Manufacturing method of PDLC (Polymer Dispersed Liquid Crystal) film roll without generating pipe bottom marks and PDLC film roll

Abstract

The invention belongs to the technical field of PDLC (polymer dispersed liquid crystal) dimming films, and particularly relates to a manufacturing method of a PDLC film roll without generating pipe bottom marks and the PDLC film roll. The manufacturing method comprises rolling treatment, the rolling treatment comprises the steps that cuboid foam and the first end of the PDLC film are fixed to the outer surface of the tube core, the tube core is rotated to roll the PDLC film, and fixing comprises the steps that the first edge of the foam is fixed in the axial direction of the tube core, and the second edge of the foam is fixed in the circumferential direction of the tube core; the length of the second side is not greater than the perimeter of the tube core, the first end of the PDLC film extends below the foam, and the end part of the foam and the end part of the first end of the PDLC film are arranged in a staggered manner; in the axial direction of the tube core, the two ends of the foam correspond to the two ends of the PDLC film or the two ends of the foam are located on the outer sides of the two ends of the PDLC film. When the PDLC film roll is manufactured, pipe bottom marks are avoided, and the yield of the PDLC film roll is high.

Description

Technical Field

[0001] The invention belongs to the technical field of PDLC dimming films, and in particular relates to a method for manufacturing a PDLC film roll without generating tube bottom marks and a PDLC film roll. Background Art

[0002] PDLC (polymer dispersed liquid crystal) dimming film becomes transparent when power is applied and becomes foggy when power is not applied. It can maintain the transparency of the space while conveniently protecting privacy. It has been widely used in building curtain walls, automotive industry, interior partitions and other fields.

[0003] PDLC dimming film includes substrate, conductive layer and dispersed liquid crystal layer. In order to facilitate the transportation and use of PDLC, PDLC dimming film is usually rolled into PDLC film roll after production. The structure of PDLC film roll is shown in the figure below. Figure 1 After being wound into a film roll, periodic tube bottom marks (traces left by the liquid crystal being compressed) are easily generated on the PDLC film that is wound at the beginning, and the PDLC film with tube bottom marks cannot be used, and the defective rate of the PDLC film roll is high.

[0004] It should be noted that this part of the present invention only provides background technology related to the present invention and does not necessarily constitute prior art or known technology. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art that after the PDLC film is wound into a film roll, periodic tube bottom marks are easily generated on the PDLC film that is initially wound, and the defective rate of the PDLC film roll is relatively high. A method for manufacturing a PDLC film roll that does not generate tube bottom marks and a PDLC film roll are provided. When manufacturing the PDLC film roll, the generation of tube bottom marks can be avoided, and the yield rate of the PDLC film roll is high.

[0006] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a method for manufacturing a PDLC film roll without generating tube bottom marks, comprising a winding process, wherein the winding process comprises:

[0007] The first ends of the rectangular foam and the PDLC film are fixed to the outer surface of the tube core, and the tube core is rotated to roll up the PDLC film, wherein the fixing includes: the first edge of the foam is fixed along the axial direction of the tube core, the second edge of the foam is fixed along the circumferential direction of the tube core, the length of the second edge is not greater than the circumference of the tube core, the first end of the PDLC film extends under the foam, and the end of the foam and the end of the first end of the PDLC film are staggered;

[0008] In the axial direction of the tube core, two ends of the foam correspond to two ends of the PDLC film or two ends of the foam are outside two ends of the PDLC film;

[0009] The outer diameter of the tube core is D, and the length of the second side is πD / 8 to πD;

[0010] The length of the first end of the PDLC film extending under the foam accounts for 1 / 6 to 5 / 6 of the length of the second side, and the length of the first end of the PDLC film is along the circumferential direction of the tube core;

[0011] The first end of the PDLC film extends under the foam to generate a first gap in front of the first end, and a second gap and a third gap located at both ends of the foam;

[0012] The distance between the first gap and the second gap and the distance between the first gap and the third gap are not less than 1 / 6 of the length of the second side.

[0013] In some preferred embodiments, the length of the second side is πD / 3 to πD2 / 3, the length of the first end of the PDLC film extending under the foam accounts for 3 / 8 to 5 / 8 of the length of the second side, and the distance between the first gap and the second gap and the distance between the first gap and the third gap are not less than 3 / 8 times the length of the second side.

[0014] In some preferred embodiments, the density of the foam is 0.01 g / cm 3 ~0.06g / cm 3 .

[0015] Preferably, the third side of the foam is fixed along the radial direction of the tube core, and the ratio of the length of the third side to the thickness of the PDLC film is 1.0-3.5.

[0016] In some preferred embodiments, the conditions of the winding process include: a winding tension of 30 N / m to 40 N / m, a winding tension taper of 15 mm to 25 mm, and a winding speed of 3 m / min to 7 m / min.

