JPS6255121A - Jointing synthetic resin materials - Google Patents

Abstract

PURPOSE:To enable synthetic resin materials to be jointed to each other easily and firmly while maintaining the strength of the materials, by providing short fibers between synthetic resin materials laminated on each other, and irradiation with laser light and application of ultrasonic waves are conducted through the surface of one of the resin materials. CONSTITUTION:YAG laser light 5 is radiated from a radiating nozzle 4 of a laser device disposed on a plate member 3 provided on the upper side of a part at which short glass fibers 2 ar placed. The laser light 5 is transmitted through the plate member 3 which is non-absorptive of the laser light. The laser light 5 reaches the short fibers 2 clamped between the plate member 3 and a plate member 1 which is absorptive of the laser light, whereby joint surfaces 1a, 3a making contact with the fibers 2 and the surrounding parts are softened by heat, resulting in a state for easy plasticization. Then, the tip of a vibrator 7 of an ultrasonic oscillator is brought into contact with the upper side of the member 3, and ultrasonic waves are applied from the vibrator 7 under the condition that a fixed load is exerted on the member 3, whereby the fibers 2 are driven into a molten part 8 under the ultrasonic energy supplied from the vibrator 7 and the pressure exerted, resulting in welding.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention involves overlapping synthetic resin materials, irradiating laser light from one side, and applying ultrasonic waves to bond the two synthetic resin materials together. It is about the method.

[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.

That is, the former physical joining method involves heating a heating element such as a metal meso or yu on 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 both synthetic resin materials.

In addition, in the latter chemical bonding method, an adhesive such as Honmelt is interposed on the joint surfaces of the synthetic resin materials to be bonded, and high frequency or ultrasonic waves are applied from the surface of the synthetic resin materials to bond the adhesive. After heating and melting, both synthetic resin materials are cooled while being pressurized, and the two synthetic resin materials are joined together.

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, 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 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 thereof will be explained using a method of joining polypropylene and polyethylene shown in FIG.

In FIG. 3, reference numeral 51 denotes 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 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 both plate members 51 and 52 from above with a gasket 54 interposed therebetween, thereby joining both plate members 51 and 52.

[Problem that the invention seeks to solve]

However, in such a mechanical joining method, through holes 53a and 53b must be formed in both plate members 51 and 52, and screws 55 must be screwed into the plate members. Not only is the joining work more complicated compared to the standard joining method, but also the through holes 5 in both plate members 51 and 52.
3a and 53b, there is a problem that the strength of both plate members 51 and 52 is reduced.

Therefore, the present invention has been made to solve the above-mentioned problems, and involves interposing short fibers between overlapping synthetic resin materials, and irradiating laser light and ultrasonic waves from the surface of one synthetic resin material. The object of this application is to easily and firmly join the resynthetic resin materials without reducing the strength of the resynthesized resin materials to be joined.

[Means for solving problems]

That is, in the method for joining synthetic resin materials according to the present invention, when overlapping synthetic resin materials and joining them, one synthetic resin material is made absorbent to laser light, and the other synthetic resin material is made absorbent to laser light. A short fiber is placed on the surface of one of the synthetic resin materials that is non-absorbent to laser light, and the other synthetic resin material is placed on top of it, and the top of the area where the short fibers are placed is After heating the short fiber portion by irradiating the laser beam from above the synthetic resin material, the vibrator of an ultrasonic oscillator is brought into contact with the surface of the upper synthetic resin material that has been irradiated with the laser beam, and the ultrasonic oscillator is applied while applying pressure. A sound wave is applied to melt and join the bonding surfaces of the overlapping synthetic resin materials.

Examples of synthetic resin materials that do not absorb laser light include polyethylene, polypropylene, and styrene-acrylonitrile copolymers; examples of synthetic resin materials that do absorb laser light include:
Examples include polyethylene to which an auxiliary material such as carbon black is added, polypropylene, or styrene-acrylonitrile copolymer to which an auxiliary material such as carbon blank is added. 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, examples of the short fibers interposed between the two synthetic resin materials include glass fibers, carbon fibers, metal fibers, etc. The length of these short fibers is not particularly limited, but is a guideline. 50μm to 500μm
Approx. m is suitable.

