JP3197111B2 - Manufacturing method of fiber reinforced synthetic resin tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a fiber-reinforced synthetic resin pipe reinforced by reinforcing fibers.

[0002]

2. Description of the Related Art A fiber-reinforced synthetic resin mortar tube used as a sewer pipe has a structure in which a fiber-reinforced synthetic resin layer is disposed on the inner peripheral side and the outer peripheral side of a resin mortar layer. Such a fiber-reinforced synthetic resin mortar tube is usually formed by winding a band-shaped base paper spirally around a rotating mandrel to form a paper tube, and on the formed paper tube, a fiber-reinforced synthetic resin layer on the inner peripheral side, It is manufactured by a paper tube manufacturing method (Japanese Patent Publication No. 48-37139) in which a resin mortar layer and a fiber-reinforced synthetic resin layer on the outer peripheral side are sequentially laminated and cured.

[0003] This paper tube type manufacturing method will be described in detail with reference to FIG. A strip-shaped base paper 23 is spirally wound around a mandrel 21 rotating in the direction of arrow A to form a paper tube 22 continuously. The paper tube 22 formed on the mandrel 21
By being spirally wound around the rotating mandrel 21, the mandrel 21 is sequentially moved on the mandrel 21 in the axial direction indicated by the arrow B. A release film 24 is wound around the paper tube 22, and an inner circumferential fiber-reinforced synthetic resin layer 2 constituting a fiber-reinforced synthetic resin mortar tube is formed on the release film 24.
5. The resin mortar layer 26 and the fiber reinforced synthetic resin layer 27 on the outer peripheral side are sequentially laminated. These laminates are moved in the axial direction by the rotation of the mandrel 21, and are introduced into a curing furnace. The laminated body cured in the curing furnace is cut into a predetermined length, and a fiber reinforced synthetic resin mortar tube is manufactured by removing the internal paper tube 22 and the release film 24.

A paper tube 22 formed on a mandrel 21
Usually, as shown in FIG. 5, when wound on the mandrel 21, the strip-shaped base paper 2 adjacent in the axial direction of the mandrel 21 is used.
3 are wound around the mandrel 21 in three layers with a gap of about 1 mm to 2 mm. As described above, when the adjacent strip-shaped base papers 23 are in a state of being appropriately spaced from each other, the formed paper tube 22 becomes the mandrel 21.
Even when moving upward in the axial direction, the axial force is not applied to the strip-shaped base paper 23, so that the paper tube 22 is prevented from being damaged. Further, since the respective side edges in the width direction of the adjacent strip-shaped base papers 23 do not overlap with each other, there is no possibility that the paper tube 22 is compressed in the axial direction.

[0005]

As described above, the paper tube 22 formed on the mandrel 21 is composed of the adjacent strip-shaped base paper 23.
Since a gap is provided therebetween, a concave portion is spirally formed on the surface. For this, the paper tube 22
While the fiber-reinforced synthetic resin layer 25 on the inner peripheral side, which is laminated via the release film 24 thereon, hardens,
It enters into the recess formed on the outer peripheral surface together with the release film 24. When the resin that has entered the concave portion is cured, a spiral convex portion is formed on the inner peripheral surface of the manufactured fiber-reinforced synthetic resin mortar tube.

If a helical convex portion is formed on the inner peripheral surface of the fiber reinforced synthetic resin mortar tube, the internal paper tube 21 cannot be pulled out from the fiber reinforced synthetic resin mortar tube. Has to be crushed and removed, and there is a problem that the removal operation takes time.

[0007] The spiral projections formed on the inner peripheral surface of the fiber reinforced synthetic resin mortar tube not only impair the aesthetic appearance but also may deteriorate the water flow performance of the fiber reinforced synthetic resin mortar tube.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a fiber-reinforced synthetic resin tube which has excellent water passage performance without a risk of forming a spiral convex portion on the inner peripheral surface. And to provide a method for efficiently producing the same.

