JPS6274629A - Joining of synthetic resin material - Google Patents

Abstract

PURPOSE:To strongly join both synthetic resin materials with each other by a method wherein one of the synthetic materials to be joined with each other is provided with a metal mesh in an exposed state and is placed upon the other synthetic resin material so as to be irradiate with laser beams from the one synthetic resin material side in order to heat and melt the joint surface of the other synthetic resin material for strongly joining both of the synthetic resin materials by pushing a metal mesh into the molten portion of the lower synthetic resin material. CONSTITUTION:Firstly, a plate member 2 made of styrene-acrylonitrile copolymer is arranged upon a plate member 1 made of polypropylene resin. In addition, a metal mesh 3, which is made of stainless steel and formed in lattice shape, is provided on the joint surface 2b of the plate member 2 simultaneously with the compression molding of the plate member 2. Secondly, the irradiation nozzle 4 of a neodymium laser is positioned above the plate member 2 in order to irradiate YAG laser beams 5 from the irradiation nozzle 4. The plate member 1 is fully heated and melted by the irradiation of YAG laser beams 5 and applied with load so as to gradually insert the metal mesh 3 provided on the joint surface 2b of the plate member 2 into the molten portion of the plate member 1. Thus, the plate members 1 and 2 are strongly joined with each other.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a metal mesh on one side of the synthetic resin materials to be joined, overlaps the other synthetic resin material, and irradiates the two with laser light from one side. The present invention relates to a method for joining synthetic resin materials.

[Conventional technology]

Conventionally, when joining synthetic resin materials, a physical joining method in which heat is applied to weld them, and a chemical joining method in which they are joined together using an adhesive have been widely used.

In other words, the former physical joining method involves heating a heating element such as a metal mesh on the joint surfaces of the synthetic resin materials to be joined, melting the joining surfaces of both synthetic resin materials, and pressurizing and cooling them. This is a method of joining resin materials. In addition, the latter chemical bonding method involves interposing an adhesive such as hot melt on the bonding surfaces of the synthetic resin materials to be bonded.
In this method, high frequency or ultrasonic waves are applied to the surface of one synthetic resin material to heat and melt the adhesive, and then both synthetic resin materials are cooled while being pressurized to join both synthetic resin materials.

However, in the former physical joining method, when joining synthetic resin materials of the same type, both synthetic resin materials to be joined have the same melting temperature and are compatible, so re-synthetic resin materials However, when joining different types of synthetic resin materials, the melting temperatures of the two synthetic resin materials are different and their compatibility is poor.
It is difficult to join resynthetic resin materials. In addition, in the latter chemical joining method, when joining synthetic resin materials of the same type, the material is passed through in the same manner as the former physical joining method, but when joining different kinds of synthetic resin materials, the synthetic resin material The adhesive strength of the adhesive decreases depending on the material, making it difficult to firmly bond resynthetic resin materials. Furthermore, even if the synthetic resin materials are of the same type, it is difficult to firmly bond synthetic resin materials with poor compatibility, such as polypropylene resin, in the same way as with different types of synthetic resin materials.

For the reasons described above, mechanical joining methods are often used when joining synthetic resin materials of poor compatibility, such as polypropylene, even if they are of the same or different types. A typical example will be explained using a method of joining polypropylene and polyethylene shown in FIG.

In FIG. 2, 51 is a plate member made of polypropylene resin, and a plate member 52 made of polyethylene resin is disposed at the bottom of this plate member 51, and this plate member 52 of polyethylene resin and polypropylene resin are disposed. Through-holes 53a and 53b are formed in opposing parts of the plate member 51.
is formed. Then, screws 55 are screwed into the through holes 53a and 53b of the drawing board members 51 and 52 from above with a gasket 54 interposed therebetween, thereby joining both the board members 51 and 52.

[Problem that the invention seeks to solve]

However, in such mechanical joining methods,
Through holes 53a and 53b are formed in both plate members 51 and 52,
The screws 55 must be screwed together, which makes the joining work more complicated than the above-mentioned physical joining method and chemical joining method.
, 53b, both plate members 51
．． There is a problem that the strength of 52 is reduced.

Therefore, the present invention has been made to solve the above-mentioned problems.The metal mesh is provided so that a part of it is exposed on one side of the synthetic resin material to be joined, and is overlapped with the other synthetic resin material. By irradiating laser light to heat and melt the joint surface of the other synthetic resin material and pushing the metal mesh into the melted area, it is possible to easily and firmly join the resynthetic resin material without reducing its strength. There is a particular thing.

