Chain link assembly, chain and film stretching device capable of reducing longitudinal shrinkage ratio

Abstract

The invention discloses a chain link assembly, a chain and a film stretching device. Transition chain links are arranged in the chain link assembly, conventional chain links can be folded in the radial direction, the axis distance between the adjacent transition chain links is changed while folding is carried out, the chain link assembly is arranged in the chain, clamps for clamping a film are arranged, the length of the chain of the film stretching device is changed wholly along with bending deformation of the chain link assembly, and accordingly the distance between the adjacent clamps is reduced; when transverse stretching is carried out, the clamping gap between the clamps shrinks, and the aim of longitudinal retraction is achieved while the transverse pulling process is carried out; and when the film stretching device caries out film transverse stretching work, longitudinal tensile force of the film is reduced under the high-temperature state, the film can be sufficiently and longitudinally pre-retracted, and the problem that the longitudinal shrinkage ratio is too large is solved in advance.

Description

technical field [0001] The invention relates to a chain link assembly, a chain and a film stretching device for reducing longitudinal shrinkage, and belongs to the technical field of plastic processing and molding devices. Background technique [0002] In order to have a general understanding of the whole picture of stretch film, here is an overview of the whole picture of film stretching: [0003] 1) Film stretching can be divided into sequential stretching and synchronous stretching according to the stretching sequence: 1. Sequential stretching is a bidirectional stretching in which a thick plastic film is first stretched longitudinally and then stretched transversely. Biaxial stretching is divided into two steps and carried out successively. (Of course, it is also possible to stretch horizontally first and then vertically) 2. Synchronous stretching is to stretch vertically while stretching horizontally. The advantage of synchronous stretching is that the properties of t...

AI Technical Summary

Problems solved by technology

[0009] There is a problem of increased shrinkage of the film after stretching: polymer materials have a tendency to de-orient after stretching and orientation, which is the main reason for shrinkage

The longitudinal shrinkage is generally carried out on the longitudinal stretching roller, so there are two main problems: one is the limitation of the heating height, if the temperature is too high, the film will adhere to the roller and cause scald scars, and the other is that the longitudinal stretching film is If the coating runs on the roller, the film will be pulled by the positive pressure of the coating on the roller. To shrink, it is necessary to reduce the tension on the film, and the excessive relaxation of the diaphragm on the roller will cause The diaphragm cannot cover the roller and slips, causing slippage and scratches on the film

Images