routes: private label on an existing size with your marking and packaging; OEM tooling to your drawing; or full-cluster supply combining liners, pulsation tubing and gaskets. Tooling and sampling charges are set out in sampling and tooling rules, and drawing handling in confidentiality and NDA.
We reply with a material and tooling recommendation based on diameter, hardness and the washing route; physical samples are welcome for comparison.