JP2006052519A - Webbing for seat belt and method for producing webbing for seat belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a webbing having high strength per a single warp and a thin and light texture and keeping abrasion resistance by using a polyester multifilament yarn for a seat belt composed of a fine single yarn fiber and having extremely high strength as the warp of the webbing. <P>SOLUTION: A multifilament yarn composed of a plurality of polyester filaments having a single fiber fineness of ≤7 de and a single fiber strength of ≥10 g/de is twisted at a high twisting degree which is not common in conventional seat belts by a nonconventional twisting method having extremely low twisting cost. The obtained yarn having unprecedentedly high convergence is used as a warp and a polyester multifilament yarn and/or monofilament yarn are used as a weft and the webbing for seat belt is woven by crossing the warp with the weft and weaving in the form of a belt. The webbing has extremely high strength per a single warp, reduces the cost of the raw yarn and keeps the abrasion resistance of the webbing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a seat belt woven in a belt shape by intersecting a weft and a warp, and is composed of a high-strength, thin single yarn fiber that is not common in a conventional seat belt, and has a high twist that is not common in a conventional seat belt. The present invention relates to a technique for knitting polyester multifilament yarn with twist processing as warp, and obtaining webbing that has extremely high strength per warp unit, is thin and light, and maintains abrasion resistance.

  In general, a webbing for a seat belt is a specification that ensures various properties such as a specified tensile strength, elongation, durability, and the like, and a multifilament yarn mainly composed of polyester or polyamide fibers is used as a warp. A multifilament yarn or monofilament yarn made of polyamide fiber is used as the weft, and the warp and weft are crossed on a loom for narrow fabric and woven into a belt shape.

  Conventionally, most webbings have been woven in a belt shape on a narrow loom power loom by crossing the warp and weft yarn by reciprocating a shuttle for the weft yarn between the upper and lower warp groups opened on the loom. .

  During the weaving operation by the narrow loom power loom, a lot of filaments were damaged in the warp group due to abrasion of the warp group by the weft shuttle passing between the upper and lower warp groups.

  In order to prevent damage to the filaments of this warp group, in the past, a polyamide yarn that has been subjected to twist processing of about 80 times per 1 m, with a single yarn fineness of about 8 denier and a strength of about 8 g per denier. Multifilament yarns were commonly used as webbing warp yarns.

  After that, weaving webbing with a narrow weaving needle weaving machine, in which the weft needles reciprocate between the upper and lower warp groups opened on the loom, crossing the warp and wefts in a belt shape, became popular. .

  During the weaving operation by this narrow weaving needle loom, the weaving of the warp group by the weft needle passing between the upper and lower warp groups is much higher than that of the warp group by the weft shuttle of the power loom. Even if the warp yarn is not twisted to maintain the yarn convergence, the warp group is less likely to be damaged by filament cutting. For this reason, the tendency to abolish the cost of webbing by eliminating the twisting process for the warp, which has been conventionally performed, and eliminating the twisting cost is increasing.

  Furthermore, along with the tendency to abolish the twisting process, the webbing woven using a multifilament thread with a large single yarn fineness is subjected to a surface treatment with a resin or an oil agent to ensure the wear resistance of the webbing. New techniques have been devised, and this technology has come to be used a lot.

  As a result, it is common for polyamide or polyester multifilament yarns having a single yarn fineness of approximately 11 denier and a strength of approximately 8.5 g per denier to be used for webbing warp yarns in an almost untwisted state. It was.

  By the way, recently, polyester fibers have been used for most webbings, mainly polyester multifilament yarns having a single yarn fineness of about 11 denier and a strength of about 9 g per denier are almost untwisted. It is becoming the mainstream of webbing production by using it for warp and weaving with a needle loom for narrow fabrics.

  Moreover, recently, the surface strength is maintained to maintain the conventional strength even if the single yarn fiber is thick, and coupled with the progress of the polyester yarn production technology with less filament cutting, the surface treatment for finishing the webbing is omitted. For the purpose, there is a tendency to further increase the single yarn fineness of the fibers used for the webbing warp, and the polyester multifilament yarn having a single yarn fineness of about 14 denier or more and a strength of about 9 g per denier is almost untwisted. In some situations, it is recommended to use it for webbing warp.

