JPH0226576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a foamed tubular body and a method for manufacturing the tubular body having a foamed layer.

(Prior art) In order to manufacture a tubular body made of a foamed curable resin, an unfoamed resin raw material is poured into a mold having the shape of the desired tubular body, and after being foamed and hardened in the mold,
A method of demolding was being used.

Furthermore, in order to provide heat retention to the piping, a method has been used in which a foam layer serving as a heat retention layer is later formed around the outer periphery of the tubular body.

(Problems to be Solved by the Invention) In order to manufacture a tubular body made of foamed curable resin using the above conventional method, it is only possible to manufacture a tubular body whose length corresponds to the length of the mold, and a continuous long body can only be manufactured. was difficult to manufacture.

In addition, in order to manufacture a tubular body having a foam layer for providing heat retention to piping, molding of the foam layer is performed in a separate process from the molding of the tubular body, which requires labor and increases manufacturing costs. Similarly, it had the disadvantage that it could only produce products with a length that corresponded to the length of the tubular body, and the standard length was regulated by the length of the tubular body.

The present invention has been made in order to eliminate the drawbacks of the prior art described above, and aims to provide a method for manufacturing a foamed tubular body and a tubular body having a foamed layer in one step.

The gist of the first invention is a core type that is wound spirally along the outer peripheral surface of a cylindrical support and moves in the axial direction of the support while rotating the support surface in the circumferential direction. Then, the belt was wound spirally along the inner circumferential surface of a cylindrical body provided concentrically with the core mold, so that it circulated endlessly through the outside of the cylindrical body. An annular molding cavity is formed between the core mold and the outer mold, and the foamed curable molding material is poured into the annular molding cavity while rotating and moving the belts of the core mold and the outer mold in the same direction at a constant speed. This method of manufacturing a foamed tubular body is characterized in that the foaming material is supplied and foamed and hardened while being rotated and moved within the annular molding cavity as a core belt and an outer mold belt move.

The gist of the second invention is a core type that is spirally wound around the outer circumferential surface of a cylindrical support body and moves in the axial direction of the support body while rotating the support surface in the circumferential direction. A reinforcing layer made of non-foamed fiber-reinforced resin is formed on the top of the cylinder, and a belt is wound spirally along the inner circumferential surface of the cylinder, which is provided concentrically with the core. An annular molding cavity is formed between the core mold and the outer mold, which are endlessly circulated through the outside of the core mold, and the belt of the core mold and the outer mold are moved in the same direction at a uniform speed. The foamed curable molding material is supplied into the annular molding cavity while the molding material is being pressed, and the foaming hardening is carried out while rotating and moving in the annular molding cavity as the core belt and the outer mold belt move. This is a method for manufacturing a tubular body having a foam layer. Next, an embodiment of the first invention will be described with reference to the drawings.

In the figure, reference numeral 1 is a core type, and one end of a cylindrical support 12 is fixed to a support stand 11, and a belt 13 is wound spirally along the outer circumferential surface of this support 12. The belt 13 can move in the axial direction of the support 12 while rotating in the circumferential direction on the surface of the support 12. This belt 13 is configured to circulate endlessly through the interior of the support body 12.

In this core type 1, the belt 13 is attached to the support body 12.
To circulate along the outer circumferential surface of the belt 13
It is preferable to use a metal belt or the like and use a bearing or the like between it and the support 12 to pull the belt 13. However, a belt-shaped cardboard is supplied as the belt 13 on the support 12, and a spiral is applied to the surface of the support. A rubber belt (not shown) that is driven by being wound in a figure 8 shape and brought into contact with the surface of the wound cardboard.
The paper tube may be rotated and moved while forming the paper tube. In this case, the inner surface of the foamed tubular body into which the paper tube is molded is formed, but it may be removed after the foamed tubular body is molded.

Further, 2 is an outer mold, in which a belt 22 spirally runs along the inner peripheral surface of the cylindrical body 21 concentrically with the core mold 1.
The belt 22 is wound around the cylindrical body 21 in an endless manner, and as a result of the circular movement of the belt 22, the inner circumferential surface of the outer mold is rotated in the circumferential direction. It is configured to move in the axial direction while rotating.

In this outer mold 2, a rigid belt such as a metal belt is used as the belt 22, and the belt 22 is forcibly fed into the cylindrical body 21 by a roll 23 driven in the direction of the arrow. While being pressed along the inner circumferential surface of the wire, the wire is wound while sliding on the inner circumferential surface. At this time, the side edges of the belt 22 wound around the circumferential surface of the cylindrical body are brought into close contact with each other by the belt fed in later, and the belts are rotated and fed while sliding, so that the belts are wound together without any delay.

Further, when the belt 22 is wound spirally, the side edges of the belts are fitted with concaves and convexes, and
If the cylindrical body 21 in the part where the belt 22 is fed into the cylindrical body 21 is provided with a guide that guides the side edge of the belt 22 in order to determine the direction in which the belt 22 is pushed into the cylindrical body 21, the circular operation of the belt 22, that is, the belt 22
It is possible to smoothly wind the side edges of the winding in close contact with each other.

In the present invention, an annular molding space 3 is formed between the belts of the core mold 1 and the outer mold 2, and the belt 13 of the core mold 1 and the belt 22 of the outer mold 2 are moved in the same direction at a constant speed. By rotating and moving the ring, the annular molding cavity 3 is held by the belts 13 and 22 and is moved in the axial direction while rotating in the circumferential direction.

