JPH02214641A - Hollow synthetic resin molded material - Google Patents

Abstract

PURPOSE:To enhance the insulation properties of a hollow synthetic resin molded material by having a material of low radiation rate compossited on an inner surface of a hollow section of the hollow synthetic resin molded material. CONSTITUTION:A hollow synthetic resin molded material 19 extruded through a mold for hollow molding is provided with flat plate sections 20, 21 and said flat plate sections 20, 21 are connected with intermediate walls 22 at given interval. Said hollow synthetic resin molded material 19 is a composite material composed of aluminum 24 bonded with the inner surfaces of flat plate sections 20, 21, upper and lower, forming the inner surface of said hollow section 23. As said aluminum foil 24 prevents heat from transferring in the thickness direction by radiation through the upper and lower inner surfaces of the hollow section 23, insulation properties of the hollow synthetic resin molded product 19 can be enhanced.

Description

[Detailed description of the invention]

``Industrial Application Field'' The present invention relates to a hollow synthetic resin molded body, and particularly to a synthetic resin molded body that is molded by extrusion molding and has a hollow portion extending in the extrusion direction formed therein. K Summary of the Invention] In a synthetic resin molded body formed by extrusion molding and having a hollow part extending in the extrusion direction formed inside, an aluminum foil is bonded to the inner surface of the hollow part or aluminum foil is bonded to the inner surface of the hollow part, or aluminum foil is bonded to the inner surface of the hollow part. A material with low emissivity is composited onto the inner surface of the hollow part by forming a layer containing aluminum powder mixed in, thereby suppressing the transfer of heat due to radiation in the thickness direction of the molded body. The present invention relates to a hollow synthetic resin molded body with further improved heat insulation properties. It becomes possible to mold a hollow synthetic resin molded body having a hollow part extending in the extrusion direction.Such a molded body will have a built-in hollow part extending in the extrusion direction, and the air filled in this part will provide insulation. Furthermore, since the hollow part is divided by an intermediate wall extending in the thickness direction, it has a structure with excellent strength, and is now used as an interior material for houses. [Problems to be Solved by the Invention] Heat transfer in the thickness direction of the panel in such a hollow synthetic resin molded body is achieved not only through heat conduction through the intermediate wall but also through surfaces facing each other in the thickness direction of the hollow portion. It has been found that there is heat transfer by radiation between the panels.In addition, there is no heat transfer by convection in such panels.And because of the above heat conduction and radiation, general foam synthetic resin The insulation properties were worse than that of panels.The present invention was made in view of these problems, and by suppressing heat conduction by radiation, the overall heat transfer in the thickness direction is reduced. It is an object of the present invention to provide a hollow synthetic resin molded body having improved heat insulation properties. In a synthetic resin molded body in which a hollow part extending in the extrusion direction is formed, means such as adhering aluminum foil to the inner surface of this hollow part or forming a layer mixed with aluminum powder. Accordingly, a material with low emissivity is composited on the inner surface of the hollow part.

[Effect]

