JPH07266426A - Bonding method of polyethylene sheet and vulcanized rubber sheet - Google Patents

Abstract

PURPOSE:To enhance the bonding strength and prevent polyethylene sheet from deforming and gapping by a method wherein ribbon-like or strap-like polyethylene is extruded with an extruder under the condition that low density polyethylene tape is interposed between vulcanized rubber sheet and polyethylene sheet for bonding both the sheets together. CONSTITUTION:Under the condition that the bonding edge of polyethylene sheet 2 and that of vulcanized rubber sheet 1 are overlapped each other and, between the bonding edges, low density polyethylene tape 3 having the same breadth as their bonding breadth is pinched, both the sheets are welded together by being heated from below and above at 130-200 deg.C. In the usage of the polyethylene tape 3, since bonding force emerges only after the solidification of the polyethylene of the bonding tape, full welding can be realized through thermally welding with a hot press. Another bonding method is to extrude polyethylene 4 in the form of ribbon to the polyethylene sheet 2 and the vulcanized rubber sheet 1 under the state that the polyethylene tape 3 is interposed between the sheets. The bonding principle by the polyethylene 4 extruded in the form of ribbon is the same principle as that of the thermal welding just mentioned above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining a polyethylene sheet and a vulcanized rubber sheet, which are favored for their good weather resistance and are used in civil engineering, particularly waterproof sheets. In particular, a method of joining a polyethylene sheet and a vulcanized rubber sheet by sandwiching a polyethylene tape between the polyethylene sheet and the vulcanized rubber sheet and extruding ribbon-shaped or string-shaped polyethylene with an extruder or heat-sealing the polyethylene tape It is about improvement.

[0002]

2. Description of the Related Art Conventionally, a polyethylene sheet and a vulcanized rubber sheet have been bonded to each other by 1) applying a rubber-based adhesive to both sides of the sheet and bonding after drying 2) rubber-based bonding via an adhesive tape 3) Method of applying adhesive agent and bonding 3) Method of sandwiching and sticking double-sided adhesive tape between sheets 4) Method of sandwiching unvulcanized rubber tape between the adhesive surfaces and fusion bonding with a heat press machine It was However, in the case of the method of using these adhesives 1, 2, and 3, since the adhesive strength is low, it is necessary to provide a wide adhesive area. This area is a so-called glue margin portion, and a wide area reduces the effective use area of the polyethylene sheet and the vulcanized rubber sheet as a sheet. In addition, such a bonding method has a drawback that the bonded portion is easily peeled off, and therefore, in order to prevent this, a reinforcing tape coated with an adhesive must be overlapped on the bonded edge paragraph to prevent peeling. Further, in the case of the heat fusion bonding method using an unvulcanized rubber tape, although the adhesive force is large, there is a drawback that the polyethylene sheet itself is melted during heating, causing deformation and perforation.

[0003]

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a joining method for joining a polyethylene sheet and a vulcanized rubber sheet, which has a strong adhesive strength and is free from deformation or perforation of the polyethylene sheet itself. It is intended.

[0004]

[Means for Solving the Problems] The present invention has been achieved as a result of intensive research to solve the above problems. That is, a low-density polyethylene tape is interposed between a vulcanized rubber sheet and a polyethylene sheet to extrude and bond ribbon-shaped or string-shaped polyethylene, and a low-density polyethylene tape is interposed between the vulcanized rubber sheet and the polyethylene sheet. , Heat fusion and adhesion.

In contrast to such a conventional method, the present inventors have researched and developed a method of fusion-bonding a polyethylene tape to a vulcanized rubber sheet by heat-sealing the polyethylene tape. In this method, the ethylene chains contained in the vulcanized rubber sheet are eutectic with the crystalline micelles generated when the molten polyethylene tape is solidified, so that the vulcanized rubber sheet and the polyethylene sheet can be strongly bonded. However, in the method of using this polyethylene tape, since the adhesive force appears only after the polyethylene of the joining tape is solidified, it is necessary to perform heat fusion using a heat press instead of a manual or movable heat fusion device. Can be completely fused. In the hot pressing, the silicone rubber can be wrapped around the contacting side of the polyethylene sheet for heat fusion.

The polyethylene tape used in the present invention is
Additives such as lubricants and mold release agents usually used,
It can be manufactured by extrusion molding or calender molding. In the joining method of the present invention, the joining edge 1a of the vulcanized rubber sheet is overlapped in FIG. 1, the polyethylene tape 3 having a width substantially the same as the joining width is sandwiched therebetween, and heated from above and below at a temperature of 130 to 200 ° C. Fuse for 20 seconds to 25 minutes. In this case, the higher the fusing temperature, the shorter the fusing time. When the polyethylene film and the vulcanized rubber sheet are heat-sealed at the construction site, a heat-sealing machine (hot joint machine manufactured by Toyo Tire & Rubber Co., Ltd.) can be used. This machine can heat-bond the joints of such sheets. By heat-sealing at a speed of about 0.3 to 2 m / min by a method of inserting two fusion plates from a portion which is not yet joined and joining them while backward sliding.

As described above, the method for joining the polyethylene sheet to the heat-sealed polyethylene film on the vulcanized rubber sheet includes a method for extruding a polyethylene ribbon or a string-like object and a method for hot welding (self-propelled type). There is a method of joining using a trowel type heat fusion machine). FIG. 2 shows a polyethylene ribbon-shaped extrusion 4 of the present invention.
FIG. 6 is a cross-sectional view in which a polyethylene tape 3 is interposed between the polyethylene sheet 2 and the vulcanized rubber sheet 1 according to to be joined. Bonding by ribbon-shaped extruded polyethylene is based on the same principle as bonding by heat fusion.