  As can be seen from the above-described prior art, the use of a narrow loom needle loom is generalized for weaving webbing, and the yarn production technology has advanced, so that there are few disadvantages of filament cutting, which has been difficult in the past, and is thick. In order to reduce the cost of webbing as fiber manufacturers can supply single-filament polyester multifilament yarns, we eliminate webbing warp twisting, and eliminate surface treatment and wear resistance. In order to ensure the properties, the webbing production technology has been shifted in the direction of increasing the single yarn fineness of the polyester fiber used for the warp.

  On the other hand, in the yarn making process, the strength of the polyester fiber increases as the fiber drawing ratio increases, but on the other hand, there are tendencies to increase the disadvantage of filament cutting.

  In addition, it is said that as the fineness of the single yarn increases, the difficulty of the drawing process in the spinning process increases, and the spinning speed decreases to maintain a certain quality.

  Recently, we have increased the strength of polyester multifilament fibers of thicker single yarn fineness, which are often used for webbing warp, without increasing the defect of filament cutting, It is very difficult to further reduce the yarn cost by raising the yarn even with the current yarn production technology, which is said to have advanced to a high degree.

  On the other hand, in the weaving process, polyester multifilament fibers with a thick single yarn fineness are used for the webbing warp in an almost untwisted state, and the drawback of filament cutting is that the thick single yarn fibers are not on the surface of the woven webbing. It becomes a defect of the webbing from which the terminal protrudes, and it becomes manifest as an appearance defect of the webbing.

  For this reason, from the viewpoint of not increasing webbing defects, it is not acceptable to have frequent filament cutting defects in the yarn making process, increasing the strength of the fiber or increasing the yarn making speed to obtain the original yarn. It is difficult to pursue cost reduction.

  Therefore, in the direction of the recent webbing weaving technology, which tends to increase the single yarn fineness, omitting the twisting process of the polyester fiber used for the webbing warp, the raw yarn price is reduced by increasing the yarn-making speed in the yarn-making process. In addition, it is difficult to reduce the yarn cost by improving the yarn strength by increasing the draw ratio, and it is technically in a state of bottoming out, and new technical development to overcome these becomes a problem.

  Accordingly, an object of the present invention is to solve the above-mentioned problems, and use a polyester multifilament yarn composed of very high strength and thin single yarn fibers for webbing warp without impairing the wear resistance of the webbing. As a result, it provides a webbing that has higher strength per warp unit, higher tensile strength, can reduce the amount of warp, and is thinner, lighter, and capable of reducing costs. That is.

  In order to achieve the above object, the present invention basically adopts the following technical configuration.

That is, the first aspect of the present invention is a multifilament yarn in which a plurality of polyester filaments having a single yarn fineness of 7 denier or less and a single yarn strength of 10 g / denier or more are assembled. Twisting coefficient α determined by equation (1)
α = T x (D1) ^1/2 (1)
(Here, T: number of twists t / m and D1: warp multifilament yarn denier.)
However, a polyester multifilament yarn twisted under conditions of 4000 to 5500 is used as the main warp, and the relationship between the density and the thickness of the weft is expressed by the following formula (2):
Weft density (3 / 3cm) x (D2) ^1/3 ≧ 179 (2)
(Here, D2: the total denier of the weft multifilament yarn and the monofilament yarn or both)
And a weft coefficient that satisfies the requirements, a thickness per 1 kN of 0.037 mm or less, a weight per 1 kN of 1.64 g / m or less, and a hexagonal bar wear strength retention of 80 % Is a webbing for seat belts having wear resistance characterized by being at least% , and as a second aspect in the present invention, the single yarn fineness is 7 denier or less and 10 g / denier or more A multifilament yarn in which a plurality of polyester filaments having a single yarn strength is assembled, and is subjected to a specified twisting of a twist coefficient α determined by the formula (1) according to claim 1 of 4000 to 5500. and it has a polyester multifilament yarn, arranged in at least a portion of the ground warp, and supplies the polyester multifilament yarn continuously weaving process with twisting, claim 1 Symbol It is of formula (2) in the manufacturing method of the seat belt webbing having abrasion resistance with weft coefficients and wherein the weaving in the weft to be supplied required.

