Roll film width on a packaging machine refers to the actual width of the roll film in its unwound state. It is usually measured in millimeters. This dimension determines the maximum bag width the machine can produce. The roll film width must be greater than the finished bag width.
How width determines bag size
The finished bag length and width are set by the roll film width and the bag-making process together.
For a three-side seal bag: bag width = (roll film width - reserved seal width) / 2. For example, with 520 mm roll film and 10 mm heat seal allowance on each side, the maximum bag width is (520 - 10 x 2) / 2 = 250 mm.
For a back seal (center seal) bag: bag width = roll film width - reserved seal width. The film is folded and one seal runs down the center, with seals on both sides.
Selection and fit
When choosing a packaging machine or packaging material, roll film width must match the machine model. If the film is too wide, it will not thread or form correctly. If it is too narrow, sealing becomes difficult or the target package size cannot be reached. The equipment manual states the applicable roll film width range, for example 100 to 320 mm. We can machine film guide rollers, formers, seal dies, and other parts matched to roll film width to customer drawings, for single pieces or small batches.
Beyond packaging machine parts, our precision component machining capability also covers non-standard parts for pharmaceutical packaging machinery, daily chemical filling equipment, and printing machinery, as well as precision structural parts for yachts and RC race cars. Hansheng Automation works to drawing, with material, tolerance, and surface finish specified by the drawing.