[0017] In some preferred embodiments, a stress release groove penetrating the foam is provided on the foam segment covering the first end of the PDLC film, and the foam segment covering the first end of the PDLC film is located between the first gap and the second gap; the stress release groove is parallel to the second edge direction of the foam or has an angle with the second edge direction of the foam; more than one stress release groove is evenly distributed along the first edge direction of the foam.

[0018] Preferably, the stress release groove and the second side direction of the foam have an angle of 10° to 25°; the straight line where the midpoint of the opposite side of the foam segment covering the first end of the PDLC film is located is taken as the axis of symmetry, and the stress release grooves located on both sides of the axis of symmetry are symmetrical about the axis of symmetry, and the axis of symmetry is parallel to the second side direction of the foam.

[0019] In some preferred embodiments, the process further includes manufacturing a PDLC film before the winding process, wherein the process of manufacturing the PDLC film includes: unwinding a conductive substrate, coating a liquid crystal material on the conductive substrate, and cutting.

[0020] Preferably, the conditions for unwinding the conductive substrate include: an unwinding tension of 20 N / m to 30 N / m, and a taper of the unwinding tension of 15 mm to 25 mm.

[0021] In a second aspect, the present invention provides a PDLC film roll, which is manufactured by the manufacturing method described in the first aspect, and comprises a tube core, foam and a PDLC film, wherein the tube core is located inside, the tube core supports the PDLC film, the foam is fixed to the outer surface of the tube core, the first side of the foam is parallel to the axial direction of the tube core, the second side of the foam is along the circumferential direction of the tube core, the PDLC film is wound along the circumference of the tube core, the first end of the PDLC film extends under the foam, and the end of the foam and the end of the first end of the PDLC film are staggered; in the axial direction of the tube core, the two ends of the foam correspond to the two ends of the PDLC film or the two ends of the foam are outside the two ends of the PDLC film;

[0022] The outer diameter of the tube core is D, and the length of the second side is πD / 8 to πD;

[0023] The length of the first end of the PDLC film extending under the foam accounts for 1 / 6 to 5 / 6 of the length of the second side, and the length of the first end of the PDLC film is along the circumferential direction of the tube core;

[0024] The first end of the PDLC film extends under the foam to generate a first gap in front of the first end, and a second gap and a third gap located at both ends of the foam;

[0025] The distance between the first gap and the second gap and the distance between the first gap and the third gap are not less than 1 / 6 of the length of the second side.

[0026] The PDLC film roll winding method of the present invention uses a rectangular foam for winding, the length of the second side of the foam is not greater than the circumference of the tube core, and during the winding process, the foam is fixed to the outer surface of the tube core, the first side of the foam is fixed in the axial direction of the tube core, the second side of the foam is fixed in the circumferential direction of the tube core, the first end of the PDLC film extends under the foam and is fixed to the outer surface of the tube core, and the end of the foam and the end of the first end of the PDLC film are staggered; the foam is fixed to the outer surface of the tube core, the first end of the PDLC film extends under the foam, a first gap is generated in front of the first end, and a second gap and a third gap are generated at both ends of the foam, the distance between the first gap and the second gap and the distance between the first gap and the third gap respectively correspond to the length of the first end of the PDLC film under the foam and the difference between the length of the foam and the length of the first end of the PDLC film under the foam;

[0027] On the one hand, after the first end of the PDLC film is fixed on the outer surface of the tube core, the upper part of the end of the first end is covered with foam, and the foam can provide a greater buffering effect to reduce the hard extrusion of the PDLC film wound above; on the other hand, there is foam on the upper part of the first gap in front of the first end, and after the PDLC film is rolled into a roll, the foam relieves the stress generated in the gap, and after the foam in front of the first end is compressed, it supplements a part of the first gap in front of the first end, and also prevents the displacement of the first end; on the third hand, by fixing the foam on the outer surface of the tube core, the first end of the PDLC film extends under the foam, and by adjusting the length of the second side, the length of the first end of the PDLC film extending under the foam is relative to the length of the second side. The proportion of, in turn, three gaps with large distances apart are generated along the foam winding direction, that is, the gaps generated when the PDLC film and the foam are wound are dispersed to avoid the formation of concentrated gaps. After the foam is compressed, the thickness is limited, the thickness of the three gaps is not greater than the thickness of the compressed foam, the gaps are very small, the stress generated in the gaps is relieved and the stress is dispersed, and the upper, lower or side parts of the three dispersed gaps have foam to buffer, especially at the first gap, the foam forms a barrier positioning and buffer protection for the end of the PDLC film to reduce the stress it is subjected to. Through the above multiple effects, the stress can be reduced and dispersed, the various parts of the PDLC film are subjected to more uniform force, the bottom marks of the tube can be avoided, and the yield of the PDLC film coil can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1It is a schematic diagram of the structure of a PDLC film roll in the prior art.