The above-described seatbelt webbing and seatbelt webbing manufacturing method according to the present invention have the above-described configuration. Therefore, Japanese Patent No. 2514884 “Creel equipped with twisting device” or Japanese Patent No. 2630567. Using the technology disclosed in “Creel equipped with double twisting device”, the warping process or weaving process is performed at the same time. In conventional seat belts, spinning is performed at the maximum draw ratio or at a high speed in the spinning process by adding high twisting twist processing, which is not common in conventional seat belts, to warp constituting webbing by using no twisting method. Use unprecedented, very high-strength polyester multifilament yarns that are unsuitable thin single yarn fibers for webbing warps Possible and then, strongly is very high per warp unit number, cost can be diminishing yarn, and it is possible to obtain a webbing maintaining the wear resistance.
Furthermore, in the present invention, a seatbelt webbing that is thin and light although the tensile strength is large is obtained and in other words, if it is a seatbelt webbing having the same tensile strength characteristics, its weight is The effect that a light and thin thing is obtained can be expected .

  The above-described seat belt webbing and seat belt webbing manufacturing method according to the present invention employs the above-described technical configuration, so that it does not impair the wear resistance of the webbing, and has a very high strength and a thin single yarn. It is possible to use polyester multifilament yarn made of fiber for webbing warp, and as a result, the strength per unit of warp is high, the tensile strength is higher, the amount of warp can be reduced, thinner, A webbing that is light in weight and allows cost reduction is obtained.

  In the present invention, a polyester multifilament yarn having a remarkably higher single yarn fineness than that of a thick single yarn fiber that has been generally used for warp recently, that is, a single yarn fineness of 7 denier or less and a remarkably high strength, That is, a yarn having a strength of 10 g / d or more is used as a webbing warp.

  That is, a yarn having a fine single yarn fineness can be produced at a higher drawing rate than before in the yarn production process, and a polyester fiber having a very high strength as compared with the present can be used as a warp. Further, a polyester fiber that can be spun at a higher speed and has a high possibility of cost reduction can be used for a webbing warp. Therefore, it becomes possible to improve the webbing strength by improving the strength of the warp of the webbing, or to reduce the cost of the webbing by reducing the amount of warp yarn and lowering the raw yarn price.

  Further, in the present invention, the warp made of polyester multifilament yarn with a very thin single yarn fineness is subjected to a strong twisting process that is not common in conventional seat belts, thereby giving the warp a strong convergence. is there. As a result, the wear resistance of the webbing can be maintained without special surface treatment. Of course, there is no problem even if the surface treatment is used together.

  Furthermore, in the present invention, the ends of the filaments cut by high drawing or high-speed spinning in the yarn making process are wound and concealed in the yarn twist, and the ends of the filaments protrude significantly on the surface of the webbing. By doing so, it is possible to reduce the appearance defects of the webbing. As the number of twists, the twist coefficient α obtained by the following formula (1) is 4,000 or more in order to maintain the strength retention after hexagonal bar wear according to JIS standards, which is generally regarded as a standard, of 80% or more. It is necessary to be in.

α = T x (D1) ^1/2 (1)
(Here, T: number of twists t / m and D1: warp multifilament yarn denier.)
Further, in the present invention, for example, using a “creel with a twisting device” of Patent No. 2514884 or “a creel with a double twisting device” of Patent No. 2630567, warping or weaving It is to adopt a twist processing means that has a very low processing cost, such as performing twist processing on warps at the same time as processing. As a result, the twisting process of webbing warp that has been deleted due to cost reduction is once again incorporated into the webbing production technology in a new form, and the single yarn fineness of the usable yarn can be freely selected. Or the allowable range of filament cutting defects generated in the spinning process can be expanded several times.

  Furthermore, in the present invention, as a weft of a webbing using the above-mentioned warp, the relationship between the density and thickness of the weft is expressed by the following formula (2) from the viewpoints of hexagonal bar wear characteristics, form stability as a webbing, and the like. Weaving webbing at a density that satisfies (this is defined as the weft coefficient).

Weft density (3 / 3cm) x (D2) ^1/3 ≧ 179 (2)
(Here, D2: the total denier of the weft multifilament yarn and the monofilament yarn or both)
In the present invention, when the weft coefficient is 179 or less, the strength retention after hexagonal bar wear is 80% or less, resulting in poor wear and easy webbing.

