JPS5831714A - Method of welding polyethylene member - Google Patents

Abstract

PURPOSE:To weld PE sheets having different thicknesses using an impulse sealing machine, by heating and pressing the PE sheets by heating plates, the temperature of the heating plates located on the side of the thinner PE sheet being higher than that of the heating plate located on the side of the thicker PE sheet. CONSTITUTION:The heating plates 9, 10 are secured respectively to upper and lower beds 7, 8 of the impulse sealing machine, and are coated with Teflon sheets 6. Using the upper and lower heating plates 9, 10, the thicker PE sheet 11 and the thinner PE sheet 12 are welded. In this case, the temperature of the heating plate 10 on the side of the thinner PE sheet is to be higher than that of the heating plate 9 on the side of the thicker PE sheet. Thus, the PE sheets that are different in the thickness can be welded together by the impulse sealing machine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for welding polyethylene members, and particularly to a method for welding polyethylene members of different thicknesses together by heat sealer impulse welding.

For example, conventionally, synthetic resin parts such as ceiling screens attached to automobile door panels, etc., have a large thickness. When parts are welded, high frequency welding is generally performed using polyvinyl chloride # (hereinafter referred to as PvO).

However, in recent years, it has been proposed to use polyethylene (hereinafter referred to as PI) in the above-mentioned ceiling screen instead of PVO from the viewpoint of weight reduction, which leads to lower costs and improved fuel efficiency of automobiles. When using members of the same thickness, p1! Since l has a smaller specific gravity than PvC, it not only can reduce weight, but also has the advantage of reducing cost since PI and PvC have almost the same cost per unit weight.

However, PI has a small dielectric loss (tan δ), making high frequency welding impossible, and PI! [When welding parts, heat sealer impulse welding, which directly heats the parts, is generally used. In this method, films or sheets as P'lAgg materials to be welded to each other are superimposed and supported on the 10,000 table of an impulse sealing machine, for example, the lower table, and the heat applied to the other table of the impulse sealing machine, that is, the base, is heated. The plate is lowered toward the lower stand, pressed against the film or sheet, and the sheet is welded by applying electricity to the hot plate.

Figure 1 shows the conventional welding method of pH [1% material] As shown in the figure, in the conventional method, the PR film or Pl sheet l to be welded to each other is overlaid on the lower base 3 of the impulse sealing machine. Lower the upper stand S with the hot plate attached to it toward the lower stand 3, press the hot plate 1 against the upper FIB sheath), and press both PI sheaths).
Electrification is applied to the hot plate in the state in which / and ) are pressed together, causing the hot plate to generate heat. This heats the parts of the overlapping P1 sheets that are to be welded together while pressing them together. Both P'l sheets) 1 and 2 are welded.

In the figure, 6 is a Teflon sheet coated on the surface of the heat plate, which prevents the hot plate from touching the P1 sheet during welding, and prevents the hot plate from touching the P1 sheet after welding is completed. AM paper is used to facilitate separation.

However, in the conventional method as described above, the PAW sheets are welded by attaching a hot plate only to either the base or the lower stand of the impulse sealing machine. Sheet F is heated only from one side, and through this one P1 sheath is heated to the other PI!
The joining surfaces of the sheets are heated to a welding temperature. Therefore, P to be welded]! If the thickness of the sheet is different, for example, if the P1 sheet on the side that the hot plate contacts is thicker than the PM sheet on the other side, the PhB on the thicker side
Of course, this thick side PH! Heat T to a temperature that allows welding of the thin PI receipt on the bottom through the sheet.
It is necessary to raise the temperature of the hot plate to a temperature sufficient to
As a result, there is a problem in that the upper thick P1 sheet is deformed. Also, if the P1B sheath on the side that the 1 heating plate contacts is thinner than the WE receipt on the other side, the PI on the thicker side! l
It is necessary to raise the temperature of the hot plate to a temperature sufficient to heat the sheet F to a temperature at which it can be welded, and as a result, the problem arises that the thinner PI sheet F is burned out. For this reason, in the conventional heat sealer impulse welding method, P
l! It was practically impossible to weld Sea F.

The present invention has been made in view of the above-mentioned conventional problems, and when welding P1 sheets of different thickness, both Pal sheets are crimped and heated from both sides with hot plates, and a thin Adjust the temperature on the pH sheet side to a thick P'B
The purpose is to solve the above problems by making the temperature higher than that on the sheath side.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 is a diagram showing an embodiment of the present invention, in which a hot plate 9 and an IO are fixed to the upper and lower floors and r of an impulse sealing machine, respectively, and each hot plate is coated with a Teflon sheath 6. , thick P using these upper and lower hot plates 9#IO
Weld Ill C) // and thin P11 C)/J.

