JPH0240489B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a cylindrical synthetic resin foam, which is used as a heat-retaining tube and whose inner and outer surfaces are covered with a covering material such as paper or a synthetic resin sheet and which has one crack in the longitudinal direction. It is.

Conventionally, various methods have been provided for manufacturing the above-mentioned heat-retaining tubes.
-19705 gazette and Japanese Patent Publication No. 49-29953 disclose that a cylindrical body having a stop communicating from end to end is used as a mold for regulating the external shape, and a core type is inserted into the cylindrical body to form a molding passage. The two sheets forming the outer and inner surfaces of the heat insulating tube are stacked together and curved so that both ends are upward, and introduced into the passageway between the two sheets. A foamable resin liquid is injected into the molding passageway, and both ends of the sheet taken out from the slit of the cylinder are held and pulled by an appropriate transfer means, and the foamable resin liquid is injected into the molding passage. A method for manufacturing a heat-retaining tube by foaming and hardening a liquid is disclosed.

However, in such a method, as described above, the material is advanced by pinching and pulling the edges of the sheet, which are the inner and outer surface forming materials, that is, the edges protruding outside the molding path, so the outer surface forming sheet Due to the high tension, it is difficult to obtain a perfectly round product.
Furthermore, it has the disadvantage that the foam density tends to be non-uniform due to excessive tension, and as a result, many defective products are produced and molding must be carried out with great care.

In addition, in order for the synthetic resin foam inside the heat insulating tube to form uniform and fine cells throughout and to ensure sufficient adhesion with the outer layer material, it is necessary to heat it for curing after foaming. Preferably, but
As in the conventional method described above, if excessive stress is applied to the outer layer material, the heating for curing causes deformation such as unevenness on the tube surface, which tends to result in a product with poor appearance. It is difficult to perform sufficient heating. In view of the above-mentioned conventional methods, the present invention makes it possible to continuously and easily produce a thermal insulation tube that has a perfect circular cross section, uniform foaming density, and high adhesive strength between the covering layer and the foam and has a good appearance. The purpose of this invention was to provide a method for manufacturing a cylindrical molded passage, which is formed into a continuous hollow column having an inlet and an outlet and a vertical slit at the top. Two continuous sheet materials, an outer layer material and an inner layer material, are introduced into a molding part that is provided with a core-shaped core arranged in a columnar shape parallel to the passageway, and the outer layer material is attached to the inner wall of the cylindrical molding passageway. , the inner layer material is in contact with the core surface of the core, and the ends of the outer layer material and the inner layer material protrude upward from the vertical slit to form ears, and the inner layer material is made to advance continuously, and the inner layer material is continuously advanced so as to be in contact with the surface of the core-type core, and the end portions of the outer layer material and the inner layer material are respectively protruded upward from the vertical slit to form ears. A foamed curable synthetic resin liquid is injected between the outer layer material and the inner layer material, and the foaming of the resin liquid is completed while passing through the molding section to form the outer layer material and the inner layer material. The combined material passed through the molding section is shaped into a continuous hollow column having an inlet at one end, an outlet at the other end, and a vertical slit at the top, and is equipped with a heating means and a pair of rotating endless clamps directly above the vertical slit. The bonded material is guided to a heating section equipped with a belt, and in the heating section, heating is performed for curing while the ear portion is held by the endless clamping pressure belt, and the bonded material that has passed through the heating section is then rotated. The present invention resides in a method of manufacturing a heat-retaining tube, characterized in that the ear portion is held and continuously taken off by a taking-off device comprising a pair of endless caterpillars.

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

FIG. 1 is a plan view showing an example of an embodiment of the method of the present invention, and FIG. 2 is a side view of FIG. 1. In the figure, 11 is an outer layer material, such as a synthetic resin film, which will cover the outer surface when the heat insulating tube is formed, and 12 is an inner layer, such as paper, which will also cover the inner surface. 14 and advanced forward, and along the way, the inner layer material 12 is positioned above to form two layers, and gradually curves into a U-shape so that the central part in the width direction protrudes downward. Then, the foamed curable resin liquid is injected by the resin liquid injection nozzle 21 between the outer layer material 11 and the outer layer material 12 in the thus curved state, and is further advanced. Polyurethane resin is suitable as this foamed curable resin liquid.

