A method of manufacturing a multilayer adhesive tape

Abstract

The present application relates to a kind of preparation methods of multilayer bonded composite strip, using the preparation device of multilayer composite of unidirectional travel, N compression units are sequentially arranged in N single-layer strip feeding units behind in the direction of travel, and (N-1) Gluing units are sequentially arranged in the interval of N compression units, the first to (N-1) layer single-layer strip of continuous travel is successively one-sidedly coated and is compressed with the layer strip downstream in the direction of travel;Then the N layer pre-bonding strip of interlayer gluing prepared is entered into the tunnel baking device downstream in the direction of travel and is baked, so that interlayer glue solidifies, obtains N layer bonded composite strip, and is wound and collected by material receiving unit in the last end in the direction of travel N layer bonded composite strip.This preparation method of the present application can make bonding glue be fully compressed, ensure the thickness consistency of each glue layer, also make the volume ratio of bonding glue in composite strip significantly reduced, thereby the leakage magnetic and eddy current loss of motor core are greatly reduced, and the comprehensive efficiency of motor is improved.

Description

Technical Field

[0001] This invention relates to the field of layered product technology, and in particular to a method for preparing a multilayer bonded composite tape. Background Technology

[0002] With the increasing demands on motor performance in high-end equipment fields such as aerospace, electric vehicles, robotics, high-speed compressors, high-speed flywheel energy storage, turbomolecular pumps, and high-speed machine tools, motors not only need to have high power density or high speed characteristics, but also need to achieve high efficiency. The key to achieving high power density or high speed lies in increasing the operating frequency of the motor. However, as the motor frequency increases, the core loss of the motor core increases sharply, which seriously restricts the further improvement of motor efficiency. In recent years, amorphous nanocrystalline alloys have received widespread attention as a new type of soft magnetic material. Compared with traditional silicon steel, amorphous nanocrystalline alloys have excellent properties such as high permeability, low coercivity, and low iron loss. Amorphous alloys have penetrated from auxiliary motors to main drive motors and have shown broad application prospects in the field of new energy vehicles. Amorphous nanocrystalline alloys have shown significant application advantages and broad prospects in the field of high-speed and high-frequency motors. In the field of motor core manufacturing, the application of amorphous and nanocrystalline alloy strips typically requires bonding multiple strips to form a composite material, followed by processes such as punching, stacking, and shaping to obtain the final motor core. Currently, multi-layer strip bonding is usually done offline. In actual production, double-sided adhesive is often used to bond adjacent strip layers. Double-sided adhesive is easy to use, requires no heating curing equipment, and is suitable for small-batch production and laboratory research. However, existing technologies still have several drawbacks. First, double-sided adhesive accounts for a large volume proportion in the composite material, affecting the lamination factor. As an independent layered adhesive material, double-sided adhesive occupies a significant volume proportion in multi-layer strip composites, leading to a decrease in the lamination factor. The lamination factor is one of the key indicators for evaluating motor core performance; a lower lamination factor means a reduced effective proportion of magnetic material in the core, resulting in increased leakage flux and eddy current losses, ultimately affecting the overall performance of the motor. Second, the high-temperature resistance of double-sided adhesive... The shortcomings of double-sided tape affect the stability of motor operation. The high temperature resistance of double-sided tape is relatively poor. In long-term high-temperature working environment, problems such as tape aging, reduced bonding strength or even failure may occur. When the performance of double-sided tape deteriorates, instability such as misalignment and slippage may occur between the multi-layer tapes, which will damage the mechanical integrity of the motor core and cause the motor performance to decline or even be damaged. This seriously affects the overall operational reliability and service life of the motor. Existing technologies also use adhesive impregnation, but it usually needs to be impregnated and cured after the core is stacked. This has problems such as complex process and introduction of curing shrinkage stress. In addition, existing multi-layer tape composite technology is mostly a step-by-step operation, such as cutting the tape first, then stacking, and finally impregnating and curing or attaching double-sided tape. There is a lack of continuity between the processes, resulting in low production efficiency, more manual intervention, and difficulty in ensuring product quality consistency. Especially for applications that require multi-layer composite, existing technologies often require multiple repeated operations, which is difficult to meet the needs of large-scale, high-efficiency industrial production. Therefore, how to reduce the volume ratio of adhesive material in composite strips, improve high-temperature resistance, and achieve continuous automated production while ensuring the quality of multilayer strip composites is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0003] This invention aims to overcome the shortcomings of the prior art, and to this end, the following technical solution is adopted: This invention provides a method for preparing a multilayer bonded composite tape. Utilizing a unidirectional multilayer composite preparation device, N pressing units are sequentially positioned behind N single-layer tape feeding units along the travel direction. (N-1) adhesive coating units are sequentially positioned between the N pressing units. The first to (N-1) consecutively traveling single-layer tapes are individually coated with adhesive on one side and pressed together with a downstream layer of tape. The resulting N-layer pre-bonded tape with interlayer adhesive is then baked in a tunnel baking device downstream of the travel direction to cure the interlayer adhesive, obtaining an N-layer bonded composite tape. At the very end of the travel direction, a receiving unit winds and collects the N-layer bonded composite tape. N is a natural number from 2 to 15.

