JPS60212329A - Joining of heterogeneous synthetic resin materials - Google Patents

Abstract

PURPOSE:To join both materials together without the lowering of strength by a method wherein one of heterogeneous synthetic resins is made non-laser light absorbable while the other laser light absorbable, after the formation of a latch groove on the joint surface of the latter, both the resins are piled one upon another and irradiated with a laser light to run the melt into the latch groove. CONSTITUTION:When heterogeneous synthetic resin materials are piled one upon another and joined together, one of the synthetic resin materials 1 and 2 is made non-laser light absorbable while the other laser light absorbable and latch grooves 1b and 1c are formed on the joint surface 1a side of the absorbable synthetic resin material 1. Then, both the synthetic resin materials 1 and 2 are piled one upon another and irradiated with a laser light 5 from an irradiation nozzle 4 from the direction of the non-absorbable synthetic resin material 2 to melt the joint surface 1a so that a part of the melt 7 runs into the latch grooves 1b and 1c of the other material to join both of the materials.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of superimposing different types of synthetic resin materials and bonding them together using a laser beam.

[Prior art]

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 uses a heating element such as a metal mesh to generate heat at the joining 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 the two synthetic resin materials.

However, in the former physical joining method, when joining synthetic resin materials of the same type, both synthetic resin materials have the same melting temperature and are compatible, so both synthetic resin materials are However, when joining different types of synthetic resin materials, the melting temperatures of the two synthetic resin materials are different and the compatibility is poor.
It is difficult to join resynthetic resin materials. In addition, the latter chemical bonding method is as suitable as the former physical bonding method when bonding synthetic resin materials of the same type, but it is suitable for bonding synthetic resin materials of different types. The adhesive force of the adhesive decreases depending on the material, making it difficult to firmly bond resynthetic resin materials.

For the reasons mentioned above, many mechanical joining methods are used when joining different types of synthetic resin materials. A typical example will be explained using the method of joining polypropylene and polyethylene shown in FIG. 2.

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. Through-holes 53a and 53b are formed in opposing parts of the polypropylene resin plate member 51.
is formed. Further, screws 55 are screwed into the through holes 53a and 53b of both plate members 51 and 52 from above with a gasket 54 interposed therebetween, thereby joining both plate members 51 and 52.

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 physical joining method and chemical joining method.
Since it is necessary to form the parts a and 53b, both plate members 5
There is a problem that the strength of 1.52 is reduced.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and its purpose is to make one of different types of synthetic resin materials non-absorbent and the other absorbent, and to bond them together. A dissimilar synthetic resin that can be easily joined without reducing the strength of the resynthetic resin material 1 by forming a latching groove on the surface and irradiating a laser beam in the direction of the non-absorbing synthetic resin material. The object of the present invention is to provide a method for joining materials.

[Structure of the invention]

In order to achieve the above object, the structure of the method for joining different types of synthetic resin materials according to the present invention is such that when overlapping different types of synthetic resin materials and joining them, one of the synthetic resin materials is heated using a laser beam. The synthetic resin material is made non-absorbent to laser beams, and the other is made absorbent to laser beams, and after forming a latching groove on the joint surface side of the absorbent synthetic resin material, the two synthetic resin materials are overlapped, The laser beam is irradiated from the direction of the synthetic resin material that does not absorb the laser beam to melt the joint surface, and a part of the melt is poured into the latching groove of the other synthetic resin material. It is something.

Examples of synthetic resin materials that do not absorb laser light include polypropylene, styrene-acrylonitrile copolymer, etc., and examples of synthetic resin materials that do not absorb laser light include carbon black. Examples include polypropylene resins to which auxiliary materials such as the like are added, styrene-acrylonitrile copolymers reinforced with glass fibers and carbon black added, and the like. These synthetic resin materials can be freely selected and bonded in combinations of those that do not absorb laser light and those that do absorb laser light.

In addition, lasers used when joining dissimilar synthetic resin materials include glass: neodymium tracer, YAG: neodymium tracer, ruby laser, helium-neon laser, krypton laser, argon laser, H2 laser, N
2 lasers, among which YAG
:Neodymium 3″″ laser is most suitable.

In addition, the wavelength of the laser used when joining dissimilar synthetic resin materials needs to be compatible with the synthetic resin materials to be joined, and a wavelength of 1.06 μm or less is best; It is impossible to melt and join the joining surfaces of different types of synthetic resin materials to each other. In addition, the output of the laser is 5W to 30W.
is suitable, and if the output is less than 5W, the joint surfaces of different types of synthetic resin materials cannot be melted together,
If the power is 30 W or more, different types of synthetic resin materials will evaporate or change in quality, making it impossible to join them.

In addition, the latching grooves formed on the joint surface of the synthetic resin material that absorbs laser light can be formed perpendicularly or inclined to the synthetic resin material, and the number of latching grooves can be one or more. can be formed. Further, the depth of the latching groove is at least 1/2 or less of the thickness of the synthetic resin material. If it is desired to further improve the bonding strength between the two synthetic resin materials to be bonded, it is desirable to form a plurality of latching grooves at an angle.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

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

In (a) to d) of FIG. 1, 1 is a plate member made of styrene-acrylonitrile copolymer reinforced with glass fiber, and the raw material color of this plate member 1 is carbon black. It is added to give it a black color and has the property of absorbing laser light of 1.06 μm or less. The joint surface 1a of the plate member 1 has two latching grooves 1b and 1c extending in the axial direction of the plate member 1.
are formed in an inclined manner, the tips of which are oriented toward sides facing each other, and the depth thereof is less than or equal to 1/2 of the thickness of the plate member 1.

