Manufacturer & Exporters of Plastic Bag Making Machines, Mumbai, INDIA

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Understanding How Plastic Bags are made.

Plastic bags, also called “poly bags,” are one of those modern conveniences that make our life easy. However about 60 years ago, no one ever considered the question. This was because the technology for creating polyethylene film didn’t emerge until the 1940s during World War II. And the methods to create plastic bags from polyethylene film weren’t developed until the 1950s. It was the retail boom after the World War II that lead to the discovery and the wide scale mass production of plastic bags.

Plastic bag making process consist of 3 major processes

  • Extrusion Process
  • Printing Process
  • Converting Process



Plastic bags are made from polyethylene (PE) material. The first step to produce poly bags is the extrusion process which is done by a Blown Film Machine.

  • In the blown-film extrusion process, small plastic pellets / plastic granules (also called resin) are melted down under controlled conditions so that they become molten and pliable. They are then pressed (extruded) through a circular die gap to form a continuous tube of plastic



  • While it is still in this molten state, the tube is pinched off at one end and then inflated and stretched (hence Blown Film Machine), 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. (Lay flat Tubing)
  • The size, thickness, profile (HDPE,LDPE,PP etc) of the film tubing, depends upon size and technical capabilities of the machine.






  • These machine come in various sizes and Number of colors, and other printing capabilities.
  • Once the Custom logo is printed on the rolls, they are now ready to undergo through the final process, know as the Converting Process.( Also called Cutting & Sealing Process)



  • Converting Process is where the plastic tubing/sheet takes its actual shape of a bag.(D- cut bags, T-shirt Type Bags, Bags on Roll, Bottom sealed bags, side sealed bags etc.)
  • The plastic tubing are fed through a Bag Making machine (Cutting & Sealing machine) that draws material out to the proper length and also performs the sealing function. (Bottom Seal, Star Seal, Perforated seal etc.)




  • Technically speaking the film tubing (Printed or Non printed) undergoes a Heat sealing and a cutting process which establishes the sealing and the cut length of the bag.
  • Machine cycle speeds vary upon various factors such as bag length, Width, thickness etc.

Though the process seems very complicated, We at SHEETAL are experts in setting up the entire Turnkey project

.We know the secret to producing high quality film is a combination of quality raw material and quality  machinery &  equipment that maintains a consistent flow of material throughout the process.

If you are interested or have any queries regarding our services in setting up a turnkey project, feel free to contact us, with your query and we shall be happy to assist you.




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