Specifying Die-Cut Hook and Loop Parts

A die-cut part is a drawing plus a liner plus a tolerance. Get any of the three wrong and the part will run badly on a machine that was working perfectly before.

Kiss-cut or through-cut

Kiss-cut cuts the hook and loop but leaves the liner intact, so the parts stay on a continuous web and can be peeled one at a time by hand or by a dispenser. This is what you want for automated placement.

Through-cut cuts the liner too, producing loose parts in a bag or box. Cheaper per part, but they must be picked individually — fine for manual assembly, painful for a pick-and-place head.

Which liner

Realistic tolerances

Rotary die-cutting holds ±0.3 mm on a profile and ±0.5 mm on position within the web. Anything tighter is a conversation, not a catalogue item. The tolerance that catches people is not the cut — it is the adhesive bleed. A soft acrylic at 40 °C will creep 0.2 mm past the cut edge in storage; if your part has 0.3 mm clearance in the fixture, that bleed is your problem.

The four mistakes we see most

1. Hook and loop on the same sheet. A sheet cannot be half hook and half loop unless the two are spliced — specify separate parts, or ask for a matched pair on one liner.
2. Sharp internal corners. Every inside corner is a stress riser and a die-wear point. Minimum internal radius 1 mm; 2 mm is better.
3. Forgetting orientation. In a manual assembly, 20% of parts get applied the wrong way round. Print “HOOK”/”LOOP” on the liner, or die-cut asymmetric shapes so it is impossible.
4. Specifying the liner thickness last. The liner decides how the web runs. Changing it after tooling is cut means new tooling.

Tooling and lead time

A rotary die for a simple shape is a one-off cost, quoted up front, and typically takes 7–10 working days. First-article samples follow in about a week. Once the die exists, repeat orders do not pay for it again — if you move to another supplier, ask who owns the tool, because the answer is often “they do”.