Therefore, when performing welding work, first set the PI combs -//, /2 having different thicknesses into the impulse sealing machine, and then, for example, step on a foot switch to start the impulse sealing machine. As a result, the hydraulic cylinder (8!J not shown) is actuated (the upper table 7 is lowered, and the hot plate 9 and the hot plate 10 attached to the upper table 7 are activated to open both PE seats).
, /2 are brought into pressure contact with each other.

At this time, a microswitch is turned on and a seal timer is activated. During the operation time of this seal timer, is the heating plate passed through the electromagnetic contactor, transformer, etc. for the heater? A current corresponding to the plate thickness is passed through the heater wires 9 and 10, respectively, and as a result, the hot plates 9 and 10 are heated to a certain temperature, and each of the hot plates 9 and 10 generates P'IA C) /I,
/J respectively, and welded for 11 times. The operation of the seal timer is completed 61, the cooling timer is activated, the cylinder device continues to tighten and cool, and at the same time as the operation of the cooling timer ends, the cylinder device closes the upper table 7.
rises to complete the l operation.

In carrying out the present invention, in order to obtain the required tensile strength of the weld, as will be clear from the examples described below,
It is better to weld the thinner pH sheet side by heating from both sides so that the temperature is higher than the thicker PIA sheet side.

Presentation 1 and main thickness 0. j us's thick Flit sheesh and thick o, o
Thin PI receipts of seagulls were welded using upper and lower hot plates coated with Teflon as shown in Figure Ill.

The temperature of the lower heating plate in contact with the thin PIil sheet is /70"
Welding was carried out at various temperatures of the upper hot plate in contact with the thick Phi sheet, and the change in the tensile strength of the welded part of the P'IA sheet after welding with respect to the upper hot plate temperature was measured. The measurement results are plotted in FIG. 3 and are indicated by curves.

Example 2 Thick P1 with a thickness of 0.1-! i sea F and thickness O, OS ■
Thin Pl! The ll sheet was welded under the same conditions as in Example 1. Thick PIi! The change in the weld tensile strength with respect to the temperature of the upper hot plate in contact with the sheet was measured, and the measurement results are plotted in FIG. 3 and indicated by curve IIB.

Example 3 Thickness 0. A thick P'l sheet and a thin P:ll sheet of 0.01-thickness were welded together using upper and lower hot plates coated with Teflon, as shown in FIG.

The temperature of the lower hot plate in contact with the thin El sheet was set at 100°C to 0°C, and the temperature of the upper hot plate in contact with the thick P1 sheet was varied to perform welding.
The change in the tensile strength of the welded part of the l sheet was measured.0 The measurement results are printed in the figure below and shown in one song JIO. A thin PIll sheet with a thickness of 0.01 m was welded under the same conditions as in Example 3. Thick Pl! The change in the tensile strength of the welded part of the ll sheet with respect to the temperature of the upper hot plate on which the ll sheet is attached was measured, and the measurement results were plotted in Figure 1 and shown as a single curve. Thin P
By lowering the heating temperature of the hot plate in contact with the thick PM sheet compared to the heating temperature of the hot plate in contact with the thick PM sheet, the required tensile strength of the welded portion can be obtained.

As explained above, according to the present invention, when Pl members having different thicknesses are welded together using an impulse sealing machine, the overlapping parts to be welded are crimped,
A hot plate is pressed against both sides of a Pli member, and each hot plate is pressed against the pHll! By heating the hot plates to a temperature corresponding to the thickness of the Is material and welding them, it is possible to weld 2119 members with different thicknesses to each other using an impulse sealing machine.

[Brief explanation of the drawing]

Fig. 117 is an explanatory diagram showing a conventional method of welding ll sheets by an impulse sealing machine, Fig. 2 is an explanatory diagram showing a method of welding ll sheets of different thicknesses according to the present invention, 9
Figure 3 and the reference figures are graphs showing the relationship between the hot plate temperature and the tensile strength of the welded part.
to...lower heating plate, //...P1g sheet as thick p:s@m material, /2...Ple sheath as thin Pl member. .

Claims (1)

[Claims] L: When welding polyethylene members of different thicknesses by heating from both sides, the thinner polyethylene member side (from both sides) is heated to a higher temperature than the thicker polyethylene member side. A method for welding polyethylene parts.