Understand The Process Of Plastic Bag
Plastic bag, also known as "poly bag" which is made from polyethylene and is popular everywhere as an industrial & useful carrier product. The production technique for each bag is totally different but there is a clear description of plastic bag making process with following steps discussed below:
1. Material Blending
First of all, polyethylene resin is blended in a blending machine. You can also buy large clear plastic bags, clear plastic bags and reclosable bags via various websites.
After the material is blended, the mixture will be treated into liquefied form at high temperature. It goes out in the form of a bubble full of cool air that reaches from the air ring. This air stream helps to inflate the bubble up & cool down the plastic.
This step is very necessary because it can affect the durability, thickness, consistency & transparency of the film. The bubble goes into the cooling tower of 25 – 35 feet tall. At the top of the tower, it is controlled to flatten constantly to form flat shape. The lay-flat film goes over a number of rollers.
With simple bag, it is usually printed, sealed & perforated at the same time of extrusion. For the complicated bag, it will be moved to the further steps in the shape of rolls. You can hop over to this site if you are looking to buy different types of bags.
The next step is printing design, color numbers. The plastic bag can be treated by flexo- printing or gravure printing. With natural printing design, it is good to use gravure printing. For simple, small amount & food contact bag, it is good to use flexo-printing.
The last step is finishing in which the three main steps are included that is cutting, sealing & folding. For various types of bags, they use proper cutting machines. In the finishing step, side gussets, bottom gussets will be produced.
In this step, the heating temperature, the speed of machine will determine the strength & the appearance of the seal.