A strip forming and extending mechanism

Abstract

The invention discloses a material strip forming and extending mechanism, comprising a longitudinal stretching mechanism; a transverse stretching mechanism, arranged at the rear of the longitudinal stretching mechanism; the transverse pulling mechanism comprises two symmetrically arranged sprocket groups, each sprocket group contacts one side edge of a polycarbonate film, and the two sprocket groups are mirror-symmetrical along the center line of the polycarbonate film; along the conveying direction of the polycarbonate film, each sprocket group in the transverse stretching mechanism is divided into a preheating section, a first stretching section, a buffer section, a second stretching section, a third stretching section, and a heat setting section in different extending directions; the extending directions of the preheating section, the buffer section, and the heat setting section are parallel to the center line of the polycarbonate film, and the spacing between the two sprocket groups increases in sequence; along the conveying direction of the polycarbonate film, the acute angle angle between the sprocket group on the same side of the first stretching section, the second stretching section, and the third stretching section and the center line of the polycarbonate film increases in sequence. By adopting this invention, the transverse pulling of the film is gradual, and the defective rate is reduced.

Description

Technical Field

[0001] The invention relates to the field of plastic polycarbonate film production equipment, and in particular to a material strip forming and extending mechanism. Background Art

[0002] In the production process, polycarbonate film strips are usually pulled longitudinally first and then transversely. The longitudinal pulling form is relatively simple, mainly relying on the interaction between several parallel rollers. The transverse pulling form is relatively complex. If the process parameters are not well controlled by pulling the two sides of the polycarbonate film, it may cause product failure in the transverse pulling stage. Summary of the invention

[0003] The problem to be solved by the present invention is to provide a material strip forming and stretching mechanism, which can gradually stretch the film horizontally and reduce the defective rate.

[0004] In order to solve the above problems, the present invention provides a strip forming and extending mechanism. In order to achieve the above objectives, the technical solution adopted by the present invention to solve the technical problems is:

[0005] A material strip forming and stretching mechanism comprises: a longitudinal stretching mechanism for longitudinally stretching a polycarbonate film; a transverse stretching mechanism, which is arranged behind the longitudinal stretching mechanism along the conveying direction of the polycarbonate film and stretches the polycarbonate film transversely; the transverse pulling mechanism comprises two symmetrically arranged sprocket groups, each sprocket group contacts one side edge of the polycarbonate film, and the two sprocket groups are mirror-symmetrical along the center line of the polycarbonate film; along the conveying direction of the polycarbonate film, each sprocket group in the transverse stretching mechanism is divided into a preheating section, a first stretching section, a buffer section, a second stretching section, a third stretching section, and a heat-setting section in different extension directions; the extension directions of the preheating section, the buffer section, and the heat-setting section are parallel to the center line of the polycarbonate film and the spacing between the two sprocket groups increases in sequence; along the conveying direction of the polycarbonate film, the acute angles formed by the sprocket groups on the same side of the first stretching section, the second stretching section, and the third stretching section and the center line of the polycarbonate film increase in sequence.

[0006] The beneficial effects of adopting the above technical scheme are as follows: the polycarbonate film is first stretched longitudinally and then stretched transversely. The polycarbonate film after longitudinal stretching is first preheated in the preheating section to increase the temperature of the film, and the polycarbonate film is not stretched transversely here, and only the polycarbonate film is stretched; the sprocket group of the first stretching section of the second stage expands in a trumpet shape, achieving a certain degree of transverse stretching of the polycarbonate film, but the duration is not long and the amplitude is small, which is equivalent to a trial stretching, and timely discovering whether the polycarbonate film meets the transverse stretching state; the third stage is the buffer section, at this time the polycarbonate film is still not stretched transversely, and it is mainly further preheated to ensure the accuracy of the temperature of the polycarbonate film and also provide observation time for the pre-stretched polycarbonate film; the second stretching section of the fourth stage is the formal transverse stretching of the polycarbonate film; the third stretching section of the fifth stage is the further high-speed transverse stretching of the polycarbonate film, and finally the transverse stretching amount is completed; the heat setting section of the fifth stage is to heat set the polycarbonate film after the transverse stretching is completed. Perfect the crystallization of the polycarbonate film, stabilize the wide width of the polycarbonate film, and eliminate internal stress. The entire horizontal stretching stage is divided into several sub-stages. The horizontal stretching process is gradual, which reduces the defective rate of the polycarbonate film and provides an initial observation window for the entire horizontal stretching process. During the entire process, the horizontal stretching mechanism limits the two sides of the polycarbonate film, generating a forced horizontal stretching effect. After the stretching is completed, the sprocket assembly releases the polycarbonate film.

