Laser welding method for plastic and plastic product

Abstract

The present application discloses a laser welding method for plastics and a plastic product, the laser welding method for plastics comprising: respectively determining welding areas on a first welding surface of a first plastic to be welded and a second welding surface of a second plastic to be welded, the welding areas being composed of a first coating area and a second coating area; coating the first coating area on the first welding surface and the second coating area on the second welding surface with a material that can absorb laser radiation; overlapping the welding areas of the first welding surface and the second welding surface to perform lap welding. The present application solves the technical problem of poor welding strength in the prior art.

Description

Technical Field

[0001] The present application relates to the technical field of plastic welding, and in particular to a plastic laser welding method and a plastic product. Background Art

[0002] Laser welding technology, as the name suggests, is a technology that uses lasers to generate high-temperature dissolution to weld two products. In recent years, due to the reduction in the cost of laser processing systems and the advancement of technology, laser welding of plastics technology has been increasingly used. At present, the common method of laser welding plastics is upper and lower overlap welding. The upper layer of plastic is a laser-transmitting material, and the lower layer of plastic is a laser-absorbing material, or both plastics to be welded are laser-transmitting materials, and at least one of the plastic materials is coated with a substance that can absorb laser radiation at the contact welding surface. The laser passes through the upper layer of light-transmitting plastic and is absorbed by the lower layer of plastic or by the plastic with a coating layer closer to the light source. At the same time, pressure is applied, and the plastic welding surface absorbs light and melts through the light-absorbing layer or the plastic welding surface with a coating closer to the light source, and then bonds to the other welding surface to achieve welding. However, the welding strength of this method is poor. Summary of the invention

[0003] The main purpose of the present application is to provide a laser welding method for plastics and plastic products, aiming to solve the technical problem of poor welding strength in the prior art.

[0004] To achieve the above object, the present application provides a plastic laser welding method, which comprises the following steps:

[0005] Determine welding areas on a first welding surface of a first plastic to be welded and a second welding surface of a second plastic to be welded, respectively, wherein the welding areas consist of a first coating area and a second coating area;

[0006] Coating a laser radiation absorbing material on a first coating region on the first welding surface and a second coating region on the second welding surface;

[0007] The welding areas of the first welding surface and the second welding surface are overlapped to perform lap welding.

[0008] Optionally, the first coating region includes at least one first coating portion, the second coating region includes at least one second coating portion, and the first coating portion and the second coating portion are arranged in a staggered manner.

[0009] Optionally, each of the first coating portions and each of the second coating portions is a rectangle with a length of 1 mm and a width of 2 mm.

[0010] Optionally, each welding area is a rectangular area formed by the first coating portions and the second coating portions of the same size and shape being alternately arranged on the same straight line.

[0011] Optionally, the step of overlapping the welding areas of the first welding surface and the second welding surface to perform lap welding comprises:

[0012] Overlapping the welding areas of the first welding surface and the second welding surface, and irradiating the welding areas with a laser beam;

[0013] Pressure is applied to the side of the plastic to be welded away from the welding surface to make the first welding surface join with the welding area of ​​the second welding surface.

[0014] Optionally, the step of irradiating the welding area with a laser beam comprises:

[0015] The laser is made to irradiate the welding area vertically to ensure that the focus is at the welding surface.

[0016] Optionally, at least one of the first plastic to be welded and the second plastic to be welded is a laser-transmitting material.

[0017] Optionally, the laser used for the lap welding includes an infrared laser or a semiconductor laser.

[0018] Optionally, the lap welding method includes circumferential welding, synchronous welding or quasi-synchronous welding.

[0019] The present application also provides a plastic product, which is manufactured by the above-mentioned plastic laser welding method.