[0030] Figure 2 It is a schematic structural diagram of the PDLC film roll of the present invention.

[0031] Figure 3 It is a first structural schematic diagram of the foam segment of the foam of the present invention covering the first end of the PDLC film.

[0032] Figure 4 It is a second structural schematic diagram of the foam section of the foam of the present invention covering the first end of the PDLC film.

[0033] Figure 5 It is a schematic structural diagram of a device for manufacturing a PDLC film roll according to Example 1 of the present invention.

[0034] Figure 6 It is a schematic diagram of the structure of the PDLC film roll of comparative example 1.

[0035] Figure 7 This is a schematic diagram of the structure of the PDLC film roll of Comparative Example 3.

[0036] Description of Reference Numerals

[0037] 1. Foam; 101. Stress release groove; 2. Tube core; 3. First end; 4. First gap; 5. Second gap; 6. Third gap; 7. Conductive substrate unwinding wheel; 8. Adhesive backing wheel; 9. Liquid crystal coating equipment; 10. Material roller; 11. Laser cutting device; 12. Automatic glue laminating machine. DETAILED DESCRIPTION

[0038] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0039] In this document, unless otherwise specified, directional words such as "upper" and "lower" are generally understood in combination with the directions shown in the drawings and actual applications, and "inside" and "outside" refer to the inside and outside of the outline of a component.

[0040] In the description of the present invention, it is necessary to understand that the terms "length", "width", "thickness", "up", "down", "front", "back", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0042] The structure of the existing PDLC film roll is referenced Figure 1 The study found that due to the certain thickness of the PDLC film itself, under the extrusion of the harder tube core and the external diaphragm, the upper part of the first end of the PDLC film is subjected to a greater pressure F1. The reaction force F2 of F1 causes periodic indentations, namely tube bottom marks, to easily appear on the PDLC film that is initially rolled up, affecting the yield of the PDLC film.

[0043] In this first aspect, the present invention provides a method for manufacturing a PDLC film roll without generating tube bottom marks, including a winding process, wherein the winding process includes:

[0044] The rectangular foam 1 and the first end 3 of the PDLC film are fixed to the outer surface of the tube core 2, and the tube core 2 is rotated to roll up the PDLC film, wherein the fixing includes: the first edge of the foam 1 is fixed along the axial direction of the tube core 2, the second edge of the foam 1 is fixed along the circumferential direction of the tube core 2, the length of the second edge is not greater than the circumference of the tube core 2, the first end 3 of the PDLC film extends under the foam 1, and the end of the foam 1 and the end of the first end 3 of the PDLC film are staggered;

[0045] In the axial direction of the tube core 2, two ends of the foam 1 correspond to two ends of the PDLC film or two ends of the foam 1 are outside two ends of the PDLC film;

[0046] The outer diameter of the tube core 2 is D, and the length of the second side is πD / 8 to πD;

[0047] The length of the first end 3 of the PDLC film extending under the foam 1 accounts for 1 / 6 to 5 / 6 of the length of the second side, and the length of the first end 3 of the PDLC film is along the circumferential direction of the tube core 2;

[0048] The first end 3 of the PDLC film extends under the foam 1, thereby generating a first gap 4 in front of the first end 3, and a second gap 5 and a third gap 6 at both ends of the foam 1;

[0049] The distance between the first gap 4 and the second gap 5 and the distance between the first gap 4 and the third gap 6 are not less than 1 / 6 of the length of the second side.

[0050] The PDLC film roll winding method of the present invention is as follows: Figure 2, a rectangular foam is used for the rolling process, and the length of the second side of the foam is not greater than the circumference of the tube core. During the rolling process, the foam is fixed to the outer surface of the tube core, the first side of the foam is fixed in the axial direction of the tube core, and the second side of the foam is fixed in the circumferential direction of the tube core. The first end of the PDLC film extends under the foam and is fixed to the outer surface of the tube core; the upper part of the end of the first end of the PDLC film is covered with foam, and the foam can buffer the extrusion of the external PDLC diaphragm, reduce the hard extrusion of the PDLC film wound above, and reduce the pressure and corresponding reaction force on the upper part of the end of the first end of the PDLC film, which can reduce stress and inhibit the generation of periodic tube bottom marks; there is foam on the upper part of the first gap 4 at the front of the first end, and after the PDLC film is wound into a roll, the foam relieves the stress caused by the existence of the first gap 4, and the foam on the first gap 4 is compressed to supplement a part of the first gap 4, reduce the first gap 4, and also prevent the displacement of the first end, and the foam can significantly reduce the stress caused by the existence of the first gap 4 , which can suppress the generation of periodic tube bottom marks; the foam is fixed to the outer surface of the tube core, and the first end of the PDLC film extends under the foam, generating a first gap 4 in front of the first end, and a second gap 5 and a third gap 6 located at both ends of the foam, the distance between the first gap 4 and the second gap 5 and the distance between the first gap 4 and the third gap 6 respectively correspond to the length of the first end of the PDLC film under the foam and the difference between the length of the foam and the length of the first end of the PDLC film under the foam, the distance between the first gap 4, the second gap 5, and the third gap 6 is large, the thickness of the foam is limited after being compressed, the thickness of the three gaps is not greater than the thickness of the compressed foam, the gap is very small, the stress generated by the existence of the gap is relieved and the stress is dispersed, the upper, lower or side of the first gap 4, the second gap 5, and the third gap 6 have foam to play a buffering role, the foam relieves the stress generated by the existence of the first gap 4, the second gap 5, and the third gap 6, the various parts of the PDLC film are more evenly stressed, and the generation of tube bottom marks can be avoided. The winding method of the present invention can reduce and disperse stress through the above multiple effects, so that each part of the PDLC film is more evenly stressed, and the generation of tube bottom marks can be avoided, thereby improving the yield of the PDLC film coil.

