KR20020024378A - Apparatus and method for welding Plastics - Google Patents

Abstract

PURPOSE: An apparatus and a method for thermally welding a synthetic resin member are provided to improve the workability and to enhance the welding force by uniformly forming a welding degree of a welding surface. CONSTITUTION: An apparatus for thermally welding a synthetic resin member includes a pair of fixing plates(3) for fixing the synthetic resin members(2). A pair of welding cylinders(4) are connected to a rear surface of the fixing plates(3) through a cylinder shaft(23) so as to adhere the fixing plates(3) to each other. A pair of rotating plates(5) are provided to arrange the synthetic resin members(2) in opposition to each other. The welding cylinders(4) are fixedly installed on the rotating plates(5). A heating section includes a heating wire heater(6), a heating wire heater fixing plate(7), and a heating cylinder(8). A rotating section includes a motor(9) and a belt(10).

Description

Apparatus and method for welding plastics for thermal welding of plastic moldings

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal welding apparatus and a method thereof for a synthetic resin molding, and more particularly, to a thermal welding apparatus and a method for thermal welding a synthetic resin molded article having a complex shape of a curved surface having a different or thinner welding surface.

As illustrated in FIG. 4, the conventional simple welding device for forming a synthetic resin molded body has a fixing part 14 for fixing the moldings 2 to face each other, and a molding fixed by the fixing part is moved up and down or melted. It consists of the 1st moving part 13 which welds the welding surfaces of the moldings, and the welding plate 16 which melts the welding surface of the said molding object, the 2nd moving part 15 which moves the heating plate to the left and right, etc.

In the conventional apparatus configured as described above, the molding 2 fixed by the fixing part is brought up and down close by the first moving part 13, and the heating plate 16 is heated on the welding part of the molding for a predetermined time, thereby forming the molding. After uniformly melting the welded portions, the heating plate is separated by the left and right movement of the second moving part 15 and welded by pressing the molten melted surfaces facing each other using the first moving part.

However, in the case of separating the heating plate heated to the welded portion, the welded portion is in a molten state, so that a part of the welded portion of the molten molded product is adhered to the surface of the heated plate without being separated cleanly, so that the molten molded product is to be welded. Since the surface became uneven and the molten resin layer formed on the surface of the welded portion was partially missing, welding of the molded product did not become uniform and the product strength was lowered.

As another known example for solving the problems of the conventional heat welding apparatus, a method of solving the defect that the molten resin of the welding surface is attached to the heating plate by coating the surface of the heating plate with Teflon resin or the like has been proposed.

However, thermal welding has become impossible with flat plates for synthetic resin molded articles having a complicated shape of curved surfaces having different thin or different heights due to the development of synthetic resin products.

Thus, in another known heat welding apparatus for solving the above problems, the heating plate is replaced with a hot wire heating apparatus 6 as shown in FIG. 5.

As shown in FIG. 6, the heating wire heating device includes a heating wire 17 for heating the welded portion, a heating wire support 18 for fixing the heating wire, and a fixing nut for fixing the heating wire support to the guide shaft in a state where the heating wire support can be adjusted. 19), the guide shaft 20 and the fixing flange 21 for fixing and protecting the hot wire supporter constitute a single object, and the plurality of objects are arranged in the shape of the welded portion of the molded plate (Plate) (22) Fix it to

Using such a device in place of the heating plate, the objects are arranged so that the connection state of the hot wire is the same as the shape of the weld surface of the molding, and then the hot wire and the weld surface are joined to heat the hot wire for a predetermined time. When the welding surface is sufficiently melted, the hot wire heating apparatus is separated as shown in FIG. 5, and the welded surfaces are welded to each other by the first moving part 13.

Here, by heating by replacing the heating plate for heating the welding surface with a heating wire, it is possible to heat-weld the molded article having the above complicated shape.

However, in the hot wire heating device, since the hot wire directly contacts the welding surface of the molding and heats the molded product having a material such as PC, which is particularly weak in heat, the hot wire heating device causes not only a phenomenon that the surface of the welding surface dries due to the molten resin on the hot wire. There is a difficulty to exactly match the curved surface of the welding surface by heating the welding surface. In addition, since the welded parts of the molded products are heated by opposing the molded products up and down and inserting a hot wire heating device therebetween, a difference occurs in the degree of melting of each weld surface of the upper and lower molded products due to the convection phenomenon. The defect of lowering the strength of the product occurs due to the uneven welding temperature of the upper and lower moldings.

