JPS59232820A - Welding method of plastic member - Google Patents

Abstract

PURPOSE:To enable a plastic member to be welded successfully by high frequency induction heating without fitting an electrode on the side of one plastic member by overlapping two plastic members and fitting a pair of electrodes only on the side of the other plastic member. CONSTITUTION:Two plastic sheets 1, 2 are overlapped and mounted on the rest 7. A pair of electrodes 3, 4 are fitted only on the side of one plastic sheet 1 on the overlapped surface 8 between said sheets 1, 2. At this time, the electrodes 3, 4 are preferably faced to each other so that an insulator 5 is centered on a part 8A to be welded on the overlapped surface 8. A high frequency voltage is applied by a high frequency oscillator 6 to the electrodes 3, 4 to weld the area 8A to be welded by high frequency induction heating on the overlapped surface 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for welding plastic members such as vinyl chloride using high frequency dielectric heating.

Hitherto, the high frequency dielectric heating welding method has been widely used as a welding method for plastic parts 4=A having a relatively large dielectric loss coefficient, such as vinyl chloride, because the welding operation is simple and reliable welding can be performed in a short time.

However, the conventional high frequency dielectric heating welding method
As shown in the figure, 1.2 plastic members/, 2.73
one plastic member 7.2 side and the other plastic part 4',
An electrode /3°/ri is installed on both sides of the A/3 side, and the /pair electrode /41. /Plastic part between the left/,!
, /(l), and then apply a high frequency voltage to the electrodes /da, /g to weld the joint surfaces /) by high frequency dielectric heating. Plastic parts i4/3. Electrode on the other plastic member/3 side from the overlapping joint surface of /'l/
If it is difficult to install 3, for example, if there are protrusions formed on the other plastic member side or other parts have been removed, or if the electrode comes into contact with it, the surface may change or become deformed. If so, the other plasti,
In cases where the member is hollow, tubular, etc., and the installation of the electrodes becomes extremely cumbersome, use both electrodes/'1. /! It was not possible to hold the joint surface with r and welding could not be performed using high frequency dielectric heating.

The present invention solves the above two drawbacks by installing a pair of electrodes only on one side of the plastic member from the overlapping bonding surfaces of the plastic parts, and placing an insulator between the pair of electrodes. The object of the present invention is to provide a method for welding plastic parts that can be successfully welded by high-frequency dielectric heating without intervening an electrode on the other plastic member side.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 2, /, - are plastic sheets to be welded such as vinyl chloride, 3. 3.G is the electrode for applying high frequency voltage, and Shio is the electrode 3. The insulator interposed between l1, B is a high frequency oscillator, and 7 is a plastic sheath to be welded.
This is a stand on which 2 is placed.

First, two plastic sheets /, 2 are stacked and placed on the pedestal 7. Then, a pair of electrodes [3,'1 is installed only on one side of the plastic sheet/ from the bonding surface g of the stacked plastic sheets/,2. At that time, the electrode? , l/1 are preferably installed so as to face the insulator S with the part gA of the joint surface g to be welded as the center. The insulator S can be arbitrarily set depending on the shape of the electrode and the thickness of the plastic member, but for example, if the thickness of one plastic sheet is 2 mm, the thickness D of the insulator S is 0 to 20 mm. It is a city. and electrode 3. A high-frequency voltage is applied from a high-frequency oscillator B to the bonding surface g, and the portion gA of the joint surface g that should be welded is welded by high-frequency dielectric heating. Then, after welding is completed, electrode 3. plastic sea)/,,
2, a plastic sheet is obtained which is welded together at the joint surface g.

In addition, as shown in FIG. 3, the members to be welded /', , ! By forming a stepped part gB on the joint surface g of ', and forming a part gA to be welded which is approximately perpendicular to the electric force lines generated between the electrodes 3 and 4, the outer surface of the welded part will be finished beautifully. The dense part of the electric lines of force acts efficiently on the part gA to be welded, and reliable welding can be carried out in a short time.

FIG. 7 shows another example of the present invention, in which one plate piece /θ and a hollow body // are overlapped, and a /pair electrode is placed only on the one plate piece 10 side from the overlapping joint surface g. 3. Install l/1
1 L, then electrode 3. A high-frequency voltage is applied to the joint surface 7, and the portion 7+ of the joint surface 7 to be welded is welded by high-frequency dielectric heating. In this way, the shape of the plastic member to be welded is not limited at all, and sheets, films, hollow bodies, tubular bodies, and other three-dimensional objects can be welded in an appropriate combination. The material of the material is preferably a plastic material having a relatively large dielectric loss coefficient, such as soft vinyl chloride, hard vinyl chloride, thermoplastic plastic such as polyamide, or thermosetting plastic such as phenol or urea. Note that when the upper IE portion is partially welded, high-frequency dielectric heating may be applied to the joint surface 7 via a vinyl acetate adhesive, a vinyl chloride adhesive, or the like.

As described above, the present invention consists of overlapping two plastic members, installing a pair of electrodes on only one plastic member side from the overlapping joint surface, and installing an insulator between the pair of electrodes. This is a welding method for plastic deck members in which a high-frequency voltage is applied to the electrode to weld the joint surface by high-frequency dielectric heating. Even in cases where it is difficult to install electrodes, the welding operation can be easily performed and reliable welding can be achieved using RIJ. Furthermore, by interposing an insulator between the pair of electrodes, it is possible to prevent the risk of short circuit between the electrodes and to stabilize the working process.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional welding method, Fig. 2 is a perspective view showing a welding method according to the present invention, Fig. 3 is a sectional view of main parts showing another example of the present invention, and Fig. 9 is a perspective view showing the welding method according to the present invention. It is a perspective view which shows another example. /, 2 Plasti, Tasheet 3, q Electrode O High frequency oscillator g 10 people Kyoraku Co., Ltd. for joint surface patent

Claims (1)

[Claims] Layer the λ horn plastic members, place a pair of electrodes on only one plastic part side from the overlapping joint surface, interpose an insulator between the pair of electrodes, and then apply a high frequency voltage to the electrodes. A method for welding plastic parts, characterized by applying high-frequency dielectric heating to the joint surfaces and welding them.