JPS63190059A - Production of thermoplastic resin net - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to cushioning materials and mats for filters.

Plant/seafood breeding cloak, reinforcing material for civil engineering work.

The present invention relates to a method of manufacturing a thermoplastic resin mat used as a slope greening protection mat, etc.

(Prior art) A three-dimensional net-like mat in which a large number of continuous monofilaments are entangled with each other and the intertwined monofilaments are bonded has irregular voids and is lightweight, so it is used for a variety of purposes. ing.

Such a mat has protrusions on its surface, for example, as disclosed in Japanese Patent Publication No. 58-9186, and a molten thermoplastic resin is applied to one roller that rotates while being vibrated in the axial direction. The fibers are produced by spinning from a large number of spinnerets arranged in the axial direction of the roller and depositing the fibers on the roller. In thermoplastic resin mats manufactured by this method, since the rollers are vibrated, the monofilaments spun from the spinnerets arranged in parallel in the vibration direction are sufficiently intertwined with each other, and the strength in that direction is increased. It has the advantage of increasing the However, there are limits to increasing the strength in that direction.

As the weight per unit area decreases, the monofilaments become less entangled with each other, and the strength in that direction increases.

There is also a drawback that the improvement is not so great, and since the monofilaments are simply deposited on the roller, the monofilaments are not firmly fused together.

Japanese Patent Laid-Open No. 57-171749 discloses that a monofilament is spun onto the surface of each of a pair of opposing rotating drums from a large number of spinnerets arranged in the axial direction of each roll, and 9. Form each web at the point where the two webs are closest.

A method is disclosed in which both webs are overlapped by each rotating drum. The cloak produced by this method has the disadvantage that the monofilaments in each web are not sufficiently entwined in the axial direction of the rotating drum (the strength in this direction is significantly lower than the strength in the direction of one rotation of the drum).

In addition, since the entanglement in the direction of the drum axis is insufficient, the produced 77 sheets have a low porosity and a high density. Cloaks with low porosity and high density can be used for filters, etc., but they can also be used for cushions, slope protection mats, etc.

The weight per unit area is large, impairing economic efficiency. Furthermore, when used as a slope protection mat, there is also the drawback that the voids are not sufficiently filled with soil, so that it cannot be used for such purposes.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and its purpose is to provide a material suitable for various uses due to its high porosity (and high strength). An object of the present invention is to provide a method for manufacturing a thermoplastic resin mat.

(Means for solving problems) The method for producing the thermoplastic resin mat of the present invention is as follows.

A large number of protrusions are arranged on each surface.

A pair of rolls are rotated so that their protrusions can mesh and each is vibrated in the axial direction. This is a method for producing a thermoplastic resin mat using an extruder having a large number of spinnerets arranged in parallel in the axial direction, and a continuous monofilament of thermoplastic resin melt is extruded from each spinneret of the extruder. .

The method includes a step of depositing the monofilament on a rotating and vibrating roll, and a step of pressing and fusing the deposited monofilament with mating protrusions, thereby achieving the above object. Ru.

(Example) The present invention will be described below with reference to Examples.

The method of the invention is carried out using the apparatus shown in FIG. The apparatus includes a pair of rolls 10 and 20, and the roll 10.
and an extruder 30 disposed above 20.

The rolls 10t-3 and 20 are arranged so that their axes are parallel to each other, and each of the rolls 10t-3 and 20 has a large number of protrusions 11.11. ...and 21.21. ...is provided. Each roll 10 and 20 is supported by a pedestal 40 so as to be rotatable. Each roll 10 and 20 is rotated in the forward direction so that the respective protrusions 11 and 21 can mesh while moving from above to below.

The pedestal 40 is capable of vibrating in the axial direction of each roll 10 and 20, and as the pedestal 40 vibrates, each roll 10 and 20 vibrates integrally in the axial direction.

The extruder 30 disposed above each of the rollers 10 and 20 has a large number of spinnerets 31, 31, arranged in two orderly rows parallel to the axes of the respective rolls 10 and 20, for example.
...and 32.32. It has... One spinneret 31, 31. ... is opposed to a portion slightly upstream in the rotational direction of one of the rollers 10 from the engagement position of the protrusions 11 and 21 on the nine rollers 10 and 20.