[0051] Compared with the winding method in which foam is only arranged at the lower part of the first end of the PDLC film, the winding method of the present invention can reduce the pressure and corresponding reaction force on the upper part of the end of the first end of the PDLC film, reduce stress, and inhibit the generation of periodic tube bottom marks, and avoid the PDLC film on the first layer of PDLC film on the foam from crossing the thickness of the foam and the thickness of the first layer of PDLC film when winding, thereby generating a large deformation stress under a large span deformation and generating a tube bottom mark.

[0052] In the winding method of the present invention, the outer diameter of the tube core 2 is D, and the length of the second side is πD / 8~πD, which can avoid the generation of tube bottom marks. The length of the second side can be, for example, πD / 8, πD / 4, 3πD / 8, πD / 2, 5πD / 8, 3πD / 4, 7πD / 8 and πD.

[0053] In the winding method of the present invention, the length of the first end 3 of the PDLC film extending under the foam 1 is 1 / 6 to 5 / 6 of the length of the second side. The length of the first end 3 of the PDLC film along the circumferential direction of the tube core 2, the distance between the first gap and the second gap, and the distance between the first gap and the third gap are not less than 1 / 6 of the length of the second side, which can increase the distance between the first gap, the second gap, and the third gap, disperse the stress, make the various parts of the PDLC film more uniformly stressed, and avoid the generation of tube bottom marks. The length of the first end 3 of the PDLC film extending under the foam 1 relative to the length of the second side can be, for example, 1 / 6, 1 / 3, 1 / 2, 2 / 3 and 5 / 6.

[0054] The present invention does not limit the size of the tube core, for example, it can be a 6-inch, 8-inch or 10-inch tube core, and the thickness can be, for example, 5mm, 10mm, 15mm and 20mm. There is no limitation on the material of the tube core, for example, it can be a PVC tube, PP tube, ABS tube with good tensile / compressive strength.

[0055] The present invention does not limit the material of the foam, for example, it can be EPE or PP.

[0056] In some preferred embodiments, the length of the second side is πD / 3 to πD2 / 3, the length of the first end 3 of the PDLC film extending below the foam 1 accounts for 3 / 8 to 5 / 8 of the length of the second side, and the distance between the first gap 4 and the second gap 5 and the distance between the first gap 4 and the third gap 6 are not less than 3 / 8 times the length of the second side. Under this preferred solution, it is more conducive to increasing the distance between the first gap, the second gap, and the third gap, dispersing stress, making each part of the PDLC film more evenly stressed, and avoiding the generation of tube bottom marks.

[0057] In some preferred embodiments, the density of the foam 1 is 0.01 g / cm 3 ~0.06g / cm 3 Under this preferred solution, the maximum compression ratio is large, which is more conducive to exerting the shock-proof and cushioning effect of the foam.

[0058] Preferably, the third side of the foam 1 is fixed along the radial direction of the tube core 2, and the ratio of the length of the third side to the thickness of the PDLC film is 1.0 to 3.5. In this preferred embodiment, based on the density of the foam being 0.01 g / cm 3 ~0.06g / cm 3 , so that the ratio of the length of the third side of the foam to the thickness of the PDLC film is 1 to 3.5, which is more conducive to compressing the sizes of the first gap 4, the second gap 5 and the third gap 6, avoiding the generation of new gaps, reducing the stress generated by the gaps, and inhibiting the generation of tube bottom marks.