[0020] The present application provides a laser welding method for plastics and a plastic product, wherein welding areas are respectively determined on a first welding surface of a first plastic to be welded and a second welding surface of a second plastic to be welded, wherein the welding areas are composed of a first coating area and a second coating area, and a laser radiation absorbing material is coated on the first coating area on the first welding surface and the second coating area on the second welding surface, thereby coating the laser radiation absorbing material in the welding areas of the two plastics to be welded, and then overlapping the welding areas of the first welding surface and the second welding surface to perform lap welding, thereby achieving melting of different parts in the welding areas of the two plastics to be welded, and then due to the softening, volume expansion and increased fluidity of the plastics after being melted by heat, fusion of different molten parts of the two plastics to be welded is achieved, thereby making the two plastics to be welded firmly combined together not only by bonding but also by fusion, thereby greatly improving the welding strength and overcoming the technical problem of poor welding strength in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0022] In order to more clearly illustrate the embodiments of the present application 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 This is a schematic diagram of a process of an embodiment of a laser welding method for plastics of the present application;

[0024] Figure 2 This is a schematic diagram of the structure of a plastic to be welded in an embodiment of the present application;

[0025] Figure 3 This is a schematic diagram of the structure of another plastic to be welded in one embodiment of the present application;

[0026] Figure 4 This is a schematic diagram of the structure of overlapping welding areas in one embodiment of the present application;

[0027] Figure 5 This is a schematic diagram of a lap welding scenario in one embodiment of the present application.

[0028] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0030] The present application embodiment provides a plastic laser welding method. In one embodiment of the plastic laser welding method of the present application, refer to Figure 1 , the plastic laser welding method comprises:

[0031] Step S10, respectively determining welding areas on the first welding surface of the first plastic to be welded and the second welding surface of the second plastic to be welded, wherein the welding areas are composed of the first coating area and the second coating area;

[0032] In the present embodiment, it should be noted that the plastic to be welded is an object made of plastic material, including plastic film, plastic plate and / or plastic parts, etc., the welding surface is any surface on the plastic to be welded, which can be a plane or a curved surface, etc., the welding area is the area where the first plastic to be welded and the second plastic to be welded are welded, the welding area can be the entire overlapping part when the first plastic to be welded and the second plastic to be welded are overlapped, or it can be a part of the overlapping part when the first plastic to be welded and the second plastic to be welded are overlapped, and it can be set according to actual needs, and this embodiment does not limit this.

[0033] Specifically, according to the preset shape and size of the welding area, the range division of the first coating area and the second coating area, and the actual welding requirements, the welding area is determined by a preset first position on the first welding surface of the first plastic to be welded and a preset second position on the second welding surface of the second plastic to be welded, respectively, wherein the welding area is composed of the first coating area and the second coating area, the coating area can be of regular shape or irregular shape, the coating area can be a whole interconnected area, or it can include two or more parts that are not connected to each other, the distribution of the coating area in the welding area on the first welding surface is axially symmetrical with the distribution of the coating area in the welding area on the second welding surface, and the axis of symmetry is the flipping axis of one of the plastics to be welded during lap welding, so that when the welding surface of one of the plastics to be welded is overlapped face to face with the welding surface of the other plastic to be welded, the welding areas on the two plastics to be welded can completely overlap.

[0034] Optionally, the first coating region includes at least one first coating portion, the second coating region includes at least one second coating portion, and the first coating portion and the second coating portion are arranged in a staggered manner.

[0035] In this embodiment, specifically, when the first coating area and the second coating area each include only one coating portion, the welding area is obtained by splicing the first coating area and the second coating area, and when at least one of the first coating area or the second coating area includes two or more coating portions, the first coating portion and the second coating portion are arranged in a staggered manner, wherein the shape and / or size of each coating portion can be set according to actual needs, and can be circular, rectangular, polygonal or irregular in shape, etc., and the shape and / or size of each coating portion can be the same or different, and the staggered arrangement means that each first coating portion is separated from another first coating portion by a second coating portion, and / or each second coating portion is separated from another second coating portion by a first coating portion.

[0036] In one practicable manner, if Figure 2 As shown, Figure 2 For a plastic to be welded, Figure 2 In the figure, the first coating area is composed of five black rectangular areas, each of which is a first coating part, that is, the first coating area is composed of five first coating parts, the second coating area is a gray rectangular area, each of which is a second coating part, that is, the second coating area is composed of five second coating parts, and the five black rectangular areas and the four gray rectangular areas together constitute the welding area, and the black rectangular areas and the gray rectangular areas are alternately arranged, that is, the first coating part and the second coating part are alternately arranged.

