Plastic bags manufacturing processing

Making plastic bags is a fairly simple process. That is one of the reasons why plastic bags become very popular. Of course, the production of plastic bags must be completed in the factory with all the procedures, technical requirements. However, generally the production of plastic bags is a fairly straightforward and easy process.

  • Step 1: Mix the ingredients

The raw materials needed to produce plastic bags are mixed in polyethylene (HDPE mixed with LLDPE, LDPE mixed with LLDPE, HDPE mixed with MDPE, LLDPE ...). All our ingredients are certified for food safety and meet EU and US standards.
Also depending on the requirements of customers, can also add some additives such as:
- EPI, D2W, P-life, Reverte or Biocom 1-2% for biodegradable bags. This bag can decompose easily under normal environmental conditions
- Color seeds: white, blue, orange, yellow, green, black, red

Ultraviolet (UVI) protection to protect plastic from ultraviolet radiation. This additive is very useful in the production of agricultural bags.


  • Step 2: Blown film (extruded film)

This is the most important process in the production process.

After mixing well, the mixture will be processed into high temperature melting form suitable for each kind of resin. The mixture is blown out in the form of a tube filled with air blown from the airflow, then blown. This step is important because it can affect the strength, thickness and transparency of the film.

With simple plastic bags of 1-4 colors, can be printed in the process of blowing, called inline printing. With high-end prints of more than four colors or complex image prints, the rolls will be transferred to a separate printer, called offline.


  • Step 3: Print

This process is mainly used for shopping bags, companies will design corporate logos, brand names, product information and printed on the bag surface ...

With modern, high-tech printing machinery, SONG BANG PLASTIC JOINT STOCK COMPANY can print 100% nylon plastic bags covering from 1 to 16 colors (8 colors per surface), CMYK printing with images Very complicated.

This process is considered to be the most difficult due to the high technical and worker skills and experience required.

Printing is an important factor to assess the level of production of the company producing plastic bags.





  • Step 4: Cut and heat welding

The plastic rolls are fed to the cutting workshop to cut into bags with different straps and shapes. Our company has a variety of cutting machines to create different straps: sponge bag, sponge bag, mango bag, hard strap bag, strap bag, soft straps, pouch with reinforced straps, triple strap bag, wavy strap bag, parachute pouch, wicker bag, wicket bag, zipper bag.

At the cutting and welding stages, the temperature and speed of the circuit breaker determines the strength of the mounting. Removal of the bag will be collected and reused for garbage bags.


  • Step 5: Packing

Plastic bags are cut into individual pieces and packed according to customer requirements. About 20-100 bags are packed in a bag (can be printed or not) and then packed into a carton.


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