Further, a plate member 2 made of polypropylene resin is disposed on the upper part of the plate member 1, and the lower surface thereof is formed flat and serves as a joint surface 2a that comes into contact with the joint surface 1a of the plate member 1. The raw material color of this plate member 2 is milky white, and has the property of not absorbing laser light of 1.06 μm or less.

When joining the plate members 2 made of different synthetic resin materials as shown in (a) of FIG. 1, the plate members 2 made of polypropylene resin are joined as shown in (b) of FIG. The surface 2a is superimposed on the joint surface 1a of the plate member 1 made of styrene-acrylonitrile copolymer. Next, as shown in FIG. 1(c), the irradiation nozzle 4 of the YAG: neodymium laser is brought into contact with the upper surface of the polypropylene resin plate member 2. At this time, the contact position of the irradiation nozzle 4 is between the latching grooves 1b and 1c formed in the plate member 1 made of styrene-acrylonitrile copolymer. After that, the irradiation nozzle 4
A YAG laser beam 5 having a wavelength of 1.06 μm and an output of 20 W is passed through a convex lens 6 and irradiated.

At that time, the YAG laser beam 5 is transmitted through the plate member 2 made of polypropylene resin and the plate member I made of styrene-acrylonitrile copolymer and the plate member made of polypropylene resin, depending on its wavelength and the composition and color difference of the synthetic resin material. It is stored as energy on the contact surface 3 with 2. The energy accumulated on the contact surface 3 causes the drawing board member l to
, 2 are heated, and the contact surface 3 between the plate member 1 made of styrene-acrylonitrile copolymer and the plate member 2 made of polypropylene resin is melted.

At this time, while irradiating the YAG laser beam 5 from the irradiation nozzle 4, a load is applied from the direction of arrow A, and a part of the melt 7 of the drawing board member 1.2 is applied to the plate member 1 made of styrene-acrylonitrile copolymer. Let it flow into the stop grooves 1b and lc.

Thereafter, the irradiation of the YAG laser beam 5 from the irradiation nozzle 4 is stopped, and the irradiation nozzle 4 is moved away from the plate member 2 made of polypropylene resin, as shown in FIG. remove the load. As a result, a part of the melt 7 of the drawing board member 1.2 sufficiently flows into the latching grooves ib and 1c of the board member 1 and hardens while sandwiching the board member, and the styrene-acrylonitrile copolymer is A plate member 1 made of polypropylene resin and a plate member 2 made of polypropylene resin.
are firmly joined. The bonding strength between the drawing board members 1 and 2 can be improved by increasing the amount of melt 7 poured into the latching grooves 1b and lc.

C Effects of the Invention] As explained above, in the method for joining dissimilar synthetic resin materials according to the present invention, one synthetic resin material is made non-absorbent to laser light, and the other synthetic resin material is made non-absorbent to laser light. In addition to making the synthetic resin material absorbent, a latching groove is formed on the joint surface, and the laser beam is irradiated from the direction of the non-absorbing synthetic resin material, so that the two synthetic resin materials are melted together from the contact surface. Since a part of the molten material flows into the latching groove and is joined, it is possible to join the two synthetic resin materials without reducing their strength.

Furthermore, in the present invention, since a latch groove is formed on the bonding surface of the other synthetic resin material among different types of synthetic resin materials, the molten material of both synthetic resin materials flows into the latch groove. The molten material flows in and hardens while sandwiching the latching groove, which has the effect of further improving the bonding strength.

In addition, in the present invention, both synthetic resin materials are joined by irradiating laser light from one side of the dissimilar synthetic resin materials, making it easier to join different synthetic resin materials compared to conventional mechanical joining methods. It has an effect that can be done easily.

Furthermore, in the present invention, when different types of synthetic resin materials are joined together, there is no fixing means such as screws at the joint between the two synthetic resin materials, so that the design effect can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view illustrating a method for joining dissimilar synthetic resin materials according to the present invention. FIG. 2 is a schematic cross-sectional view illustrating a conventional method of joining different types of synthetic resin materials. 1.---Plate member 1 made of styrene-acrylonitrile copolymer reinforced with glass fiber a----Joint surfaces 1b, 1c---Latching groove 2.---- --- Plate member 2 made of polypropylene resin a --- One joint surface 3 --- One contact surface 4 --- Irradiation nozzle 5 --- -Y A G laser beam 6 - - m - - Convex lens 7 - - Melt 1st E! 1

Claims (1)

[Claims] When overlapping and bonding different types of synthetic resin materials, one of the synthetic resin materials is made non-absorbent to laser light, and the other is made absorbent to laser light, and this absorbing property is After forming a latching groove on the joining surface side of the synthetic resin material, the two synthetic resin materials are overlapped,
irradiating the laser beam from the direction of the non-absorbing synthetic resin material with respect to the laser beam to melt the joint surface, and
A method for joining dissimilar synthetic resin materials, characterized in that a part of the melt is poured into a latching groove of the other synthetic resin material.