  In addition, by forming a webbing using polyester monofilament yarns alone or in combination with polyester multifilament yarns as wefts, adjusting the stiffness (rigidity) in the width direction of the webbing to obtain comfort when wearing the webbing, or It is possible to prevent reversibility when the webbing is wound around the winding device. By appropriately selecting the weft thickness within a range that satisfies this weft coefficient and changing the thickness of the webbing, the webbing at the time of collision and the metal fitting for guiding the webbing, or the webbing caused by the high-speed friction between the webbing and the human body are used. In order to prevent melting deterioration, the heat-resistant capacity of the webbing can be adjusted.

  Also, as part of the warp, use a polyester multifilament yarn having a single yarn fineness, single yarn strength, twist number other than the polyester multifilament yarn, or use a multifilament yarn made of a material other than polyester. You can also.

  Furthermore, by inserting warp yarns having a relatively small fineness into both end portions of the webbing, the end portions of the webbing are made substantially circular or cylindrical, thereby having a flexible touch terminal. Webbing can also be provided. In order to identify the webbing appearance, it is possible to insert the same warp (s) into any part of the warp, or to change the weave structure of the part of the warp that forms the webbing. It can also be an identifying sign.

Embodiments Hereinafter, the configuration of a specific example of a seatbelt webbing and a seatbelt webbing manufacturing method according to the present invention will be described in detail with reference to the drawings.

That is, FIG. 1 is a view showing a configuration of a specific example of a seat belt webbing according to the present invention, in which the single yarn fineness is 7 deniers or less and has a single yarn strength of 10 g / denier or more. A multifilament yarn 1 in which a plurality of polyester filaments are assembled, and the twist coefficient α obtained by the following formula (1)
α = T x (D1) ^1/2 (1)
(Here, T: number of twists t / m and D1: warp multifilament yarn denier.)
However, we use polyester multifilament yarn 1 with 4000 or more twists as main warp yarn 2 and weave it at a weft density such that the relationship between the density and thickness of weft yarn 3 satisfies the following formula (2): A webbing 4 for a seat belt characterized by being formed is shown.
Weft density (3 / 3cm) x (D2) ^1/3 ≧ 179 (2)
(Here, D2: the total denier of the weft multifilament yarn and the monofilament yarn or both)
According to the equation (1) used in the present invention described above, the twist coefficient α is determined based on the twist number T (t / m) of the multifilament yarn 1 and the denier (D1) of the multifilament yarn 1 used as the warp yarn 2. ) And the square root.

  On the other hand, according to the formula (2) used in the present invention, the relationship between the density of the weft 3 and the total denier thickness of the multifilament yarn and the monofilament yarn used as the weft, or both, is expressed by the weft density ( Book / 3 cm) and the product of the weft denier (D2) cube root.

  In the present invention, the seat belt webbing 4 is preferably woven by a needle loom.

  Further, in the present invention, after the seat belt webbing 4 is dyed, heat set or finished, the single yarn strength of the polyester multifilament yarn 1 constituting the main warp yarn 2 is 9 g / denier or more. It is also desirable that

  Furthermore, in the present invention, polyester multifilament yarn, polyester monofilament yarn or both may be used as weft yarn.

  On the other hand, in the seat belt webbing 4 according to the present invention, the warp yarn 6 constituting the ear portion 5 of the seat belt webbing is the fineness of the multifilament yarn 1 constituting the main warp yarn 2. It is also preferred that a multifilament yarn having a smaller fineness is used.

  Further, as a specific example of the method for producing a seat belt webbing according to the present invention, for example, a plurality of polyester filaments having a single yarn fineness of 7 denier or less and a single yarn strength of 10 g / denier or more are assembled. A polyester multifilament yarn, which has been subjected to the specified twisting having a twist coefficient α of 4000 or more, as defined above, is disposed at least in part of the ground warp yarn, The filament yarn is supplied to the weaving process and twisted while twisting.

