Most of the time, we only know that there is such a kind of packaging bag, but we don’t know what material and equipment it is made of, and we don’t know that different packaging bags have different characteristics. Below, the professional flexible packaging manufacturer Jiuxinda Packaging (www.baozhuang-dai.com) will take everyone to see the production materials of packaging bags.
- HDPE/ HDPE/low pressure polyethylene/low pressure membrane
This is the most common material. Shopping bags that can often be seen in supermarkets are made of HDPE, which can be bagged separately. It is a common and cheap material in the market-PO bag. This kind of packing bag is brittle and hard, with low expansion rate and brittle sound when kneading.
- LDPE/ low density polyethylene/high pressure polyethylene/high pressure membrane
The packaging bag made of this material has good texture, softness, toughness, transparency and smooth hand feeling. The thicker and harder the bag, the greater the expansion rate. This kind of material can also be bagged separately, which is as common and cheap as PO bag.
- OPP/ oriented polypropylene
This kind of material is the most brittle and transparent material in plastic packaging bags. It has insufficient tensile force, so it can be said that there is no tensile force at all, and the printing is easy to decolorize. It needs to be placed for a period of time after printing, and then the bags are cut.
- CPP/ cast polypropylene/unstretched polypropylene
This kind of material has high transparency, higher hardness than PE film, and is clearer. It is often used as the base film of composite materials and often combined with other films to form bags, which is a good composite film. CPP also has a cooking grade material, which can be used to make retort pouch.
- PET/ polyethylene terephthalate
The transparency of this material is also very good, its strength and toughness are better than polystyrene and PVC, and it is not easy to break, and its surface is smooth and shiny. It is also one of the common composite materials.
- PA/ nylon
This kind of material is often used as the composite material of retort pouch/boiled bag, which has good toughness and is relatively soft.
- Aluminum foil /AL
Aluminum foil is an extremely thin sheet formed by rolling high-purity aluminum for many times, and it is an excellent heat conductor and shading body. Good mechanical strength, light weight, no thermal adhesion, metallic luster, good light shielding property, strong reflection ability to light, not easy to be corroded, good barrier property, moisture-proof and waterproof, strong air tightness and fragrance retention. It has metallic luster, high gas barrier property and low adhesion viscosity, so it is easy to transfer the aluminized layer after composite processing.