How are plastic bags made?

How are plastic bags madeI often get asked how our plastic bags are made and there is really no simple answer to such a seemingly simple question. How we manufacture our plastic bag products at Hilex Poly largely depends on what type of plastic bag product is being produced, although most of our plastic bags are made from high density polyethylene (HDPE). Any easy way to talk about the process of manufacturing plastic bags starts with whether the plastic bag is made from virgin materials or recycled materials. So here it goes…

  1. The plastic bag making process begins when high and low density resin travels from our silos where it is stored and is blended together, following specific recipes. Once the resins are blended it reaches the extrusion department, where the film for the plastic bag will be created.
  2. The blended resin is fed into extruders where the material is heated to a specific temperature and mixed. The material in the heated barrel then reaches a molten plastic state and can literally be blown overhead from the extruder into a bubble formation.
  3. How are plastic bags madeThe bubble is blown vertically 3 stories high, which allows for the proper material distribution and cooling time required before the film is laid flat.
  4. The final step in the extrusion process sends the bubble through a series of rollers to lay the film flat and then wind the film on large cores, resulting in a roll of film weighing several thousands of pounds.
  5. Next, the roll of film reaches the converting department, the area where film is manufactured into bags, and the roll of film is placed into the unwinder. After the film is started on the unwinder, it is treated with an electrostatic wave of current. This is done so that the film can be properly prepared for the printing procedure, where bags are printed with various messages and logos for our customers.
  6. After the printing process is complete, the large roll of film is then cut to size with hot knives that seam the sides of the bags together when cut.
  7. Then, the film is fed into bag manufacturing machines where the top and bottom seals are formed and the handles are cut out. All of our internal “scrap” is then reintroduced into our manufacturing process so that we have a closed loop system to eliminate any wasted material.
  8. Voila! The plastic bags have been created and are then distributed to our customers!

production of recycled content buff bagsFor the plastic bags that we produce through our Bag-2-Bag recycling program, which are made from recycled materials, we take a slightly different approach. First, consumers recycle their plastic bags by placing them in in-store recycling bins and those bags are bundled into bales and shipped to our recycling facility in North Vernon, Indiana. Once those bales arrive at our facility they are washed and processed into pellets which are used to make brand new bags with the same quality and performance as virgin bags using the same process outlined above.

Hopefully this provides a bit more clarity on our approach to manufacturing plastic bags here at Hilex Poly. If you still have questions, feel free to contact us.