JP3298370B2 - Braid for blind cord - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is, braid, in particular, Bra
The present invention relates to a braid used for Indian cord, which requires extremely high breaking strength, abrasion resistance, dimensional stability and durability.

[0002]

2. Description of the Related Art Hitherto, for example, a braid made of polyester filament has been mainly used as a braid used for a blind cord, and has a high track record of use. However, in recent years, blinds have become
With the increase in size, or with higher added value, the weight tends to increase by increasing the number of wings of blinds called slats and reducing the width.
Further, from the viewpoint of improving the aesthetic appearance, there is a strong demand for reducing the diameter of the blind cord, so that the load applied to the blind cord is increasing. For this reason, the conventional braid made of polyester filament has a problem that the required breaking strength, abrasion resistance, dimensional stability and durability cannot be satisfied.

[0003]

In order to address this problem, attention has been paid to braids using high-strength fibers in the core, the sheath, or both the core and the sheath, and some attempts have been made. It has been clarified that the braid using this high-strength fiber causes the following new problem. In other words, braids using high-strength fibers such as PPTA, PBI, and PBO cannot achieve the most preferred white color as a blind cord in the color of the fibers themselves, and in view of a severe use environment exposed to ultraviolet rays, Since there is a problem with weather resistance (light resistance) and the cost increases significantly,
Not suitable for practical use. In addition, usually, the blind cord is replaced before the blind cord is broken in consideration of deterioration of appearance due to aging dirt due to use and deterioration of performance due to abrasion, etc. After the end of the newly applied blind cord and the end of the used blind cord are melted and fixed by heat such as flame, pull the end of the used blind cord that has not been fixed by melting and remove it to obtain a new blind cord. Although the braiding method using the high-strength fiber for both the core and the sheath cannot fuse and fix the blind cords, this simple and practical replacement method is used. Can not be adopted. Also, if a fiber that is melted and fixed by heat to the core is used, when the melted and fixed portion passes through the hole provided in the slat, the sheath may be turned up and cannot pass through the hole, On the other hand, when fibers that are melted and fixed by heat are used for the sheath, since the core is not bonded, slippage occurs between the core and the sheath, biased stress is applied to the sheath, and blinds are applied. A tension state with spots occurs in the longitudinal direction of the sheath portion of the cord, and both performance and appearance are reduced.

On the other hand, braids using high-strength fibers made of a drawn product of ultra-high-molecular-weight polyolefin have been promising in recent years because the fibers themselves are white in color. In addition, the above-mentioned problem at the time of switching cannot be overcome, and cannot be a decisive solution to the problem.

[0005] From the above, braids using polyester filaments are still used as blind cords. To compensate for the breaking strength, abrasion resistance, dimensional stability, and durability, aesthetic appearance is sacrificed. The diameter of the blind cord is increased.

[0006] The present invention relates to the above conventional blind code.
For blind cords that solve the problems of the braids used, are inexpensive, can be melt-fixed to each other by heat, and have high breaking strength, abrasion resistance, dimensional stability and durability. The purpose is to provide a braid.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies with the above objects in mind, and as a result, have arrived at the present invention. That is, blind cord braids of the present invention includes a core, a braid comprising a sheath portion, and high-strength fiber is used in 25 to 75% by weight of the yarn constituting the sheath part Bed
The braid for a lined cord is characterized in that, as the high-strength fiber, a multifilament made of a stretched product of an ultrahigh molecular weight polyolefin having a weight average molecular weight of 1,000,000 or more is used.

[0008] Here, a high strength fiber is used for the yarn constituting the sheath.
Is used in any of the yarns that make up the sheath
Use high-strength fibers for the number of fibers and use other fibers for the rest.
Braided or high-strength fibers and other fibers
Align or ply twist to form a yarn, braid this yarn
Means composed etc. In the sheath, high strength
Fibers used in combination with force fibers
Terfilaments are preferred, but are not limited to
Not something.

