JP2640257B2 - Manufacturing method of synthetic resin reinforced pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a synthetic resin reinforced pipe used as a plumbing pipe for agricultural and civil engineering, a plumbing pipe for industrial use, and more specifically, a thermoplastic resin molded in advance. Using a belt-shaped sheet, thermoplastic resin strip-shaped tape, and metal tape as raw materials, a large-diameter synthetic resin pipe with a substantially smooth surface and uniform thickness and excellent pressure resistance, internal pressure resistance and water tightness is located near the construction site. The present invention relates to a method for manufacturing a synthetic resin reinforced pipe which can be formed efficiently and continuously.

[Conventional technology]

Conventionally, as a method of manufacturing this kind of synthetic resin reinforced pipe, an extrusion molding method of directly shaping while inserting a metal reinforcing material through a crosshead die of an extruder has been generally used. However, there is a drawback in that the manufacturing cost increases because the apparatus becomes large and a die matching the size of the tube must be prepared each time.

Therefore, when manufacturing a large-diameter synthetic resin tube, a synthetic-resin band member reinforced with metal is spirally wound on a virtual cylindrical rotating shaft, and this is fused or bonded to manufacture a tube member. The method has been used.

[Problems to be solved by the invention]

However, the above manufacturing method uses a single-leaf strip when spirally winding the strip on the top surface of the virtual cylindrical rotary shaft, and the strip wound first and the strip wound later are used. Due to the fact that the tube is formed by winding it as if it overlaps at the side, a thin strip is used because the width of the above-mentioned polymerized part must be widened to maintain a specific thickness. However, when a thick band is used, not only is it impossible to obtain a uniform wall thickness than the moldability of the band, but also there are problems such as the occurrence of a step in the polymerized portion. Was.

The present invention has been invented to solve the disadvantages of the above conventional method, the surface has a substantially smooth and uniform thickness,
It is another object of the present invention to provide a method for manufacturing a synthetic resin reinforced pipe capable of efficiently and continuously forming a large-diameter synthetic resin pipe excellent in pressure resistance, internal pressure and water tightness.

[Means for solving the problem]

The present invention has been devised in view of the above, and has a two-leaf thermoplastic resin strip sheet preformed to form a surface layer and a multi-leaf thermoplastic resin strip tape preformed to form an intermediate layer. And at least one leaf metal tape coated with an adhesive on the surface and heated to a temperature not lower than the softening point and not higher than the melting point of the band-shaped sheet and the band-shaped tape through a heating zone, so that both sides are not located on the same line with each other. As described above, the belt is spirally wound on the imaginary cylindrical rotating shaft while the belt-like tape is interposed between the belt-like sheets so as to be shifted in the lateral direction, and at the same time, the belt-like tape wound at least first and the belt-winding later come into contact with this winding. The wound belt-shaped tape is wound so as to be juxtaposed to each other without polymerization to form a tubular body, and the belt-shaped sheet and the belt-shaped tape are still in a temperature range from a softening point to a melting point. Manufacturing a synthetic resin reinforced pipe, characterized in that in a certain stage, a pipe having a substantially smooth surface is continuously manufactured by press-welding with a pressing roll in contact with a virtual cylindrical rotary shaft body, cooling and hardening the pipe body, and having a substantially smooth surface. It is about the method.

