Silicone Heat Transfer Labels: The Full Production Flow and the Equipment Behind It
Production Technology · Anysil Silicone Co., Ltd, Panyu, Guangzhou
Silicone heat transfer labels look like a printing job and behave like a moulding job. Lines that treat them as ordinary screen printing are the ones that peel on the third wash.
Meta description: Silicone heat transfer labels look like a printing job and behave like a moulding job. The five-layer film structure, the two production routes, the eight-step roll-to-roll line, the equipment configuration for each stage, and the parameters that decide whether a label survives fifty washes or peels on the third. Slug: /blog/silicone-heat-transfer-label-production Tags: silicone heat transfer label, 3D silicone label, roll to roll screen printing, liquid silicone rubber, vacuum vulcanisation, hot melt adhesive, silicone printing ink, label production process
Silicone heat transfer labels are built, not printed. Liquid silicone rubber is deposited in layers, crosslinked at controlled temperature between passes, and finished with a hot-melt adhesive that bonds the whole structure to fabric under heat. Set the line up as an ordinary screen press - conventional squeegee, conventional mesh, one-pass cure - and the parameters that matter most are the ones you never set. Here is the full flow, the equipment each stage needs, and the numbers that decide whether the label survives fifty washes.
The film is five layers, not two
| Layer | Material | Thickness | |
|---|---|---|---|
| ⑤ | Protective film | Silicone paper or PE, peeled off before use | 40–80 µm |
| ④ | Hot-melt adhesive | PA or PU, melts during heat press | 20–80 µm |
| ③ | Silicone pattern layer | Addition-cure LSR plus colour paste - the printing target | 80–800 µm |
| ② | Release coating | Controls clean peel-off after transfer | 0.5–2 µm |
| ① | PET substrate | BOPET carrier, heat-resistant, holds the web | 25–75 µm |
Layer ③ is where the printing happens - and where the equipment specification is really decided. Every additional colour or relief step is another pass over the same layer stack.
Two production routes
| Route | How the pattern forms | Best for | Main risk |
|---|---|---|---|
| Roll-to-roll screen printing | LSR overprinted in layers onto PET release film, cured between passes, adhesive coated last | Flat and medium-relief labels, multi-colour art, jersey numbers, brand logos, volume runs | Cure shortfall in thick builds |
| Vacuum mould forming | LSR dispensed into an engraved mould, covered with hot-melt film, cured under vacuum so bonding happens in the same cycle | Thick 3D moulded labels; fine small text where a pinhole is scrap | Tooling cost and changeover |
The vacuum route exists for one reason: LSR traps air. At half a millimetre of relief, a bubble is not a cosmetic defect, it is a reject - which is why de-airing and mould forming replace screening entirely on the thicker products.
The roll-to-roll line, in eight steps
Each step has a parameter attached to it, and skipping one shows up downstream rather than on the machine.
| Step | What happens | Why it matters |
|---|---|---|
| 01 Substrate conditioning | PET release film held at 23 ± 2 °C and 50 ± 5% RH for at least 24 hours to relieve stress | A web that shrinks mid-run takes the registration with it |
| 02 Release primer | Printed on the PET and pre-dried at low temperature - the step most tutorials omit | Without it there is no clean cold peel: adhesive residue, stringing, pattern lift |
| 03 Base layer | White or transparent silicone base; typically 160-mesh with a 20 µm stencil, cured at 120 °C for 3 min | A base layer is what makes colour saturation possible on dark fabric |
| 04 Colour layers | Each colour printed and fully cured before the next; registration held to ±0.05 mm | Partially cured layers delaminate - and the failure shows in the wash, not on the rack |
| 05 Relief build-up | 60–100 mesh with 100–300 µm stencil, overprinted 2–8 times | Relief comes from repetition, so the dryer length limits throughput, not the press |
| 06 Post-cure | 170 °C for 30 minutes, completing crosslinking through the full thickness | Fixes elasticity and wash performance for the life of the label |
| 07 Adhesive coating | Hot-melt applied at 160–180 °C to a dry thickness of 30–50 µm | Adhesive weight decides bond strength on the customer's fabric, not on yours |
| 08 Lamination and rewinding | Release paper laminated on and the roll rewound - or die-cut / laser-cut into discrete labels | Delivered form has to match the customer's applicator |
Equipment configuration
| Stage | Equipment | What it has to deliver |
|---|---|---|
| Pre-press | Vector and colour-separation software; mesh stretching machine; exposure unit; tension meter | 140–180 mesh screens for fine lines and small text; 80–120 mesh thick screens for relief; screen tension held to 18–22 N/cm |
| Printing | Multi-station roll-to-roll screen printer | CCD vision registration at ±0.025 mm per pass (cumulative ≤ ±0.1 mm across eight passes); servo web tension control; static elimination |
| Curing | Circulating hot-air tunnel dryer, 40–60 m | ±2 °C uniformity. A 300 µm layer needs 8–12 minutes at 150 °C. A short dryer cannot make the schedule above |
| Adhesive | Hot-melt coating unit | 160–180 °C application; 30–50 µm dry film; even weight across the web width |
| Finishing | Lamination and rewinding unit; die-cutter or laser cutter | Stable lamination, clean cutting edge, no adhesive bleed |
| Quality | Thickness gauge; colour difference meter; wash tester; tensile and bending tester | Relief height and ΔE per batch; wash cycles and 100,000-cycle bending for sportswear programmes |
On the vacuum mould route, the equipment set is different: a vacuum vulcanisation machine (vacuum de-airing, multi-stage pressure, temperature uniformity within ±2 °C), a dispensing unit to fill each pattern zone, engraved moulds, a chill plate for de-moulding, and a deflash-and-transfer station.
