KR20000070752A - Fabric Providing Protection from Chain Saws - Google Patents

Abstract

Disclosed is a consumable fabric structure for protection from a chain moving in a chain saw. The structure includes a fabric woven in a loose jersey.

Description

Fabric Providing Protection from Chain Saws

Background of the Invention

The present invention relates to a consumable fabric for protecting against the danger of a chain moving on a chain saw. It has long been known that special fabrics are used in clothing to protect them from chain saws.

US Pat. No. 4,279,956 to Bartels, issued July 21, 1981, discloses a protective layer of multiple layers of nylon fabric. Nylon is woven into plain or half twill. Each layer was made using interwoven strips, making the structure of the pad more difficult to crush than when the layers were not interwoven with each other.

US Pat. No. 5,395,683 (Bledsoe et al.), Issued March 7, 1995, discloses protective pads made from so-called hybrid fabric layers comprising various types of knitted fibers.

In European Patent Application Publication No. 202,183, published November 20, 1986, several fabric layers for chain saw protection, in which the fabric was loosely woven with aramid yarn and the layers were loosely sewn so that all the separated layers stopped the chain. The structure of the is disclosed. Fabric tissue is disclosed in linen-type (plain weave).

Summary of the Invention

The invention relates to the periphery of a fabric layer woven in a 1 / x runner, where x is 3 to 9, using a yarn of tenacity of at least 10 g / dtex and a tensile modulus of at least 150 g / dtex. It is generally intended to provide a spent fabric structure for protecting from moving chain saw blades comprising a plurality of stacks that are tied together.

It is also to provide a spent fabric structure comprising multiple stacks of fabrics woven from aramid yarns.

Preferred embodiments of the structures of the present invention use aramid yarns having a linear density of at least 1200 dtex made from filaments of poly (p-phenylene terephthalamide). It is preferred when the fabric structure is 1/3 runner (also known as four runners) and when the stack of fabrics is alternately laminated with the felt layer.

1 schematically shows runners, twills, and plain weaves.

Figure 2 shows a cross-section of the wasted structure of the present invention.

The yarn used in the fabric structure of the present invention is a yarn formed from continuous filaments. Preferred yarns are made from aramids. "Aramid" means a polyamide in which at least 85% of the amide bonds (-CO-NH-) are directly linked to two aromatic rings. Para-aramid is the main polymer in the fibers of the invention and poly (p-phenylene terephthalamide) (PPD-T) is the preferred para-aramid.

The present invention intends a protective material for a chain saw that can stop the chain saw motor by stopping the chain to eliminate or reduce damage by the chain. In the case of protective fabrics for chain saws, the fabric component should be made of a strong thread that is relatively easily torn from the fabric and sucked into the chain transmission. Thus, the fabric must be consumed to provide protection from moving chain saw blades. Aramid yarns have been found to be particularly suitable for use as protective materials for chain saws, so that the spent fabric structures of the present invention comprise a plurality of layers of fabric woven from aramid yarns with tissues that have been found to provide particularly effective protection.

The inventors have found that combining the strength of the aramid fibers with the weaving to runners so that the fibers are stable in woven form but can easily stop the chains significantly improves the protection against the chain saw.

Referring to Fig. 1, a general schematic of three basic types of weaving patterns is shown. FIG. 1A shows a plain weave with each weft 11 successively passing up and down the slope 12 with each row filtered one by one, resulting in a regular, relatively dense weft / tilt intersection 13. Pattern. FIG. 1B is a twill pattern in which the weft yarns 11 rise above the warp yarns 12 staggered with each other such that the weft / tilt intersection 13 makes a twill rib or a diagonal rib. 1C is a runner pattern in which each weft 11 is floated over a slope 12 so that the weft / tilt intersection 13 is as evenly and widely distributed as possible.

As can be seen from FIG. 1, the runners have a maximum distance between the weft / tilt intersections and a maximum number of ratios between adjacent weft / tilt intersections. In the protection for the chain saw, it was found that for a short time when the chain saw is in contact with the fabric, the fabric with the smallest number of weft / tilt intersections and the maximum allowable length of the fiber will provide maximum protection. Runners provide the smoothest (rib-free) surface for a flatter stack of fabric components with maximum distance in all directions between weft / tilt intersections.

