What are the specifications of wound film?

Wrapping film, also known as stretch film and heat shrinkable film, can bind products tightly and firmly into a unit with the help of the super winding force and flexibility of the film, which is a widely used packaging material. What are the specifications of wound film? The following small series will introduce you to the specifications of the wound film. Specification for stretch wound films

Compared with ordinary wound film, the specifications of machine wound film are relatively fixed, only 10_, 15_, 20_, 25_, 50_, etc. This is mainly determined by the tray or winding hub, and the weight will be determined according to the installation size.

Common specifications of stretched films for machines:

2.5 kg, 22μm, 50CM thick and about 260 meters wide.

3.0 kg, 22μm, 50CM thick and about 350 meters wide.

4.0 kg, 22μm, 50CM thick and about 450 meters wide.

5.0 kg, 22μm, 50CM thick and 550 meters wide.

1, thickness

Generally, the thickness of machine-drawn film is relatively thick, and the thickness of ordinary drawn film is between 13μm-22μm, while the thickness of machine-drawn film will reach 20μm-35μm, and the mechanical properties of machine-drawn film will be improved accordingly with the strengthening of thickness. As we all know, if things are packed by hand, we will pack them according to the quality of the packaging film, and if the quality is poor, we will slow down to complete the packaging work. The machine roll film belongs to the mechanical setting and runs by itself. If the mechanical properties of the wound film can't meet the requirements, it can't work normally. Therefore, in order to ensure the mechanized packaging, the quality of machine-used stretch wound film will be improved accordingly, and increasing the thickness is an effective method.

2. Stretch rate

We have all heard that the stretching rate of stretched films is between 200% and 600%. Because the mechanical stretching film belongs to mechanical operation, there are additional requirements for stretching rate. At present, the general requirement is 700%, that is, one meter of stretched film for machine can be stretched for 7 meters without breaking.

3. Expansibility

Ductility refers to the transverse stretching rate. Polyethylene, the raw material of winding film, is linear particles, which has strong longitudinal tensile ability and weak transverse tensile ability, and obviously cannot meet the packaging requirements. Therefore, suitable metallocene (other density polyethylene isomers) will be added to the raw materials to increase the molecular weight per unit volume and further strengthen the transverse tension.