[0037] In this embodiment, the staggered arrangement of the coating parts makes the areas coated with the laser radiation absorbing material on the two pieces of plastic to be welded staggered, so that the melting areas on the two pieces of plastic to be welded are also staggered during welding, thereby increasing the parts of the two pieces of plastic to be welded that are fused and connected to each other, making the connection between the two pieces of plastic to be welded more firm, and greatly improving the welding strength. For welding areas of the same size, the number of coating parts is appropriately increased, the density of the staggered distribution is increased, the connection between the two pieces of plastic to be welded is more firm, and the welding strength is greater.

[0038] Optionally, each of the first coating parts and each of the second coating parts are rectangles with a length of 1 mm and a width of 2 mm, which not only ensures a larger staggered distribution density of the coating parts, but the rectangular shapes of the same size can also reduce the processing difficulty, and can effectively reduce costs while ensuring a certain welding strength.

[0039] Optionally, each of the welding areas is a rectangular area formed by the first coating parts and the second coating parts of the same size and shape being staggered on the same straight line. The welding area shown is a regular shape and a rectangle, which is conducive to simplifying the subsequent laser irradiation process design and the uniformity of the laser irradiation process.

[0040] Optionally, at least one of the first plastic to be welded and the second plastic to be welded is a laser-transmitting material. Specifically, one or both of the two plastics to be welded are laser-transmitting materials, so as to ensure that when laser irradiation occurs, the plastic to be welded that is first irradiated by the laser is a laser-transmitting material, thereby ensuring that the laser can pass through one layer of the plastic to be welded and irradiate the laser radiation-absorbing material on the other layer of the plastic to be welded.

[0041] Step S20, coating a laser radiation absorbing material on a first coating region on the first welding surface and a second coating region on the second welding surface;

[0042] In this embodiment, specifically, a material that can absorb laser radiation is coated on the first coating area on the first welding surface and the second coating area on the second welding surface, so that when the laser is irradiated, the first coating area on the first welding surface and the second coating area on the second welding surface absorb the laser radiation and then melt.

[0043] Step S30, overlapping the welding areas of the first welding surface and the second welding surface to perform lap welding.

[0044] In this embodiment, specifically, the first welding surface of the first plastic to be welded and the second welding surface of the second plastic to be welded are overlapped so that the welding areas on the two overlap, and laser welding is performed, wherein the overlapping method can be placing them together, fixing them by a clamp, or applying pressure on the side of the plastic to be welded away from the welding surface to make the first welding surface and the second welding surface fit together, etc. At this time, the first coating area on the first welding surface coated with a laser radiation absorbing material and the second coating area on the second welding surface coated with a laser radiation absorbing material are just spliced ​​into a complete welding area, and then the welding area is irradiated with a laser, and the first coating area on the first welding surface and the second coating area on the second welding surface absorb the laser radiation and then melt, and the lap welding is achieved by the bonding of the melted part with the unmelted plastic part on the other side, and the mutual fusion of the melted parts after thermal expansion, and the specific welding parameters can be set according to the material, shape, size and welding requirements of the actual plastic to be welded.

[0045] Optionally, the step of overlapping the welding areas of the first welding surface and the second welding surface to perform lap welding comprises:

[0046] Step A10, overlapping the welding areas of the first welding surface and the second welding surface, and irradiating the welding areas with a laser beam;

[0047] Step A20, applying pressure on the side of the plastic to be welded away from the welding surface to make the welding area of ​​the first welding surface join with the welding area of ​​the second welding surface.

[0048] In this embodiment, specifically, Figure 5 As shown, the first welding surface of the first plastic to be welded and the second welding surface of the second plastic to be welded are overlapped so that the welding areas on the two overlap, the laser beam irradiates the welding area, and pressure is applied to the side of the plastic to be welded away from the welding surface to make the first welding surface and the second welding surface fit together. During the welding process, the plastic in the coating area absorbs light and melts. After the pressure is applied, the melted parts of the first plastic to be welded and the second plastic to be welded are squeezed outward, so that they are firmly combined together, which greatly improves the welding strength.

[0049] Optionally, the step of irradiating the welding area with a laser beam comprises:

[0050] The laser is made to irradiate the welding area vertically to ensure that the focus is at the welding surface, thereby ensuring the accuracy of the laser irradiation melting position.

[0051] Optionally, the laser used in the lap welding includes an infrared laser or a semiconductor laser.