[0059] In some preferred embodiments, the conditions of the winding process include: a winding tension of 30N / m to 40N / m, a winding tension taper of 15mm to 25mm, and a winding speed of 3m / min to 7m / min. Under this preferred solution, a winding method is adopted in which the first edge is fixed in the axial direction of the tube core, the second edge is fixed to the outer surface of the tube core in the circumferential direction of the tube core, and the first end of the PDLC film extends under the foam, so that the tension, taper and speed of the winding process are respectively within the above ranges, which can promote the compression deformation of the foam, supplement the first gap, reduce the stress generated by the existence of the first gap, compress the size of the first gap, the second gap and the third gap, relieve the stress generated by the existence of the first gap, the second gap and the third gap, and make the various parts of the PDLC film more uniformly stressed, thereby being more conducive to suppressing the generation of tube bottom marks. In addition, it is more conducive to making the PDLC film in a flat and taut state during winding, suppressing the slipping problem and the tensile deformation of the PDLC film.

[0060] In some preferred embodiments, reference Figure 3 and Figure 4, a stress release groove 101 penetrating the foam 1 is provided on the foam section covering the first end 3 of the PDLC film, the foam section covering the first end 3 of the PDLC film is located between the first gap 4 and the second gap 5, and more than one stress release groove 101 is evenly distributed along the first side direction of the foam 1; in some cases, when the PDLC film is bonded to the foam, due to the different properties of the two materials (such as different deformation capabilities, etc.), when the force is applied during winding, the PDLC film may produce excessive local stress and wrinkles, and when the PDLC film is bonded to the foam, the air remaining between the two may also affect the close combination of the two, which may also Problems such as wrinkles may occur, which will undoubtedly aggravate the problem of tube bottom marks. By arranging stress release grooves on the foam to penetrate the thickness of the foam (grooves can be made by local cutting, etc.), the foam and the PDLC film at the grooved position are not bonded, and the PDLC film here will not be affected by the foam. When the PDLC film generates local stress, the PDLC film can deform toward the foam groove to release the stress. After winding, even if the PDLC film generates local slight deformation, the influence of the deformation can be eliminated due to the large deformation capacity of the foam. At the same time, when the PDLC film is bonded to the foam, the remaining air between the two can also be discharged into the stress release groove, which further reduces the generation of wrinkles and avoids the generation of tube bottom marks.

[0061] Optionally, the stress release groove is parallel to the second side direction of the foam. Since the winding direction of the PDLC film is along the circumferential direction of the tube core 2, it is deformed by force in the circumferential direction but not subject to force along the axial direction of the tube core 2. Due to the difference in force, the PDLC film will produce a large stress concentration along the axial direction of the tube core 2. By having the stress release groove parallel to the second side direction of the foam, the stress of the PDLC film can be effectively relieved and released, reducing the generation of wrinkles and thereby avoiding the formation of tube bottom marks.

[0062] And / or the stress release groove has an angle with the second side direction of the foam. By setting the angle, the stress release groove is inclined at a certain angle with the second side direction of the foam. Relatively speaking, the stress release groove can cover more in the axial direction of the tube core 2, thereby facilitating the stress release groove to relieve and release the stress of the PDLC film. Optionally, the stress release groove has an angle of 10° to 25° with the second side direction of the foam. The stress release groove can be a continuous groove or a plurality of grooves intermittently opened in the circumferential direction of the tube core 2.

[0063] Optionally, the straight line where the midpoints of the opposite sides of the foam segment covering the first end 3 of the PDLC film are located is taken as the axis of symmetry, and the stress release grooves 101 located on both sides of the axis of symmetry are symmetrical about the axis of symmetry, and the axis of symmetry is parallel to the second side direction of the foam 1, that is, along the axis of symmetry, the stress release grooves are inclined in opposite directions, which is beneficial to guiding the stress to be released in the opposite direction along the axial direction of the tube core 2, so as to further reduce the generation of wrinkles and avoid the generation of tube bottom lines.

[0064] In some preferred embodiments, the manufacturing method further comprises manufacturing a PDLC film before the winding process, and the process of manufacturing the PDLC film comprises: unwinding a conductive substrate, coating a liquid crystal material on the conductive substrate, and cutting. In this preferred embodiment, cutting is more conducive to aligning the first end of the PDLC film with the tube core and fixing it to the outer surface of the tube core by means of tape or the like.

[0065] Preferably, the conditions for unwinding the conductive substrate include: the unwinding tension is 20N / m-30N / m, and the unwinding tension taper is 15mm-25mm. Under this preferred solution, it is more conducive to making the unwound film in a flat and taut state, suppressing the problem of slipping and the tensile deformation of the film.

