A film bidirectional precise stretching device

Abstract

The invention provides a film bidirectional precise stretching device, which includes a first drive motor, a transverse stretching mechanism, a longitudinal stretching mechanism and a tension sensor, the transverse stretching mechanism and the longitudinal stretching mechanism are arranged horizontally and vertically, and the transverse stretching mechanism Both the stretching mechanism and the longitudinal stretching mechanism include a strip pressing and stretching mechanism and several point pressing and stretching mechanisms, and the point pressing and stretching mechanisms are relatively slidingly connected on the strip pressing and stretching mechanism; and the strip pressing and pulling of the transverse stretching mechanism The stretching mechanism and the point-pressing stretching mechanism of the longitudinal stretching mechanism act simultaneously correspondingly, and the point-pressing stretching mechanism of the transverse stretching mechanism and the strip-pressing stretching mechanism of the longitudinal stretching mechanism act correspondingly and simultaneously. In the operation of stretching in one direction, it can avoid the deformation disadvantages of the stretched film being wide at both ends and narrow in the middle, and initially ensure the overall shape of the stretched film; ensure the stretching effect and make the stretching thinness uniform; avoid It solves the disadvantages of uneven thickness of the stretching point that all adopt "point pressure" to fix and carry out fixed-point stretching in the prior art.

Description

technical field [0001] The invention relates to stretching processing of polymer films, in particular to a film bidirectional precise stretching device. Background technique [0002] The final properties of polymer films strongly depend on processing methods and process conditions. The same polymer, different processing methods such as film blowing, casting, stretching, can produce films with different properties. Stretched films such as biaxially oriented polypropylene (BOPP) and polyester (BOPET) have the characteristics of high strength, strong light transmission, good air and moisture barrier properties, and excellent dimensional stability, so stretching has become the first choice for high-performance film processing. mainstream development direction. However, there are still big problems in the film stretching industry. For example, polyethylene (PE), the most important raw material for polymer films, has no mature biaxial stretching technology (BOPE) in the world. ...

AI Technical Summary

Problems solved by technology

[0003] Behind the industrial problem is actually the scientific problem of film stretching processing, which can be summarized as the following points: (1) In the prior art, "point pressure" is used to fix fixed-point stretching, so there is uneven thickness at the stretching point; (2) In the operation of unidirectional stretching, the stretched film is prone to deformation with wide ends and narrow middle; (3) Non-linear rheology of structural fluid in high-speed stretching; (4) Stretch flow induced Polymer conformational order and crystallization; (5) Crystal deformation, orientation and destruction in post-stretching

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