Will your rollstock run on the packing machine? Six parameters decide

Will your rollstock run on the packing machine? Six parameters decide

The same printed roll can run smoothly on one machine and cause web breaks or weak seals on another. The film has not changed; the machine requirements have.

Six things worth confirming up front

1. Roll diameter and core size - what the unwinder accepts and whether the core is 3 inch or 6 inch determines how we wind.
2. Web width and tolerance - the former sets the width, and tolerance is usually controlled in millimetres; different machines allow different deviation.
3. Winding direction - print face in or out decides whether the artwork must be reversed for printing.
4. Thickness and stiffness - too thin and the web wrinkles at speed; too thick and it will not pass the former.
5. Seal parameters - whether the machine seals by heat, impulse or ultrasonic, and the jaw temperature and pressure range.
6. Coefficient of friction - a film that is too slip will track off the former; too much friction and it will not pull.

The fastest way to get this right

Photograph the machine nameplate showing model, web width, roll diameter and sealing method. That is quicker and more accurate than describing it in messages. We then build the film structure around the machine instead of asking the machine to adapt to a film we already made.

A common misunderstanding

Many buyers assume thicker film means a stronger bag. What determines strength is the structure and the material ratio, not thickness alone. At the same thickness, a PA/PE structure and a plain PE film behave very differently in puncture resistance.