The other spinneret 32.32. ... is opposed to a portion slightly upstream in the rotational direction of the other roller 20 from the engagement position of the protrusions 11 and 21. Each spinneret 31.31. in the extruder 30. ...and 32.32.・・・
・From.

a continuous monofilament 51 of thermoplastic resin melt;
51. ...and 52.52. ... are respectively spun.

In a device configured in this manner, each roll 10 and 20 is rotated such that the protrusions 11 and 21 on the respective surfaces can engage with each other while moving from upward to downward, and during the rotation, When the frame 40 is vibrated, both rolls 10 and 20 are vibrated as a unit in their axial direction. In this state, from each spinneret 31 and 32 of the extruder 30.

Monofilaments 51 and 52 made of thermoplastic resin are extruded.

Monofilament 5 extruded from a large number of spinning holes 31 located above the roll 10 and arranged in the roll axis direction.
1 is a roll 10 that rotates while vibrating.

The top of each protrusion 11 on the surface, or each protrusion 1, at a position slightly upstream of the protrusion engagement position by one rotation direction.
It is contacted between 1 and 2. At this time, since the roll 10 is vibrated in its axial direction, the protrusions 11 on the roller 10
The monofilaments 51 in contact with the upper or adjacent protrusions are deposited on the surface of the roll 10 in a state in which adjacent ones in the roll axis direction are well intertwined with each other.

Monofilament 5 is extruded from a large number of spinnerets 32 located above the roll 20 and arranged in parallel in the roll axis direction.
2 also comes into contact with or between the protrusions 21 of the roll 2o, is well intertwined with each other in the axial direction of the roll 2o, and is deposited on the surface of the roll 20.

As the rolls 10 and 20 rotate, the monofilaments 51 and 52 deposited on the surfaces of the rolls 10 and 20 reach the engagement position of the projections 11 and 21, respectively.
1 and 21 to forcibly fuse the 2 parts together. As a result, a mat 5o in which the monofilaments 51 and 52 are firmly fused together is manufactured.

The manufactured mat 50 is wound up using a winding machine 6o, for example.

The spinneret in the extruder 30 is connected to the roll 10 or 2.
It is sufficient that a large number of them are arranged in the direction of the axis of zero, and it is not necessary to arrange them in two orderly rows as in the above embodiment. For example, they may be arranged in one row or three or more rows in an orderly manner in the axial direction of the roll 1o or 2o.

Moreover, when arranged in two or more rows, a houndstooth check pattern may be used.

The spacing between the numerous spinnerets arranged in the axial direction of the roll 10 or 20 is between 2 and 2 in terms of the distance between the centers of adjacent spinnerets.
30m is appropriate. If this distance is below the lower limit,
The monofilaments spun from each spinneret may come into contact with each other due to slight air vibrations, and there is a risk that each monofilament may not reach the roll surface regularly. Also,
If the upper limit of 30 is exceeded, the monofilaments spun from each spinneret and reaching the roll surface may not be sufficiently entangled with each other even by the vibration of the roll.

This leads to a decrease in the strength of the formed cloak.

The diameter of each spinneret is suitably 0.2 to 2.0 fi.

If this diameter is less than the lower limit of 0.2fi, there is a risk that drifting will occur during spinning of the thermoplastic resin melt, or that the pressure within the extruder will become too high. Also, the upper limit value is 2.0
If fi is exceeded, the diameter of the monofilament to be spun becomes thicker, which causes an increase in the weight of the produced mat.

The distance between each spinneret and each roll 10 and 20 varies depending on the diameter of the spinneret, but the distance from the spinneret to the meshing position of each protrusion 11 and 21 on the nine-sided rolls 10 and 20 is in the range of 3 to 30 cm. It is preferable that If it exceeds the upper limit of 30 aa, the spun monofilament will be cooled while freely falling from the spinneret, and its fusing ability will be impaired. For this reason, 30
When the rolls are arranged at a distance of more than G, it is necessary to heat the spun monofilament with a far-infrared heater or the like to prevent a decrease in fusing ability, which is disadvantageous in terms of equipment.

It also hurts economic efficiency.