The present invention has been made to overcome the above disadvantages, the molten resin is buried in the hot wire by melting the resin of the weld surface using indirect heat while maintaining a constant interval without directly heating the hot wire to the weld surface of the molding The workability is improved by solving the difficulty of matching the defects and the curved surface of the molten surface accurately. Also, the moldings are placed in the same position horizontally so that the moldings face each other up and down with a hot wire heating device therebetween. It is an object of the present invention to provide a thermal welding apparatus and a method for forming a synthetic resin molded article which can improve the welding strength by suppressing the difference in melting temperature of the weld surface due to convection.

1 is a side cross-sectional view of a heat welding apparatus of a synthetic resin molding according to the present invention.

Figure 2 is a perspective view of a thermal welding apparatus of a synthetic resin molding according to the present invention.

Figure 3 shows an example of welding by the thermal welding method of the synthetic resin molding according to the present invention

Side cross section shown.

4 is a side cross-sectional view of a conventional welding apparatus.

Figure 5 is a side cross-sectional view of another conventional welding apparatus.

6 is a partial side cross-sectional view of a heating wire heating apparatus used in another conventional welding apparatus;

Degree

* Description of the symbols for the main parts of the drawings *

1: welding machine, 2: molding, 3: fixing plate, 4: welding cylinder, 5: rotating plate

6: heater heater, 7: heater heater fixing plate, 8: heating cylinder

9: motor, 10: belt, 11: pulley, 12: shaft

In order to achieve the above object, the heat welding apparatus of the synthetic resin molding according to the present invention is a welding portion for fixing and welding the molding, a heating part for heating the welding portion of the molding and a rotating part to rotate so that the welding parts face each other. In more detail, the present invention provides a welding part for fixing and welding a molded product, a heating part having a heating device for indirectly heating the welding surface of the fixed molding, and welding of the molded product melted by the heating part. It consists of a rotating part for rotating the molding so that the faces face each other,

The welding part includes a welding cylinder for welding the molding to weld the molding, a rotating plate for rotating and fixing the welding part by a belt, a pulley, and a rotating shaft of the rotating part, and a fixing plate connected to the shaft of the welding cylinder to fix the molding. and,

The heating unit includes a hot wire heating device for indirectly heating and melting the welding surface of the molded product, and a heating cylinder for operating the hot wire heating device up and down to approach or separate from the molded product.

The rotating part includes a motor for controlling rotation of the welding part and a belt connecting the motor and the rotating plate of the welding part.

Then, the welds are arranged in parallel in the vertical direction to fix the moldings in a straight line horizontally, and the heating parts are heated while maintaining a constant interval, and then the welds are rotated and the moldings are welded so that the moldings face each other.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Reference numerals for the same components are referred to here.

1 is a side cross-sectional view of a heat welding device of a synthetic resin molding according to the present invention, as shown in the preferred embodiment of the heat welding device according to the present invention is a fixing plate (3) for fixing the synthetic resin molding (2), of the fixing plate Rotating plate rotatably connected to the cylinder 23 of the cylinder and the welding plate (4) and the welding cylinder is fixed to the welding plate fixed to each other by fixing the fixed plate by the fixed plate and the moldings are opposed to each other ( Welding part composed of 5),