Runner fabrics are used in the present invention, with runners being characterized by 1/3 to 1/9 runners. The most commonly used runners are one-third, also known as four runners, which are repeated in succession, passing over one slope and then down three slopes, and the resulting weft / tilt intersection is possible. far away. Dense runners, which are denser than one-third runners, have too many weft / tilt intersections and are thought to have low contact fiber and low contact with the chain saw. Loose runners, which are looser than the 1/9 runners, have found that the weft thread is pulled out of the fabric too easily by the chain saw and consequently insufficient resistance to slow the chain.

It has been found that aramid yarns having a linear density of 200 dtex or more are useful in the present invention. The yarn of the structure of the present invention must have sufficient strength to prevent the fabric from rupturing or pulling out of the fabric before it is rolled into the chain. The linear density of the yarn should be between 200 and 3400 dtex, preferably between 1000 and 1700 dtex, the filaments of this room should be continuous and the linear density should be greater than 1 dtex and less than 8 dtex, preferably greater than 1.5 dtex and less than 5 dtex. In order to achieve sufficient protection, a lower limit is required, and above all, an upper limit is required because of its ease of operation. When yarns or filaments of greater linear density than specified are used, it is difficult to form a fabric and is too stiff to handle even if formed.

In addition to the fabric bulk provided by the use of fabrics woven with yarns of at least 200 dtex, preferably at least 1000 dtex, the fabrics of the present invention are highly capable of pulling the fibers out of the fabric rather than just breaking the fibers by the moving chain. There must be high strength. The required strength is obtained by using a yarn having a specific strength of at least 10 g / dtex, preferably at least 15 g / dtex, and a tensile modulus of 150 to 2000 g / dtex, preferably 500 to 1500 g / dtex. If the modulus of elasticity is less than 150 g / dtex, excessive stretching occurs during use, and if the modulus of elasticity is greater than 2000 g / dtex, the fibers are too stiff for practical use. If the specific strength is less than 10 g / dtex, the fabric will flake rather than roll into the chain. Since strength is of paramount importance in these applications, there is no upper limit of specific strength for these fibers.

In the structure of the present invention, the fabric is, for example, in addition to poly (p-phenylene terephthalamide), chain-extended polyolefins such as ultra high molecular weight polyethylene, high strength poly (vinyl alcohol), poly (ethylene naphthalate), poly (p-phenyl Len benzobisoxazole) and the like.

The inventors have found that the protection against the chain saw is improved when adjacent layers of the protective structure are not joined to the parts necessary for the most protection. In other words, the protective structures should not be sewn together, for example by sewing the body of the material crosswise. It was found that sewing the layers together reduced the free length of the thread that could be pulled out by the chain teeth, reducing the protective effect of the structure. The fabric layers can be sewn together or otherwise attached to the periphery of the layers, but it is important that the individual layers of protective material act independently of each other where possible in contact with the chain teeth.

Preferred structures of the layers in the protective structure of the present invention include alternating layers of woven fabrics as described above and felt materials, generally made from aramid staple fibers using a bonding method by needling or hydraulic entanglement. The felt is 100 g / m ² to 140 g / m ² (3 to 4 oz / yd ² ) and has a thickness of 1 to 2.5 mm (0.04 to 0.1 inch). Specifications for felt are provided in the US Department of Agriculture, Forestry Bureau, Standards Collection 6170-4D.

Referring to FIG. 2, the protective structure 20 includes a pulp layer 22 and a fabric layer 21 in alternating state. Optionally, cover layer 23 may be provided for decoration, comfort, waterproofing, or other desirable incidental purposes. The cover layer 23 is a lightweight inner or outer shell fabric and does not participate in providing protection for the chain saw.

<Inspection method>

The fabric structure of the present invention is evaluated according to ASTM F 1414-92a (standard test method for measuring cut resistance for chain saws of lower body (leg) protective clothing). The test results are expressed in Threshold Stopping Speed (TSS).

Unless otherwise noted, the fabric structure being evaluated is an alternating fabric / felt material structure described in US Department of Agriculture Forest Service Standard 6170-4D, and felt is also described in the specification.

