How Poly Bags Are Made
Here at A-Pac manufacturing, we use a blown-film extrusion process to manufacture the plastic that makes poly bags. Once the plastic is formed and wound on a roll, our poly bag manufacturing machines seal and cut bags according to each client’s custom poly bag specifications. Here’s a closer look at how poly bags are made.
Step 01:
The Blown-Film Extrusion Process
The first step of making poly bags is the blown-film extrusion process. The following occurs when using this process:
- Small plastic pellets (called resin) are first melted down under controlled conditions, until they become molten and pliable.
- Once resin pellets reach the desired level of pliability, they are then pressed (extruded) through a circular die gap to form a continuous tube of plastic. In this molten state, the tube of plastic is pinched off at one end, and then inflated and stretched to the size and thickness of the desired finished product.
- The inflated bubble of plastic is drawn vertically up a tower so that it has a chance to cool before it is flattened out and wound onto a roll.
- Once the plastic is on a roll, it can be cut to form tubing, single-wound sheeting, or centerfold sheeting. Most often, we transform the plastic into poly bags.
Step 02:
Making Poly Bags from Plastic Rolls
After the blown-film extrusion process is complete, we take those rolls of plastic and transform them into poly bags by doing the following:
- Rolls of plastic tubing or sheeting are first fed through a machine that draws the material out to the proper length.
- The machine then places a seal on the material at the correct length and cuts it off to make an individual bag.
- This process is then repeated until we have the number of poly bags we need for an order.