  As a more preferred specific example of the method for producing a seat belt webbing in the present invention, a plurality of bobbins made of untwisted polyester multifilament yarns are mounted on a creel having an appropriate twisting mechanism as warp supply means, Twisting while pulling out the polyester multifilament yarn from each of the plurality of bobbins mounted on the creel, and simultaneously supplying the warp while supplying the warp to the weaving step. It is constituted so that it may be formed.

  Furthermore, as another aspect of the method for producing a seat belt webbing according to the present invention, a plurality of bobbins made of untwisted polyester multifilament yarn are mounted on a creel having an appropriate twisting mechanism as a warp supply means. The coarse woven fabric is formed while twisting while pulling out the warp made of the polyester multifilament yarn from each of the plurality of bobbins mounted on the creel, and at the same time supplying the coarse weaving process to the coarse woven fabric. The warp portion is supplied to the weaving process and woven.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1
As a polyester multifilament having a fine single yarn fineness used for webbing in the present invention, 200 yarns having a 288 filament (single yarn fineness of 5.2 denier) at 1500 denier and a strength of 10.5 g / d are used as warp 1 Using a “creel equipped with a double twisting device” shown in Japanese Patent No. 2630567, the warp yarn 1 is supplied to the needle loom while being twisted so as to change the number of warp twists in various ways. As weft 3, polyester multifilament 750 denier yarn is supplied to the same needle loom at a density of 20 / 3cm (weft coefficient: 182) to create coarsely woven draft webbing, and finally dyeing / resin processing A plurality of types of webbings as shown in Table 1 were prepared.
In Table 1, D and E correspond to the examples of the present invention, and A, B, C and F indicate comparative examples .

As another comparison, a polyester having a single yarn fineness of 144 denier (single yarn fineness of 10.4 denier) and a strength of 9.1 g / d, which is currently used as a warp for webbing, is used. Using it as a warp, webbings as shown in G and H of Table 1 were prepared by the same processing method.

  From this result, as shown in FIG. 2, by performing a twisting process with a twisting coefficient (α) of 4,000 or more, a good webbing with a JIS standard hexagonal bar wear strength retention of 80% or more can be achieved. I understand. Further, it was found that by performing such a twisting process, as shown in Table 1, the surface fluff defects can be suppressed to a good level.

Example 2
As a polyester multifilament composed of fine single yarn fineness used for webbing in the present invention, a yarn of 1260 denier and 192 filament (single yarn fineness of 6.6 denier) and a strength of 10.8 g / d is used as warp yarn 1. Using weft 3 which is coarsely woven at the same time while twisting the warp 1 with a warp twist of 120 t / m using the “creel with double twisting device” shown in Japanese Patent No. 2630567 Then, when forming the webbing with a needle loom, webbings were prepared in which the number of weft yarns, the type of weft yarn, the weft yarn thickness, and the density were variously changed as shown in Table 2. The webbing produced the thing which gave only the dyeing process, and the thing which gave the resin process.

  As a comparative example, polyester 1260 denier made of thick single yarn fineness, which is generally used as a webbing warp yarn recently, is used for warp with 108 filaments (single yarn fineness of 11.7 denier) and strength of 9 g / d. The webbing of S in Table 2 was made.

From this result, in comparison with the comparative example S which is generally flown as a 30 kN type webbing at present, in the present invention, the weft yarn having a weft coefficient as defined above of 179 or more is used. The webbings of Examples L, M, P, Q, and R configured with thickness and density are good in performance, thin in thickness, and light in weight of 16-20 %.

  Compared to this, the webbings of Comparative Examples J, K, and N are not satisfactory in the weft coefficient, and are therefore poor in hexagonal bar wear and easily misaligned.

  Further, the webbing of Example R in which the polyester monofilament 600 denier is used in combination with the weft is a product having a weft rigidity about twice that of Example P.

Furthermore, the relationship between the strength retention ratio and the weft coefficient after the above hexagonal bar wear shows a specific curve as shown in FIG. 3 and is ideally located in the vicinity of the graph shown by the curve shown in the figure. Although it is conceivable, it is understood that a product satisfying the object of the present invention can be obtained if at least the weft coefficient is 179 or more .

