JPS609889B2 - Manufacturing method of thermal tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cylindrical synthetic resin foam whose inner and outer surfaces are covered with a covering material such as a synthetic resin sheet or paper to be used as a heat-retaining tube.

Various methods have been proposed as conventional methods for manufacturing the above-mentioned heat insulating tubes, for example, Japanese Patent Publication No. 48-1970
In Publication No. 5 and Japanese Patent Publication No. 49-29953, a cylindrical body having a slit extending from one end to the other is used as a mold for regulating the external shape, and a core core 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 piled up and bent so that both ends are upward, and introduced into the passage. A foamable resin liquid is injected between them, and both ends of the sheet taken out from the slit of the cylinder are held and pulled by appropriate transfer means, and the sheet is advanced through the molding passage, and the foaming resin liquid is injected into the molding passage. A method of manufacturing a heat insulating tube by foaming and curing a resin liquid is disclosed.

However, in such a method, as described above, the material is advanced by pinching and pulling the edges of the sheet that are the material for forming the inner and outer surfaces, that is, the edges protruding outside the forming path, so the outer surface is formed. Due to tension in the sheet, it is difficult to obtain a perfectly round product, and the foam density tends to be uneven due to excessive tension.

The present invention has been made in view of the above-mentioned conventional methods, and has been made with the object of providing a method that can continuously and easily manufacture high-quality heat-insulating tubes with a perfect circle in cross section and a uniform foaming density. The gist of this method is to arrange two endless belts each having a concave surface on one side and a large number of splits, with the concave surfaces facing each other, and rotate the endless belts so that the facing surfaces move in the same direction. By this, a molding passage having a circular cross section is formed and is rotating forward, and a core type core is provided inside the molding passage over almost the entire length of the passage, and a core type core is provided inside the molding passage over almost the entire length of the passage. A two-layer coating material Z consisting of an inner layer coating material and an outer layer coating material is formed so that the inner layer coating material is in contact with the surface of the self-core type core, and at least both ends of the outer layer coating material protrude beyond the molding passage. The foamed curable resin liquid injected into the gap J between the inner layer coating material and the outer layer coating material is introduced into the molding passageway to advance these coating materials so as to form a section. Curing the foam and filling the inside of the molding passage with foamed resin to form a hollow cylindrical foam having an inner layer and an outer layer covering material,
The ear portion of the hollow two-cylindrical foam is pulled by a pulling machine disposed further forward in the direction of travel than the molding path, and the pulling speed is slightly faster than the speed of travel of the molding path. The present invention relates to a method of manufacturing a heat insulating tube.

The present invention will be explained 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, 1 is an outer layer covering material, such as a synthetic resin resin film, which will cover the outer surface when it is formed into a heat insulating tube, and 12 is an inner layer covering material, such as paper, which will also cover the inner surface.
These are supplied from the roll bodies 13 and 14 and moved forward, and along the way, the inner layer covering material 12 is located above, so that they are arranged in two layers, and gradually the central 3 parts in the middle direction protrude downward. The foamed curable resin liquid is injected through the resin liquid injection nozzle 21 between the outer layer and inner layer coating materials 11 and 12 that are curved in this way and further advanced. A polyurethane resin is preferably used as the foamed curable resin liquid. 1 and 2, 3 is an endless belt, 31 is a split mold having a concave surface on one side, the other side of the split mold 31 is attached to the endless belt 3, and the two endless belts 3 are made into a pair. The concave surfaces of the split molds are arranged so as to face each other, and the opposing surfaces are rotated so that they move in the same direction as indicated by the arrows.

In this way, a cylindrical cavity is formed by the concave surfaces of the split molds 31 that move facing each other, and this cylindrical cavity is used as a molding passage having a circular cross section for manufacturing a heat insulating tube. Inside the molding passage, there is a core 4 along the entire length of the passage.
will be provided. The core-shaped core 4 is used to form a hollow part of the heat-retaining tube to be manufactured, and is held in place by support odors 42 and 43. The outer layer and inner layer covering materials 11 and 12 are supplied with the foamed curable resin liquid in the middle of the molding passage formed as described above.
is introduced and moves within the passage according to the rotation of the endless belt 3. The introduction is performed so that the inner layer coating material 12 is in contact with the surface of the core type core 4, and both ends of the outer layer and inner layer coating materials 11 and 12 are introduced upward from between the split molds 31 facing each other forming the molding passage. This is done so that the material protrudes out and forms the ear portion 61.While the material thus introduced passes through the molding passage, the foamed curable resin liquid foams and fills the passage, and hardens, forming a hollow columnar synthetic resin. The inner layer covering material 12 and the outer layer covering material 11 are adhered to the inner and outer surfaces of the foam to form an integrated heat insulating tube.