[0007] As a further improvement of the present invention, the acute angles formed by the sprocket set on the same side of the first stretching section, the second stretching section, and the third stretching section and the center line of the polycarbonate film are 5°, 10°, and 25° respectively.

[0008] The beneficial effect of adopting the above technical solution is that the corresponding lateral stretching amplitude per unit time is larger as time goes on, and the main lateral stretching action is completed in the second half, giving the polycarbonate film a sufficient gradual reaction process in the initial stage.

[0009] As a further improvement of the present invention, the lengths of the first stretching section, the second stretching section, and the third stretching section are also increased successively.

[0010] The beneficial effect of adopting the above technical solution is that the actual horizontal pulling effect becomes greater as time goes on, and the main horizontal pulling action is completed in the second half, giving the polycarbonate film enough gradual reaction process in the early stage.

[0011] As a further improvement of the present invention, the temperature of the polycarbonate film in the first stretching section, the second stretching section, and the third stretching section increases successively.

[0012] The beneficial effect of adopting the above technical solution is that as the temperature gradually increases, the higher the temperature within a certain range, the greater the elastic increment of the polycarbonate film. The high temperature area corresponds to the part with large horizontal pulling amplitude, ensuring that the polycarbonate film can adapt to the horizontal pulling amplitude.

[0013] As a further improvement of the present invention, the temperatures of the polycarbonate film in the preheating section, the first stretching section, the buffer section, the second stretching section, the third stretching section, and the heat setting section are 90°C, 92°C, 93°C, 94°C, 95°C, and 200°C, respectively.

[0014] The beneficial effects of adopting the above technical solution are: the selection of the specific temperature ensures the final quality of the polycarbonate film, and the temperature required for the heat setting section is relatively high.

[0015] As a further improvement of the present invention, the transverse stretching mechanism has two bending tracks arranged in mirror symmetry along the center line of the polycarbonate film, the sprocket set is assembled with the bending track through a pulley, each sprocket set has a plurality of sprockets, and adjacent sprockets are connected by chains.

[0016] The beneficial effect of adopting the above technical solution is that the curved track can be pre-bent and manufactured according to the trend of the preheating section, the first stretching section, the buffer section, the second stretching section, the third stretching section, and the heat setting section. The pulley has the rolling freedom along the curved track, and the chain ensures a stable spacing between adjacent sprockets.

[0017] As a further improvement of the present invention, a plurality of rotating motors are arranged at intervals in the pulleys on each sprocket assembly, the number of the rotating motors is less than the number of the pulleys, and the rotating motors are surrounded by heat insulation covers.

[0018] The beneficial effects of adopting the above technical solution are: the rotating motor provides the main power for the movement of the sprocket group and the stretching of the polycarbonate film. At the same time, the rotating motor is not single, and the spaced rotating motors share the tension of each section of the sprocket group, ensuring that each section of the sprocket group is subjected to uniform force. At the same time, the heat insulation cover prevents the influence of heat preservation on the rotating motor.

[0019] As a further improvement of the present invention, along the conveying direction of the polycarbonate film, the polycarbonate film passes through an extruder, a cooling roller, a preheating roller, a longitudinal stretching mechanism, and a transverse stretching mechanism in sequence.

[0020] The beneficial effect of adopting the above technical solution is that the extruder, the cooling roller, the preheating roller, the longitudinal stretching mechanism and the transverse stretching mechanism form a complete polycarbonate film production line.

[0021] As a further improvement of the present invention, a pair of flattening rollers are provided after the longitudinal stretching mechanism along the conveying direction of the polycarbonate film. The flattening rollers are in contact with the front and back surfaces of the polycarbonate film, and the spatial planes where the axes of the two flattening rollers are located are perpendicular to the polycarbonate film in contact.