The height of each of the protrusions 11 and 21 provided on the surfaces of the rolls 10 and 20 is set in accordance with the thickness of the mat to be molded, and is preferably in the range of 3 to 3 looms. If the height of the protrusion is below the lower limit value 3fi.

On the other hand, if the upper limit of 100 fins is exceeded, the area in which the monofilament is in contact with the protrusion becomes large, and the monofilament is not sufficiently compressed by the interlocking protrusions, making it impossible to firmly fuse the monofilament. Since the pressure applied to the monofilament is uneven, the thickness of the molded product may be uneven and the desired thickness may not be obtained.

In the case where the protrusions on one roll mesh with adjacent protrusions on the other roll. What is the gap (roll clearance) between the top of a protrusion on one roll and the valley between adjacent protrusions on the other roll?

A range of approximately 0.2 to 100 fl is suitable. If the lower limit of this range is less than 0.2, the monofilament sandwiched in the gap may be pressed too tightly and break, leading to a decrease in the strength of the molded product as a whole. On the other hand, if it exceeds the upper limit of 100, the monofilament within the 9 gaps will not be pressed firmly, which will also result in a decrease in the strength of the molded product.

The protrusions arranged on each roll are lX
The density is preferably 10″ to 2×10′ pieces/rd, and below the lower limit of this range, 1×103 pieces/−,
The monofilament deposited on the roll surface cannot be sufficiently pressed over the entire surface, resulting in a decrease in fusion strength. When the upper limit of the range 2×103 pieces/rrr is exceeded, the gaps between the protrusions become small, and the spun monofilament does not enter the gaps between the protrusions, resulting in uneven thickness of the formed mat. arise.

Since each roll is vibrated in its axial direction, the monofilaments deposited next to each other in the axial direction of the roll are sufficiently entangled with each other, and the formed mat is oriented in this direction (lateral direction). Strength is significantly improved. The vibration conditions for each roll vary depending on the diameter of the spinneret, the number and spacing of the spinnerets, the density of protrusions on the roll surface, etc., but the amplitude is about 10 to 30 cm and the frequency is about 80 to 200 times/min. is suitable. If the amplitude and frequency are below the above lower limit values, the monofilaments will not be sufficiently entangled with each other, and no improvement in the strength of the molded product can be expected.

Even if the amplitude and frequency exceed the above upper limits.

Since the strength in the lateral direction of the molded article is hardly improved, it is sufficient within the upper limit range.

Thermoplastic resins used in such devices include polyolefins such as polyethylene and polypropylene, polyurethane, polyamide, polyester, polyvinyl chloride, and polycarbonate, but in all cases, resins with relatively low viscosity are used. It is preferable to use

(Experiment example i) A mat was manufactured using the apparatus shown in FIG. 1 under the following conditions.

(a) The spinneret in the extruder has a diameter of 0.6 m, and is arranged in two directions in the roll axis direction so that the center-to-center distance is 6 m.
arranged in columns. The distance between the rows is 6 cranes.

(b) The protrusions arranged on each roll have a density of 5000
pcs/a, height 1 (1 m), and the gap (roll clearance) when the protrusions on each roll are engaged is 1.0
It is n.

(c) The distance between the spinneret and the position where the protrusions engage on the roll is 10
It is 0 cranes.

(d) Both rolls are vibrated in the axial direction at an amplitude of 15 and a frequency of 150 times/min.

Using an apparatus under these conditions, a mat having two widths (in the roll axis direction) of 1500 nm and a length of 30 m (in the roll rotation direction) was molded using nylon 6 as the thermoplastic resin.

A sample piece was cut from the formed mat to a length of 150 m in the forming direction (rotation direction of the rolls) and 50 fl in the roll axis direction, and the sample piece was tested in the longitudinal direction at a speed of Loom/min using a tensile tester. The strength in the longitudinal direction was determined by measuring the tensile force until breaking. In addition, a sample piece was cut to a length of 150 m in the roll axis direction and 50 m in the roll rotation direction, and a similar tensile test was conducted, and the measurement results were taken as the transverse strength.

Vertical strength is 10.0ON/m, horizontal strength is 10.2
9N/m, weight (converted to thickness 10-) is 200 g
/g. Table 1 shows each condition and measurement results.

Experimental Examples 2 to 12 below are also listed in Table 1.

