Q: How are plastic bags made?

A: First, plastic resins are fed into an extruding machine. As the resins are fed through a heated screw, they are forced to mix and melt to a liquid state. The screw forces the melted resins through a die forcing it into a tube. Blowing air through the center of the die ring expands the tube, sometimes called a bubble (much like blowing up a balloon). The amount of air and speed in which the tube travels up a tower determines the size and thickness of the plastic. The bubble travels up a tower to cool the melted plastic. Once cooled, the bubble is flattened and travels down the tower through a set of rollers. When the plastic reaches the bottom, it is wound on a large roll. The large plastic roll is then fed to a sealing machine where it is then fitted with a self-adhesive tape and cut to the customer's desired plastic size.

Q: What are the types of plastic materials most commonly used in plastic packaging?

A: There are four main types of plastic material that are most commonly used in the plastic packaging industry.

Polypropylene (PP):
PP is the most widely used plastic in the local market, because of its good clarity and durability. It can withstand a fair amount of tension, making it ideal for heavier items.

Oriented Polypropylene (OPP):
Preferred for small and light objects. Has a higher clarity than Polypropylene (PP), but with less tensile strength it is more likely to tear or break under heavy stress. Therefore using OPP material is not advisable for heavy and/or irregular shaped items.

High-density Polyethylene (HDPE):
Made especially for items that require higher tensile strength and greater durability. HDPE is the material of choice for fabricating milk or juice bottles.

Low-density Polyethylene (LDPE):
Also referred to as simply PE. Has a wide range of applications. Recommended for packaging that requires high stress, crack resistance and elasticity.

Q: Why is choosing the right type of plastic material important?

A: Choosing the right plastic material is important because it has to meet the packaging requirement of your product. For heavier products, you should use Polyethylene (PE) material as it has a higher tensile strength and doesn't break easily when pressure is applied. If you need a plastic bag that offers excellent display value, then you should use the high clarity Polypropylene (PP) or Oriented Polypropylene (OPP).

Q: What is a Gusset?