[0022] The beneficial effect of adopting the above technical solution is that the flattening roller further flattens the polycarbonate film in the finished product stage, thereby ensuring the flatness of the polycarbonate film and improving the hardness of the surface of the polycarbonate film. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a structural schematic diagram of an implementation mode of the present invention;

[0025] Figure 2 It is a schematic structural diagram of a transverse stretching mechanism according to an embodiment of the present invention.

[0026] 1-extruder; 2-cooling roller; 3-preheating roller; 4-longitudinal stretching mechanism; 5-transverse stretching mechanism; 6-flattening roller; 7-sprocket set; 8-thick segment; 9-longitudinal stretching section; 10-transverse stretching section; 11-finished product section; A-preheating section; B-first stretching section; C-buffer section; D-second stretching section; E-third stretching section; F-heat setting section; G-first angle; H-second angle; I-third angle. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with specific embodiments:

[0028] In order to achieve the purpose of the present invention, a material strip forming and stretching mechanism includes: a longitudinal stretching mechanism for longitudinally stretching a polycarbonate film; a transverse stretching mechanism, which is arranged behind the longitudinal stretching mechanism along the conveying direction of the polycarbonate film, and the transverse stretching mechanism stretches the polycarbonate film transversely; the transverse pulling mechanism includes two symmetrically arranged sprocket groups, each sprocket group contacts one side edge of the polycarbonate film, and the two sprocket groups are mirror-symmetrical along the center line of the polycarbonate film; along the conveying direction of the polycarbonate film, each sprocket group in the transverse stretching mechanism is divided into a preheating section, a first stretching section, a buffer section, a second stretching section, a third stretching section, and a heat-setting section in different extension directions; the extension directions of the preheating section, the buffer section, and the heat-setting section are parallel to the center line of the polycarbonate film and the spacing between the two sprocket groups increases successively; along the conveying direction of the polycarbonate film, the acute angles between the sprocket groups on the same side of the first stretching section, the second stretching section, and the third stretching section and the center line of the polycarbonate film increase successively.

[0029] The beneficial effects of adopting the above technical scheme are as follows: the polycarbonate film is first stretched longitudinally and then stretched transversely. The polycarbonate film after longitudinal stretching is first preheated in the preheating section to increase the temperature of the film, and the polycarbonate film is not stretched transversely here, and only the polycarbonate film is stretched; the sprocket group of the first stretching section of the second stage expands in a trumpet shape, achieving a certain degree of transverse stretching of the polycarbonate film, but the duration is not long and the amplitude is small, which is equivalent to a trial stretching, and timely discovering whether the polycarbonate film meets the transverse stretching state; the third stage is the buffer section, at this time the polycarbonate film is still not stretched transversely, and it is mainly further preheated to ensure the accuracy of the temperature of the polycarbonate film and also provide observation time for the pre-stretched polycarbonate film; the second stretching section of the fourth stage is the formal transverse stretching of the polycarbonate film; the third stretching section of the fifth stage is the further high-speed transverse stretching of the polycarbonate film, and finally the transverse stretching amount is completed; the heat setting section of the fifth stage is to heat set the polycarbonate film after the transverse stretching is completed. Perfect the crystallization of the polycarbonate film, stabilize the wide width of the polycarbonate film, and eliminate internal stress. The entire horizontal stretching stage is divided into several sub-stages. The horizontal stretching process is gradual, which reduces the defective rate of the polycarbonate film and provides an initial observation window for the entire horizontal stretching process. During the entire process, the horizontal stretching mechanism limits the two sides of the polycarbonate film, generating a forced horizontal stretching effect. After the stretching is completed, the sprocket assembly releases the polycarbonate film.

[0030] In other embodiments of the present invention, the acute angles formed by the sprocket set on the same side of the first stretching section, the second stretching section, and the third stretching section and the center line of the polycarbonate film are 5°, 10°, and 25°, respectively.

[0031] like Figure 2 As shown, the first angle G, the second angle H, and the third angle I are 5°, 10°, and 25° respectively.

[0032] The beneficial effect of adopting the above technical solution is that the corresponding lateral stretching amplitude per unit time is larger as time goes on, and the main lateral stretching action is completed in the second half, giving the polycarbonate film a sufficient gradual reaction process in the initial stage.