[0066] In a second aspect, the present invention provides a PDLC film roll, which is manufactured by the manufacturing method described in the first aspect, and comprises a tube core 2, a foam 1 and a PDLC film, wherein the tube core 2 is located inside, the tube core 2 supports the PDLC film, the foam 1 is fixed to the outer surface of the tube core 2, the first side of the foam 1 is parallel to the axial direction of the tube core 2, the second side of the foam 1 is along the circumferential direction of the tube core 2, the PDLC film is wound along the circumference of the tube core 2, the first end 3 of the PDLC film extends under the foam 1, and the end of the foam 1 and the end of the first end 3 of the PDLC film are staggered; in the axial direction of the tube core 2, the two ends of the foam 1 correspond to the two ends of the PDLC film or the two ends of the foam 1 are outside the two ends of the PDLC film;

[0067] The outer diameter of the tube core 2 is D, and the length of the second side is πD / 8 to πD;

[0068] The length of the first end 3 of the PDLC film extending under the foam 1 accounts for 1 / 6 to 5 / 6 of the length of the second side, and the length of the first end 3 of the PDLC film is along the circumferential direction of the tube core 2;

[0069] The first end 3 of the PDLC film extends under the foam 1, thereby generating a first gap 4 in front of the first end 3, and a second gap 5 and a third gap 6 at both ends of the foam 1;

[0070] The distance between the first gap 4 and the second gap 5 and the distance between the first gap 4 and the third gap 6 are not less than 1 / 6 of the length of the second side.

[0071] In the PDLC film roll of the present invention, the foam is fixed to the outer surface of the tube core, the first side of the foam is parallel to the axial direction of the tube core, the second side is along the circumferential direction of the tube core, and the first end of the PDLC film extends under the foam, which can reduce and disperse the stress caused by the winding of the PDLC film, and each part of the PDLC film is subjected to more uniform force, which can avoid the generation of tube bottom marks and improve the yield of the PDLC film roll.

[0072] The present invention is further described in detail below with reference to specific embodiments.

[0073] Example 1

[0074] A method for making a PDLC film roll without producing a tube bottom mark, comprising making a PDLC film and rolling it up, and referring to Figure 5 The PDLC film roll manufacturing device shown is carried out, and the manufacturing device includes a conductive substrate unwinding wheel 7, a backing glue wheel 8, a liquid crystal coating device 9, a belt roller 10 for conveying the film sheet forward, a laser cutting device 11, an automatic glue sticking machine 12 and a tube core 2;

[0075] The process of making the PDLC film includes: controlling the unwinding tension to be 25N / m, the unwinding tension taper to be 20mm, unwinding the conductive substrate through the conductive substrate unwinding wheel 7, and after unwinding the conductive substrate, the conductive substrate is transmitted forward through the adhesive backing wheel 8, and transmitted to the liquid crystal coating device 9, and the liquid crystal material is coated on the conductive substrate, and then the film is further transmitted forward by the belt roller 10 to the laser cutting device 11, and the laser head and the film are kept relatively still for cutting and trimming to obtain the PDLC film;

[0076] The winding process includes: Step 1: cutting the rectangular foam, the length of the first side is consistent with the width of the PDLC film, the outer diameter of the tube core 2 is D, the length of the second side is πD / 2, the ratio of the length of the third side to the thickness of the PDLC film is 2, and the density of the foam is 0.03g / cm 3 ;

[0077] Step 2: pre-treat the tube core 2, attach one side of the double-sided adhesive tape to the bottom surface of the foam, and fix the rectangular foam to the outer surface of the tube core 2, with the first edge fixed in the axial direction of the tube core 2, the second edge fixed in the circumferential direction of the tube core 2, and the third edge fixed in the radial direction of the tube core 2;

[0078] Step three: After cutting by the laser cutting device 11, the material roller 10 transfers the PDLC film forward to the tube core 2 below. According to the length of the first end of the PDLC film extending under the foam being πD / 4, the length of the first end 3 of the PDLC film extending under the foam 1 is 1 / 2 of the length of the second side, so that the first end of the PDLC film extends under the foam, and the foam covers the first end of the PDLC film. After the automatic gluing machine 12 fixes the first end of the PDLC film with tape, the tube core 2 below is rotated and rolled on the tube core 2 below. After the tube core below is rolled to a predetermined length, the material roller 10 transfers the PDLC film to the tube core 2 above, and adopts the same rolling method to roll on the tube core 2 above. The process of rolling on the tube core 2 below and on the tube core 2 above is performed alternately, wherein the rolling tension is 35N / m, the rolling tension taper is 20mm, and the rolling speed is 5m / min.

[0079] A PDLC film roll is manufactured by the above-mentioned PDLC film roll manufacturing method, and the structure is shown in Figure 2 , including a tube core 2, a foam 1 and a PDLC film, the tube core 2 is located inside, the tube core 2 supports the PDLC film, the foam 1 is fixed to the outer surface of the tube core 2, the first edge of the foam 1 is parallel to the axial direction of the tube core 2, the second edge of the foam 1 is along the circumferential direction of the tube core 2, the PDLC film is wound along the circumference of the tube core 2, the first end 3 of the PDLC film extends under the foam 1, and the end of the foam 1 and the end of the first end 3 of the PDLC film are staggered.