[0004] Preferably, the multilayer composite preparation device is equipped with a central controller, and the pressing unit, the coating unit, the tunnel baking device, and the receiving unit are all electrically connected to the central controller.

[0005] Preferably, the pressing unit is one or more pairs of pressing rollers with heating function and pressure sensor, the nth pressing unit is located in front of the nth glue coating unit, and the Nth pressing unit is located behind the Nth single-layer strip feeding unit; where n is a natural number from 1 to (N-1).

[0006] Preferably, along the strip travel direction, the spacing between the pressing rollers in the next pressing unit is greater than the spacing between the pressing rollers in the previous pressing unit, and the difference in spacing between the pressing rollers in two adjacent pressing units gradually decreases.

[0007] Preferably, all the pressing rollers are active rotating rollers connected to the drive device, and each pair of pressing rollers rotates in opposite directions and at the same speed.

[0008] Preferably, each of the pressing units is provided with a corresponding feeding unit, the feeding unit including a feeding roller and the single-layer strip roll disposed on the feeding roller.

[0009] Preferably, the bottom surface of the first single-layer strip is first laminated with a release film by the first pressing unit, and the width of the release film is greater than the width of the strip.

[0010] Preferably, the multilayer composite preparation apparatus further includes a coating unit, comprising a coating roller and a release film roll disposed on the coating roller.

[0011] Preferably, the adhesive application unit is arranged sequentially along the strip travel direction, including an adhesive application device for applying adhesive to the surface of the strip and an adhesive scraping device for smoothing the adhesive on the surface of the strip.

[0012] Preferably, the adhesive applicator is an adhesive cup with a slit on the bottom surface, the length of which is not greater than the width of the single-layer strip. The adhesive cup is connected to an adhesive storage tank via a pipe and a pump, and the pipe is equipped with a flow meter and a valve for controlling the flow rate.

[0013] Preferably, the adhesive scraping device is a flexible scraper or a flexible scraper blade; the adhesive scraping device has an angle with the composite strip below it, and the angle is 5°-60°.

[0014] Preferably, the receiving unit includes: A peeling roller, connected to a drive device, is driven to rotate by the drive device to peel the release film off the multilayer adhesive composite tape and wind and collect it. A take-up roller, connected to a drive unit, is driven to rotate, completing the take-up of the multilayer bonded composite strip. A guide roller is positioned in front of the stripping roller and the receiving roller.

[0015] The parameters such as the rotation speed of the receiving roller, the rotation speed of the peeling roller, the rotation speed of each pressing roller, the heating temperature of each pressing roller, the adhesive flow rate of the coating device, and the heat preservation temperature of the tunnel baking device are all controlled and dynamically adjusted by the central controller.