Therefore, aluminum foil composited on the inner surface of the hollow part,
By using a material with low emissivity, such as a layer containing aluminum powder, it is possible to suppress the transfer of heat by radiation through the inner surface of the hollow part, and this makes it possible to suppress the transfer of heat by radiation through the inner surface of the hollow part. This makes it possible to reduce heat transfer and improve its insulation properties. K Embodiment FIG. 3 shows a molding apparatus for molding a hollow synthetic resin molded body according to a first embodiment of the present invention, and this molding apparatus is equipped with an extruder 5. As shown in FIG. The extruder 115 extrudes molten polypropylene resin. Further, the extruder 5 is connected to a feed block 7, and a mold 10 for extrusion molding is attached to the tip side of the feed block 7. This mold 1
0 is equipped with a special core, which constitutes a hollow molding die 10. The structure of the blow molding die 10 will be explained with reference to FIGS. 4 to 6. This mold 10 has upper and lower guide plates 11 and 12.
The core 13 is arranged between these. The core 13 is supported by bolts 14 in a floating state relative to the upper and lower guide plates 11,12. And middle child 13
Slits 15 and 16 are formed between the core 13 and the guide plate 11 and between the core 13 and the guide plate 12, respectively. As shown in FIG. 6, the core 13 has a substantially battledore-like cross-sectional shape, and slits 17 are formed at regular intervals at its tip. The slit 17 is cut to an appropriate depth beyond the tip of the core 13, and has sloped surfaces on its upper and lower sides, and these upper and lower slopes are shaped to meet at the tip. Next, a hollow molded body extruded through such a mold 10 will be explained. The extruder 5 shown in FIG. 1 extrudes the molten polypropylene resin. Then, the resin extruded from the extruder 5 is supplied to the feed block 7 shown in FIG. 3, and is extruded through the die 10. The polypropylene resin supplied to the feed block 7 is transferred to the mold 1 shown in FIGS. 4 and 6.
It will be extruded through the upper and lower slits 15, 16 at 0. The resin extruded from these slits 15 and 16 forms the upper and lower flat plate parts. Roughly some of the resin flows into the slit 17 of the core 13 and is extruded from the slit 17 toward the front side. Therefore, the resin extruded from the slit 17 forms a large number of intermediate walls connecting the flat plate parts. 7 and 1 show a hollow synthetic resin molded body 19 extruded through such a hollow molding die 10. FIG. This molded body 19 is inserted into the slit 1 of the extrusion device 10.
5.16, each of which has flat plate portions 20 and 21 formed by extruded portions, and these flat plate portions 20.
．． 21 are connected by intermediate walls 22 at predetermined intervals. This intermediate wall 22 is formed of resin extruded from the slit 17 of the core 13. Moreover, in such a hollow synthetic resin molded body 19,
The inner surface of the hollow portion 23 is the upper and lower flat plate portions 20.
An aluminum foil 24 is bonded and composited to the inner surface of 21 as shown in FIGS. 1 and 2. The aluminum foil 24 is used to prevent heat from being conducted in the thickness direction by radiation through the upper and lower inner surfaces of the hollow portion 23, thereby improving the heat insulation properties of the hollow synthetic resin molded body 19. It is designed to play a role in improving Next, a method for bonding aluminum foils 24 to the upper and lower inner surfaces of the hollow portion 23 of the hollow synthetic resin molded body 19 will be explained. As shown in FIG. 8, an aluminum foil 24 is placed on a rectangular release paper 27 of a predetermined size via an adhesive layer. After this, the aluminum foil 24 and the release paper 27 are placed together at a cutting line 2 indicated by a chain line.
Cut along 8. As a result, an elongated strip-shaped aluminum foil 24 is obtained as shown in FIG. 9, and a release paper 27 is adhered to the adhesive surface thereof. The width of the aluminum foil 24 is approximately equal to the width of the intermediate portion 23 of the hollow synthetic resin molded body 19. Aluminum foil 24 adhered to release paper 27 in this way
An adhesive tool 30 as shown in FIG. 10 is used to adhere the material to the inner surface of the hollow portion 23 of the synthetic resin molded body 19. This adhesive tool 30 includes a handle 31, and a rod 32 protrudes from the tip side of the handle 31.
An adhesive head 33 is attached to the tip of the adhesive head 33 . The adhesive head 33 has a peeling part 34 curved in a spatula shape at its tip, and a pressing part 35 on the front side of the peeling part 34.
It is equipped with The pressing portion 35 is elastically deformable, and the aluminum foil is bonded by the elastic restoring force on the tip side thereof. 11 and 12 show the operation of bonding the aluminum foil 24 to the upper inner surface of the hollow portion 23 of the molded body 19 using such an adhesive tool 30. The tip of the aluminum foil 24 adhered to the release paper 27 is peeled off a little, and the end of the aluminum foil 24 is temporarily fixed by adhering it to the entrance edge of the hollow portion 23 as shown in FIG. Then, the aluminum foil 24 adhered to the release paper 27 is inserted into the hollow portion 23 of the molded body 19. In this case, the release paper 27 is inserted so that the lower surface of the release paper 27 is along the lower surface of the hollow portion 23. Then, while pressing the aluminum foil 24 from which the tip has been peeled off with the peeling part 34 of the adhesive tool 30, the aluminum foil 24 is pasted onto the upper inner surface of the hollow portion 23 using the adhesive layer 36 provided on the surface thereof. The pasted aluminum foil 24 is further pushed upward by the elastic restoring force of the pressing part 35 of the adhesive head 33, thereby firmly adhering it to the inner surface of the hollow part 23 via the adhesive layer 36. become. In this way, the adhesive tool 30
When the head 33 is gently pushed into the hollow part 23, the aluminum foil 24 is gradually adhered to the inner surface of the hollow part 23, and the release paper 27 from which the aluminum foil 24 has been peeled off is left in the hollow part. By repeating this operation twice, the hollow part 2
