JP2001003257A - Spring-structured resin-molded product and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a spring-structured resin-molded product excellent in strength, elasticity and impact-absorbing property by forming an intertwined three dimensional-structured body with the random loops and curls of a filament made from a thermoplastic resin. SOLUTION: This spring-structured resin-molded product is obtained by bringing contact with, twining and gathering the adjacent filaments each other, of the random loops and curls of a continuous filament or short filaments consisting of a thermoplastic resin, preferably a polypropylene, polyester, nylon or polyvinyl chloride elastomer and having 0.3-3.0 mm, preferably 0.7-1.0 mm filament diameter to form a three dimensional structured body having 0.005-1.08 g/cm3 bulk density, and also form optionally coarse parts A and dense parts B by taking a suitable interval in the longitudinal direction of the three dimensional structured body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spring-structured resin molded product and a method for producing the same, and more particularly, to a spring-structured resin molded product having excellent impact resistance and load resistance and suitable for use as a filter medium and the like. The present invention relates to a product and a method of manufacturing the same.

[0002]

2. Description of the Related Art Impact energy absorbers used for walls and fences of sports fields, helmet linings, sports mats, shock absorbers for car bumpers and bodies, cushioning materials for packing, etc. Foams such as polypropylene and polyurethane are used.

On the other hand, fiber reinforced resins have been developed as materials for members requiring high strength and light weight, such as automobile bodies.

[0004]

However, these materials do not always absorb impact energy sufficiently,
Depending on the application, a material having a higher shock absorbing ability has been demanded.

[0005] Although fiber-reinforced resin materials are excellent in strength and lightness, further improvements are required in terms of elasticity, shock absorbing ability and load resistance. In addition, fiber reinforced materials are molded by various methods, but products manufactured by the SMC method have large variations in strength, and the resin injection method has a small degree of freedom in the shape of the molded product, and also has a hand lay-up method and a spray-up method. Although the degree of freedom of the shape is large, molding work is difficult and it is difficult to keep the quality constant, and the filament winding method etc. requires large-scale equipment, so it has advantages and disadvantages, the molding process is easy, and the shape process is easy. No method has been obtained that satisfies all of the physical properties such as the degree of freedom, the strength of the molded product, the elasticity, and the shock absorbing ability.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a molded article having desired properties, particularly high impact resistance and load resistance. Further, the present invention provides a method capable of easily producing a molded article having a physical property such as a desired load resistance, impact resistance, etc., in which the molding step is easy and the degree of freedom of the shape is high. Aim.

[0007]

SUMMARY OF THE INVENTION A spring-structured resin molded product 30 of the present invention is formed by contacting and entangling adjacent filaments of random loops or curls of continuous filaments and / or short filaments of thermoplastic resin. (Hereinafter referred to as a three-dimensional structure) having voids having a predetermined bulk density.

According to the present invention, the continuous filament and / or the short filament are made of, for example, a thermoplastic elastomer, and the diameter of the continuous filament and / or the short filament is
For example, 0.3 to 3.0 mm, preferably 0.7 to 1.0 mm
mm, and the bulk density of the structure of the three-dimensional structure is, for example, 0.005 to 1.08 g / cm ^3. For example, the present invention relates to a bumper, a cushion material for a chair of an automobile, and a filter material.

The present invention further comprises a step of melt-extruding a thermoplastic resin and / or a thermoplastic elastomer into a plurality of filaments so that adjacent filaments of random loops or curls of continuous filaments are intertwined and assembled with each other. When forming a three-dimensional structure having voids of bulk density, by changing the take-up speed of the melt-extruded continuous filament, the three-dimensional structure of the three-dimensional structure through an appropriate interval in the longitudinal direction of the three-dimensional structure The present invention relates to a method for manufacturing a resin article 30 having a spring structure, wherein a portion having a large bulk density is formed in a width direction.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION (Three-dimensional structure) A three-dimensional structure used in the present invention is a three-dimensional structure having a continuous filament and / or a void in which, for example, short filaments are randomly entangled. Wherein the continuous filament and / or the short filament form a plurality of loops or curls. Such a three-dimensional structure is, for example, melt-extruded thermoplastic elastomer from a plurality of nozzles at a predetermined extrusion rate, and takes it by a take-off machine described below, and obtains 600 to 90,000 denier, preferably 3,000 to 30,000 denier. Preferably, a solid or hollow continuous filament of 6,000 to 10,000 denier is formed, and the filament in a molten state, for example, having a diameter of 1 to
Forming a loop of 10 mm, preferably 1-5 mm in diameter,
While forming a random loop by contacting and entangled with adjacent filaments in water, the take-up speed of the take-up machine is adjusted to a low speed at intervals of, for example, 3 to 5 m by the take-up machine in water, and the longitudinal length is adjusted. A portion having a large bulk density at the time of low-speed take-off of 30 to 50 cm, that is, a thickness of 30 to 100 m including a dense portion and the other coarse portion.
m, can be manufactured by forming a three-dimensional spring structure with a width of 1,000 mm. At least some of the contact entanglement sites are melt bonded to each other.

The diameter of the continuous filament and / or the short filament is as follows:
It is 0.3 to 3.0 mm, preferably 0.7 to 1 mm.

The continuous filament and / or the short filament are preferably made of a thermoplastic elastomer, for example, polypropylene, polyester, nylon or PVC elastomer.

The bulk density of the three-dimensional structure is approximately
009 to 0.280 g / cm ³ , preferably 0.027 to 0.210, especially 0.1.
045 to 0.09, 0.45 to 1.25 g / cm ³ in the dense part, preferably 0.54 to 1.17, particularly 0.63 to 1.10.

