Heat-seal patch backing is a hot melt adhesive film laminated to the back of an embroidered patch. The same layer is sold as iron-on backing or heat activated adhesive for patches: it stays dry and tack-free on the patch, then melts and bonds when the patch is pressed onto a garment, hat or bag. This guide covers the two film families we supply for embroidery patch backing, TPU and PES. Our grades press between 80 and 200 °C (176–392 °F), at 0.1–0.4 MPa, for 5 to 20 seconds, depending on the grade.
Heat-seal patch backing at a glance
This guide to hot melt adhesive film for embroidery patches is for patch makers, embroidery shops, hat and apparel decorators, and brands sourcing patches in volume. It covers how heat-seal backing compares with other patch backings, how to choose between TPU and PES film, how the two pressing steps work, what changes on hats, and why patches come off in the wash. For how to find the exact setting on your own press, see our hot melt adhesive film temperature, pressure and time guide.
Patch Backing Types Compared: Heat-Seal Film, Sew-On, Hook and Loop, Adhesive and Glue
Heat-seal film is one of several ways to attach a patch. The right choice depends on whether the patch must be permanent, how the product is used and washed, and what equipment the person applying it has.
| Backing | How it attaches | Typical use | Watch for |
|---|---|---|---|
| Heat-seal (hot melt film) | Film melts in a heat press and bonds the patch to the product | Apparel, hats, bags, uniforms where sewing is slow or not possible | Needs the right grade and enough heat at the glue line; coated or heat-sensitive fabrics need testing |
| Sew-on | Stitched around the edge | Workwear and items washed hard or often | Labor per piece; some hats and bags are hard to sew |
| Heat-seal + stitching | Pressed first, then stitched | Uniforms and workwear that go through heavy or industrial laundering | Both costs apply |
| Hook and loop | Hook side sewn or bonded to the patch back, loop side sewn to the product | Removable patches on uniforms and gear | Not a permanent bond; the loop panel still has to be sewn |
| Pressure-sensitive (sticker) adhesive | Peel and stick, no heat | Events, temporary placement | Not made for washing |
| Liquid fabric glue | Brushed or squeezed on by hand | One-off repairs | Uneven coverage and slow curing; hard to control in production |
For production work, heat-seal film has two practical advantages over glue: the adhesive amount is fixed by the film thickness, so every patch carries the same layer, and the patch can be shipped with the backing already applied, so the customer only needs a press.
Heat Activated Adhesive for Patches: TPU or PES Film?
Both TPU and PES are used as heat activated adhesive for patches. The difference shows in hand feel, the temperature the garment has to take, and the fabrics involved. Our grades give a concrete starting point:
| Grade | Base | Melting point | Press window | Hardness | Listed fabrics / use |
|---|---|---|---|---|---|
| ZF-8816 | PES | 110–120 °C | 140–160 °C (284–320 °F), 10–15 s | 90A | Embroidery, trademark labels; Lycra, cotton, polyester |
| ZF-6235 | TPU | 95–100 °C | 160–200 °C (320–392 °F), 10–20 s | 65A | Clothing labels; Lycra, polyester, cotton |
| ZF-7608 | TPU | 85 °C | 110–130 °C (230–266 °F), 10–20 s | 80A | Lycra and cotton fabrics |
| ZF-5180 | TPU | 75–80 °C | 80–110 °C (176–230 °F), 5–20 s | 90A | Leather, PU, microfiber, nylon; textile bonding |
All four grades: 0.1–0.4 MPa (1–4 bar). Values are reference starting points from our grade data, not guaranteed production settings.
- PES (ZF-8816) is the grade our data lists for embroidery and trademark labels, on Lycra, cotton and polyester. It presses in a narrow, mid-range window, so it is the first sample to try for standard embroidered and woven patches on apparel. On dyed polyester, the top of the window can cause dye migration or platen shine, so start low in the window. See PES hot melt adhesive film for embroidery patches.
- Soft TPU (ZF-6235) is the softest of these grades (65A) and suits labels and patches where a soft back matters, such as on stretch garments. Its press window sits well above its melting point (160–200 °C against 95–100 °C): follow the published window, and check that the garment can take that heat.
- TPU ZF-7608 has the lowest press window of these three textile grades (110–130 °C) and a mid hardness (80A). Our data lists it for Lycra and cotton rather than for labels, so treat it as a test option rather than a first sample.
- Low-temperature TPU (ZF-5180) presses from 80 °C. Our data lists leather, PU and microfiber, which makes it the starting point for leather and faux-leather patches and for products that cannot take high heat. Because it has the lowest melting point of these grades, send us the wash and drying condition before choosing it for garments that are washed hot or tumble-dried. See low-temperature TPU hot melt adhesive film.
Film thickness matters too. A densely stitched patch with an uneven back needs enough adhesive to fill the gaps between the stitches and the product surface; a thin film can leave the edges unbonded. If you are comparing two thicknesses, press both on the real patch and product.
How Heat-Seal Patch Backing Is Applied in Two Pressing Stages
Heat-seal backing is pressed twice. The patch maker bonds the film to the patch, and the decorator or brand later presses the patch onto the product.