[0009]

According to the present invention, there is provided a method for producing a fiber reinforced synthetic resin tube, comprising: forming a paper tube by spirally winding a strip-shaped base paper around a rotating mandrel; a laminating the thermosetting resin layer, laminating a release film to the thermosetting resin layer, by laminating the respective resin layers constituting the fiber-reinforced synthetic resin pipe in the release film A step of forming a laminate, and placing the laminate in a curing furnace.
Heating and curing each resin layer, and curing
After cutting the laminate taken out of the furnace to a predetermined length,
Withdrawing the cured thermosetting resin layer together with
And the above object is achieved.

[0010]

Since the thermosetting resin is laminated on the paper tube formed on the mandrel, the gap between the strip-shaped base papers constituting the paper tube is filled with the thermosetting resin. Then, a release film is laminated on the smoothed surface of the thermosetting resin, and each resin layer constituting the fiber-reinforced synthetic resin tube is laminated on the release film. Each resin layer is heated and cured together with the paper tube. Thereafter, the paper tube is taken out from the inner peripheral surface of the fiber-reinforced synthetic resin tube together with the cured thermosetting synthetic resin layer, and a fiber-reinforced synthetic resin tube having an inner peripheral surface smoothed is manufactured.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

The present invention is practiced when manufacturing a fiber reinforced synthetic resin mortar tube in which a fiber reinforced synthetic resin layer is disposed on the inner peripheral side and the outer peripheral side of the resin mortar layer, respectively.

FIG. 1 is a schematic structural view showing an example of a method for manufacturing a fiber-reinforced synthetic resin mortar tube of the present invention, FIG. 2 is a longitudinal sectional view of a main part thereof, and FIG. 3 is a transverse sectional view thereof.

In this manufacturing method, a mandrel 1 rotated in the direction shown by arrow A is used. This mandrel 1
, The strip-shaped base paper 3 is spirally wound around the mandrel 1.
The paper tube 2 is formed on the outer peripheral surface of the paper tube. The band-shaped base paper 3 is shown in FIG.
As shown in FIG. 2, strip-shaped base papers 3 adjacent to each other in the width direction are wound around three layers on the outer peripheral surface of the mandrel 1 with a gap of about 1 to 3 mm. At this time, the gaps between the strip-shaped base papers 3 in the layers vertically adjacent to each other do not overlap with each other. As a result, a spiral concave portion is formed on the outer peripheral surface of the paper tube 2.

As shown in FIG. 1, the mandrel 1 is rotated in the direction of the arrow A so that the paper tube 2 formed of the helically wound strip-shaped base paper 3 is moved in the axial direction indicated by the arrow B. It is moved sequentially. The strip-shaped base paper 3 constituting the paper tube 2 is
Since they are adjacent to each other with a gap in the axial direction, there is no fear that the strip-shaped base paper 3 is subjected to stress in the width direction when the belt-like base paper 3 is moved in the axial direction, so that the paper tube 2 is not damaged, and that the paper tube 2 is compressed in the axial direction. Nor.

As described above, when the strip-shaped base paper 3 is wound around the mandrel 1 over three layers to form the paper tube 2,
On the paper tube 2, a thermosetting resin layer 4 is laminated. The thermosetting resin layer 4 is laminated so as to completely cover the strip-shaped base paper 3 constituting the outer peripheral surface of the paper tube 2. Thermosetting resin layer 4
Enters a spiral recess formed on the outer peripheral surface of the paper tube 2 and fills the gap. The thermosetting resin layer 4 is made of, for example, an unsaturated polyester resin containing 1.5% of a curing agent.

When the thermosetting resin layer 4 is laminated on the paper tube 2, a strip-shaped release film 5 is spirally wound and laminated so as to cover the entire thermosetting resin layer 4. .

When the release film 5 is wound on the thermosetting resin layer 4, the fiber-reinforced synthetic resin layers 7 and 9 are formed on the release film 5 on the inner and outer peripheral sides of the resin mortar layer 8. Are arranged to form a fiber-reinforced synthetic resin mortar tube 6.

