JPH0317667B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to decorative materials, cushion materials, gas-liquid filtration or purification materials, marine materials such as artificial seaweed attached to artificial fishing reefs, etc., and culverts for civil engineering works. The present invention relates to synthetic resin three-dimensional mesh bodies used for drainage materials, etc., particularly those exhibiting a mold shape.

(Prior art) So-called mall-shaped moldings with tufted bodies attached around a core have traditionally been constructed mainly by knitting fibers, etc., and it is rare to see molded moldings made of synthetic resin. . This is because molding from synthetic resin requires multiple steps due to the complexity of the structure, resulting in high costs. By the way, structures exhibiting a molded shape have been mainly used as decorative materials, but by utilizing their structural characteristics, they can also be widely used in industrial applications such as filtration and purification materials for gas and liquid. However, as mentioned above, conventional products are mostly composed of knitted fibers, etc., so when used industrially, the core mesh in the center may become uneven or stretch due to the harsh environment. However, there were drawbacks in terms of strength, such as the possibility of cutting or the tufts growing densely around the core falling off. There has been a strong demand for a molded body that can eliminate these drawbacks in terms of strength and that can be manufactured at low cost. Therefore, in order to meet such demands, the present applicant proposed "Method for producing a molded synthetic resin three-dimensional network (1)" in an application filed on the same day as the present application.
In this method, a molded body is obtained by integrally melting and bonding filaments made by similarly creasing and intertwining synthetic resin filaments around a straight synthetic resin filament serving as a core. However, according to this method, the degree of wrinkling and entanglement of the fibers in the peripheral area is determined only by two factors, the extrusion speed and the take-up speed, so the structure of the fibers, such as the voids, becomes somewhat regularized and constant. There was a tendency to

(Problems to be Solved by the Invention) Therefore, the present invention further improves the fabrication of a molded synthetic resin three-dimensional network in which the wrinkles and entanglements of the filaments around the core can be made more complex and irregular. The purpose is to provide a method.

(Means for Solving the Problems) A method for manufacturing a mold-like three-dimensional synthetic resin network of the present invention devised to achieve the above-mentioned object is to provide a method for manufacturing a mold-like three-dimensional synthetic resin network body, which has been devised to achieve the above object. A heated solvent body of thermoplastic synthetic resin is extruded from a nozzle of the required diameter at the required speed, and filaments are continuously spun downward and hang down. The filaments on the periphery are pulled at their ends at an appropriately slower speed than the falling speed, and during the falling process hot air is jetted in a spiral shape by a nozzle, causing them to become irregularly wrinkled. At the very least, the filaments are intertwined with each other and fused together, and the straight core filament at the center and the irregularly wrinkled and intertwined filaments around it are also melted and bonded together during the falling process. It is characterized in that it is then cooled and solidified.

(Example) FIG. 1 is a schematic diagram of the manufacturing process of an example of the present invention, and will be described below in light of the drawings.

1 is an extruder, the inside of which is filled with a heated melt of polypropylene. Nozzles 2, 2' are projected from the lower surface of the extruder 1, and the nozzles 2, 2' are arranged at the center and at a plurality of locations on the circumference surrounding the center. The nozzle 2 at the center has a somewhat larger diameter than the nozzle 2' at the periphery. The nozzles 2, 2' are replaceable, and a desired diameter can be selected and installed. A cylindrical partition wall 3 surrounding the outer periphery of the nozzles 2 and 2' is provided on the lower surface of the extruder 1, and hot air injection nozzles 4 and 4' are attached to the partition wall 3 so as to penetrate into the partition wall 3. . The directions of the nozzles 4, 4' can be up, down, left and right. A water tank filled with cooling water 5 is arranged below the partition wall 3, and take-up rolls 6, 6' are installed inside the water tank. The extruder 1 has its respective nozzles 2,
The extrusion speed of the polypropylene melt from 2' can be freely set. The tip of the filament 7 of the polypropylene melt extruded and spun from the nozzle 2 in the center is pulled off at a speed higher than the falling speed, and the polypropylene melt extruded and spun from the nozzle 2' in the periphery is The filament 7' is attached to each nozzle 2, so that the tip of the filament 7' is taken up at a speed slower than the falling speed.
The extrusion speed and take-up speed of 2' are adjusted and set. That is, the falling speed of the filament 7' in the peripheral portion is set to be somewhat higher than that of the filament 7 in the central portion. As a result, the filament 7 at the center hangs straight, but the filament 7' at the periphery has to be wrinkled. At this time, hot air is also injected from the hot air injection nozzles 4, 4' attached to the partition wall 3. The hot air does not affect the filament 7 in the center and the surrounding filament 7'.
Nozzle 4 so as to create a vortex flow that only disturbs the
4' is injected by adjusting the direction. Due to the injection of this hot air vortex, the degree of wrinkling of the filaments 7' in the surrounding area is amplified, and the filaments 7' in the surrounding area are melted and bonded in a state where they become entangled with each other, so that the filaments 7' have irregular pores and irregular texture. 8 is formed, and this filament 8 is also fused and bonded to the straight filament 7 serving as the core at the center. Thereafter, these are introduced into the cooling water 3, cooled and solidified, and the manufacturing process is completed. All that is left to do is to wind it up with a winding roll. FIG. 2 is a partial perspective view of the molded three-dimensional synthetic resin network body manufactured in this manner.

(Operation and Effect) According to the present invention, the filament at the center is pulled at a speed higher than its falling speed, and the filaments around it are pulled at a speed lower than the falling speed, so that the filament at the center is immediately extruded. By setting the extrusion speed of the filaments in the peripheral area to be appropriately higher than the extrusion speed, a mold having a straight filament in the center and irregularly wrinkled filaments intertwined with each other is created around the straight filament. There is an effect that a three-dimensional network body made of synthetic resin having a shape can be manufactured continuously in one step, easily and at low cost. In particular, in the present invention, since the vortex of hot air jetted from a nozzle acts on the surrounding filaments during the falling process of the filaments, the degree of wrinkling and entanglement of the filaments becomes more irregular and complicated. is remarkable. In addition, the fabricated mold-like three-dimensional synthetic resin network has a straight synthetic resin filament as its core, making it difficult to stretch and break, and since the surrounding filaments are melted and bonded to each other, they are resistant to peeling and have significantly improved strength. In addition, the desired structure, such as the porosity of the fibers, can be easily obtained by appropriately selecting the nozzle diameter, extrusion speed, take-up speed, etc., and can be used for a wide range of purposes. There are possible effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a manufacturing process according to an embodiment of the present invention, and FIG. 2 is a partial perspective view of a molded synthetic resin three-dimensional network body manufactured according to an embodiment of the present invention. 1... Extruder, 2, 2'... Nozzle, 3... Partition wall, 4, 4'... Hot air injection nozzle, 5... Cooling water, 6, 6'... Take-up roll, 7, 7'... ...Striae,
8... filaments.

Claims (1)

[Claims] 1. A heated melt of thermoplastic synthetic resin is extruded at a required speed from nozzles of a desired diameter arranged at multiple locations in the center and surrounding areas, and filaments are continuously spun and suspended downward. The filament at the center pulls its tip at a speed higher than its falling speed and maintains its straight shape, and the filament at the periphery pulls its tip at a speed that is appropriately slower than the falling speed and blows hot air in the process of falling. By spraying in a spiral shape with a nozzle, the fibers are irregularly wrinkled and intertwined with each other to form a melt-bonded filament. A method for producing a mold-like three-dimensional synthetic resin network, characterized in that the combined fibers are also melted and bonded together in the falling vortex, and then cooled and solidified.