JPH07203742A - Monofilament for lawn grass bush cutter - Google Patents

Abstract

PURPOSE:To obtain a monofilament for lawn grass bush cutter, composed of a specific polyamide resin, having a prescribed breaking elongation and a long duration of bush cutting performances, capable of carrying out the bush cutting with good operating efficiency, excellent in abrasion and heat resistances and suitable as a rotating blade, etc. CONSTITUTION:This monofilament for lawn grass bush cutter is composed of a polyamide resin such as nylon 46 resin, e.g. a crystalline polyamide prepared by polycondensing 1,4-diaminobutane with adipic acid or nylon 46-6 copolymer resin consisting essentially of the nylon 46 and has 40-120% breaking elongation. Furthermore, the shape of the monofilament is preferably 2-4mmphi diameter and the cross section may be any of circular, square, triangular shapes, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monofilament for a lawn mower used as a rotary blade of a rotary brush cutter for cutting grass and weeds.

[0002]

2. Description of the Related Art A rotary brush cutter is widely used as a means for cutting grass in a garden, grass in a pasture, weeds in an arable land, and weeds along a road. As a rotary blade of a rotary brush cutter, a metal disk with a blade is used. However, while this metal rotary blade is very good at mowing grass grass, if it comes in contact with an obstacle such as a stone or a pillar during mowing work, the metal rotary blade will be damaged and metal pieces will scatter. There is a risk. Further, the metal rotary blade has a problem that even trees such as garden trees and hedges are easily damaged.

To compensate for the drawbacks of metal rotary blades, relatively thick monofilaments made of synthetic resins such as nylon 6, nylon 66, and copolymer resins of nylon 6 and nylon 66 are used as rotary blades. To use this monofilament as a rotary blade of a rotary brush cutter, a storage container accommodating the monofilament wound around the rotary body is attached, and 10 to 10
Pull out 20 cm and rotate at high speed. By receiving the centrifugal force due to the rotation, the monofilament strikes off lawns, weeds, etc., so that they can be cut off.

[0004] These monofilaments are worn and consumed by strongly striking lawn grass and the ground, and the lawn mowing ability is reduced in proportion to the abrasion of the monofilaments. Therefore, the monofilaments are appropriately pulled out from the container and used. . Therefore, if the monofilament is worn out quickly, or the monofilament is overheated due to high-speed rotation and generates heat and melts and cuts, the brush cutter is stopped and the monofilament is pulled out from the storage container many times, resulting in poor work efficiency. Become.

[0005] In recent years, as the performance of monofilaments used for rotary blades has improved, they have been used even in areas where conventional brush cutters using metal rotary blades have only been used, and are more excellent in wear resistance and heat resistance. Although the demand for monofilaments has increased, monofilaments made of synthetic resins such as nylon 6, nylon 66, and a copolymer resin of nylon 6 and nylon 66 have not yet been obtained with sufficient performance.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides a monofilament which is excellent in wear resistance and heat resistance and which is suitable as a rotary blade of a rotary brush cutter. It is what

[0007]

In order to solve such a problem, the inventors of the present invention have studied a monofilament having a high melting point and excellent wear resistance, and as a result, a high elongation containing nylon 46 resin as a main component. The present invention has been achieved by finding that a monofilament is optimal.

That is, the present invention provides a monofilament made of a nylon 46 resin or a polyamide resin containing nylon 46 as a main component, which has a breaking elongation of 40 to 120%. It is a summary.

The present invention will be described in detail below. The monofilament of the present invention comprises nylon 6 and nylon 6
Compared with monofilaments made of resins such as 6, nylon 6-10 and nylon 6-12, it is necessary to use nylon 46 resin as the main component, which has the highest melting point and is excellent in abrasion resistance and flexibility.

The nylon 46 resin used in the monofilament for lawnmower of the present invention is a crystalline polyamide obtained by polycondensing 1,4-diaminobutane and adipic acid, and contains nylon 46 as a main component. The polyamide resin is not particularly limited, but nylon 46-6 copolymer resin obtained by copolymerizing nylon 6 and nylon 46-66 copolymer resin obtained by copolymerizing nylon 66 are preferable.

