SU1699799A1 - Method for high-frequency welding elongated polymer workpieces - Google Patents

Abstract

The invention relates to the welding of plastics and can be used in the high-frequency welding of long polymer materials. The goal is to improve the quality of welding. For this, in the method of high-frequency welding of long polymer materials, the ends of the electrodes are connected to the power source in the process of heating the joined surfaces alternately on one or the other side of the electrodes at regular intervals. At the same time, when the ends of the electrodes are connected to the power supply on one side, the opposite ends of the electrodes are disconnected. 2 Il.

Description

The invention relates to the welding of plastics and can be used in the high-frequency welding of long polymer materials.

The aim of the invention is to improve the quality of welding.

FIG. 1 shows an apparatus for carrying out the method; in fig. 2 is a graph of the variation of the electric field strength i along the length of the electrodes.

For implementing the method, a device is used which contains a power source in the form of generators 1 and 2, to which the switching unit 3 is connected. In this case, generator 1 is connected, on the one hand, to electrodes 4, 5, and generator 2 of the opposite side - to electrodes 4.5.

The method of high-frequency welding of long polymeric materials is as follows.

The materials to be welded are placed between the parallel electrodes 4, 5 and are heated by their joined surfaces in an electric standing wave field. For this, the ends of the electrodes are connected to a power source / alternately on one or the other side of the electrodes at regular intervals. The connection is carried out in the mode of two fixed actions, i.e., the materials are heated in opposite voltage phases, with one phase shifted relative to the other by 1/4 period.

One fixed action connects one side of the electrodes 4 and 5, and the other side of the electrodes off, and when

ABOUT

v

the other fixed action connects the other side of the electrodes, and the first side of the electrodes 4 and 5 disconnect.

In this case, after the general switching on, the switching unit 5 switches on the generator 1, standing waves of the electric field are generated on the electrodes, which leads to uneven heating of the material, and in the nodes the material heats up less and in the antinodes more. At the point where the generator 1 is connected, the first node Ешщ is formed, and at the free ends of the electrodes the latter is the antinode Enti. The generator 1 operates in the time interval ti, after which the switching unit 3 switches off the generator 1 and turns on the generator 2, which runs for a time period t2, with t2 - ti. On the electrodes, standing waves of the electric field intensity are formed.

Since the working frequency of generators 1 and 2 is the same, the nodes and antinodes are distributed at the same distances as when generator 1. At the connection point of generator 2, the first electric field Eit2 is formed, and the free ends of the electrodes are the last antinode Ent2.

Thus, the standing waves of the electric field intensity for the time interval t2 are a mirror image of the standing waves for

time interval c. This achieves uniform heating of the materials being welded along the seam length and eliminates the limitation on the length of the electrodes with high quality welding.

Fo rmu l and z o bre n i Method of high-frequency welding of long polymer materials, including placement of welded

materials between parallel electrodes and the heating of their connected surfaces in a standing-wave electric field by connecting the ends of the electrodes to a power source, characterized in

that, in order to improve the quality of welding, the ends of the electrodes are connected to the power source in the process of heating the joined surfaces alternately on one side or the other side of the electrodes

at equal intervals of time, while connecting the ends of the electrodes to the power supply on one side, the opposite ends of the electrodes are turned off.

2

/

W

one

Јib

i

FIG. one

Ј;

W

M2

Fig 2

Claims (1)

Claim A method for high-frequency welding of long polymer materials, including placing welded materials between parallel electrodes and heating their joined surfaces in an electric field of a standing wave by connecting the ends of the electrodes to a power source, characterized in that, in order to improve the quality of welding, connecting the ends of the electrodes to a power source the heating of the surfaces to be joined is carried out alternately on one or the other side of the electrodes at regular intervals, while and connecting the ends of the electrodes to the power source from one side, the opposite ends of the electrodes are turned off.