Follow each film roll from resin blend and gauge reading to slit width.

A film plant turns polymer granules into thin, wide webs of polyethylene, polypropylene or multilayer film. Extruder screws melt the resin. A die forms a bubble or a sheet, cooling sets it, and winders collect it onto jumbo rolls. Small drifts in the blend or the die gap change thickness across the web. The customer finds out at the printing press. Thickness is the whole product.

Software for film extruders ties each jumbo roll to its resin blend, line settings and gauge readings. Slitters see which rolls to cut into which widths. Quality staff see the dyne level and the profile for a roll before it goes out. Sales staff quote from the same recipes the line runs, so the price a converter hears is built on the blend, gauge and width that will actually be extruded.

A converter orders film by material, width, thickness in microns, core size and roll weight, and often asks for a treatment level so ink will hold. The planner sets the order on a blown film or cast film line and checks stock of virgin resin, linear grades and colour or slip masterbatch. A recipe sets the blend by percentage of each component. The operator loads hoppers, starts the extruder and tunes the die gap, air ring and haul-off speed until the gauge settles.

A scanner or hand micrometer reads thickness across the web, and corona treatment then brings the surface to the dyne level the converter asked for before winders start. Winders produce jumbo rolls that are weighed and tagged. Slitters cut them to customer widths on smaller cores. Trim and start-up film go to the granulator, and regrind goes back into approved blends. Waste is counted, not guessed. Rolls are wrapped, palletised and sent with a certificate of analysis where the customer asks for one. Then the truck leaves.