Example 3
The webbing of Example D described above was subjected to 500 denier, 48-filament polyester multifilament yarn and 250 denier, 24-filament polyester multifilament yarn, each having 16 twists of about 120 t / m, both ends of webbing 4 By inserting the warp 6 of the portion 5 and weaving with the weave structure shown in FIG. 4, it is possible to form a webbing having both ends of the webbing in a substantially circular shape and having a flexible touch end.

Also, 32 yarns of about 120 t / m twisted on a 500 denier, 48-filament polyester multifilament yarn are inserted into the warp yarns at both ends of the webbing and woven with the weaving structure shown in FIG. The webbing with the terminal of the soft touch can be formed by making the shape of both ends of the tube substantially cylindrical.
Here, in order to confirm the characteristic that the tensile strength, which is characteristic of the seat belt webbing of the present invention is large, light and thin, Table 1 and Table 2 are developed and analyzed in Table 3 and Table 4, respectively. .
That is, Tables 3 and 4 are based on the thickness, weight, and tensile strength data for each sample in Tables 1 and 2, and for each sample, warp total denier d, 1 denier d per kN, The thickness mm per 1 kN and the weight g / m per 1 kN were obtained, respectively.
Examining these experimental result data, it is considered that the twist coefficient α is preferably 4000 or more as judged from FIG. 2. However, as shown in Comparative Example F, when the twist coefficient α exceeds 6000, the twist coefficient α is considerably large. Since it has been found that the tensile strength is reduced and the meaning of using a high-strength yarn is diminished, the thickness is increased, and the weight is increased, referring to Example E, the upper limit of the twist coefficient α is 5500. It is judged to be desirable.
Next, Comparative Examples A, B, C, N, J, and K all have an abrasion resistance of 80% or less and do not satisfy the wear characteristics required by the present invention. It is clear that this is not the case.
Further, Comparative Example G does not twist warp, and Comparative Example H shows that the twist coefficient α is in the preferred range of the present invention described above, and the wear resistance is also in the preferred range. However, in order to obtain the same strength as that of Examples D and E of the present invention, it is necessary to increase the number of warps, resulting in an increase in weight and thickness. .
On the other hand, the comparative example S corresponds to a webbing for seat belts that is generally commercially available, and is a comparative example in that the warp is not twisted. The same configuration as the comparative example S In comparison with Example P that satisfies the requirements of the present invention, Example P is 19% lighter than Comparative Example S in weight and 13% thinner in thickness. I understand that.
More specifically, in the present invention, the seat belt webbing has a characteristic value that the thickness per 1 kN is 0.037 mm or less and the weight per 1 kN is 1.64 g / m or less. As is clear from the data in the above tables, in the specific examples of the embodiments of the present invention, the thickness per 1 kN is 0.037 mm or less and the weight per 1 kN is 1. It is clear that the characteristic value is 64 g / m or less.
Moreover, in the Example of this invention, it is shown that it is still more preferable that the total warp fineness per 1 kN is 11700 denier or less.

  The above-described seatbelt webbing and seatbelt webbing manufacturing method according to the present invention have the above-described configuration. Therefore, Japanese Patent No. 2514884 “Creel equipped with twisting device” or Japanese Patent No. 2630567. Using the technology disclosed in “Creel equipped with double twisting device”, the warping process or weaving process is performed at the same time. In conventional seat belts, spinning is performed at the maximum draw ratio or at a high speed in the spinning process by adding high twisting twist processing, which is not common in conventional seat belts, to warp constituting webbing by using no twisting method. Use unprecedented, very high-strength polyester multifilament yarns that are unsuitable thin single yarn fibers for webbing warps Possible and then, strongly is very high per warp unit number, cost can be diminishing yarn, and it is possible to obtain a webbing maintaining the wear resistance.

  Furthermore, in the present invention, by applying a strong twisting process to the warp of the webbing to give the warp unprecedented high convergence, the ends of the cut filaments generated in the yarn making process are incorporated into the yarn twist. It is possible to reduce the defects in the appearance of the webbing by preventing the end of the filament from projecting conspicuously on the surface of the webbing. , And further increase the draw rate and spinning speed of the yarn, allowing the use of higher strength, lower cost raw yarns, further improving the strength per unit number of warp yarns, and reducing the cost of webbing To do.