[0052] Optionally, the lap welding method includes circumferential welding, synchronous welding or quasi-synchronous welding.

[0053] In one practicable manner, if Figure 2 and Figure 3 As shown, Figure 2 FIG. 1 is a schematic diagram of a structure of an embodiment of a plastic to be welded in this application. Figure 2 In the figure, the black rectangular area is the first coating part, and the gray rectangular area is the second coating part. Figure 3 This is a schematic diagram of the structure of another embodiment of a plastic to be welded in this application. Figure 3 In the figure, the black rectangular area is the second coating part, the gray rectangular area is the first coating part, and the area coated with the material that can absorb laser radiation is Figure 2 and Figure 3 The black rectangular area in Figure 2 and Figure 3 The black areas in the figure are the areas that need to be coated with materials that can absorb laser radiation. Figure 2 The first welding surface and Figure 3 After the welding area of ​​the second welding surface in overlaps, as Figure 4 As shown, each first coating portion and each second coating portion are arranged in a straight line to form a rectangular welding area, and the areas coated with the laser radiation absorbing material are spliced ​​to form a complete welding area.

[0054] In this embodiment, welding areas are respectively determined on the first welding surface of the first plastic to be welded and the second welding surface of the second plastic to be welded, the welding area is composed of a first coating area and a second coating area, and the first coating area on the first welding surface and the second coating area on the second welding surface are coated with a laser radiation absorbent material, thereby achieving a distributed coating of the laser radiation absorbent material in the welding areas of the two plastics to be welded, and then overlapping the welding areas of the first welding surface and the second welding surface to perform lap welding, thereby achieving melting of different parts in the welding areas of the two plastics to be welded, and then due to the softening, volume expansion and increased fluidity of the plastic after melting, fusion of different molten parts of the two plastics to be welded is achieved, thereby making the two plastics to be welded not only firmly bonded together by bonding, but also firmly bonded together by fusion, thereby greatly improving the welding strength and overcoming the technical problem of poor welding strength in the prior art.

[0055] Furthermore, the present invention also provides a plastic product, which is manufactured by the above-mentioned plastic laser welding method, solving the technical problem of poor welding strength in the prior art. Compared with the prior art, the beneficial effects of the plastic product provided by the embodiment of the present invention are the same as the beneficial effects of the plastic laser welding method in the above-mentioned embodiment, which will not be described in detail here.

[0056] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent processing scope of the present application.

Claims

1. A laser welding method for plastics, characterized in that: The laser welding method of the plastic comprises the following steps: Determine welding areas on a first welding surface of a first plastic to be welded and a second welding surface of a second plastic to be welded, respectively, wherein the welding areas consist of a first coating area and a second coating area; Coating a laser radiation absorbing material on a first coating region on the first welding surface and a second coating region on the second welding surface; Overlapping the welding areas of the first welding surface and the second welding surface to perform lap welding; The first coating area includes at least two first coating parts, the second coating area includes at least two second coating parts, the first coating parts and the second coating parts are arranged alternately, and each of the first coating parts and each of the second coating parts is a rectangle with a length of 1 mm and a width of 2 mm; Each of the welding areas is a rectangular area formed by the first coating parts and the second coating parts of the same size and shape being alternately arranged on the same straight line; The step of overlapping the welding areas of the first welding surface and the second welding surface to perform lap welding comprises: Overlapping the welding areas of the first welding surface and the second welding surface, so that the laser irradiates the welding area vertically to ensure that the focus is on the welding surface; Pressure is applied to the side of the plastic to be welded away from the welding surface to make the first welding surface join with the welding area of ​​the second welding surface.

2. The laser welding method for plastics according to claim 1, characterized in that: At least one of the first plastic to be welded and the second plastic to be welded is a laser-transmitting material.

3. The laser welding method for plastics according to claim 1, characterized in that: The laser used in the lap welding includes an infrared laser or a semiconductor laser.

4. The laser welding method for plastics according to claim 1, characterized in that: The welding method of the lap welding includes circumferential welding, synchronous welding or quasi-synchronous welding.

5. A plastic product, characterized in that: The plastic product is manufactured by the laser welding method for plastics as claimed in any one of claims 1 to 4.

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