<Example 1>

Both fabrics were woven into continuous filament aramid yarns with a linear density of 1260 dtex. The yarn had a specific strength of 21.5 g / dtex and a tensile modulus of 850 g / dtex. The linear density of these filaments in the room was 1.65 dtex. In fact, the trade name is Kevlar K-49. children. It is the same as sold at E. I. du Pont de Nemours and Company.

One of the fabrics was 17 × 17 plain weave weighing 170 g / m ² (5 oz / yd ² ). This fabric was used as a control standard or comparison for this example.

Another fabric was a 17 × 17 1/3 (4 sheets) runner (often called “Crowfoot Weave”) weighing 170 g / m ² (5 oz / yd ² ).

Meets the requirements of Specification 6170-4D mentioned above, i.e. made from para-aramid fiber staples with an area density of about 200 g / m ² (3.5 oz / yd ² ) and thickness of about 1.5 mm (0.06 inch) The test constructs were aggregated using in felt.

The test structures included two layers of fabric alternating with two layers of felt and a cover layer at the top and bottom. The cover layer was usually a weight nylon cloth and the layers only connected to each other around the outer edge of the layer. In all cases, the first layer below the top cover layer was a woven aramid fabric. The limit stop speed was measured according to ASTM F1414-92a.

The limit stop speeds for both test structures were measured as follows.

sample (TSS) (m / s) Invention 13.6 to 15.0 Comparative 11.5 to 12.2

<Example 2>

Again, both fabrics were woven with continuous filament aramid yarns with a linear density of 1260 dtex. The filament of this room had a linear density of 1.65 dtex, specific strength of 21.5 g / dtex and tensile modulus of 674 g / dtex. In fact, the trade name is Kevlar K-29 (registered trademark of Kevlar K-29). children. It was the same as sold at E. I. du Pont de Nemours and Company.

One of the fabrics was 17 × 17 plain weave weighing 170 g / m ² (5 oz / yd ² ). This fabric was used as a control standard or comparison for this example.

Another fabric was a 17 × 17 1/3 (4 sheets) runner (often called “Crowfoot Weave”) weighing 170 g / m ² (5 oz / yd ² ).

Fabrics were used in the form with all the processing agents of the common filaments and yarns commonly associated with commercially available fabrics (so-called "greige"), and these processing agents were also used from textiles as a common commercial means using water and detergents. Used in refined form. The test was performed using both forms.

Meets the requirements of Specification 6170-4D mentioned above, i.e. made from para-aramid fiber staples with an area density of about 200 g / m ² (3.5 oz / yd ² ) and thickness of about 1.5 mm (0.06 inch) The test constructs were aggregated using in felt.

The test structures included two layers of fabric alternating with two layers of felt and a cover layer at the top and bottom. The cover layer was usually a weight nylon cloth and the layers only connected to each other around the outer edge of the layer. In all cases, the first layer below the top cover layer was a woven aramid fabric. The limit stop speed was measured according to ASTM F1414-92a.

The measured value of the limit stop velocity for both test structures is as follows.

sample (TSS) (m / s) Improvement (m / s) (%) Gray Invention 15.5 Comparative 12.7 2.4 18.9 After refining Invention 14.6 Comparative 12.3 2.3 18.7

Claims (10)

Movable chain saw blade comprising multiple stacks of fabrics woven in 1 / x runners (where x is 3 to 9) with yarns having a tenacity of at least 10 g / dtex and a tensile modulus of 150 g / dtex Consumable fabric construction to protect against. The fabric structure of claim 1 wherein the yarn is an aramid yarn. The fabric structure of claim 1, wherein the yarn is made from filaments having a linear density of 1 to 8 dtex. The fabric structure of claim 1, wherein the layers are only connected to each other around the periphery of the layers. The fabric structure of claim 1 comprising one or more felt layers. 6. The fabric structure of claim 5 wherein the fabric layer and the felt layer are alternating. The fabric structure of claim 6, wherein the felt is made from aramid staple fibers. The fabric structure of claim 1, wherein the aramid yarn comprises poly (p-phenylene terephthalamide) fibers. The fabric structure of claim 1, wherein the fabric is woven from aramid yarn in a third runner. 10. The fabric structure of claim 9, wherein the aramid yarn comprises poly (p-phenylene terephthalamide) fibers.