Industrial plastics and materials can be pelletized, and these plastic resin pellets can be manufactured into many different types of bags and covers.
Some of the most common byproducts of plastic resin pellets include:
- Parts bags for items being packaged and shipped by OEMs
- Kit bags that hold fasteners and small parts for assemblies
- Anti-static bags for static sensitive parts
- Trash bags and drum liners
- Box liners for processed meats, chemical preparations, powdered foods, and pharmaceuticals
- Dust covers that protect warehoused goods from dust and moisture
- Furniture and mattress bags
- Bread bags with high clarity that are FDA approved for bakeries and food distributors
- Pallet covers
- Bags and film used to protect magazines, newspapers, and books
Not every manufacturer processes their plastic resin pellets the exact same way, but here is typically how the plastic resin pellets are turned into the aforementioned materials.
Once delivered to the manufactured, the plastic resin pellets are stored in silos. The plastic resin pellets are then vacuumed up by a resin conveying system and they enter the extruders. This is also the time when color additives, fragrance additives and film conditioning additives are blended for customers.
In solid pellet form, the resin then falls into the feed section of an extruder and is pulled by a screw. The screw augers the resin through the extruder barrel, and as the resin is moved it gets melted by the heater bands around the barrel and the frictional heat from the screw and the barrel.
Once the hot resin melt exits the barrel and gets filtered through a series of screen to remove any impurities, the resin enters the die block. The die recipes made for customers are then added at this time as well.
The resin is exposed to temperatures that range from 300-400 degrees Fahrenheit, but it cools as it is pulled from the die and placed on nip rollers. On these nip rollers, the plastic, which is now in film form, gets manipulated and cooled to bring out various properties.
After the nip roller, the plastic film is wound into rolls or converted into bags.
We use plastic bags and film products virtually every day. And now you know how some of those materials are made.