[Means for solving problems]

That is, in the method for joining synthetic resin materials according to the present invention, when the synthetic resin materials are overlapped and the two synthetic resin materials are joined by irradiating a laser beam from one side, one of the synthetic resin materials to be overlapped is , the lower part is made absorbent to laser light, the upper part is made non-absorbent to laser light, and a metal mesh is provided so that a part of the joint surface is exposed, and these two synthetic resin materials are overlapped, A laser beam is irradiated from the direction of the upper synthetic resin material to heat and melt the bonding surface of the lower synthetic resin material, and a metal mesh exposed on the bonding surface of the upper synthetic resin + material is placed in the melted area. It was designed to be pushed in.

Examples of the synthetic resin material that is non-absorbent to the laser beam disposed in the upper part include polyethylene resin, polypropylene resin, styrene-acrylonitrile copolymer, etc. Examples of synthetic resin materials that have absorption properties include polyethylene resins to which 0.1 to 0.3% by weight of auxiliary materials such as carbon black are added, polypropylene resins, styrene-acrylonitrile copolymers, and glass fibers. Examples include polyethylene resins, polypropylene resins, and styrene-acrylonitrile copolymers reinforced with short fibers such as carbon fibers and metal fibers, and to which 0.1 to 0.3% by weight of auxiliary materials such as carbon are added. .

Further, the metal mesh provided on the joining surface of the upper synthetic resin material is preferably formed of a metal material having a higher melting point than the synthetic resin material to be joined, so as to have spaces in a mesh or lattice shape. , for example, iron, copper, stainless steel, brass, etc. When a metal mesh made of these metal materials is provided on a synthetic resin material, it is necessary to provide it so that a portion thereof is exposed from the joint surface of the synthetic resin material in order to improve the joint strength. In addition, methods for providing the metal menoche include a method of providing the synthetic resin material at the same time as compression molding, injection molding, etc., a method of providing it by mechanically embedding it after molding the synthetic resin material, a method of providing it by mechanically embedding it after molding the synthetic resin material, Examples include a method of attaching with an adhesive or the like so that a portion thereof is exposed.

When the above-mentioned two synthetic resin materials are joined, the synthetic resin material placed at the bottom becomes absorbent to the laser beam, and the synthetic resin material placed at the top is non-absorbent to the laser beam. They can be freely selected and joined in any desired combination.

In addition, the laser beams irradiated when bonding both synthetic resin materials include argon laser beam, glass: neodymium 3+ laser beam, YAG: neodymium 3+ laser beam, ruby laser beam, helium-neon laser beam, krypton laser beam, H2 Laser light, N, laser light, etc. can be mentioned, and among these, YAG: neodymium 3+ laser light and glass: neodymium 3+ laser light are the most excellent.

In addition, the wavelength of the laser beam must be such that it can pass through the synthetic resin material placed on the top and heat and melt the synthetic resin material placed on the bottom. Determined by absorption spectral characteristics. For example, in the combination of synthetic resin materials mentioned above, Y
AG: 2Odium 3+1 which is the oscillation wavelength of the laser beam
, 06 μm is the most penetrating.

Further, the output of the laser beam needs to be sufficient to heat and melt the synthetic resin material disposed below, and is determined as appropriate. At this time, consideration must be given to the fact that if the output is too large, the synthetic resin material to be melted will evaporate or change in quality, making joining difficult.

For example, when using YAG:Neodymium 1+ laser light, 5W to too much is suitable, and 5W to 30W is the best.

〔Example〕

Hereinafter, one embodiment of the joining method according to the present invention will be described based on the drawings.

FIG. 1 is a schematic cross-sectional view illustrating a method of joining synthetic resin materials according to the present invention.

In (a) to d) of Fig. 1, ``■'' is a plate member made of polypropylene resin, and the plate member 1 has a thickness of 1 (In) and has a flat upper surface. The joint surface 1a is formed, and the lower surface is also formed flat to form a pedestal (
(not shown), etc., is the mounting surface 1b. The raw material color of this plate member l is carbon blank.
It is black when mixed with 1% by weight, and has the property of absorbing laser light of around 1.06 μm.

Further, a plate member 2 made of styrene-acrylonitrile copolymer is disposed on the upper part of the plate member 1, and the plate member 2 has a thickness of 15 m. Further, the upper surface of this plate member 2 is a flat portion 2a, and the lower surface is a joint surface 2b that comes into contact with the joint surface 1a of the plate member l. Furthermore, the raw material color of this plate member 2 is semi-transparent, and the color is 1.06 μm.
It has a non-absorbing property for laser light in the vicinity of m.

Further, a metal mesh 3 made of stainless steel and formed in a lattice shape is provided on the joint surface 2b of the plate member 2 at the same time when the plate member 2 is compression-molded. The metal mesh 3 is formed to have a plate thickness of 51 layers, and its side portions are tapered surfaces 3a. Further, the metal mesh 3 is provided to be exposed from the joint surface 2b of the plate member 2, and the degree of exposure is about 2.