(Experimental Example 2) A cloak was formed using the same apparatus as in Experimental Example 1, except that the diameter of the spinneret was 1.8 mm, and its strength was measured. 41 direction strength is 13.15N/m, lateral direction strength is 12.91N
/m, and the weight was 290 g/rd.

(Experimental Example 3) The same as Experimental Example 1 except that the distance between the spinneret and the roll was 250 fi. The longitudinal strength of the obtained mat was 9.21 N/m, and the transverse strength was 8.76 N/m1.
The weight was 205 g/bo.

(Experimental Example 4) This was the same as Experimental Example 1 except that the amplitude of vibration in the axial direction of each roll was set to 30. The longitudinal strength of the obtained cloak was 12.15 N/m, and the transverse strength was 13.64.
N/m, weight was 210 g/rd.

(Experiment Example 5) The density of protrusions arranged on the surface of each roll was set to 2000 pieces/
B. Same as Experimental Example 1 except that the height was set to 20 fl. The longitudinal strength of the obtained mat was 11.05N/
m, lateral strength is 11.0ON/m, weight is 205
g/rrr.

(Experimental Example 6) This was the same as Experimental Example 1 except that the density of the protrusions disposed on the surface of each roll was 15,000 protrusions/I, and the height was 5 cranes. The longitudinal strength of the obtained mat was 10.95N/
m, lateral strength is 10.0ON/m, weight is 215g
/rtr.

(Experimental Example 7) Same as Experimental Example 1 except that the diameter of the spinneret was 2.5 fi. The longitudinal strength of the obtained mat is io, o.

N7m, and the lateral strength was 10.21N/m.

The weight increased to 406 g/rd.

(Experimental Example 8) The same as Experimental Example 1 except that the distance between the spinneret and the roll was set to 400 fl. The longitudinal strength of the obtained cloak was 2.1 ON/m, and the transverse strength was 1.1 ON/m, which were significantly lower. The weight was 210 g/rrr.

(Experimental Example 9) This was the same as Experimental Example 1 except that each roll was not vibrated. The longitudinal strength of the obtained mat was 5.41N/
m, while the lateral strength further decreased to 1
．． It became 9ON/m. Weight was 225'glrd.

(Experimental Example 10) This was the same as Experimental Example 1 except that the density of protrusions arranged on each roll was 500 pieces/d. The obtained cloak had a longitudinal strength of 4.2ON/m and a transverse strength of 4.0ON/m.
/m, and the mat had no waist. Weight is 20
3g/rr? Met.

(Experimental Example 11) This was the same as Experimental Example 1 except that the height of the protrusions disposed on each roll was 150 mm. The resulting mat had a longitudinal strength of 8.61 N/m and a transverse strength of 7.29. The weight was 221 g/rd, but the thickness was uneven.

(Experimental Example 12) The same as Experimental Example 1 except that the roll clearance was set to 15.0 m. The monofilaments did not fuse together between the interlocking protrusions, and a mat was not formed.

(The following is a margin) (Effects of the invention) The method of the present invention is thus excellent not only in longitudinal direction (longitudinal direction) strength but also in lateral direction (width direction) strength.

Moreover, it is possible to manufacture a cloak made of thermoplastic resin with low density. As a result, the resulting cloak is lightweight and has excellent workability when used as a green protection net for slopes, etc., and has a high porosity.

It has the advantage that seeds, fertilizers, etc. can be filled into the voids without unevenness.

4. Flower buds FIG. 1 is a schematic diagram of the apparatus used to carry out the method of the invention.

10, 20. ... Roll, 11.21 ... Protrusion, 30 ... Extruder, 31.32 ... Spinneret,
40... mount, 50... mat.

51, 52...monofilament.

that's all

Claims (1)

[Claims] 1. A large number of protrusions are arranged on each surface,
A pair of rolls are rotated so that their protrusions can mesh with each other, and each roll is vibrated in the axial direction. This is a method for producing a thermoplastic resin mat using an extruder having a large number of spinnerets arranged in parallel in the axial direction, and a continuous monofilament of thermoplastic resin melt is extruded from each spinneret of the extruder. , a step of depositing the monofilament on a rotating and vibrating roll, and a step of compressing and fusing the deposited monofilament with interlocking protrusions.