The porosity of the three-dimensional structure is 8
0-99%, preferably 85-97%, especially 90-9%
5%, 25-50% in the dense part, preferably 15-4
0%, especially 20-30%.

[0015]

(Equation 1) (Manufacturing method) In the manufacturing method of the spring-structured resin molded product 30 of the present invention, as shown in FIG. 1, a raw material resin, for example, an elastomer of polypropylene is charged from a hopper 11 of an extruder 10 and melt-kneaded to form a molding die. 12 is extruded from a large number of injection ports having a predetermined diameter provided in the bath 12, and the thickness and bulk density are set between the take-up rolls 14, 14 of the take-up machine 13 in the bath 15. And rolled up, take-up rolls 16,1
By 6, it is taken out as a resin product 30 having a spring structure.

If the take-up speed of the take-off rolls 14 is set to a low speed within a set time by a timer or the like at a set time, the set length is set at predetermined intervals in the longitudinal direction of the spring-structured resin molded product 30. , A spring-structured resin molded product 30 having a dense and dense structure having a portion with a large bulk density can be obtained.

As an example, a 30-mm-thick spring-structured resin molded product 30 having a dense portion T of 30 cm in length for every 3 m of coarse portion C was obtained.

The three-dimensional structure can be manufactured using one or a combination of a plurality of different properties. (Use) The spring-structured resin molded product 30 of the present invention is used as a filter medium such as an artificial pond, the dense part is used as a filter member by attaching it to a water passage as a support member, and a body including an automobile bumper and a door part. Impact absorbing material, and a reinforced roadbed material as a reinforcing material for a pavement underlayer subjected to direct traffic load such as a road, a reinforcing material having excellent drainage properties as an embankment material, which can be used by including earth and sand in voids. . It can also be used as a reinforcing material on the slope.

Further, as the above-mentioned strengthening of the ground of roads and the like, since it does not freeze, it has a function as a material for preventing frost heaving, and at the same time, can secure the trafficability of the construction machine in the high-moisture-content viscous soil. It is effective and can be widely applied to various ground improvement methods.

Embodiment 1 (FIG. 2)

[0021]

[Table 1]

Comparative Example 1

[0023]

[Table 2]

Test Example 1

A compression test was performed on the above Example 1 and Comparative Example 1 to evaluate stress-distortion characteristics. Test piece Example 1 (FIG. 2) Comparative example 1 Area: 1,000
× 500 mm, thickness: 100 mm

[0026]

[Table 3] It has been found that the porosity does not decrease due to the compressive load, so that it can be used under a high load.

Test Example 2

The water permeability was evaluated. The test piece had an area of 150 × 150 mm and a thickness of 100 mm.
The length of the rough portion A is 115 mm, and the length of the dense portion B is 35 mm. Test apparatus 20 (Fig. 3) Water pipe 21 100 x 100mm

In the first embodiment, a spring-structured resin molded product 3 is used.
0 so that the dense part B occupies 10% of the inner cross-sectional area of the water pipe 21.

(Equation 2) The water permeability (cm / sec) was 1.07 × 100 ⁰ in Example 1.
However, in Comparative Example 1, it was 8.88 × 10 ⁻¹ .

It was found that Example 1 had better water permeability.

[0031]

According to the present invention, a resin molded product having a spring structure is provided.
Since a three-dimensional structure of a thermoplastic elastomer is used as the reinforcing fiber and has a close-packed structure, properties such as impact resistance and load resistance of the molded product are remarkably improved. Further, according to the method for manufacturing a resin article having a spring structure of the present invention, a molded article having excellent properties such as strength, elasticity, and shock absorption can be manufactured by an easy method without requiring large-scale equipment. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic view showing steps of a manufacturing method according to one embodiment of the present invention;

FIG. 2 is a perspective view of the first embodiment;

FIG. 3 is a schematic diagram of a water permeability test device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Extruder 11 Hopper 12 Forming die 13 Take-up machine 14 Take-up roll 15 Bus 16 Take-up roll A Rough part B Dense part 30 Spring-structured resin molded product 31 Water pipe

Claims (8)

[Claims] 1. A three-dimensional structure having voids of a predetermined bulk density formed by contacting and intertwining adjacent filaments of random loops or curls of continuous filaments and / or short filaments of a thermoplastic resin. A spring-structured resin molded product having a dense and dense void formed by increasing the bulk density in the width direction of the three-dimensional structure at appropriate intervals in the longitudinal direction of the three-dimensional structure. 2. The molded article having a spring structure according to claim 1, wherein said continuous and / or short filaments are made of a thermoplastic elastomer. 3. The spring according to claim 1, wherein the continuous filament and / or the short filament have a diameter of 0.3 to 3.0 mm, preferably 0.7 to 1.0 mm. Structural resin molded product. 4. The three-dimensional structure has a bulk density of 0.
Spring structure resin molded article according to item 1 or 1-3 claim 1, characterized in that it is a 005~1.08g / cm ^3. 5. The molded resin article having a spring structure according to claim 1, which is a bumper member. 6. A cushion material for a chair.
A resin article having a spring structure according to any one of the above. 7. The molded resin article having a spring structure according to claim 1, which is a filter medium. 8. A thermoplastic resin and / or thermoplastic elastomer is melt-extruded into a plurality of filaments, and random filaments of continuous filaments or adjacent filaments of a curl are intertwined with each other to obtain a predetermined bulk density. In molding the three-dimensional structure having voids, the melt-extruded continuous filament is drawn at a different speed to change the bulk in the width direction of the three-dimensional structure at appropriate intervals in the longitudinal direction of the three-dimensional structure. A method for producing a resin article having a spring structure, wherein a portion having a high density is formed.