[0080] Example 2

[0081] The preparation method of the PDLC film roll is carried out with reference to Example 1, with the difference that in step 1 of the winding process, the length of the second side is πD / 2, and in step 3, the length of the first end of the PDLC film extending under the foam is 3πD / 8, and the length of the first end 3 of the PDLC film extending under the foam 1 accounts for 3 / 4 of the length of the second side, so that the first end of the PDLC film extends under the foam.

[0082] Example 3

[0083] The method for manufacturing the PDLC film roll is carried out in accordance with the method of Example 1, except that in step 1 of the winding process, the ratio of the length of the third side to the thickness of the PDLC film is 4.

[0084] Example 4

[0085] The method for preparing the PDLC film roll is carried out with reference to the method of Example 1, except that the winding tension in step 3 of the winding process is 50 N / m.

[0086] Example 5

[0087] The method for preparing the PDLC film roll is carried out with reference to the method of Example 1, except that the winding tension taper in step 3 of the winding process is 40 mm.

[0088] Example 6

[0089] The method for preparing the PDLC film roll is carried out with reference to the method of Example 1, except that the winding speed in step 3 of the winding process is 2 m / min.

[0090] Comparative Example 1

[0091] The method for making the PDLC film roll of Example 1 is carried out with reference to the method, except that in the step 1 of the winding process, the length of the second side is πD, and in the step 3, the length of the first end of the PDLC film extending under the foam is πD / 8, and the length of the first end 3 of the PDLC film extending under the foam 2 accounts for 1 / 8 of the length of the second side, so that the first end of the PDLC film extends under the foam. The obtained PDLC film roll structure is shown in FIG. Figure 6 .

[0092] Comparative Example 2

[0093] The method for making the PDLC film roll is carried out in accordance with the method of Example 1, except that no foam is used during the rolling process. The structure of the obtained PDLC film roll is shown in FIG. Figure 1 .

[0094] Comparative Example 3

[0095] The method for making the PDLC film roll is carried out in accordance with the method of manufacturing the PDLC film roll of Example 1, except that, during the rolling process, only the foam is arranged at the lower part of the first end of the PDLC film. The structure of the obtained PDLC film roll is shown in FIG. Figure 7 As an alternative, foam may be disposed on the upper portion of the first end of the PDLC film, but a gap is formed between the PDLC film and the foam.

[0096] Test Case

[0097] According to the method for making the PDLC film rolls of Examples 1 to 6 and Comparative Examples 1 to 3, the PDLC films were rolled up to 100πD, and the whole roll was placed in an oven at 80°C for 1 hour. After cooling, the PDLC film was 500mm away from the lamp tube, and the width of the bottom of the tube was × A PDLC film with a length of 4πD was hung on a light box. A person stood on the side of the PDLC film away from the lamp tube at a distance of 1m from the PDLC film and visually observed the tube bottom marks on the PDLC film. During the visual observation of the tube bottom marks on the PDLC film, the light intensity of the lamp was controlled at 3000lux, 500lux and 500lux respectively, and the human eye vision was required to be ≥1.0. The observation results of the tube bottom marks are shown in Table 1.

[0098] Table 1

[0099]

[0100] Comparing the comparative example and the embodiment, compared with the winding process, no foam is used or foam is only set at the lower part of the first end of the PDLC film, the first edge of the foam 1 is fixed in the axial direction of the tube core 2, the second edge of the foam 1 is fixed in the circumferential direction of the tube core 2, the length of the second edge is not greater than the circumference of the tube core 2, the first end 3 of the PDLC film extends under the foam 1, the end of the foam 1 and the end of the first end 3 of the PDLC film are staggered, the length of the first end 3 of the PDLC film extending under the foam 1 accounts for 1 / 6 to 5 / 6 of the length of the second edge, and the scheme of the present invention can suppress the generation of tube bottom marks.

[0101] Comparing Example 1 to Example 2, the length of the first end 3 of the PDLC film extending under the foam 1 accounts for 3 / 8 to 5 / 8 of the length of the second side. ， It is more conducive to further suppressing the generation of tube bottom marks. Comparing Examples 1 and 3, the ratio of the length of the third side of the foam 1 to the thickness of the PDLC film is 1-3.5, which is more conducive to suppressing the generation of tube bottom marks. Comparing Example 1 and Example 4, the winding tension is 30N / m-40N / m, which is more conducive to suppressing the generation of tube bottom marks. Comparing Example 1 and Example 5, the winding tension taper is 15mm-25mm, which is more conducive to suppressing the generation of tube bottom marks. Comparing Example 1 and Example 6, the winding speed is 3m / min-7m / min, which is more conducive to suppressing the generation of tube bottom marks.