The short fibers can be placed in a spot shape, a plurality of parallel bead shapes, a zigzag bead shape, etc. depending on the desired bonding strength.

Furthermore, when placing short fibers on a synthetic resin material, there are several methods: placing the short fibers directly, mixing the short fibers in an ethyl acetate ring-friendly solvent and spraying the mixture, and mixing the short fibers in a welding agent such as hot metal. This can be done by selecting an appropriate method of attaching.

In addition, the lasers used when joining both synthetic resin materials include glass: neodymium 3+ laser, YAG:
Neodymium 3+ lasers, ruby lasers, helium-neon lasers, krypton lasers, argon lasers, N2 lasers, N2 lasers, etc. can be mentioned, and among these, YAG:Neodymium 3+ lasers are the most permeable.

In addition, the wavelength of the laser used when joining both 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; In some cases, it is difficult to maintain the joint surfaces of both synthetic resin materials in a molten state. In addition, the output of the laser is 5W to 100W.
W passes through, and 5W to 30W is the best.

If the output is less than 5W, the joint surfaces of both synthetic resin materials cannot be melted together, and the io'o
If it is more than w, both synthetic resin materials will evaporate or change in quality, making it impossible to join them.

Further, as the ultrasonic oscillator, a commonly used one can be used as is, and it is preferable that the combination consists of an ultrasonic oscillator and a vibrator provided in the vibrating part of the ultrasonic oscillator. The ultrasonic waves applied to the vibrator are selected depending on the combination of synthetic resin materials to be bonded, and as a guideline, r'o-
It passes KHz to 50KHz.

〔Example〕

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

FIG. 1 is a schematic sectional view illustrating the method of joining synthetic resin materials according to the present invention, and FIG. 2 is an enlarged sectional view of the ellipse of section A in FIG. 1.

In (a) to d) of Figure 1, 1 is styrene-
This plate member 1 is made of acrylonitrile copolymer and has a thickness of 15 mm.The upper surface is a flat joint surface 1a, and the lower surface is also flat and has a pedestal ( (not shown). The raw material color of this plate member 1 is black due to the addition of 0.5% by weight of carbon black, which is 1.0% by weight.
It has the property of absorbing laser light of 6 μm or less.

In addition, styrene-acrylonitrile copolymer plate member 1
Short glass fibers 2 are placed directly in spots on the top surface of the part to be joined, and their thickness is 1.0 +n.
The width is approximately 10 mm. and,
The thickness of the short glass fibers 2 is approximately 0.5 f1, and the length thereof is in the range of 0.5 vm to 20 mm.

Further, a plate member 3 made of polypropylene resin is disposed on the upper surface of the short glass fiber 2, and the thickness of the plate member 3 is 1511 mm, which is the same as the thickness of the lower part. Further, the lower surface of this plate member 3 is a flat joint surface 3a so as to come into contact with the joint surface 1a of the plate member 1, and the upper surface is a flat surface 3b.

When joining the overlapping plate members 1.3 made of synthetic resin materials as shown in FIG. 1(a), short glass fibers 2 are placed as shown in FIG. 1(b). An irradiation nozzle 4 of a YAG: neodymium 3+ laser device is arranged on the plate member 3 above the cut part, and the irradiation nozzle 4 has a wavelength of 1.06 μm and an output of YAG of IOW.
The G laser beam 5 is passed through a convex lens 6 and irradiated.

At this time, the YAG laser beam 5 is not absorbed by the plate member 3 made of polypropylene resin due to the relationship between its wavelength and the absorption spectrum of the synthetic resin material, and is therefore transmitted. At this time, the YAG laser beam 5 does not travel straight in the irradiation direction, but in a synthetic resin material that does not have a single crystal structure, it travels in a scattered state. Next, the same
It reaches the short glass fibers 2 sandwiched between the plate member 1 made of acrylonitrile copolymer and the plate member 3 made of polypropylene resin, and is stored there as energy. Joint surface 1a
, 3a are preheated to about 100°C to 250°C. Both plate members l in contact with the short glass fiber 2
, 3, the joint surfaces la, 3a and their vicinity are heated and softened,
It becomes a state where it becomes easily plasticized.