Hereinafter, the features of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partially cutaway perspective view illustrating a manufacturing process of the present invention, FIG. FIG. 3 is a partially cutaway plan view of the same, and FIG. 1 is a thermoplastic resin strip-like sheet forming the surface layer of the tubular body A, which is a polyethylene sheet previously formed in a long shape with a predetermined thickness and width. And a belt-shaped sheet made of a thermoplastic resin sheet such as a polypropylene sheet as a base material, which is wound into a roll,
Reference numeral 2 denotes a plurality of leaves of a thermoplastic resin band-shaped tape for forming an intermediate layer of the tube A, which is wound in a roll shape similarly to the above-mentioned band-shaped sheet 1, and 3 denotes the band-shaped tape. A tape made of stainless steel, steel, aluminum, or the like, coated with an adhesive 4, and the band-shaped sheet 1, the band-shaped tape 2, and the metal tape The tape 3 is heated to a temperature not lower than the softening point and not higher than the melting point of the strip-shaped tape 2 and the metal tape 3 through a heating zone B using a heat source such as hot air or an infrared lamp, and then both sides are not located on the same line with each other. As described above, while the belt-like tape 2 and the metal tape 3 are interposed between the belt-like sheets 1 while being shifted in the lateral direction, the peripheral surface of the virtual cylindrical rotary shaft C is provided with an inclination angle at one end side at the same time. Then, the tube A is wound in a spiral shape and wound so that at least the band tape 2 wound first and the band tape 2 wound later are arranged side by side without superposition. In the stage where the tube A is still at a temperature not lower than the softening point and not higher than the melting point, the tube A is pressure-welded by the pressing roll D in contact with the virtual cylindrical rotary shaft C and cooled while being transferred to the other end. The tube A is formed by being cured.

The virtual cylindrical rotary shaft C shown here is composed of a set of a plurality of rolls C (a), C (b),... C (i) each composed of a round bar, and each roll C (a), C (b),... C (i) are arranged side by side so as to keep a constant distance between adjacent rolls along one virtual circumference, and the front and rear ends thereof are provided on the substrate a.
And the bearing plate b are freely rotatably supported, and a combination of these components substantially constitutes one virtual cylindrical rotary member. Each of the rolls C (a), C
(B), .. c (i) rotate the bearing plate b by a required angle in one direction with respect to the substrate a,
(A), C (b), ..C (i) are supported on the bearing plate b at one end, and by displacing the bearing at the other end, that is, each roll C (a), C (b),. By twisting and tilting .C (i) about the axis of the virtual cylindrical rotating shaft C, the belt-shaped sheet 1, the belt-shaped tape 2 and the metal tape 3 are spirally wound.

Each of the rolls C (a), C (b),... C (i) is provided with a sprocket c at the front end thereof. (B), .. C
(I) is rotated at a constant speed in the same direction.

In order to further improve the water tightness, the belt-shaped sheet 1 used in the present invention was spirally wound around the imaginary cylindrical rotating shaft C, and was wound first and thereafter. The belt-shaped sheet 1 can be wound so as to be polymerized at the side portions, and can be formed so as to be thinner and wider than the belt-shaped tape 2 so that the step of the polymerized portion after winding is extremely small. Preferably, the band-shaped tape 2 is made of a relatively thick material within a range allowable for molding. Therefore, as shown in FIG. It is preferable to use a composite tape having a resin layer.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings.A two-leaf strip composed of a low-density polyethylene sheet having a thickness of 0.5 mm that has been formed in advance and wound into a roll to form a surface layer. Layering of a sheet 1 and a high-density polyethylene sheet and a low-density polyethylene sheet which are preformed and rolled into a roll to form an intermediate layer and have a thickness of 1 mm and a width equal to or less than half that of the belt-shaped sheet 1 A four-leaf strip-shaped tape 2 made of a sheet and a metal tape 3 made of a steel sheet having a thickness of 0.5 mm and a width equal to or less than half of that of the strip-shaped sheet 1 are passed through a heating zone 6B using hot air as a heat source, thereby forming a strip-shaped sheet. 1
By heating to a temperature equal to or higher than the softening point and lower than the melting point of the belt-shaped tape 2 and shifting the position in the lateral direction so that both side portions of the four-leaf belt-shaped tape 2 are not located on the same line with each other,
The two-leaf strip-shaped tapes 2 arranged side by side are positioned vertically in two stages, and the metal tapes 3 are interposed between the strip-shaped tapes 2 so as to reach between the strip-shaped sheets 1 and spiral on the virtual cylindrical rotary shaft C. At the same time, the strip-shaped tape 2 wound at least first and the strip-shaped tape 2 wound later are wound side by side so that they do not overlap with each other without being superposed, thereby forming a tube A. At a stage where the pipe A is still at a temperature not lower than the softening point but not higher than the melting point, the surface as shown in FIG. 5 is obtained by press-welding with the pressing roll D in contact with the virtual cylindrical rotary shaft C and cooling and hardening. A substantially smooth tube A was formed.