Stage 1, at the patch maker
- Laminate the film to the patch back. Lay the film side against the back of the patch sheet with the release liner toward the heated platen. Press just long enough for the film to bond to the patch back without flowing through to the front; many makers use the lower end of the grade’s window, for ZF-8816 around 140 °C (284 °F) for 10 seconds. After cooling, the film must not lift at the edges. On a roll laminator the same rule applies, with line speed in place of dwell.
- Die-cut or laser-cut. Cut the patch with the film and liner on, so the adhesive footprint matches the patch outline.
- Ship with the liner on. The liner keeps the adhesive clean through storage and shipping.
Stage 2, at the decorator or brand
- Peel the liner and place the patch adhesive side down on the product.
- Press at the grade’s full temperature and dwell, at 0.1–0.4 MPa (15–58 psi). On a pneumatic press the gauge shows air-line pressure, which is not the same as the pressure on the part; our temperature, pressure and time guide explains how the two relate. Presses without a readout can be checked with a pressure pad. Compared with stage 1, what changes is dwell and the heat path: the heat now has to pass through the embroidery to reach the film, so a thick patch usually needs the upper half of the dwell range. On flat garments, a second press from the inside helps the heat reach the glue line. If you received pre-backed patches and do not know the film, ask your supplier for the grade and its press window before you set the press.
- Cool, then wait before washing. Let the patch cool flat, or on the form for hats. Hot melt film bonds as it cools, but many patch suppliers still advise waiting 24 to 48 hours before the first wash; put this in the care instructions you ship with the product.
Heat Press Patches on Hats: What Changes
Hats are harder than flat garments. The crown is curved, structured hats have buckram or foam behind the front panel, and many shops use a dedicated hat press. The bonding rules are the same; the heat path is longer.
- Start from the film’s window, then adjust for the hat. A structured crown and a thick patch both slow heat down, so expect the upper part of the dwell range before you raise temperature.
- Pre-press the hat for a few seconds without the patch. This removes moisture picked up in storage and shipping, which otherwise absorbs heat and leaves a weak bond.
- Check the platen, not only the display. A temperature strip or contact thermometer on the platen often reads differently from the controller, and curved platens can have cold spots.
- Support the panel. The hat must sit firmly on the lower platen or form so pressure reaches the whole patch, including the edges, and it should cool on the form.
Example: a patch backed with PES ZF-8816 on a structured cap. Start at 150 °C (302 °F), mid-range pressure and 12 seconds. If the patch peels cleanly from the crown after cooling, extend to 15 seconds, then raise temperature toward 160 °C. If the patch still lifts at the top of the window, send us the cap construction, the patch thickness and your press settings so we can check the grade.
If you are setting up a new hat line, our nine-press trial method works the same way on a hat press: fix pressure, vary temperature and dwell inside the grade’s window, and judge where each sample fails.
Why Heat-Seal Patches Peel After Washing
Patches that come off in the wash usually point to one of a few causes. Change one thing at a time.
| What you see | Likely cause | What to change |
|---|---|---|
| Patch lifts off cleanly, adhesive stays on the patch | Glue line too cold at final pressing, or the fabric has a coating or finish | Longer dwell, then temperature inside the window; test the fabric for water-repellent or silicone finishes |
| Patch separates from the film, adhesive left on the garment | Film was not fully bonded to the patch back in stage 1 | Lengthen the stage-1 press so the film bonds to the patch back |
| Edges lift first | Film footprint smaller than the patch, or pressure not reaching the edge | Match the cut to the patch outline; use a pad or form under curved areas |
| Patch fails only after the first few washes | A marginal bond from final pressing that only shows under washing, or a wash or drying temperature too hot for the adhesive grade | Re-check dwell and platen temperature; send us the wash and drying condition so we can check the grade; give care instructions with the product |
| Adhesive shows on the garment face | Too much heat or pressure on a thin or open fabric, or film too thick | Lower pressure first, then temperature; try a thinner film |
| Patch back feels stiff | Hard grade or thick film for the use | Compare a softer TPU grade such as ZF-6235 (it needs 160 °C or more) or a thinner film |
How many washes a patch survives depends on the garment fabric, the wash temperature and detergent, drying, and the patch construction, so there is no single figure for a film on its own. Run your own wash test on finished samples before a production order, using the wash method your customer specifies, and peel-check samples as described in our peel strength test guide. If you need a target confirmed, send us the garment fabric, wash condition and patch type.
What to Send When Requesting Patch Backing Samples
A useful first sample depends on details only you have. Send these and we can suggest a starting grade and thickness:
- patch type (embroidered, woven, printed, leather or faux leather) and size;
- the product it goes on, with the fabric or material and any coating;
- how it will be applied: flat press, hat press or another machine, and who presses it;
- the wash or use condition the finished product must pass;
- the order quantity and any wash or laundering standard you must meet;
- photos of failed samples, if you are replacing a current backing.
VELNORA supplies the film in rolls to patch makers. If you are a brand sourcing finished patches, pass this list to your patch maker. Related pages: TPU hot melt adhesive film, TPU hot melt adhesive film for fabric lamination, textile hot melt adhesive film applications, and release paper vs PET release film. If you are new to the material, start with what hot melt adhesive film is.
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To request patch backing samples or a quote, send the details above through the request a quote page.
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