Four parameters that decide the outcome
Mesh and stencil thickness. 120–180 mesh with 15–30 µm stencil for fine art and text; 60–100 mesh with 100–500 µm stencil for the relief build. A 100 µm stencil deposits 80–120 µm per pass; a 300 µm stencil deposits 200–280 µm. Relief beyond 500 µm comes from overprinting.
Squeegee. Polyurethane at 55–70 Shore A - softer than conventional printing, so high-viscosity LSR (working range roughly 20,000–30,000 mPa·s) fills thick mesh. Blade angle 50–65°, well below the usual 75°. Flood bar pressure kept under half of squeegee pressure, or you pull the printed layer back off.
Cure schedule by thickness. Up to 50 µm: 120–140 °C for 2–4 minutes. 100–300 µm: 130–150 °C for 4–8 minutes. Above 300 µm: stepped ramps, e.g. 80 °C → 100 °C → 130 °C → 150 °C. Surface skinning over an uncured interior is the classic thick-build defect.
Verify the cure instead of assuming it. Soak a cured sample in n-heptane for 30 minutes. Swelling of 10% or less passes. This one check separates a controlled line from a hopeful one.
Where lines lose money
Omitting the release primer. Everything looks correct until the customer tries a cold peel.
One-pass curing on a thick layer. Passes inspection, fails at wash three.
Ordinary squeegees and mesh. Under-filled thick mesh reads as pinholes and soft relief edges - and no amount of reprinting fixes it.
No bonding test on the customer's actual fabric. Bond strength is a property of the pair. A label that holds on cotton can lift on a spandex-rich knit.
On the customer's side of the process, the transfer itself has its own parameters: preheat the fabric at 150–160 °C for 8–12 seconds, then press at 145–155 °C and at least 4 kg/cm² for 8–12 seconds, and allow the assembly to cool before peeling. Cold peel, not hot - hot peeling is what rolls the edges.
quipment cannot tell you the answer
Notice what nothing on that list covers: whether the silicone will actually do it. Mesh, stencil, squeegee hardness, blade angle, dwell time and cure schedule are all set around the material's viscosity, cure speed and adhesion. Change the LSR and every number above moves.
Anysil manufactures both sides of that equation. Founded 2016 in Panyu District, Guangzhou, we produce addition-cure liquid silicone rubber and the printing inks and coatings that go onto the film - certified REACH, FDA and LFGB, with inks additionally RoHS, ISO and OEKO-TEX. We ship to more than 50 countries and supply lot-level certificates of analysis as standard.
Tell us the label, not the machine - send the relief height, the substrate it will be pressed onto, the wash requirement and the performance target. We will recommend the ink system and cure schedule, and put a sample through your own washing test before you commit to a line. → Request a material recommendation
*Sources: published 2026 process guidance on roll-to-roll screen printing of thick-film silicone heat transfer labels (five-layer film structure and thickness ranges; mesh, stencil, squeegee and ink-viscosity parameters; segmented cure schedules and the n-heptane swelling check; eight-step roll-to-roll flow; CCD registration and tunnel-dryer specifications); published guidance on vacuum vulcanisation and mould-forming production of liquid silicone transfer labels (dispensing, vacuum de-airing, in-cycle hot-melt lamination); 2026 wash-durability and bending test requirements for sportswear, bag and automotive interior applications; REACH Annex XVII (PFHxA, applicable from 10 Oct 2026); Regulation (EU) 2024/1328 (D4/D5/D6 siloxanes, from 6 Jun 2026); company information, Anysil Silicone Co., Ltd. Parameters are typical industry ranges, not guarantees.