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PRODUCT LINE 11 · MOULDING

Moulded gaskets
and custom silicone parts

Compression moulding and liquid silicone rubber for gaskets, O-rings, diaphragms, bellows and over-moulded components. Tooling, first article and production under one roof.

AT A GLANCE

ProcessCompression · LSR injection

Hardness20 – 80 Shore A

Part sizeup to 300 mm

Tolerance±0.10 mm (machined tool)

MOQ500 pcs per part

Finishingdeflashed · post-cured · assembled

WHY THIS SPEC

Two processes,
two different answers.

Compression moulding is the workhorse: a preformed blank, a heated tool, a press. It suits parts from a few millimetres to 300 mm, in hardnesses from 20 to 80 Shore A, and it is tolerant of simple tooling. Liquid silicone rubber injection is the other answer: it fills a closed tool at low viscosity, so it produces thin walls, fine detail and flash-free parts without a deflashing step.

The choice is made by geometry and volume, not by preference. A thick 40 Shore A gasket at 2 000 pieces a year is a compression job. A 0.5 mm wall bellows at 200 000 a year is LSR. We quote both where both are viable and say which one we would tool, because choosing wrong is expensive to undo.

Tooling quoted separately

You see what the tool costs, what it is made of, and how many shots it is rated for.

First article before volume

Dimensional report and a full cross-section on the first shots, before production.

Both processes in house

Compression and LSR, so the recommendation follows the part rather than our equipment.

Finishing included

Deflashing, post-cure, assembly and bagging, priced into the piece rate.

OPTIONS

Four ways to specify it

Same compound family, different construction. Mixing two options on one order is common and usually cheaper than splitting the purchase.

O-Rings & Seals

Standard and metric sizes, plus custom sections

ID 1–200 mm · 50–70 A

Flat & Formed Gaskets

Moulded or die-cut from sheet

to 300 mm · 30–70 A

Diaphragms & Bellows

Thin-wall rolling diaphragm and bellows

0.3–2 mm wall · LSR

Over-Moulded Parts

Silicone bonded to metal or plastic inserts

insert loaded · LSR

WHERE IT RUNS

Applications this line is specified into

Pumps & valves

Diaphragms and seats for dosing and transfer pumps.

Medical devices

Seals and components with USP Class VI compound.

Automotive

Connector seals, boots and grommets on harness routes.

Appliance seals

Oven, dishwasher and refrigeration door gaskets.

Food equipment

FDA gaskets on filling and processing equipment.

Electronics

Keypads, seals and thermal pads moulded to shape.

DIMENSIONS

Process, tolerance and minimum

Tolerance is quoted on the functional dimension. A moulded part has a tolerance band per dimension, and the band on a 50 mm overall length is not the band on a 1 mm seal lip.

Process	Part size	Tol. (mm)	Shore A	MOQ	Lead time
Compression	5 – 300 mm	±0.15	30–80	500 pcs	15–20 d
Compression (precision)	5 – 120 mm	±0.10	40–70	1 000 pcs	18–25 d
LSR injection	2 – 150 mm	±0.08	20–70	5 000 pcs	25–30 d
LSR over-mould	2 – 120 mm	±0.10	20–70	5 000 pcs	25–35 d
Bonded to insert	5 – 200 mm	±0.15	30–70	1 000 pcs	20–28 d
Prototype (soft tool)	5 – 150 mm	±0.30	30–80	50 pcs	7–10 d

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FAQ

Questions engineers ask first

What does tooling cost?

A simple compression tool starts in the low thousands of US dollars; an LSR tool with a cold runner is several times that because the tooling is more complex. We quote the tool with its material, cavity count and shot rating so you can see where the money goes.

Do I need LSR or compression?

Geometry and volume decide. Thin walls, fine detail, flash-free requirement or high volume point to LSR. Thick sections, low volume, large parts or a soft 20–30 Shore A compound point to compression. If both work, we quote both.

What is the real minimum order?

500 pieces for a compression part, 5 000 for LSR, because the tool and the set-up dominate the cost below that. A soft-tool prototype at 50 pieces is available to validate the design before you commit to a production tool.

How do you handle a tolerance I cannot meet?

We say so before cutting the tool. A moulded part has a natural tolerance band set by shrinkage and flash; asking for ±0.05 mm on a soft 30 Shore A part is not a pricing question, it is a design question.

Can you bond silicone to metal or plastic?

Yes, with a primer and a vulcanising bond, or mechanically with a dovetail. Bond strength is tested on the first article. Tell us the substrate and the temperature it sees, because the primer choice depends on both.

Send the part drawing and the annual volume.

Those two decide the process and the tool. We come back with a tool quote, a piece price at two volume bands, and a first-article plan, so you can compare the total cost rather than the piece rate alone.

sales16@yutiansilicone.com
+86 136 6281 5387

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Moulded gaskets and custom silicone parts

Two processes, two different answers.