[0016] Compared with the prior art, the beneficial effects of this invention are reflected in: The multiple pressing units and adhesive coating units in this invention, combined with the design of the pressure roller spacing, enable the adhesive between each new layer of strip and the previous composite strip to be fully and uniformly pressed, effectively controlling the thickness consistency of each adhesive layer. Through multi-stage pressure roller groups to compact layer by layer, the volume ratio of adhesive in the composite strip is also significantly reduced, thereby greatly reducing the leakage flux and eddy current loss of the motor core and improving the overall efficiency of the motor. This invention effectively solves the technical problems of low lamination coefficient, poor high temperature resistance, and discontinuous production in the prior art, and realizes high-quality, high-efficiency, and automated preparation of multilayer composite strips. It is particularly suitable for the large-scale production and application of amorphous and nanocrystalline alloy strips in high-speed and high-frequency motor cores. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the preparation method of the present invention; Figure 2 This is a schematic diagram of the preparation apparatus in this invention; Figure 3 This is a schematic diagram of the pressing unit and the coating unit in this invention; Figure 4 This is a schematic diagram of the structure of the adhesive scraping device near the end of the composite strip in this invention; Figure 5This is a schematic diagram of another adhesive scraping device in this invention, located near the end of the composite strip. The reference numerals in the figures include: 1. Feeding unit; 11. Feeding roller; 12. Single-layer strip roll; 2. Coating unit; 21. Coating roller; 22. Release film roll; 3. Pressing unit; 4. Glue coating unit; 41. Glue coating device; 42. Glue scraper device; 421. Glue scraper device near the end of the composite strip; 5. Tunnel baking device; 6. Receiving unit; 61. Guide roller; 62. Peeling roller; 63. Receiving roller; 7. Strip; 8. Bonded composite strip; 9. Release film. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in detail below.

[0019] Unless otherwise defined, the technical or scientific terms used in the claims and description shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0020] The word "comprising" or similar terms used in the specification and claims of this patent application mean that the objects preceding "comprising" include the objects listed after "comprising" or their equivalents, and do not exclude other objects.

[0021] Example 1

[0022] A method for preparing a multilayer bonded composite tape, such as... Figure 1 As shown, using a unidirectional multilayer composite preparation device, N pressing units 3 are sequentially arranged behind N single-layer strip feeding units 1 along the travel direction, and (N-1) adhesive coating units 4 are sequentially arranged in the intervals between the N pressing units 3. The first to (N-1) layers of single-layer strip 7 that travel continuously are coated with adhesive on one side and pressed together with a layer of strip 7 downstream in the travel direction. Then, the N layers of pre-bonded strip with interlayer adhesive are entered into the tunnel baking device 5 downstream in the travel direction for baking, so that the interlayer adhesive is cured to obtain an N-layer bonded composite strip 8. At the very end of the travel direction, the N-layer bonded composite strip 8 is wound and collected by the receiving unit 6. N is a natural number from 2 to 15.

[0023] Specifically, such as Figure 2As shown, the preparation apparatus for the multilayer bonded composite tape 8 in this embodiment includes: a plurality of unloading units 1, a coating unit 2, a plurality of pressing units 3, a plurality of adhesive coating units 4, a baking unit, and a take-up unit 6 arranged sequentially along the traveling direction of the tape 7. It realizes fully automated continuous production from unwinding the tape 7, coating the release film 9, applying adhesive, scraping adhesive, multilayer pressing to baking, curing, and take-up. Compared with the step-by-step and offline multilayer tape composite process in the prior art, it greatly reduces manual intervention and improves production efficiency and product quality consistency. The multilayer composite preparation device is equipped with a central controller. The pressing unit 3, adhesive coating unit 4, tunnel baking device 5, and material collection unit 6 are all electrically connected to the central controller. The central controller centrally sets and controls the parameters of the material collection unit 1, pressing unit 3, adhesive coating unit 4, tunnel baking device 5, and material collection unit 6, thereby achieving integrated preparation of the multilayer bonded composite tape. In some preferred embodiments, the strip 7 is an amorphous nanocrystalline alloy strip; The feeding unit 1 is located in front of the pressing unit 3, and each pressing unit 3 is provided with a corresponding feeding unit 1. The feeding unit 1 includes a feeding roller 11 and a single-layer strip roll 12 disposed on the feeding roller 11.