When joining both plate members l and 2, (
As shown in a), the lower surface of the metal mesh 3 provided exposed on the joint surface 2b of the plate member 2 is brought into contact with the joint surface 1a of the lower plate member 1, and the metal mesh 3 is centered.

Next, as shown in FIG. 1(b), the irradiation nozzle 4 of the YAG:Neodymium 1+ laser device is positioned above the metal mesh 3 provided on the plate member 2 made of styrene-acrylonitrile copolymer. In this state, a Y with a wavelength of 1°06 μm and an output of 20 W is emitted from the irradiation nozzle 4.
The AG laser beam 5 is passed through a processing lens 6 and irradiated thereon.

At this time, the YAG laser beam 5 becomes non-absorbent to the plate member 2 made of styrene-acrylonitrile copolymer due to the relationship between its wavelength and the absorption spectrum of the synthetic resin material. The light passes through while repeating scattering and refraction, and reaches the joint surface 1a of the plate member 1 made of polypropylene resin.

The YAG laser beam 5 that has reached the joint surface 1a of the plate member 1 is accumulated as energy in the irradiated area and its surroundings, and the joint surface 1a of the plate member 1 is quickly heated and melted by the energy. Ru.

Then, while the plate member 1 is sufficiently heated and melted by irradiation with the YAG laser beam 5, a load is applied from the direction of arrow A as shown in FIG. The metal mesh 3 is gradually inserted into the melted part of the plate member 1. At this time, the molten material IC of the plate member 1 bulges from the gap 7 toward the upper plate member 1 and covers the tapered surface 3a of the metal mesh 3. Then, the irradiation of the YAG laser beam 5 is continued until the bonding surface 2b of the upper plate member 2 comes into contact with the bonding surface 1a of the lower plate member 1, and the load from the direction of arrow A is also continuously applied.

Then, when the bonding surfaces 1a and 2b of both plate members 1 and 2 come into sufficient contact, the irradiation of the YAG laser beam 5 is stopped, and the load on the plate member 2 from the six directions of the arrows is removed. After that, the irradiation nozzle 4 is moved away from the plate member 2.

As a result, as shown in FIG. 1(d), the metal mesh 3 provided on the joint surface 2b of the plate member 2 bites into the melted part of the plate member l, and the melt IC naturally hardens, and the polypropylene resin Plate member 1 consisting of styrene and
The plate member 2 made of acrylonitrile copolymer is firmly joined.

〔Effect of the invention〕

As explained above, in the method for joining synthetic resin materials according to the present invention, a part of the metal mesh is provided on one side of the synthetic resin materials to be joined so that it is exposed, and the metal mesh is overlapped with the other synthetic resin material, and from that one side. The joining surface of the other synthetic resin material is heated and melted by irradiation with a laser beam, and the metal mesh is pushed into the melted area, making it possible to join both synthetic resin materials without reducing their strength. be.

In addition, in the present invention, since the metal mesh provided on the upper synthetic resin material is pushed into the melted part of the lower synthetic resin material and joined, the effect is that both synthetic resin materials can be joined more strongly. be.

In addition, in the present invention, since the laser beam is irradiated from one side of the synthetic resin materials to be joined, it is easier to join the two synthetic resin materials compared to conventional mechanical joining methods. There is an effect that can be done.

Further, in the present invention, when the synthetic resin materials are joined, there is no fixing means such as screws at the joint portion of the two synthetic resin materials, so there is an effect that the design effect can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view illustrating a method of joining synthetic resin materials according to the present invention. FIG. 2 is a schematic cross-sectional view illustrating a conventional method of joining synthetic resin materials. 1---Plate member 1a...Joint surface 1c-
------1 molten material 2・----1 slope member 2b-
−−・Joint surface 3−・−Metal mesh 4−・
・−・Irradiation nozzle 5・−・−・YAG laser beam 6−
・−・Ellens 7−−−−−One gap applicant
Toyota Motor Corporation (i3)
tb) (C) (
d) Figure 2

Claims (1)

[Claims] When synthetic resin materials are overlapped and irradiated with a laser beam from one side to bond the two synthetic resin materials, the lower part of the overlaid synthetic resin materials is made absorbent to the laser beam, and the upper part is made absorbent to the laser beam. In addition to being non-absorbent to light, a metal mesh is provided on the joint surface so that a portion is exposed, and these two synthetic resin materials are overlapped.
Laser light is irradiated from the direction of the upper synthetic resin material to heat and melt the joint surface of the lower synthetic resin material, and the metal mesh exposed on the joint surface of the upper synthetic resin material is pushed into the melted area. A method for joining synthetic resin materials, characterized by: