The reason of PE stretch film shrinkage
Source：The reason of PE stretch film shrinkageTime：2020-10-29Visitors：
PE stretch film is a kind of film with relatively good shrinkage performance, which plays a very important role in product packaging in many fields, but there will be a problem in the production process of this product, that is, the shrinkage is relatively large. Although this problem does not occur frequently, once it occurs, it will have a greater impact on the use of the product.
Therefore, in solving the problem of excessive shrinkage of the PE stretch film, we must first know what causes it.
Reasons for large shrinkage of PE stretch film:
The raw material of the OE stretch film is an amorphous polymer. When it receives a tensile force greater than its stretch within a certain temperature range, the rescue will produce plastic elongation, resulting in deformation. In the process of deformation, the polymer structural units begin to orient due to stretching.
As the degree of orientation increases, the force between the macromolecules increases, resulting in an increase in the viscosity of the polymer, a tendency to harden, and the change tends to be stable , No longer develop, this phenomenon is called stress hardening.
As the degree of orientation increases, the force between the macromolecules increases, resulting in an increase in the viscosity of the polymer, a tendency to harden, and the change tends to be stable , No longer develop, this phenomenon is called stress hardening.
When the temperature is increased appropriately, the ductility of the PE stretched film will be further improved, the stretch ratio can be increased, and even some polymers with poor ductility can be stretched. Generally, the deformation when the room temperature is adjusted to a very low processing temperature is called cold stretching.
After the polymer undergoes stress hardening during the stretching process, the flow of polymer molecules will be restricted, thereby preventing the stretching ratio from further increasing. The PE stretch film after cold stretching returns to its original shape after the stretching force is released.
After the polymer undergoes stress hardening during the stretching process, the flow of polymer molecules will be restricted, thereby preventing the stretching ratio from further increasing. The PE stretch film after cold stretching returns to its original shape after the stretching force is released.
Ways to prevent excessive shrinkage:
The design should take into account the heat preservation of the workshop and the convection of the air, because the PE stretch film dissipates heat very quickly during the stretching process. The thinner and wider the stretch, the faster its heat dissipation. The surface temperature within 3m from the wire drawing entrance to the wire drawing exit is reduced from 175 degrees Celsius to 135 degrees Celsius, so the temperature in the production workshop is generally not less than 20 degrees Celsius.
When designing the workshop, only the exhaust windows are left at the top and no windows at the bottom. In addition, in order to avoid the phenomenon of cold stretching, a heat preservation chamber can be made by transverse stretching part to pack the ambient temperature. Appropriately reducing the speed ratio of each machine can also reduce the stretching of the product.
Simply put, the PE stretch film shrinks too much because the product shrinks too much during the stretching process and cannot reach the required width of the product. The heat shrinks too much during the secondary compounding process, which exceeds the standard requirements.
Zhiteng is a professional PE stretch film manufacturer，provide quality product and competitive price，if you have any questions，please feel free to contact us，we will reply you soon.
Recommended Products
Ranked in the same article
- how to use the stretch film technology to r
- How can we get detailed price list？
- Five common quality problems of PE protecti
- Plastic film degradation
- How to guarantee punctual shipment for our
- What is the difference between stretch film
- Testing the permeability of stretch film
- Why insufficient transparency of stretch w
- Electrical wire film VS electrostatic film
- Stretch film temperature requirements
- The elastic characteristics of plastic film
Latest news articles
- Method of shortening stretch film
- Why vacuum packaging materials need stretc
- How Does Color Affect the Performance and D
- How to handle the surface of stretch wrappi
- The characteristics of the stretched film q
- The elastic characteristics of plastic film
- How should the viscosity in the adhesive la
- Is PE stretch film suitable for the logisti
- Enhancing Electrical Safety with Innovative
- Advantage of Stretch film
- How to solve the bubble in the stretch film