As shown in FIGS. 1 and 2, an aluminum foil 24 is bonded to the upper and lower surfaces of 3 to form a composite structure. FIG. 13 shows the results of measuring the effective thermal conductivity in the thickness direction of the hollow synthetic resin molded body 19 composited with the aluminum foil 24 as a function of temperature. As is clear from these results, the thermal conductivity of the panel made of the molded body 19 of this example is less than half that of the panel without aluminum foil. That is, by reducing heat radiation with the aluminum foil 24, it is possible to reduce heat conduction in the thickness direction of the molded body 19 and obtain a panel with high overall heat insulation properties. Next, a second embodiment of the present invention will be described with reference to FIGS. 14 to 16. In this embodiment, a hollow synthetic resin molded body 19
Flat plate portion 20.2 located at the upper and lower portions of the intermediate portion 23 of
1 is made up of a polypropylene layer 38 and a layer 39 mixed with aluminum powder. In order to form such a panel 19, an apparatus as shown in FIG. 16 is used. This molding device is equipped with a first extruder 5 and a second extruder 816, and these extruders 5.6 are connected to a feed block 7, and the tip of the feed block 7 An extrusion mold 10 is attached to the side. The first extruder 115 of such an apparatus extrudes a polypropylene resin melt, and the second extruder 6 extrudes a polypropylene resin melt containing aluminum powder. Then, the resin extruded from the two extruders 5.6 is supplied to the feed block 7 and extruded through the die 10. Note that the shape of the base 10 is similar to that of the first embodiment. Due to the shape of the resin passage provided inside the feed block 7, the resin containing aluminum powder extruded from the second extruder 6 is transferred to the molded body 19 as shown in FIGS. 14 and 15. The upper and lower parts of the inner surface of the hollow part 23 are faced to each other. In other words, the outer surface of the flat plate portion 20.21 is composed of the polypropylene layer 38, and the hollow portion 23
The surface portion facing the surface is composed of a layer 39 containing aluminum powder. By forming the layer 39 mixed with aluminum powder □ on the inside of the flat plate portion 20.21 in the portion facing the hollow portion 23, the portion facing the inner surface of the hollow portion 23 is made of a material with low emissivity. It will be combined. Therefore, it becomes possible to suppress heat transfer by radiation through the hollow portion 23. In other words, heat conduction occurs only through the material of the intermediate wall 22, and as a result, the heat insulation is improved compared to the conventional case. Note that the intermediate wall 22
In order to further suppress heat conduction in the part I!, the width of the slit 17 of the core 13 shown in FIG. The wall thickness of 1122 may be made thinner. Application Example 1 Although the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to the above embodiments, and various modifications can be made based on the technical idea of the present invention. In 1g3 and the second embodiment, aluminum foil is glued to the inner surface of the hollow portion 23, or a resin layer mixed with aluminum powder is formed, but instead of such a structure, It is also possible to form a metal reflective coating on the inner surface of the hollow portion 23 by electroless plating, vapor deposition, thermal spraying, or other methods to prevent radiation.In such a case, In order to prevent a metal layer from being formed on the surface of the intermediate wall 22, this portion may be masked in advance and plating, vapor deposition or thermal spraying may be performed. A material with low emissivity is composited by bonding aluminum foil or forming a layer mixed with aluminum powder on the inner surface of the hollow part of a hollow synthetic resin molded body. Such a composite prevents the transfer of heat by radiation through the hollow part, making it possible to improve the heat insulation properties of the hollow synthetic resin molded body.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a hollow synthetic resin molded body according to a first embodiment of the present invention, FIG. 2 is an enlarged sectional view of the same main part, FIG. 3 is a plan view of the same molding apparatus, and FIG. Front view of molding die, No. 5
The figure is an external perspective view of the core, and Figure 6 is from ■ to ■ in Figure 4.
A line sectional view, FIG. 7 is an external perspective view of the molded hollow synthetic resin molded body, FIG. 8 is a perspective view of aluminum foil adhered to release paper, and FIG. 9 is a perspective view of the cut aluminum foil. Fig. 10 is an external perspective view of the adhesive tool, Fig. 11 is a perspective view of the main part showing the operation of adhering aluminum foil with the adhesive tool, Fig. 12 is an enlarged sectional view of the main part, and Fig. 13 is a diagram showing the thermal conductivity. A graph showing the measurement results, FIG. 14 is a sectional view of the hollow synthetic resin molded body of the second example, FIG. 15 is an enlarged sectional view of the same essential part, and FIG. 16 is a plan view of the same molding apparatus. Also, the names of the main parts in the drawings are as shown. 19...Hollow synthetic resin formed body 20.21...Flat plate portion 22...Intermediate wall 23...Hollow portion 24...Φ aluminum foil

Claims (1)

[Scope of Claims] 1. In a synthetic resin molded body formed by extrusion molding and having a hollow portion extending in the extrusion direction formed therein, the inner surface of the hollow portion is A synthetic resin molded body characterized by being made of a composite of materials with low emissivity. 2. The hollow synthetic resin molded article according to claim 1, wherein an aluminum foil is bonded to the inner surface of the hollow portion and a material having a low emissivity is composited therein. 3. The hollow synthetic resin molding according to claim 1, characterized in that a layer containing aluminum powder is formed so as to face the inner surface of the hollow portion, and a material with low emissivity is composited therein. body.