[0024] The coating unit 2 is located on the same side as the first feeding unit 1, and includes a coating roller 21 and a release film roll 22 disposed on the coating roller 21. The bottom surface of the first single-layer strip 7 is first coated with a release film 9 by the first pressing unit 3. The width of the release film 9 is greater than the width of the strip 7. This arrangement ensures that the adhesive applied in subsequent pressing units 3 is always located on the side of the composite strip away from the release film 9. Thus, during the multi-layer pressing process, the release film 9 can effectively receive and absorb excess adhesive overflowing from the edge of the composite strip, preventing the overflow adhesive from contaminating the surface of the strip or adhering to the pressure roller, ensuring the surface cleanliness of the composite strip and the accuracy of subsequent punching processes. like Figure 2 and Figure 3 As shown, the pressing unit 3 and the adhesive coating unit 4 are arranged alternately along the traveling direction of the strip.

[0025] The pressing unit 3 consists of one or more pairs of pressing rollers equipped with heating function and pressure sensor. The nth pressing unit 3 is located in front of the nth adhesive application unit 4, and the Nth pressing unit 3 is located behind the Nth single-layer strip feeding unit 1; n is a natural number from 1 to (N-1). All pressing rollers are active rotating rollers connected to the drive device. The rotation directions of each pair of pressing rollers are opposite, and their rotation speeds are the same. The heating function is achieved by embedding heating components inside the pressing rollers or by setting heating components on the circumference of the pressing rollers away from the composite strip, thereby enhancing the fluidity of the adhesive and helping to obtain a flat, uniform, and thin adhesive layer during the subsequent scraping and leveling process. The pressure sensor can monitor the pressure applied by the pressing rollers to the surface of the strip in real time, effectively ensuring the consistency of the pressing effect and the integrity of the strip.

[0026] The adhesive application unit 4 includes an adhesive application device 41 for applying adhesive to the surface of the composite strip away from the release membrane 9 and an adhesive scraping device 42 for leveling the adhesive on the composite strip, enabling layer-by-layer adhesive application and leveling of multi-layer strips; the adhesive application device is an adhesive cup with a slit on the bottom surface, the length of which is not greater than the width of the single layer strip, and the adhesive cup is connected to an adhesive storage tank through a pipe and a pump, and the pipe is equipped with a flow meter and a valve for controlling the flow rate.

