Differences in the plastic bag production process according to material

We can see plastic packaging or nylon bags be available in almost every place today. We use them for food storage, packaging, supermarket storage, etc. Besides, the process of producing plastic bags is not too complicated, so they are cheap and popular.

However, the process of creating plastic bags also has strict procedures to ensure product quality criteria as well as user safety.


Basically, the plastic bag production process is divided into 4 steps:

Mix ingredients

The process of making a plastic bag begins when mixing plastic granules take place in a specialized hopper or mixing tank. These plastic beads can be 100% virgin or mixed with recycled beads depending on the intended use of the product. People also add characteristic additives at this stage and scoop the mixture into the extruder or use a tube to suck it directly.

Form nylon film

The extruder will heat the plastic pellets to the melting temperature of each material. Then we blow the plastic into a cylindrical bubble that points straight up. The shell of this balloon is a layer of nylon membrane. During this stage, the machine operator will adjust the thickness and width of the nylon film using specialized techniques.

Wrap into a plastic roll

After the process of touching and blowing the plastic film, this plastic bubble layer is pulled up to cool, then run through a series of rollers to press it into a flat shape. Finally, people roll them into paper or plastic cores to save space. Here we have a product that is a double nylon roll. For single film, the roll wrapping process will include the additional step of cutting this double layer of film into 2 and wrapping it on 2 paper cores at the same time.

Cut into plastic bags

This is the final step of the process. After putting the nylon roll into the cutting machine, the sensors on the machine will accurately measure the length needed to divide the nylon roll into equal segments. People weld the bottom of plastic bags using the integrated heat press system on the cutting machine.

The production process is specific for each different type of material

The production process of each type of material is also slightly different.

Production process of LDPE plastic bags

LDPE material has outstanding properties of being flexible and transparent. They have significant elasticity, are very resistant to water, chemicals, and solvents and are safe for food storage.

The LDPE bag production process is completely similar to the basic steps of the plastic bag production process. This material has a melting temperature of about 105-115 degrees Celsius.

This nylon bag is easy to print but difficult to punch due to the flexible nature of the material. In addition, this material is a very good electrical insulator but is easily charged with electricity. If used to store electronic components or in explosive environments, the surface needs anti-static treatment.

 production process// plastic resin LDPETúi nhựa LDPE, đặc tính và công dụng - Túi nilon cỡ lớn

Production process of HDPE plastic bags

HDPE bags, also known as HD bags, have average clarity and surface gloss. This material is hard and not flexible like LDPE. HD bags are prone to folds and wrinkles, they make clear noises when rubbed and are made thicker to limit the above disadvantages.

The HD bag production process is similar to LD, however there is a difference in the machinery system. Specifically, the first mold used to shape plastic bubbles has a central stabilizing bar. This central stabilizing bar blows out surrounding air currents to help the plastic bladder stay upright, while also cooling the inside of the film. The reason for this difference is because HDPE has a higher melting temperature (130-150 degrees Celsius), the temperature of the film layer when extruded is very high and needs to be cooled quickly.

 production process// plastic resin HDPE

For your reference, you could explore further via our website: hanpak.com.vn or mail to info@hanpak.com.vn.

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