PES Hot Melt Film UF-251W
UF-251W is a white opaque thermoplastic copolyester (PES) hot melt adhesive film supplied on a release liner, cast from copolyester resin. Dry and tack-free at room temperature, it melts at 105–125 °C and forms a soft, thin bond that sets hard on cooling — and its solid white body does a second job while it bonds: blocking dye migration out of the fabric underneath.
That anti-sublimation barrier is why UF-251W exists. Sublimation-printed polyester holds loose dye that re-activates under press heat, and a clear or translucent film lets that dye bleed straight into whatever you laminate on top — turning white overlays pink or grey within days. UF-251W is formulated with a dye-blocking agent and a fully opaque white body, so it bonds and screens at the same time: the laminate above stays clean white, wash after wash. Where UF-2510 is the all-round PES film, UF-251W is the one to specify whenever a light-coloured overlay meets printed or deeply dyed polyester.
Key Features
- White opaque film with anti-sublimation protection — a dye-blocking formulation and full opacity stop sublimation dyes from migrating into white or light-coloured overlays during pressing and service
- Wash and dry-clean resistance — no delamination and no blistering after 50 domestic wash cycles at 40 °C, and the bond holds through dry cleaning as well
- Excellent adhesion to polyester and blends — copolyester chemistry is compatible with PET fibres, so bonding is strong without surface treatment
- Highest heat resistance in our film range — melting point 105–125 °C keeps laminates stable in curtains, wall coverings and automotive interiors
- Free-flowing at pressing temperature — melt flow rate of 25–35 g/10 min (160 °C) lets the film penetrate fabric structures for mechanical anchorage
- Made to your dimensions — thickness 0.05–0.30 mm, width slitted from 20 to 1520 mm, rolls of 100 m or 200 m
Technical Specifications
| Property | Value |
|---|---|
| Main component | Copolyester (PES) |
| Appearance | White opaque film |
| Anti-sublimation | Dye migration barrier for sublimation-printed and deeply dyed polyester |
| Thickness | 0.05-0.30 mm (standard 0.05 / 0.08 / 0.10 / 0.12 / 0.15 mm, customizable) |
| Width | 20-1520 mm, slitting on request |
| Roll length | 100 m / 200 m, customizable |
| Density | 1.25-1.30 g/cm3 (23 °C) |
| Melting temperature | 105-125 °C (DSC) |
| Melt flow rate | 25-35 g/10 min (160 °C, 2.16 kg) |
| Wash resistance | No delamination, no blistering (40 °C, 50 home laundering cycles) |
| Packaging | PE-sealed rolls in cartons or on pallets |
Recommended Pressing Conditions
| Parameter | Value |
|---|---|
| Pressing temperature | 120-150 °C (adjust to fabric and film thickness; film must fully melt and penetrate) |
| Pressure | 0.2-0.4 MPa (flat press or continuous laminator) |
| Pressing time | 10-20 s (adjust to fabric thickness and thermal conductivity) |
| Cooling | Natural cooling to room temperature; avoid moving the laminate before it sets |
Cut the film to size, heat-press according to the conditions above, and allow it to cool and set. Always run a small trial to establish the optimum temperature, pressure and time before volume production.
Applications
UF-251W is the barrier film for any laminate where dye migration is the risk and white is the colour that must stay white:
- Sublimation-printed sportswear and fashion — laminating white logos, panels and reinforcements over printed polyester without the dye bleed that stains clear-film bonds
- Footwear — white overlays and heat-cut parts bonded to sublimation-printed mesh uppers, keeping edges and logos clean
- Home textiles — white and light-coloured wall coverings, curtains and furnishing fabrics laminated over deeply dyed base cloth
- Apparel — interlinings and facings on intensely coloured or printed fabrics, where back-staining would show through light outer layers
- Bags, luggage and automotive interiors — trim and fabric-to-substrate bonding that sees heat in service, with printed substrates underneath
Because the film activates only above 105 °C and sets hard on cooling, it is equally at home on a flat bed press and on a continuous laminating line.
Why Choose Us
Shanghai United Industry Co., Ltd, founded in 2017, is a specialized manufacturer and exporter of hot melt adhesives — powders, films and polyamide grades — supplying customers worldwide. Every batch passes in-house checks on key parameters before shipment, so what you approve in sampling is what you receive in bulk production. We provide free technical consultation on pressing temperature, pressure and dwell time, and support each customer from first sample through mass production. Widths are slitted to order from 20 mm upward, and export packing in sealed PE bags with cartons or pallets makes us an easy partner for both trading companies and end users.
Frequently Asked Questions
What does the anti-sublimation function actually do?
Sublimation-printed polyester carries dye that is not fully fixed. At pressing temperatures that dye re-activates and migrates into anything in contact with the fabric. A conventional clear film bonds well but transmits the dye, so white overlays turn pink, blue or grey — sometimes only after a few days. UF-251W combines an opaque white body with a dye-blocking formulation, so it bonds the overlay and screens the dye in one step.
Do I still need UF-2510 if I have UF-251W?
For white or light overlays on printed or deeply dyed polyester, specify UF-251W. On unprinted fabrics, or where the film sits between two coloured layers and opacity does not matter, UF-2510 remains the standard all-round PES film. Both share the same melting range, pressing conditions and wash resistance, so switching between them does not change your process.
How is PES film different from TPU film?
PES is a copolyester, TPU a polyurethane elastomer, and the difference shows up in service. PES melts higher (105–125 °C against roughly 95 °C for our TPU film), resists dry cleaning, and bonds polyester fabrics more aggressively. TPU is the softer, more elastic option with a lower pressing temperature. Choose PES when the laminate must survive commercial cleaning and heat; choose TPU when stretch and softness matter most.
Will the bond survive dry cleaning?
Yes. UF-251W is formulated to resist both home laundering and dry cleaning, and it shows no delamination or blistering after 50 domestic wash cycles at 40 °C. The dye barrier is equally durable — it is part of the film, not a coating that washes out.
Can I get the film in custom thickness and width?
Yes. Standard thicknesses run from 0.05 to 0.30 mm and rolls are slitted from 20 to 1520 mm on request, in lengths of 100 m or 200 m. Tell us the fabric pair and press you use, and we will recommend a starting specification with samples to confirm.