[0027] Specifically, along the strip's travel direction, the spacing between the pressing rollers in the subsequent pressing unit 3 is greater than the spacing between the pressing rollers in the preceding pressing unit 3, and the difference in spacing between the pressing rollers in adjacent pressing units 3 gradually decreases. This progressive roller spacing design allows for gradual adjustment of the pressing gap according to the increase in the number of composite strip layers, ensuring that the adhesive between each newly added strip 7 and the previous composite strip is fully and uniformly pressed, effectively controlling the consistency of the thickness of each adhesive layer. Compared with the traditional method of using double-sided adhesive, using an adhesive cup with a long, narrow slit to apply adhesive to the strip surface... Liquid adhesive is applied and leveled using a scraping device 42, and then compacted layer by layer by a multi-stage pressure roller group. This significantly reduces the volume ratio of adhesive in the composite strip, thereby greatly reducing the leakage flux and eddy current loss of the motor core and improving the overall efficiency of the motor. At the same time, the adhesive forms a stable adhesive layer after being cured by the baking unit. Compared with the problem of double-sided adhesive aging and failure at high temperatures, the multi-layer composite strip can still maintain excellent interlayer bonding strength and dimensional stability under high temperature conditions. This effectively avoids failures such as strip misalignment and slippage caused by adhesive layer failure, and significantly improves the operational reliability and service life of the motor core. In some preferred embodiments, the scraping device 42 is a flexible scraper; in other preferred embodiments, the scraping device 42 is a flexible scraper; in some preferred embodiments, the scraping device 42 has an angle with the composite strip, and the scraping device 42 faces the adhesive application device 41 from the end 421 of the composite strip. This allows the scraping device 42 to evenly spread the applied adhesive and scrape off the excess, forming an adhesive layer of uniform thickness and a smooth surface. Those skilled in the art will understand that if the end 421 of the scraping device 42 near the composite strip is an edge, the angle between the bisector of the dihedral angle formed by the two adjacent faces of the edge and the composite strip is the angle between the scraping device 42 and the composite strip; if the end 421 of the scraping device 42 near the composite strip is a surface, the supplementary angle between the surface and the composite strip is the angle between the scraping device 42 and the composite strip; the angle of the angle is preferably 5°-60°. In one embodiment, another strip 7 is located on the surface of the preceding composite strip coated with the adhesive, and the width of the release liner 9 is greater than the width of the strip 7; in some preferred embodiments, the width of the adhesive scraping device 42 near the end 421 of the composite strip is between the width of the strip 7 and the width of the release liner 9, and the adhesive scraping device 42 near the end 421 of the composite strip, at least extending beyond the outer edge of the strip 7, is recessed at a certain arc towards the traveling direction of the strip 7, such as... Figure 4 or Figure 5 As shown, this helps to guide excess adhesive that accumulates inside or at the edge of the strip during the coating process to the release membrane 9, preventing the adhesive from forming lumps on the bonding surface of the strip, thereby ensuring the neatness of the composite strip surface and the precision of subsequent punching processes. The baking unit is used to cure and form the multilayer bonded composite tape 8; In some preferred embodiments, the baking unit is a tunnel baking device 5, which can cure or pre-cure the continuously passing composite strip online, ensuring the complete curing of the adhesive layer and avoiding process interruption and energy waste caused by setting up a separate curing oven. In some preferred embodiments, the receiving unit 6 includes: A peeling roller 62 is connected to a drive device and is driven to rotate by the drive device to peel the release film 9 off the multilayer adhesive composite strip 8 and wind and collect it. A take-up roller 63 is connected to a drive device and is driven to rotate to complete the take-up of the multilayer bonded composite strip 8; The guide roller 61 is located in front of the peeling roller and the receiving roller, and plays a guiding role in the baking and curing of the multi-layer bonded composite strip 8, so that it can be smoothly connected with the receiving unit 6.

[0028] Example 2

[0029] This embodiment provides a method for preparing a multilayer bonded composite tape 8, using the preparation apparatus described in Example 1, and the steps include: S1. The feeding roller 11 of the first feeding unit 1 feeds out the strip 7, the coating roller 21 of the coating unit 2 feeds out the release film 9, and the first pressing unit 3 presses the strip 7 and the release film 9 together to form the first composite strip. S2, The adhesive application device 41 applies the adhesive to the surface of the first composite strip away from the release membrane 9; In some preferred embodiments, the adhesive is applied to the surface of the composite strip in an array. After being leveled by the adhesive scraper 42, the adhesive forms a continuous and uniform thin layer on the surface of the strip 7, which ensures sufficient bonding area and avoids overflow and uneven thickness caused by excessive adhesive. S3. The adhesive scraping device 42 smooths the adhesive on the first composite strip. S4. The next feeding unit 1 feeds out another strip 7, and the next pressing unit 3 attaches the other strip 7 to the surface of the first composite strip coated with the adhesive, and presses the two together to form a second composite strip. S5. Repeat S2 to S4 several times; S6. The baking unit bakes and cures the multilayer bonded composite strip 8 formed. S7. The receiving unit 6 peels off the release film 9 and winds up the baked and cured multilayer bonded composite tape 8.

[0030] In summary, this invention effectively solves the technical problems of low lamination coefficient, poor high temperature resistance, and discontinuous production in the prior art, and realizes high-quality, high-efficiency, and automated preparation of multilayer composite strips. It is particularly suitable for the large-scale production and application of amorphous and nanocrystalline alloy strips in high-speed and high-frequency motor cores.

