The polyethylene bags are, like those of polypropylene, a type of bag widely used for packaging or stored for various products, but have some differences highlight throughout this article.
According to its chemical composition we can find polyethylene, high or low density. This difference lies mainly in the branches in their chains and the molecular weight of them. That is, the more branches, the less crystalline and the higher the molecular weight, the lower the crystalline. It also affects its mechanical properties, higher density, and better performance. The first are characterized by being thermoplastic and basically used to carry out the creation of disposable plastic containers. Therefore, applied to high density polyethylene bags , we can highlight the following characteristics:
- It is solid and colourless.
- It is very resistant to shocks and different chemical and thermal situations.
- It also has a great lightness.
- It has a great rigidity.
- It is flexible.
- They can withstand up to 120ºC.
- They admit a more varied use than those of low density.
The density of low density ถุงซิปล็อค polyethylene bags (LDPE or PE-LD) can be said to range from 0.910 to 0.925 g / cm3 and is mainly amorphous.
- They can withstand temperatures of up to 80 degrees Celsius. Weak resistance to temperature
- The bags of low density polyethylene are more flexible than high density.
- Very resistant to chemical attacks.
- Waterproof to water.
- They have excellent electrical properties.
- Good hardness and impact resistance at low temperatures.
Applications of polyethylene bags
We can say that high density polyethylene have better mechanical properties (strength, hardness …) than low density polyethylene , so it is used to manufacture toys, bottles, containers and more rigid elements. The low density polyethylene is mainly used for food packaging and various products such as cables, electronic parts, some stationery … We can find numerous applications of polyethylene high and low density but with regard to bags, the main one is the packaging of products.
This type of bags is ideal for introducing an undetermined number of products since then we have 2 options:
- Seal with some bag sealer
- Close with bag seamier
Main poly bags
There are currently a great diversity of sizes and types of polyethylene bags in the market, but we are going to focus on the main ones, which constitute 80% of the market share:
Open poly bags
These bags are made of low density polyethylene, have a great transparency and flexibility. These polyethylene bags are suitable for containing solid or powdery articles. They are also suitable to contain food. It is recommended to store in a dry place at temperatures between 10 ° and 30 ° C in its original packaging, without exposing it to direct sunlight.
Self-closing polyethylene bags
This type of bags has a practical self-closing, which avoids having to seal them each time. They are 100% transparent, flexible and suitable for food use. It is used for the conservation and packaging of solids or powdery foods, including food. They can be frozen.