[0102] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for producing a PDLC film roll without producing tube bottom marks, characterized in that: The invention comprises a winding process, wherein the winding process comprises: The rectangular foam (1) and the first end (3) of the PDLC film are fixed to the outer surface of the tube core (2), and the tube core (2) is rotated to roll up the PDLC film, wherein the fixing includes: the first edge of the foam (1) is fixed along the axial direction of the tube core (2), the second edge of the foam (1) is fixed along the circumferential direction of the tube core (2), the length of the second edge is not greater than the circumference of the tube core (2), the first end (3) of the PDLC film extends under the foam (1), and the end of the foam (1) and the end of the first end (3) of the PDLC film are staggered; In the axial direction of the tube core (2), two ends of the foam (1) correspond to two ends of the PDLC film or two ends of the foam (1) are outside two ends of the PDLC film; The outer diameter of the tube core (2) is D, and the length of the second side is πD / 8 to πD; The length of the first end (3) of the PDLC film extending below the foam (1) accounts for 1 / 6 to 5 / 6 of the length of the second side, and the length of the first end (3) of the PDLC film is along the circumferential direction of the tube core (2); The first end (3) of the PDLC film extends into the bottom of the foam (1), thereby generating a first gap (4) in front of the first end (3), and a second gap (5) and a third gap (6) located at both ends of the foam (1); The distance between the first gap (4) and the second gap (5) and the distance between the first gap (4) and the third gap (6) are not less than 1 / 6 of the length of the second side.

2. The method according to claim 1, characterized in that: The length of the second side is πD / 3 to πD2 / 3, the length of the first end (3) of the PDLC film extending under the foam (1) accounts for 3 / 8 to 5 / 8 of the length of the second side, and the distance between the first gap (4) and the second gap (5) and the distance between the first gap (4) and the third gap (6) are not less than 3 / 8 times the length of the second side.

3. The method according to claim 1, characterized in that: The density of the foam (1) is 0.01 g / cm 3 ~0.06g / cm 3 .

4. The method according to claim 3, characterized in that: The third edge of the foam (1) is fixed along the radial direction of the tube core (2), and the ratio of the length of the third edge to the thickness of the PDLC film is 1.0 to 3.

5.

5. The method according to claim 1, characterized in that: The conditions for the winding process include: a winding tension of 30 N / m to 40 N / m, a winding tension taper of 15 mm to 25 mm, and a winding speed of 3 m / min to 7 m / min.

6. The method according to claim 1, characterized in that: A stress release groove (101) penetrating the foam (1) is provided on the foam section covering the first end (3) of the PDLC film, and the foam section covering the first end (3) of the PDLC film is located between the first gap (4) and the second gap (5); the stress release groove (101) is parallel to the second side direction of the foam (1) or has an angle with the second side direction of the foam (1); and more than one stress release groove (101) is evenly distributed along the first side direction of the foam (1).

7. The manufacturing method according to claim 6, characterized in that: The stress release groove (101) and the second side direction of the foam (1) have an angle of 10° to 25°; the straight line where the midpoint of the opposite side of the foam section covering the first end (3) of the PDLC film is located is taken as the symmetry axis, and the stress release grooves (101) located on both sides of the symmetry axis are symmetrical about the symmetry axis, and the symmetry axis is parallel to the second side direction of the foam (1).

8. The manufacturing method according to claim 1, characterized in that: It also includes making a PDLC film before the winding process, and the process of making the PDLC film includes: unwinding a conductive substrate, coating a liquid crystal material on the conductive substrate, and cutting.

9. The manufacturing method according to claim 8, characterized in that: The conditions for unwinding the conductive substrate include: an unwinding tension of 20 N / m to 30 N / m, and an unwinding tension taper of 15 mm to 25 mm.

10. A PDLC film roll, characterized in that: It is manufactured by the manufacturing method according to any one of claims 1 to 9, and comprises a tube core (2), a foam (1) and a PDLC film, wherein the tube core (2) is located inside, the tube core (2) supports the PDLC film, the foam (1) is fixed to the outer surface of the tube core (2), the first side of the foam (1) is parallel to the axial direction of the tube core (2), the second side of the foam (1) is along the circumferential direction of the tube core (2), the PDLC film is wound along the circumference of the tube core (2), the first end (3) of the PDLC film extends under the foam (1), and the end of the foam (1) and the end of the first end (3) of the PDLC film are staggered; in the axial direction of the tube core (2), the two ends of the foam (1) correspond to the two ends of the PDLC film or the two ends of the foam (1) are outside the two ends of the PDLC film; The outer diameter of the tube core (2) is D, and the length of the second side is πD / 8 to πD; The length of the first end (3) of the PDLC film extending below the foam (1) accounts for 1 / 6 to 5 / 6 of the length of the second side, and the length of the first end (3) of the PDLC film is along the circumferential direction of the tube core (2); The first end (3) of the PDLC film extends into the bottom of the foam (1), thereby generating a first gap (4) in front of the first end (3), and a second gap (5) and a third gap (6) located at both ends of the foam (1); The distance between the first gap (4) and the second gap (5) and the distance between the first gap (4) and the third gap (6) are not less than 1 / 6 of the length of the second side.

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