Method and device of film stepless biaxial tension based on saddle-shaped surface transition

Patent metadata

Field	Value
Publication number	US-10836096-B2
Application number	US-201515559892-A
Country	US
Kind code	B2
Filing date	Dec 29, 2015
Priority date	Mar 25, 2015
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

The present invention discloses a method and device of film stepless biaxial tension based on saddle-shaped surface transition. In the film surface biaxial stretching process, with the lateral and longitudinal tensile forces applied to a different tangent plane, the film is subjected to smooth transition in a three-dimensional space from a narrow plane via a saddle-shaped surface to a wide plane, with the thickness uniformity of the biaxial tension film regulated by controlling the shape of the saddle-shaped surface; the device comprises a lateral tension unit and a longitudinal tension unit, the angle between the two lateral tension wheels in the lateral tension unit being adjustable, the two longitudinal tension wheels in the longitudinal tension unit being arranged in parallel; the lateral tension of the film is achieved by the rotation of the lateral tension wheel, and the longitudinal tension of the film is achieved by the linear velocity difference between the lateral tension wheel and the longitudinal tension wheel. The present invention, adopting the binding wheel structure, effectively uses the saddle-shaped surface to regulate the bowing phenomenon, and reduces the contact surface between the film and the tension element, thus preventing the surface performance from deteriorating by friction, which is advantageous for improving the thickness uniformity of the film product.

First claim

What is claimed is:

1. A film biaxial tension device characterized in that: the device comprises a lateral tension unit and a longitudinal tension unit, wherein a wheel angle between two lateral tension wheels in the lateral tension unit being adjustable wherein the wheel angle being an angle between non-parallel rotation directions of the two lateral tension wheels, two longitudinal tension wheels in the longitudinal tension unit being arranged in parallel; binding portions against the two lateral tension wheels and the two longitudinal tension wheels are used to bind opposing edges of the film to a circumferential surface of the lateral tension wheels and the longitudinal tension wheels; a lateral tension of the film is achieved by the rotation of the lateral tension wheels, and a longitudinal tension of the film is achieved by a linear velocity difference between the lateral tension wheels and the longitudinal tension wheels; wherein the binding portions around the two lateral tension wheels and the two longitudinal tension wheels provide uniform tension on the film, without using clamps that provide non-uniform tension on the film; wherein the binding portions follow the shapes of the two lateral tension wheels and the two longitudinal tension wheels, where the binding portions press the film against the two lateral tension wheels and the two longitudinal tension wheel; and, in operation of the of the film biaxial tension device, lateral and longitudinal tensile forces are applied respectively in different planes such that the film forms a saddle-shape surface during a transition from a narrow plane to a wide plane, wherein a uniformity of thickness of the film is regulated by controlling a shape of the saddle-shaped surface.

2. The film biaxial tension device according to claim 1 , characterized in that: the lateral tension unit comprises two lateral sub-units arranged symmetrically with respect to a central line, each of which is provided with one lateral tension wheel of the two lateral tension wheels; each of the two lateral tension wheels is provided with a first binding assembly, and with a first support plate in parallel with the respective lateral tension wheel, and an axle of each of the two lateral tension wheels passes through the first support plate, which is provided with an underplate; the underplate is provided proximal to an inlet of the lateral tension unit with a fork positioning column, and at an end near an outlet of the lateral tension unit with a first outlet positioning column, with a fork arranged at the fork positioning column; the respective forks are connected at the end to a first lead screw through a corresponding inlet nut, and the respective first outlet positioning columns are connected to a second lead screw through a corresponding first outlet nut.

3. The film biaxial tension device according to claim 1 , characterized in that: the longitudinal tension unit comprises two longitudinal sub-units arranged symmetrically with respect to a central line, each of which is provided with one of the two longitudinal tension wheels, with the two longitudinal tension wheels arranged to rotate in parallel directions; each of the two longitudinal tension wheels is provided with a second binding assembly, and with a second support plate in parallel, with an axle of each of the longitudinal tension wheels passing through the second support plate; the second support plate is provided proximal to an inlet of the longitudinal tension unit with a guide hole, and at an end near an outlet of the longitudinal tension unit with a second outlet positioning column; respective guide holes are connected with a guide rod, and the respective second outlet positioning columns are connected to a third lead screw through a corresponding second outlet nut.

4. The film biaxial tension device according to claim 3 , characterized in that: the second binding assembly comprises a second binding rope, a second sliding wheel and a second preloaded wheel, the second binding rope being wound on a plurality of the second sliding wheels and provided external of the second preloaded wheel; and the axle of the respective second sliding wheels passes through the second support plate.

5. The film biaxial tension device according to claim 1 , characterized in that: the wheel angle of the two lateral tension wheels is in the range 0°<β<180°.

Assignees

• Univ South China Tech
• Guangzhou Huaxinke Intelligent Manufacturing Tech Co Ltd

Inventors

• Qu Jinping
• Zhang Guizhen

Classifications

• B29C55/16 Primary

  simultaneously · CPC title

• B29C55/165 Primary

  Apparatus therefor · CPC title

• B29L2007/00

  Flat articles, e.g. films or sheets (B29L2024/00 takes precedence) · CPC title