Tape extrusion 拉丝

Polypropylene granules are melted, extruded as a thin sheet, slit into narrow tapes and stretched.

Front end 前道 Required by 87 of the 247 products we catalogue.

What actually happens

Stretching is the step that matters: drawing the tape 5–7× aligns the polymer chains along its length, which is where the strength of a woven sack actually comes from. Under-stretched tape makes a bag that feels right and fails under load.

What to specify

Specify tape denier and the draw ratio, not just fabric weight.

How it goes wrong, and what catches it

The failure mode. Under-drawn or unevenly drawn tape gives inconsistent tensile strength across a lot — the bag holds on the sample and splits in the field.

The control. Tape denier checked at the winder; finished fabric weighed and back-calculated against the specified GSM.

We publish which of our plants runs this process — see the capability matrix. We do not publish which plant runs a given order.