  Further, in the present invention, by inserting a plurality of warp yarns having a relatively small fineness into both end portions of the webbing, the shape of both ends of the webbing is made substantially circular or cylindrical, or a terminal having a soft feel. It is possible to ensure the comfort of the shape of the ear part of the webbing.

  On the other hand, in the present invention, the webbing is mounted by adjusting the width (stiffness) of the webbing in the width direction by selecting the filament shape (multifilament or monofilament) or fineness (thread thickness) of the weft of the webbing. The comfort of time can be obtained, or the webbing can be prevented from being reversed when the webbing is wound around the winding device.

Further, in the present invention, in order to prevent the webbing and the metal fitting for guiding the webbing at the time of collision or the high temperature friction between the webbing and the human body from being melted and deteriorated, the heat-resistant capacity of the webbing is reduced by the thickness of the webbing. It can be adjusted by changing.

FIG. 1 is a diagram for explaining the outline of the configuration of a seat belt webbing according to the present invention. FIG. 2 is a graph showing the relationship between the twist coefficient and the strength retention after hexagonal bar wear. FIG. 3 is a graph showing the relationship between the weft coefficient and the strength retention after hexagonal bar wear. FIG. 4 is a diagram illustrating an example of a woven structure for making the shapes of both webbing terminals circular. FIG. 5 is a diagram showing an example of a woven structure for making the shape of both webbing ends into a cylindrical shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multifilament yarn 2 Main ground warp 3 Weft 4 Seat belt webbing 5 End of seat belt webbing 6 Warp of end of seat belt webbing

Claims (8)

A multifilament yarn in which a plurality of polyester filaments having a single yarn fineness of 7 denier or less and a single yarn strength of 10 g / denier or more are assembled, and the twist coefficient α obtained by the following formula (1)
α = T x (D1) ^1/2 (1)
(Here, T: number of twists t / m and D1: warp multifilament yarn denier.)
However, a polyester multifilament yarn subjected to twisting of 4000 or more is used as the main warp, and the weft density is so woven that the relationship between the density and the thickness of the weft satisfies the following formula (2). Seat belt webbing, characterized by
Weft density (pieces / 3cm) x (D2) ^1/3 > 175 (2)
(Here, D2: the total denier of the weft multifilament yarn and the monofilament yarn or both)   2. The seat belt webbing according to claim 1, wherein the seat belt webbing is woven by a needle loom.   The single yarn strength of the polyester multifilament yarn constituting the main warp yarn of claim 1 is maintained at 9 g / denier or more after the seat belt webbing is dyed, heat set or finished. The webbing for seatbelts of 1 or 2.   The webbing for a seat belt according to any one of claims 1 to 3, wherein a polyester multifilament yarn, a polyester monofilament yarn or both are used as weft yarns.   The multifilament yarn having a fineness smaller than the fineness of the multifilament yarn constituting the main warp is used as the warp constituting the ear portion of the seat belt webbing. The webbing for seatbelts in any one of thru | or 4.   A multifilament yarn in which a plurality of polyester filaments having a single yarn fineness of 7 denier or less and a single yarn strength of 10 g / denier or more are assembled, and the twist coefficient α obtained by the formula according to claim 1 is 4000 or more. The polyester multifilament yarn that has been subjected to the specified twisting is placed on at least a part of the ground warp yarn, and the polyester multifilament yarn is supplied to the weaving process while twisting and woven. A method for manufacturing a webbing for a seat belt.   A plurality of bobbins made of the untwisted polyester multifilament yarn are mounted on a creel having an appropriate twisting mechanism as a warp supply means, and each of the plurality of bobbins mounted on the creel is made of the polyester multifilament yarn. The method for producing a webbing for a seatbelt according to claim 6, wherein the warp is twisted while being drawn, and the warp warped while being supplied to the warping process is supplied to the weaving process and woven.   A plurality of bobbins made of the untwisted polyester multifilament yarn are mounted on a creel having an appropriate twisting mechanism as a warp supply means, and each of the plurality of bobbins mounted on the creel is made of the polyester multifilament yarn. The twisting is performed while pulling out the warp, and at the same time, the coarse woven fabric is formed while being supplied to the coarse weaving process, and the warp portion of the coarse woven fabric is supplied to the weaving process and woven. The manufacturing method of the webbing for seatbelts of description.

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