The blending ratio of the copolymerization component in the nylon 46 copolymer resin is preferably 15 mol% or less. A nylon 46 copolymer resin with a blending ratio of 15 mol% or less has a slightly lower melting point than nylon 46 resin, but since it is softened, the wear resistance of the rotary blade is improved and it is easy to handle. Become. However, when the blending ratio of the copolymerization component exceeds 15 mol%, the flexibility is improved, but the melting point is too low, which is not preferable.

The shape of the monofilament of the present invention is preferably about 2 to 4 mmφ in diameter, and the cross-sectional shape may be any of round, square, triangular and the like.

The breaking elongation of the monofilament is an important factor for determining the durability, and the breaking elongation of the monofilament needs to be 40 to 120% in order to obtain a rotary blade having good durability. If the elongation at break is low, less than 40%,
When used as a rotary blade, it easily wears out and has poor durability. Also, if it exceeds 120%, it breaks before it wears out.

[0014]

EXAMPLES Next, the present invention will be specifically described with reference to examples. Incidentally, the mowing property maintenance time in the examples is to evaluate the mowing ability of the monofilament, continuously mowing, part of the monofilament of the rotary blade is worn,
It is time to disconnect.

Example 1 Nylon 46 resin was melt-spun and stretched to a diameter of 3.5 mm.
A monofilament having φ and a breaking elongation of 80% was obtained. The obtained monofilament is a bell cutter manufactured by Shingu Shokosha (rotation speed
(10000 RPM), the monofilament was pulled out from the storage container by 15 cm and used as a rotary blade, and this brush cutter was operated to perform brush cutting in a meadow with many stones, and the cutting performance maintaining time was measured.

Example 2 Nylon 6 raw material was mixed with 5 mol% of nylon 6 raw material,
Nylon 46-6 copolymer resin obtained by polymerization was melt-spun and stretched, and then was mowed in the same manner as in Example 1 except that a monofilament having a diameter of 3.5 mmφ and a breaking elongation of 50% was used as a rotary blade. It carried out and measured the mowing property maintenance time.

Examples 3, 4 Except that the breaking elongation of the monofilament was changed as shown in Table 1, the cutting was carried out in the same manner as in Example 2 and the cutting-matter maintenance time was measured.

Comparative Example 1 Nylon 6 raw material (adipic acid and hexamethylene diamine salt) was blended in an amount of 5 mol% into nylon 6 raw material, and the nylon 6-66 copolymer resin obtained by polymerization was melt-spun and stretched. Mowing was carried out in the same manner as in Example 1 except that the obtained monofilament having a diameter of 3.5 mmφ and a breaking elongation of 80% was used for the rotary blade, and the mowing property maintaining time was measured.

Comparative Examples 2 and 3 Mowing was carried out in the same manner as in Example 2 except that the breaking elongation of the monofilament was changed as shown in Table 1, and the mowing property maintaining time was measured.

Table 1 shows the properties of the monofilaments and the shaving performance maintaining time in each of the examples and comparative examples.

[0021]

[Table 1]

As is clear from Table 1, the filaments of Examples 1 to 4 which were made of nylon 46 resin and nylon 46 copolymer resin and had a breaking elongation within the scope of the present invention were the rotary blades of the rotary brush cutter. When it was used for a long time, the maintenance time was good and the workability was good. On the other hand, the filaments of Comparative Example 1 in which the nylon 46 resin was not used and Comparative Examples 2 and 3 in which the breaking elongation was out of the range of the present invention even when the nylon 46 copolymer resin was used were the rotation of the rotary brush cutter. When used as a blade, the maintenance time was low and the workability was poor.

[0023]

INDUSTRIAL APPLICABILITY The monofilament for a lawn mower of the present invention is mainly composed of nylon 46 resin and has a high elongation, so that it has excellent wear resistance and heat resistance, and is used for a rotary blade of a rotary mower. When the brush is used, the brush is maintained for a long time, and it is possible to perform the brush cutting with good workability.

Claims (1)

[Claims] 1. A monofilament for a lawn mower, which is a monofilament made of a nylon 46 resin or a polyamide resin containing nylon 46 as a main component and having a breaking elongation of 40 to 120%.