The fiber-reinforced synthetic resin layer 7 on the inner peripheral side constituting the inner peripheral side of the fiber-reinforced synthetic resin mortar tube 6 is formed by impregnating a long fiber glass fiber with an unsaturated polyester resin containing 1% of a curing agent. The fiber reinforced synthetic resin layer 7
Is spirally wound and laminated on the release film 5 over the entire surface. The release film 5 prevents the fiber-reinforced synthetic resin layer 7 from mixing with the thermosetting resin layer 4 below the release film 5.

Next, a resin mortar layer 8 is laminated on the fiber reinforced synthetic resin layer 7, and a fiber reinforced synthetic resin layer 9 on the outer peripheral side is laminated on the resin mortar layer 8. The fiber-reinforced synthetic resin layer 9 on the outer peripheral side is also impregnated with long-fiber glass fibers with an unsaturated polyester resin containing 1.5% of a curing agent.

As described above, when the fiber-reinforced synthetic resin layer 7, the resin concrete layer 8, and the fiber-reinforced synthetic resin layer 9 are sequentially laminated on the paper tube 2 provided on the mandrel 1, the mandrel 1 As the paper tube 2 is sequentially moved in the axial direction by the rotation, the laminate is introduced into a curing furnace together with the paper tube 2 and heated. Thereby, each resin layer is cured.

On the paper tube 2 carried out of the curing furnace, a cured thermosetting resin layer 4, a release film 5, and a fiber-reinforced synthetic resin mortar tube 6 are laminated.
Then, the fiber reinforced synthetic resin mortar tube 6 is cut into a predetermined length together with the paper tube 2, the thermosetting resin 4, and the release film 5, and the paper tube 2 on the inner peripheral surface of the fiber reinforced synthetic resin mortar tube 6 is cut. Is extracted from the fiber-reinforced synthetic resin mortar tube 6 together with the cured thermosetting resin layer 4. At this time, the release film 5 is in a state where the inner peripheral surface of the fiber-reinforced synthetic resin mortar tube 6 and the outer peripheral surface of the thermosetting resin layer 4 are separated from each other. Since the surfaces are smooth, the cured thermosetting resin layer 4 and the paper tube 2 can be easily removed from the inner peripheral surface of the fiber-reinforced synthetic resin mortar tube 6. Thus, a fiber-reinforced synthetic resin mortar tube 6 having a predetermined length with an inner peripheral surface smoothed is manufactured.

[0023]

As described above, the method for producing a fiber-reinforced synthetic resin tube of the present invention is based on the fact that the thermosetting resin layer is provided on the paper tube formed by winding the strip base paper on the mandrel. Even if a gap is formed between adjacent strip-shaped base papers, there is no possibility that a protrusion is formed on the inner peripheral surface of the manufactured fiber-reinforced synthetic resin tube, and the inner peripheral surface is smooth. Is obtained. Since the cured fiber-reinforced synthetic resin tube has a smooth inner peripheral surface, the paper tube can be easily pulled out, and the working efficiency is significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one example of a method for producing a fiber-reinforced synthetic resin tube of the present invention.

FIG. 2 is a longitudinal sectional view thereof.

FIG. 3 is a cross-sectional view thereof.

FIG. 4 is a schematic configuration diagram showing a method for manufacturing a conventional fiber-reinforced synthetic resin tube.

FIG. 5 is an enlarged view of the main part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mandrel 2 Paper tube 3 Strip base paper 4 Thermosetting resin layer 5 Release film 6 Fiber reinforced resin mortar tube 7 Fiber reinforced synthetic resin layer 8 Resin mortar layer 9 Fiber reinforced synthetic resin layer

Claims (1)

(57) [Claims] 1. A step of spirally winding a strip-shaped base paper around a rotating mandrel to form a paper tube; a step of laminating a thermosetting resin layer on the formed paper tube; laminating the release film onto the layer, the respective resin layers constituting the fiber-reinforced synthetic resin pipe in the release film laminated
Forming a laminate by introducing the laminate into a curing furnace.
And heating to cure each resin layer.
After cutting the laminate taken out of the machine into a predetermined length, the paper tube is hardened.
And a step of extracting the fiber-reinforced synthetic resin tube together with the converted thermosetting resin layer .