In FIG. 1 and FIG. 2, 3 is a molding part.
31 is a split mold having a concave surface on one side; the other surface of the split mold 31 is attached to a rotating endless belt; two endless belts are arranged as a pair so that the concave surfaces of the split molds face each other; The opposing faces are rotated so that they move in the same direction as indicated by the arrows. In this way, the concave surfaces of the split molds 31 that move facing each other form a cylindrical molding passage, and the cylindrical molding passage is made into a passage with a circular cross section for manufacturing a heat insulating tube. A core type core 32 is provided inside the molding passageway over substantially the entire length of the passageway. The core type core 32 is used to form the hollow part of the heat insulating tube to be manufactured, and is held by supports 35 and 36.
Further, the forming passage has a continuous vertical slit 34 at its top, as shown in FIG. 3, which is a cross-sectional view taken along line A--A in FIG. 1.

The outer layer material 1 is provided with the foamed curable resin liquid in the middle of the molded part 3 formed as described above.
1 and inner layer material 12 are introduced and move within the molding section 3 as the endless belt rotates. Then, the outer layer material 11 is introduced into the inner layer material 1 on the inner wall of the cylindrical molding passage.
2 is in contact with the surface of the core type core 32, and both ends of the outer layer material 11 and the inner layer material 12 are
As shown in the figure, this is done so that the ears 61 protrude upward from the vertical slits 34.

While the material introduced in this way passes through the molding section 3, the foamed curable resin liquid foams, fills the passage, and hardens, so that an inner layer material 12 and an outer layer material 11 are formed on the inner and outer surfaces of the hollow columnar synthetic resin foam. They are glued together to form an integrated thermal tube.

FIG. 3 shows that a space surrounded by split molds 31, 31 and a core core 32 to form a molded part is occupied by a hollow columnar synthetic resin foam 2 covered with an outer layer material 11 and an inner layer material 12. Indicates the state in which the

In FIG. 3, reference numeral 33 denotes a fin-like plate extending upward from the core 32 in parallel with the long axis, and the fin-like plate 33 protrudes upward from the molding path to form the ear portion 61. Therefore, in the present invention, it is preferable to use a core type core 32 provided with the fin-like plate 33, and the height of the fin-like plate is equal to that of the split mold 3.
It is preferable that the height is equal to or higher than the position of the inner circumferential surface formed by 1 and 31. Furthermore, in the embodiment shown in FIG. 1, the cylindrical molding passage of the molding section 3 has a large number of split molds 3 attached to a plurality of rotating endless belts.
1 and 31, but the present invention is not limited to these, and it is also possible to form the cylindrical forming passage with a hollow cylinder having one vertical slit. Further, in this embodiment, the core type core 32 is provided with approximately the same length as the molding part 3, but it is also possible to extend the length further, for example, by extending it to the end of the heating part 4, which will be described later. I can do it. The combined product formed into a hollow cylindrical body in the molding section 3, that is, the heat insulating tube 6, comes out of the molding section 3 and is guided to the heating section 4.

The heating section 4 has the shape of a continuous hollow column having an inlet at one end and an outlet at the other end, and has a vertical slit at the top that communicates from one end to the other, and is equipped with an appropriate heating means. Combined substance 6 passing through 4
It is designed to heat the and the heating section 4
As shown in FIG. 4, which shows a cross section taken along the line B--B in FIG.
and 41', 41', and a heat insulating tube 6
The ears 61 are made to protrude outward from the vertical slit 42, and the ears 61 are connected to the belt 41,
41' and is held under pressure. Note that 4 in the figure
Reference numerals 3 and 43' denote an inlet and an outlet for a heat medium, such as hot air, which are introduced and discharged in the direction of the arrow. As the heating means, other appropriate heating means such as an infrared lamp can be used. As the heating temperature, a temperature condition suitable for curing the foam may be selected from a range of about 40 to 100°C.

In this manner, the heat retaining tube 6 is held at its ear portion 61 by the belts 41, 41' in the heating section 4.
Because it is heated under uniform tension,
There is no curvature or surface wrinkles, and heating for curing can be performed even at high temperatures.
Furthermore, since no external force is applied to the surface of the heat insulating tube 6 body during curing, the foam cells in contact with the outer layer material 11 are not damaged, and the bond between the foam and the outer layer material 11 is good. .

Next, a take-off device 5 is arranged in front of the heating section 4, and the take-off device 5 provides a driving force for the heat retention tube 6 formed in the forming section 3 to pass through the heating section 4 and further advance. It will be done.

