Why do stretch films need to be stretched before use?
In our lives, we often see the use of stretch film to package items, the packaging of stretch film is very tight, enough to surface the good quality of the product. Generally, we must go through a stretching operation before using a stretch film for packaging. Many users do not understand why it is stretched. Today, the joypack stretch film manufacturer will introduce to you why the stretch film needs to be stretched before use. 1. The packaging of stretch film must be stretched. The stretch form of pallet mechanical packaging includes direct stretching and pre-stretching. There are two types of pre-stretching, one is roller pre-stretching, and the other is electric stretching. Direct drawing is completed between the tray and the drawing film. The drawing rate of this method is low, about 15%-20 %, if the stretch ratio exceeds 55%-60%, then the stretch of the stretched film will be exceeded, the width of the stretched film will be reduced, the perforation performance ...