In the first invention, a foamed curable molding material is supplied into the annular molding cavity 3, and foamed and hardened while rotating and moving as the belts 13 and 22 rotate. The annular molding cavity 3 moves while the belt 13 of the core mold 1 and the belt 22 of the outer mold 2 rotate in the same direction at the same speed, so that the inner and outer surfaces of the cavity 3 do not shift as they move. Because of the rotational movement, when the foam curable molding material foams, its dimensions are regulated by the inner and outer surfaces of the cavity 3, and the foamed tubular body can be molded by rotating and moving while maintaining this state. The foamed and hardened tubular body is guided from the end of the core mold 1 first and cut into a predetermined length.

As a foam curable molding material, it has foamability,
Any material that is initially liquid and that foams and hardens within a relatively short period of time may be used, such as a prepolymer for producing polyester resin with a foaming agent added,
A mixture of a polyisocyanate and a polyhydric alcohol for producing a polyurethane resin is suitable, and initial condensates of phenolic resins, initial condensates of urea resins, etc. can also be used.

These foam curable molding materials are molded into an annular shape.
In order to supply the cylindrical body to
It is also possible to coat the surface of the belt 22 facing the annular molding cavity 3 to a predetermined thickness while it is outside the cylinder body 1 and then wind the belt 22 along the inner surface of the cylindrical body 21.

Next, in the second invention, the core type is wound spirally along the outer peripheral surface of the cylindrical support and moves in the axial direction of the support while rotating the support surface in the circumferential direction. Glass roving 4 on which thermosetting resin liquid such as unsaturated polyester resin is impregnated in advance
Then, as in the first invention, the belts 13 and 22 of the core mold 1 and the outer mold 2 are rotated in the same direction at a constant speed while moving and hardening, and the foamed curable molding material is poured into the annular molding cavity. A tubular body having a foam layer can be manufactured by supplying the foam and foaming and hardening it while rotating and moving it with the belts 13 and 22.

In addition, after forming a foamed tubular body having a reinforcing layer on the inner surface in the annular molding chamber 3, while moving it onto the core mold 1, a material similar to that of the reinforcing layer on the inner surface is applied to the outer surface. By forming the reinforcing layer 5,
It is possible to obtain a tubular body with a foam layer in the middle,
By providing the foam layer, a tubular body with excellent heat retention can be obtained. In addition, by forming fiber-reinforced resin layers on the inner and outer layers, a tubular body that has not only heat retention properties but also heat resistance and corrosion resistance can be obtained, and can be used as hot spring hot water supply pipes, district heating pipes, hot water supply pipes for solar water heaters, and chemical liquid transport pipes. It can be suitably used for etc.

In the present invention, the dimensions of the core mold 1 and the outer mold 2, the rotational speeds of the belts 13 and 22, etc. are appropriately determined depending on the dimensions of the tubular body to be molded, the foaming curing time of the foaming curable molding material, etc.

(Effects of the Invention) The method for manufacturing a foamed tubular body according to the first invention has the configuration as described above, and the core belt and the outer belt are both rotated in the circumferential direction and moved in the axial direction. During this process, the foamed curable molding material supplied to the annular molding cavity is regulated by synchronizing the rotational movements of the belts of the core mold and the outer mold, so that the inside and outside surfaces of the foamed curable molding material supplied to the annular molding cavity are regulated. The foam can be continuously foamed and cured, and a foamed tubular body can be continuously produced.

In the second invention, since the reinforcing layer can be molded on the inner and outer surfaces of the foam layer in the same process, the tubular body having the foam layer can be easily manufactured, and the tubular body that is continuously molded can be cut. By doing this, any length can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the - line in FIG. 1. DESCRIPTION OF SYMBOLS 1... Core mold, 11... Support stand, 12... Support body, 13... Belt, 2... Outer mold, 21... Cylindrical body, 22... Belt, 23... Roll, 3... Annular molding Empty, 4...Glass roving, 5...Reinforcement layer.

Claims (1)

[Claims] 1. In a spiral manner along the outer peripheral surface of a cylindrical support body.
A core mold that is wound around the support body and moves in the axial direction of the support body while rotating in the circumferential direction on the surface of the support body, and a belt that runs along the inner circumferential surface of a cylindrical body that is provided concentrically with the core mold. An annular molding cavity is formed between the outer mold, which is wound in a spiral shape and circulates endlessly through the outside of the cylindrical body, and the belt between the core mold and the outer mold The foamed curable molding material is supplied into the annular molding cavity while rotating and moving in the same direction at a constant speed, and the core belt and the outer mold belt rotate within the annular molding cavity as they move. A method for manufacturing a foamed tubular body, characterized by foaming and hardening while moving the body. 2 spirally along the outer peripheral surface of the cylindrical support
A reinforcing layer made of non-foamed fiber-reinforced resin is formed in advance on a core mold that is wound around the core mold and moves in the axial direction of the support body while rotating in the circumferential direction on the surface of the support body. A belt is wound spirally along the inner circumferential surface of a cylindrical body provided in the cylindrical body, and an annular molding is formed between the belt and the outer mold, which is made to circulate endlessly through the outside of the cylindrical body. A cavity is formed, and the foamed curable molding material is supplied into the annular molding cavity while rotating and moving the belts of the core mold and the outer mold in the same direction at a constant speed. A method for manufacturing a tubular body having a foam layer, characterized in that foaming and hardening is carried out while rotating and moving an inner core belt and an outer belt as they move.