[0031] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a multilayer bonded composite tape, characterized in that, Using a unidirectional multilayer composite preparation device, N pressing units are sequentially arranged behind N single-layer strip feeding units along the travel direction, and (N-1) adhesive coating units are sequentially arranged in the intervals between the N pressing units. The first to (N-1) layers of single-layer strips traveling continuously are coated with adhesive on one side and pressed together with a layer of strip downstream in the travel direction. Then, the N-layer pre-bonded strip with interlayer adhesive is placed into a tunnel baking device downstream in the travel direction for baking, so that the interlayer adhesive is cured to obtain an N-layer bonded composite strip. At the very end of the travel direction, the N-layer bonded composite strip is wound and collected by a receiving unit. N is a natural number from 2 to 15.

2. The method for preparing the multilayer bonded composite tape according to claim 1, characterized in that, The multilayer composite preparation device is equipped with a central controller, and the pressing unit, coating unit, tunnel baking device, and material collection unit are all electrically connected to the central controller.

3. The method for preparing the multilayer bonded composite tape according to claim 1, characterized in that, The pressing unit is one or more pairs of pressing rollers with heating function and pressure sensor. The nth pressing unit is located in front of the nth glue coating unit, and the Nth pressing unit is located behind the Nth single-layer strip feeding unit; where n is a natural number from 1 to (N-1).

4. The method for preparing the multilayer bonded composite tape according to claim 3, characterized in that, Along the strip travel direction, the spacing between the pressing rollers in the next pressing unit is greater than the spacing between the pressing rollers in the previous pressing unit, and the difference in spacing between the pressing rollers in two adjacent pressing units gradually decreases.

5. The method for preparing the multilayer bonded composite tape according to claim 3, characterized in that, All the pressing rollers are active rotating rollers connected to the drive device, and each pair of pressing rollers rotates in opposite directions and at the same speed.

6. The method for preparing the multilayer bonded composite tape according to claim 1, characterized in that, Each of the pressing units is provided with a corresponding feeding unit, the feeding unit including a feeding roller and the single-layer strip roll disposed on the feeding roller.

7. The method for preparing the multilayer bonded composite tape according to claim 1, characterized in that, The bottom surface of the first single-layer strip is first laminated with a release membrane by the first pressing unit, and the width of the release membrane is greater than the width of the strip.

8. The method for preparing the multilayer bonded composite tape according to claim 1, characterized in that, The multilayer composite preparation apparatus further includes a coating unit, comprising a coating roller and a release film roll disposed on the coating roller.

9. The method for preparing the multilayer bonded composite tape according to claim 1, characterized in that, The adhesive application unit is arranged sequentially along the strip's travel direction, and includes an adhesive application device for applying adhesive to the surface of the strip and an adhesive scraping device for smoothing the adhesive on the surface of the strip.

10. The method for preparing the multilayer bonded composite tape according to claim 9, characterized in that, The adhesive applicator is an adhesive cup with a slit on the bottom surface. The length of the slit is no greater than the width of the single-layer strip. The adhesive cup is connected to an adhesive storage tank via a pipe and a pump. The pipe is equipped with a flow meter and a valve to control the flow rate.

11. The method for preparing the multilayer bonded composite tape according to claim 9, characterized in that, The adhesive scraping device is a flexible scraper or a flexible scraper plate; the adhesive scraping device has an angle with the composite strip below it, and the angle is 5°-60°.

12. The method for preparing the multilayer bonded composite tape according to claim 1, characterized in that, The receiving unit includes: A peeling roller, connected to a drive device, is driven to rotate by the drive device to peel the release film off the multilayer adhesive composite tape and wind and collect it. A take-up roller is connected to a drive device and is driven to rotate to complete the take-up of the multilayer bonded composite strip. A guide roller is positioned in front of the stripping roller and the receiving roller.

13. The method for preparing the multilayer bonded composite tape according to any one of claims 1 to 12, characterized in that, The parameters such as the rotation speed of the receiving roller, the rotation speed of the peeling roller, the rotation speed of each pressing roller, the heating temperature of each pressing roller, the adhesive flow rate of the coating device, and the heat preservation temperature of the tunnel baking device are all controlled and dynamically adjusted by the central controller.

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