Thereafter, the irradiation of the YAG laser beam 5 from the irradiation nozzle 4 is stopped, and as shown in FIG. (not shown) is brought into contact with the tip of a vibrator 7. At this time, with respect to plate member l from the direction of arrow B,
Apply a certain amount of weight from the tip.

Next, the ultrasonic oscillator is operated with a certain load applied to the plate member 3, and the vibration frequency from the vibrator 7 is 20KHz to 40KH.
Apply z ultrasonic waves. At that time, the energy of the ultrasonic wave from the vibrator 7 is applied to the bonding surface 3a of the plate member 3 and the short glass fiber 2.
and the bonding surface 1a between the short glass fiber 2 and the plate member l.
It propagates to the interface with and is stored as energy.

The accumulated energy melts both interfaces and the plate members 1.3 in the vicinity thereof, and the pressing force from the vibrator 7 causes the short glass fibers 2 to enter the melted region 8 and be welded and joined. As shown in FIG. 1(d) and FIG. 2, the welded joint area is fiber-reinforced with short glass fibers 2 entangled across the fused areas 8 of both plate members 1.3. , can be firmly bonded.

After the bonding to the predetermined portion is completed, application of ultrasonic waves to the vibrator 7 is stopped, and the vibrator 7 is left for about 2 to 5 seconds. Thereafter, the vibrator 7 is separated from the plate member 3, and its tip is positioned above the plate member 3.

As a result, the melts of both plate members 1.3 enter each other, and the short glass fibers 2 naturally harden as mediators of the melts of both plate members 1.3, and the plate member 1 made of styrene-acrylonitrile copolymer and The plate member 3 made of polypropylene resin is firmly joined.

〔Effect of the invention〕

As explained above, in the method for joining synthetic resin materials according to the present invention, short fibers are interposed between the overlapped synthetic resin materials, and laser light irradiation and ultrasonic waves are applied from the direction of one synthetic resin material. Since the short fibers are used as intermediaries to join the two synthetic resin materials,
It can be widely used for joining synthetic resin materials with poor compatibility, and has the effect of being able to join firmly due to the intermingling effect of the short fibers.

In addition, since the present invention uses laser light and ultrasonic waves for bonding, it has the effect of making bonding easier compared to conventional mechanical bonding methods that require tedious work such as drilling holes. be.

Furthermore, in the present invention, since no holes or the like are formed in any of the synthetic resin materials to be joined, the strength of the synthetic resin materials after joining can be maintained for a long period of time.

[Brief explanation of drawings]

FIG. 1 shows a method for joining synthetic resin materials according to the present invention. It is a schematic sectional view explaining. Figure 2 is 1H! FIG. 2 is an enlarged cross-sectional view of the inside of the A section ellipse of J. FIG. 3 is a schematic cross-sectional view illustrating a conventional method of joining synthetic resin materials. 1.--Plate member la-1.--Jointing surface 2.--Glass short fiber 3.--One plate member 3a.--Jointing surface 4.--One irradiation nozzle 5...-Y A G laser beam 6...-Convex lens 7--1--Vibrator 8--1 Melting part Applicant Toyota Motor Corporation (211) (b) (
C) Cd) Figure 1 Figure 2

Claims (1)

[Claims] When overlapping synthetic resin materials and joining them, one synthetic resin material is made absorbent to laser light, the other synthetic resin material is made non-absorbent to laser light, and the synthetic resin material of the one is made to be absorbent to laser light. Place the short fibers on the surface of the resin material, and overlap the other synthetic resin material on top of the short fibers.
After heating the short fiber portion by irradiating a laser beam from above the synthetic resin material above the area where the short fibers are placed, an ultrasonic oscillator is applied to the surface of the upper synthetic resin material irradiated with the laser beam. 1. A method for joining synthetic resin materials, characterized in that ultrasonic waves are applied while a vibrator is brought into contact and pressurized to melt and join the joint surfaces of the superimposed synthetic resin materials.