[0008]

[Function] A polyethylene tape is interposed between the polyethylene sheet and the vulcanized rubber and heat-bonded or joined by ribbon-shaped extruded polyethylene.

[0009]

EXAMPLES The present invention will be described in more detail by way of examples. Manufacturing of polyethylene tape Using LLDPE (trade name Sumikasen-L FA-101-0, film, for blowing) manufactured by Sumitomo Chemical Co., Ltd., the mixture shown in Table 1 was mixed by an open roll type mixing machine, Was extruded to produce a polyethylene tape A having a thickness of 1 mm and a width of 150 mm.

[Table 1]

Example 1 A polyethylene tape A was used as a vulcanized rubber sheet (manufactured by Toyo Tire & Rubber Co., Ltd., Toyo Civil Engineering sheet, thickness 1.5 mm).
Place it on the top of the plate and use a heat press machine at 180 ° C for 60 seconds ×
Thermal fusion was performed under the condition of 0.3 kg / cm ² .

Example 2 A high-density polyethylene sheet is produced on a polyethylene tape of a heat-sealed product of a polyethylene tape A and a vulcanized rubber sheet by a Leister-type hot-air welding machine and pressed by a hand roller 5 to perform temporary joining. It was (See Figure 3)
When the surface was smooth, a high density polyethylene and a polyethylene tape were each buffed with a width of about 25 mm using a rotary paper sander as shown in FIG. 4, and the end edge 6a of the high density polyethylene was scraped off. String-shaped (4 mmφ) polyethylene was melt-extruded on the buff surface using an extrusion welder and molded into the shape shown in FIG. The extrusion welder 8 is a polyethylene extruder in which a hot air generator 9 and hot air generated by a trowel are attached to a nozzle 11 of a polyethylene extruder (see FIG. 6).

Example 3 The polyethylene surface of the heat-sealed product of the polyethylene tape A and the vulcanized rubber sheet and the high-density polyethylene sheet were superposed and joined by a hot wedge welder. The hot wedge welder shown in FIG. 7 is a self-propelled heat fusion machine having a nip roll which is rotated by a heat iron and a motor power, the temperature of the heat iron is 360 ° C., the traveling speed by the nip roll rotation is 2.0 m.
/ Min. The cross-sectional shape of the joined product obtained by installing the double wedge 13 in the hot wedge welder is shown in FIG. The double wedge has two heat-sealed parts with a width of about 25 mm.
The joint cross section has a void at the location and at the center of it that does not cause heat fusion. The air channel 14 is a void for buffing the end of the joint to insert compressed air and inspecting for air leakage to find a defective joint in the heat fusion joint.

Example 4 The shear strength of the joint thus obtained was measured. The shear strength was measured by measuring the maximum stress per 1 inch width at break. An autograph type tensile tester was used as a tester, and the test was performed at a pulling speed of 500 mm / min.

[Table 2] As shown in Table 2, strong bonding was obtained until the main body of the vulcanized rubber sheet was broken.

[0014]

According to the joining method by heat-sealing vulcanized rubber sheets according to the present invention, strong joining can be obtained with a much smaller adhesive area than the conventional method using a rubber-based adhesive.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of thermal fusion bonding of the present invention.

FIG. 2 is a schematic sectional view showing adhesion of the ribbon-shaped extruded polyethylene of the present invention.

FIG. 3 is a cross-sectional view showing joining by a Leister type hot air welding machine used in the present invention.

FIG. 4 is a cross-sectional view of a surface buff when the surface is smooth.

FIG. 5 is a cross-sectional view of a ribbon-shaped polyethylene extrusion joint after buffing.

FIG. 6 is a schematic view of a polyethylene extruder used in the present invention.

FIG. 7 is a schematic view of a hot wedge welding used in the present invention.

FIG. 8 is a cross-sectional view of a joint obtained by installing a double wedge on a hot wedge welder.

FIG. 9 is a perspective view of a sample for measuring shear strength of extrusion welding according to the present invention.

FIG. 10 is a perspective view of a sample for measuring the shear strength of the hot wedge welding of the present invention.

[Explanation of symbols]

 1 Vulcanized Rubber Sheet 1a Vulcanized Rubber Sheet Bonding Edge 2 Polyethylene Sheet 3 Polyethylene Tape 4 Ribbon Extruded Polyethylene 5 Hand Roller 6 High Density Polyethylene Sheet 6a High Density Polyethylene Sheet Edge 7 Leister Type Hot Air Welding Machine 8 Extrusion Welding 9 Hot Air Generator 10 Hot air outlet 11 Nozzle 12 Polyethylene extruder 13 Double wedge 14 Air channel 15 Extrusion die 16 Hot wedge welding B Buff H Heat fusion N Hot air

Claims (2)

[Claims] 1. A method for joining a polyethylene sheet and a vulcanized rubber sheet, characterized by interposing a low-density polyethylene tape between the vulcanized rubber sheet and the polyethylene sheet and extruding and adhering ribbon-shaped or string-shaped polyethylene with an extruder. . 2. A method for joining a polyethylene sheet and a vulcanized rubber sheet, characterized in that a low-density polyethylene tape is interposed between the vulcanized rubber sheet and the polyethylene sheet and heat-sealed to bond them.