[0033] In some other embodiments of the present invention, the lengths of the first stretching section, the second stretching section, and the third stretching section also increase sequentially.

[0034] The beneficial effect of adopting the above technical solution is that the actual horizontal pulling effect becomes greater as time goes on, and the main horizontal pulling action is completed in the second half, giving the polycarbonate film enough gradual reaction process in the early stage.

[0035] In some other embodiments of the present invention, the temperatures of the polycarbonate film in the first stretching section, the second stretching section, and the third stretching section increase sequentially.

[0036] The beneficial effect of adopting the above technical solution is that as the temperature gradually increases, the higher the temperature within a certain range, the greater the elastic increment of the polycarbonate film. The high temperature area corresponds to the part with large horizontal pulling amplitude, ensuring that the polycarbonate film can adapt to the horizontal pulling amplitude.

[0037] In other embodiments of the present invention, the temperatures of the polycarbonate film in the preheating section, the first stretching section, the buffer section, the second stretching section, the third stretching section, and the heat setting section are 90°C, 92°C, 93°C, 94°C, 95°C, and 200°C, respectively.

[0038] The beneficial effects of adopting the above technical solution are: the selection of the specific temperature ensures the final quality of the polycarbonate film, and the temperature required for the heat setting section is relatively high.

[0039] In other embodiments of the present invention, the transverse stretching mechanism has two bending tracks arranged in mirror symmetry along the center line of the polycarbonate film, and the sprocket group is assembled with the bending track through a pulley. Each sprocket group has several sprockets, and adjacent sprockets are connected by chains.

[0040] The beneficial effect of adopting the above technical solution is that the curved track can be pre-bent and manufactured according to the trend of the preheating section, the first stretching section, the buffer section, the second stretching section, the third stretching section, and the heat setting section. The pulley has the rolling freedom along the curved track, and the chain ensures a stable spacing between adjacent sprockets.

[0041] In other embodiments of the present invention, a plurality of rotating motors are arranged at intervals in the pulleys on each sprocket assembly, the number of the rotating motors is less than the number of the pulleys, and the rotating motors are surrounded by heat insulation covers.

[0042] The beneficial effects of adopting the above technical solution are: the rotating motor provides the main power for the movement of the sprocket group and the stretching of the polycarbonate film. At the same time, the rotating motor is not single, and the spaced rotating motors share the tension of each section of the sprocket group, ensuring that each section of the sprocket group is subjected to uniform force. At the same time, the heat insulation cover prevents the influence of heat preservation on the rotating motor.

[0043] In some other embodiments of the present invention, along the conveying direction of the polycarbonate film, the polycarbonate film passes through an extruder, a cooling roller, a preheating roller, a longitudinal stretching mechanism, and a transverse stretching mechanism in sequence.

[0044] The beneficial effect of adopting the above technical solution is that the extruder, the cooling roller, the preheating roller, the longitudinal stretching mechanism and the transverse stretching mechanism form a complete polycarbonate film production line.

[0045] In other embodiments of the present invention, a pair of flattening rollers are provided after the longitudinal stretching mechanism along the conveying direction of the polycarbonate film, and the flattening rollers are in contact with the front and back surfaces of the polycarbonate film, and the spatial planes where the axes of the two flattening rollers are located are perpendicular to the polycarbonate film in contact.

[0046] The polycarbonate film is therefore divided into a thick section 8, a longitudinally drawn section 9, a transversely drawn section 10, and a finished product section 11 in sequence.

[0047] The beneficial effect of adopting the above technical solution is that the flattening roller further flattens the polycarbonate film in the finished product stage, thereby ensuring the flatness of the polycarbonate film and improving the hardness of the surface of the polycarbonate film.