In order to heat the welded part of the molding, the heated wire heating device 6 for indirectly heating and melting the welded part of the molded product, the hot wire heating device fixing plate 7 for fixing the hot wire heating device, and the hot wire heating device are operated up and down. A heating part consisting of a heating cylinder 8 for accessing or separating the welded portion of the welded portion and a motor 9 for controlling the rotation of the welded portion to rotate the welded portion, and a belt 10 connecting the motor and the rotating plate of the welded portion. It can be seen that it is composed of a rotating unit consisting of, the state that the synthetic resin molded article to be welded is set in the welding machine (1). Fig. 2 shows the hot wire heating device 6 preheated to an appropriate temperature according to the material to heat the welded part of the molded part from this state by the heating cylinder 8 to the welded part of the molded part and maintaining a constant interval. It is a perspective view which shows the state which melts a welded part by indirect heat. At this time, since each molded article 2 to be welded is horizontally present at the same position, a layer of a resin uniformly melted is formed at the welded portion of the molded article. In addition, by using indirect heat, it is possible to prevent defects in which the molten resin of the welded portion is missing or the molten resin is buried in the hot wire. When a layer of molten resin suitable for welding is formed on the welded portion of the molding, the heating wire 6 is lowered to the original position by the heating cylinder 8. As soon as the heating part returns to its original position, the motor 9 of the rotating part rotates so that the pulley 11 and the rotating shaft 12 connected to the motor by the belt face each other with the rotating plate 12. The welded parts of the molten moldings face each other as the rotary plates 5 face each other, and the welded portions of the molded products having the molten resin layer are welded to each other by the welding cylinder 10 fixed to the rotary plates as shown in FIG. 3. do.

Next, the thermal welding method of the synthetic resin molding according to the present invention will be described. The conventional heat welding method includes an opposing fixing step of fixing synthetic resin moldings to face each other, a direct melting step of melting the welded portions of the fixed molding by direct heat, and a welding step of pressing and welding the molten molding. As described above, in the conventional thermal welding method, a problem in which the weld surface of the molding is caused by the difference in melting temperature due to convective heat, and a melted resin phenomena due to the direct heating of the hot wire or the heating plate on the welding surface of the molding occurs. Therefore, the preferred embodiment of the present invention for improving the conventional problems is a horizontal fixing step of fixing the synthetic resin molding in the same position horizontally, indirect melting step of melting the welded portion of the fixed molding by indirect heat, molten molding Rotate step of rotating so as to face each other, welding step of pressing and welding the moldings facing each other.

According to the heat welding apparatus of the synthetic resin molding of the present invention having the above-described configuration, since the welding wire and the heating wire do not have to be precisely matched to the curved surface because indirect heat is used to maintain a certain distance without directly contacting the welding wire with the welding surface. Not only can the efficiency be improved, but also the production efficiency can be remarkably improved by preventing a part of the melted resin layer formed on the surface of the welded portion by the direct contact of the hot wire. In addition, when heating the welded part of the molded part, the temperature distribution of the welded part of the upper and lower moldings due to the convection phenomenon, which is a conventional problem caused by placing the molding on the upper side and the lower side with a hot wire heating device having hot wires on the upper and lower sides, is placed. By placing the upper and lower moldings on the same line and heating them with a heating wire heating device, the temperature distribution between the welded portions is uniformed, thereby improving the welding strength.

In addition, according to the thermal welding method of the synthetic resin molding of the present invention, the welding surface of the molding and the heating wire heating device are improved by placing the horizontal fixing step and the indirect melting step using indirect heat, so that the optimum melting temperature is reached during continuous operation. In order to shorten the heating time, there is an effect of shortening the working time and improving productivity.

Claims (4)

A welding cylinder for welding the molded article; A rotating plate for rotating and fixing the welding cylinder; A fixing plate connected to the shaft of the welding cylinder to fix the molding; A heating section for heating the welded portion of the molding; Heat welding device of a synthetic resin molding, characterized in that the rotating plate is configured to rotate to face each other. The method of claim 1, The heating unit includes a hot wire heating device for heating and melting the welded portion of the molded article; A heating wire fixing device for fixing the heating wire heating device; And a heating device cylinder configured to access or separate the molded product by operating the hot wire heating device up and down. The method of claim 1, Rotating unit, the thermal welding device of a synthetic resin, characterized in that consisting of a motor for controlling the rotation of the rotating plate and the belt connecting the rotating plate. A horizontal fixing step of fixing the molding to the same position horizontally; An indirect melting step of melting the welded portion by indirect heat at a predetermined distance from the welded portion of the fixed molding; Rotating the molten molding to face each other; A method of thermal welding of a synthetic resin molding comprising a welding step of pressing and welding the moldings opposed to each other.