The take-up device 5 is constituted by a pair of rotating endless caterpillars 51, 51, and the ear portion 61 of the heat insulating tube 6 is moved between the caterpillars 51, 5.
1 and rotate in the direction of the arrow, a thrust is applied to the heat insulating tube 6. At this point, foaming has already been completed and the curing process has also been completed, so the adhesive strength between the outer layer material 11 and the foam inside is sufficient, and even if the ear portion 61 is pulled, the surface layer and the foam will not peel off. will not occur, and will not adversely affect the physical properties of the internal foam. In addition, if you pinch and pull only the ears 61 without touching the main body of the heat-retaining tube 6, the pressure caused by the tension may locally destroy the bubbles in the foam, or create unevenness, which may deteriorate the appearance. This is to prevent After passing through the take-off device 5, the heat retaining tube 6 is cut into an appropriate length, but the ear portion 6 is cut either before or after the cutting.
Preferably, the ends of the outer layer material 11 and the inner layer material 12 forming the outer layer material 1 are cut off leaving only one end of the outer layer material 11. FIG. 5 is a sectional view showing an example of a heat insulation tube obtained by the method of the present invention, in which the space between the outer layer material 11 and the inner layer material 12 is filled with foam 2 to form a hollow columnar shape. To use the tube, it is necessary to cut it into two lengthwise so that they are connected by the outer layer material 11, cover the body to be heat-insulated such as a tube, overlap the remaining ear portion 61' on the surface of the heat-insulating tube, and seal it. Note that it is convenient to use double-sided adhesive tape for the seal.

The method for manufacturing a heat-retaining tube of the present invention is as described above, and in particular, after the forward force is applied to the heat-retaining tube formed by the molding part and passing through the heating part for curing, the ear part of the heat-retaining tube is Since it is given by pinching and pulling,
Unlike conventional methods, when the resin liquid foams and hardens, there is no need to apply excessive tension to the inner and outer layer materials, and it is therefore possible to obtain a product with a uniform foam density and a perfectly circular cross section. Since the heating for curing is carried out under uniform tension, there is no occurrence of curvature or wrinkles during curing, and there is also a slight amount of foaming due to unreacted parts remaining inside the foam due to the heating. Expansion can also be controlled favorably and molded products with good shapes can be obtained. As described above, according to the present invention, heating for curing can be performed without deterioration of appearance, and a product with good adhesion between the outer layer material and the foam and good appearance can be obtained.

[Brief explanation of drawings]

Fig. 1 is a plan view showing one embodiment of the method of the present invention, Fig. 2 is a side view of Fig. 1, Fig. 3 is a sectional view taken along line A-A in Fig. 1, and Fig. 4 is Fig. 2. FIG. 5 is a cross-sectional view taken along the line BB in FIG. 11...Outer layer material, 12...Inner layer material, 2...Synthetic resin foam, 21...Resin liquid injection nozzle, 3...
Molding part, 31... split mold, 32... core type core, 3
3...fin-like plate, 34...vertical slit, 35,3
6...Support, 4...Heating part, 41, 41'...
Endless clamping pressure belt, 42... Heating section vertical slit, 5
...Take-off device, 51...Endless caterpillar, 6...
...Thermal tube, 61...Ear part.

Claims (1)

[Scope of Claims] 1. A cylindrical molded passage formed in the shape of a continuous hollow column having an inlet and an outlet and a vertical slit at the top is provided with a core-shaped core arranged in a columnar shape parallel to the passage. Two continuous sheet materials, an outer layer material and an inner layer material, are introduced into the molding section formed by the molding section, so that the outer layer material is in contact with the inner wall of the cylindrical molding channel, and the inner layer material is in contact with the surface of the core-shaped core. Each end of the material protrudes upward from the vertical slit to form an ear, and the material is advanced continuously, and a foamed hardening synthetic resin liquid is applied between the outer layer material and the inner layer material at the entrance of the molding section. While injected and passing through the molding section, the foaming of the resin liquid is completed and the outer layer material and the inner layer material are integrally bonded by the foam, and the bonded material that has passed through the molding section is connected to an inlet at one end. , is formed into a continuous hollow column having an outlet at the other end and a vertical slit at the top, and is guided to a heating section equipped with a heating means and a pair of rotating endless clamping pressure belts directly above the vertical slit, and in the heating section, the above-mentioned ear Heating for curing is carried out while holding the portion under clamping pressure with the endless clamping pressure belt, and the bonded material that has passed through the heating section is then continuously held by a pulling device consisting of a pair of rotating endless caterpillars by pinching the ear portion. A method for manufacturing a heat-retaining tube, characterized in that the tube is taken up into sections. 2. The manufacturing method according to item 1, wherein the cylindrical molding passage is formed by a large number of split molds attached to a plurality of rotating endless belts.