[0048] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A strip forming and extending mechanism, characterized in that: include: A longitudinal stretching mechanism for longitudinally stretching the polycarbonate film; A transverse stretching mechanism, which is arranged behind the longitudinal stretching mechanism along the conveying direction of the polycarbonate film and performs transverse stretching on the polycarbonate film; The transverse stretching mechanism comprises two symmetrically arranged sprocket groups, each sprocket group contacts one side edge of the polycarbonate film, and the two sprocket groups are mirror-symmetrical along the center line of the polycarbonate film; along the conveying direction of the polycarbonate film, each sprocket group in the transverse stretching mechanism is divided into a preheating section, a first stretching section, a buffer section, a second stretching section, a third stretching section, and a heat-setting section in different extension directions; the extension directions of the preheating section, the buffer section, and the heat-setting section are parallel to the center line of the polycarbonate film, and the spacing between the two sprocket groups increases in sequence; along the conveying direction of the polycarbonate film, the acute angles formed by the sprocket groups on the same side of the first stretching section, the second stretching section, and the third stretching section and the center line of the polycarbonate film increase in sequence; The acute angles formed between the sprocket set on the same side of the first stretching section, the second stretching section, and the center line of the polycarbonate film are 5°, 10°, and 25°, respectively; The temperatures of the polycarbonate film in the preheating section, the first stretching section, the buffer section, the second stretching section, the third stretching section, and the heat setting section are 90°C, 92°C, 93°C, 94°C, 95°C, and 200°C, respectively; The polycarbonate film is first stretched longitudinally and then stretched transversely. After longitudinal stretching, the polycarbonate film is first preheated in the preheating section to increase the temperature of the film to increase the elasticity of the film. Here, the polycarbonate film is not stretched transversely, and only the polycarbonate film is stretched; the sprocket group of the first stretching section of the second stage expands in a trumpet shape, and the polycarbonate film is stretched in a small amplitude and for a short time to promptly find out whether the polycarbonate film meets the transverse stretching state; the third stage is the buffer section, at this time, the polycarbonate film is still not stretched transversely, and it is mainly preheated further to ensure the accuracy of the temperature of the polycarbonate film and provide observation time for the pre-stretched polycarbonate film; the second stretching section of the fourth stage is to stretch the polycarbonate film The formal horizontal stretching; the third stretching section of the fifth stage is a further high-speed horizontal stretching of the polycarbonate film, and finally the horizontal stretching amount is completed; the heat setting section of the fifth stage is to heat set the polycarbonate film after the horizontal stretching; improve the crystallization of the polycarbonate film, make the wide width size of the polycarbonate film stable, and eliminate the internal stress; the entire horizontal stretching stage is divided into several sub-stages, and the horizontal stretching process is gradual, which reduces the defective rate of the polycarbonate film and provides an initial observation window for the entire horizontal stretching process; during the whole process, the horizontal stretching mechanism limits the two sides of the polycarbonate film to produce a forced horizontal stretching effect. After the stretching is completed, the sprocket group releases the polycarbonate film.

2. A strip forming and extending mechanism according to claim 1, characterized in that: The lengths of the first stretching section, the second stretching section, and the third stretching section also increase sequentially.

3. A strip forming and extending mechanism according to claim 1, characterized in that: The temperatures of the polycarbonate film in the first stretching section, the second stretching section, and the third stretching section increase in sequence.

4. The strip forming and extending mechanism according to claim 1, characterized in that: The transverse stretching mechanism is provided with two bending tracks which are arranged in mirror symmetry along the center line of the polycarbonate film. The sprocket set is assembled with the bending tracks via a pulley. Each sprocket set is provided with a plurality of sprockets, and adjacent sprockets are connected via chains.

5. A strip forming and extending mechanism according to claim 4, characterized in that: A plurality of rotating motors are arranged at intervals in the pulleys on each sprocket assembly, the number of the rotating motors is less than the number of the pulleys, and the rotating motors are surrounded by heat insulation covers.

6. The strip forming and extending mechanism according to claim 1, characterized in that: Along the conveying direction of the polycarbonate film, the polycarbonate film passes through an extruder, a cooling roller, a preheating roller, a longitudinal stretching mechanism, and a transverse stretching mechanism in sequence.

7. A strip forming and extending mechanism according to claim 6, characterized in that: Along the conveying direction of the polycarbonate film, the longitudinal stretching mechanism is further followed by a pair of flattening rollers, which are in contact with both the front and back surfaces of the polycarbonate film, and the spatial planes where the axes of the two flattening rollers are located are perpendicular to the polycarbonate film in contact.

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