〔The invention's effect〕

As is clear from the above, the present invention adheres to a surface of a two-leaf thermoplastic resin strip sheet preformed to form a surface layer and a plurality of preformed thermoplastic resin strip tapes to form an intermediate layer. At least one leaf metal tape coated with an agent is heated to a temperature not lower than the softening point and not higher than the melting point of the strip-shaped sheet and the strip-shaped tape through a heating zone, so that both sides are not located on the same line with each other in the lateral direction. The belt is spirally wound on the virtual cylindrical rotating shaft while the belt-like tape is interposed between the above-mentioned belt-like sheets with the position shifted, and at least the belt-like tape wound first and the belt-like wound later on hitting this winding A step in which the tape and the tape are wound so as to be juxtaposed to each other without being polymerized to form a tubular body, and the band-shaped sheet and the band-shaped tape are still at a temperature not lower than the softening point and not higher than the melting point. In this configuration, the tube is formed by pressing and fusing with a pressing roll in contact with the virtual cylindrical rotating shaft and cooling and hardening it. It enables continuous molding of a tube with a uniform thickness and a substantially smooth surface. Furthermore, since the surface layer and a plurality of intermediate layers and reinforcing layers are simultaneously wound, formability, pressure resistance and internal pressure resistance are improved. However, since the strip-shaped sheet and the strip-shaped tape to be layered are wound so as to be different from each other, the water-tightness is further improved.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a partially cutaway perspective view illustrating a manufacturing process of the present invention, FIG. FIG. 3 is a partially cutaway plan view of the same, FIG. 4 is a partially enlarged cross-sectional view showing an example of a thermoplastic resin strip tape used in the present invention, and FIG. 5 is a view of a tube formed by the present invention. FIG. 3 is a partially enlarged cross-sectional view. DESCRIPTION OF SYMBOLS 1 ... Strip-shaped sheet 2 ... Strip-shaped tape 3 ... Metal tape A ... Tubular body B ... Heating area C ... Virtual cylindrical rotary shaft body D ... Press roll

Claims (5)

(57) [Claims] An adhesive is applied to the surface of a two-leaf thermoplastic resin strip formed in advance to form a surface layer, a plurality of thermoplastic resin strip tapes formed in advance to form an intermediate layer, and the surface. At least one leaf of the metal tape is heated to a temperature not higher than the softening point and lower than the melting point of the band-shaped sheet and the band-shaped tape through a heating zone, and the positions are shifted laterally so that both sides are not located on the same line with each other. It is wound spirally on a virtual cylindrical rotary shaft body while interposing a band-shaped sheet between the band-shaped sheets, and at least the band-shaped tape wound first and the band-shaped tape wound later are polymerized in this winding. And forming a tubular body by winding them so that they are juxtaposed to each other, at a stage where the band-shaped sheet and the band-shaped tape are still at a temperature not lower than the softening point and not higher than the melting point. Method for producing a synthetic resin reinforced pipe, characterized in that at pair contact pressing roll in guinea body was cooled cured by press fusion bonding surface to continuously produce a substantially smooth Naru tube. 2. The method according to claim 1, wherein a steel sheet is used as the metal sheet. 3. A helical winding of the belt-like sheet on a virtual cylindrical rotary shaft body is performed by winding the belt-like sheet wound first and the belt-like sheet wound later so as to be superimposed on the side part. The method for producing a synthetic resin reinforced pipe according to claim 1, characterized in that: 4. The method for producing a synthetic resin reinforced pipe according to claim 1, wherein a thinner sheet and a wider sheet are used as the band-shaped sheet than the band-shaped tape. 5. A composite tape comprising a laminated tape of a high-density polyethylene tape and a low-density polyethylene tape as a belt-shaped tape.
The method for producing a synthetic resin reinforced pipe according to the above item.