. FIG. 3 is a cross-sectional view taken along line A-A in FIG. It is occupied by a hollow columnar synthetic resin foam 2 covered with an inner layer covering material 12. Reference numeral 41 denotes a fin-like plate extending upward from the core in parallel with the long axis, and the fin-like plate 41 protrudes upward from the molding path to form ears at both ends of the covering material. Therefore, in the present invention, it is preferable to use the core-shaped core 4 provided with the fin-like plate 41, and the height of the fin-like plate is equal to the inner periphery formed by the split molds 3i, 31. It is best to set the height to the same level or higher than the surface position. After passing through the molding passage, the thus formed heat insulating tube passes through the first,
As shown in Fig. 2, the heat insulating tube 6 is held at the ears 61 by the take-up machine 5 and pulled forward, where it is cut into a product by a cutter or the like (not shown). In particular, the pulling speed by this pulling machine 5 is slightly higher than the traveling speed of the forming path, that is, the moving speed of the endless belt 3, preferably 102 when the traveling speed of the forming path is 100.
The speed is in the range of ~120.

By increasing the pulling speed of the pulling machine 5 as described above,
The heat-insulating tube is molded while sliding in the molding passage, and as a result, when molded in the molding passage composed of a large number of split molds, the heat-insulating tube is formed on the surface of the heat-insulating tube by minute differences in level between the split molds. It is possible to prevent streaks and obtain a heat insulating tube with a smooth and beautiful surface.
Furthermore, the reason why the ear portion 61 is pulled by the tensioning machine 5 is to avoid deterioration of the appearance due to pressure on the cylindrical portion and deterioration of the adhesive strength between the outer layer covering material 11 and the foam 2. Next, FIG. 4 is a sectional view showing an example of a heat insulating tube obtained by the method of the present invention, in which one end of the outer covering material 11 is left from the ear part of the heat insulating tube shown in FIG. It can be obtained by cutting off three pieces, namely the end of the outer layer covering material 11 and both ends of the inner layer covering material 12.

To use the heat insulating tube shown in Figure 4, split the tube in half in the axial direction leaving the skin layer intact, fit it into the tube to be heat insulated, and attach both sides to the sheet piece protruding from one end of the tube. Apply adhesive tape etc. to give adhesive properties.
By attaching this to the end of the tube and sealing it, the piping is kept warm by the tube. The method for manufacturing the heat insulating tube of the present invention is as described above, and in particular, a pair of endless belts provided with a large number of split molds as forming passages is used, so that a perfectly circular cylindrical body can be obtained. In addition, a take-off machine was installed in front of the molding passage, and the take-up speed by the take-off machine was made slightly faster than the advancing speed of the molding passage. It is possible to prevent the formation of streaks.

Thus, according to the method of the present invention, it is possible to continuously produce heat-retaining tubes with a perfect circular cross section, uniform foam density, and good appearance.

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[Brief explanation of drawings]

Fig. 1 is a plan view showing an 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 a method of the invention It is a sectional 0 view showing an example of the heat insulation tube obtained by. 11...Outer layer coating material, 12...Inner layer coating material, 2...Synthetic resin foam, 21...Resin liquid injection/slip, 3...Endless belt, 31...Split mold , 4...
... core-shaped core, 41 ... fin-like plate, 42,
43 evening...Supporting odor, 5...Collection machine, 6...
...Heat insulation tube, 61...Ear part. Na' figure OZ evil o 3 evil gay figure

Claims (1)

[Claims] 1. Two endless belts each having a large number of split molds each having a concave surface on one side are arranged with the concave surfaces facing each other, and the endless belts are arranged so that the facing surfaces move in the same direction. By rotating, a molding passage having a circular cross section is formed which is rotating forward, and a core type core is provided inside the molding passage over almost the entire length of the passage, and an inner layer is formed in the molding passage. A two-layer coating material consisting of a coating material and an outer layer coating material, the inner layer coating material is in contact with the surface of the core type core, and at least both ends of the outer layer coating material protrude beyond the molding path to form ears. These coating materials are advanced forward, and the foamed curable resin liquid injected between the advancing inner layer coating material and outer layer coating material is foamed and hardened in the molding passage to form the molding material. The inside of the passage is filled with foamed resin to form a hollow cylindrical foam having an inner layer and an outer covering material, and the ear part of the hollow cylindrical foam is removed by a pulling machine disposed further forward in the direction of travel than the molding passage. A method for producing a heat insulating tube, which comprises pulling the tube at a speed slightly higher than the speed at which the molding path advances. 2. The manufacturing method according to item 1, wherein the pulling speed of the pulling machine is 102 to 120 when the speed of the forming path is 100. 3. The manufacturing method according to item 1, wherein the core is columnar and has fin-like plates in its longitudinal direction.