[0009] Fibers corresponding to multifilaments formed by drawing an ultrahigh molecular weight polyolefin include Dyneema (registered trademark) of Toyobo Co., Ltd., Techmilon (registered trademark) of Mitsui Petrochemical Co., Ltd., and Allied (US)
A) Spectra (registered trademark) and the like, but are not limited thereto.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a blind code according to the present invention will be described.
An embodiment of the use braid will be described. This braid is mainly used for a blind cord, and as shown in FIG. 1, a core member composed of a braid obtained by braiding an arbitrary number of yarns or a twisted string obtained by twisting an arbitrary number of yarns. 1 and an arbitrary number of yarns covering the outer periphery of the core member 1 in the form of three, four, six, eight, sixteen, twenty-four, twenty-four, etc. And a sheath member 2 composed of a braided braid.

Among these, the sheath portion 2 uses a multifilament made of a stretched product of an ultra-high molecular weight polyolefin which is a high-strength fiber for an arbitrary number of yarns 2a constituting the sheath portion 2, or The multifilament composed of a stretched product of ultra-high molecular weight polyolefin, which is a high-strength fiber, and a fiber such as a polyester filament are formed on the yarn 2a constituting the yarn 2a by using a aligned or twisted yarn. I have.

[0012] The multifilament composed of a stretched ultra-high molecular weight polyolefin used herein is lightweight and has excellent properties in terms of breaking strength, abrasion resistance, dimensional stability and durability. Ultrahigh molecular weight polyethylene fibers obtained by stretching ultrahigh molecular weight polyethylene mainly composed of ethylene and having a weight average molecular weight of 1,000,000 or more at a high magnification of 10 times or more are preferable.

A method for obtaining such an ultrahigh molecular weight polyethylene fiber is described in, for example, JP-A-59-216912.
JP, JP-A-59-216913, JP-A-59-216913
JP-A-216914, JP-A-60-45630, JP-A-60-52647, JP-A-60-52
613, JP-A-60-59172, JP-A-60-151311, JP-B-3-57963, and JP-B-3-57964.

The ultra-high molecular weight polyethylene fiber has a breaking strength of 20 g / d or more, a breaking elongation of 6% or less,
Those having an initial elastic modulus of 600 g / d or more are preferable,
Among the fibers that are commercially available, the corresponding fibers include Dyneema (registered trademark) of Toyobo Co., Ltd., Techmilon (registered trademark) of Mitsui Petrochemical Co., Ltd., and Spectra (registered trademark) of Allied (USA). ), But are not limited to these.

It is preferable to use polyester filament as the fiber to be combined with the high-strength fiber, but it is not limited to this.

By the way, as of April 1995, ultrahigh molecular weight polyethylene fibers are sold at a price about eight times or more that of polyester filaments. Invite you. Further, since ultra-high molecular weight polyethylene fiber alone is difficult to be melt-fixed by heat, the conventional simple method cannot be adopted in the operation of changing the blind cord. In other words, the blind cord is replaced before the blind cord is broken in consideration of deterioration in aesthetic appearance due to aging dirt due to use and deterioration in performance due to abrasion, etc. After melting and fixing the ends of the inside blind cord by heat such as flame, pull the end of the blind cord in use that is not fixed and remove it to replace it with a new blind cord. Therefore, the blind cords can be melt-fixed to each other by heat, that is, the size is such that the melt-fixed portion can easily pass through the hole provided in the slat, and is firmly joined. Is an essential condition. For this reason, in the case of a braid used for a blind cord, it is necessary to combine an ultrahigh molecular weight polyethylene fiber with a polyester filament that can be melt-fixed by heat. As a result of various examinations of the ratio of the composite, when the weight ratio is lower than 25% by weight, the degree of improvement of the performance required for the braid is small, and when the weight ratio is higher than 75% by weight, the fusion by heat is incomplete. Therefore, the weight ratio of the ultrahigh molecular weight polyethylene fiber is 25 to 7
5% by weight has been found to be suitable.

On the other hand, the fiber used for the core portion 1 is not particularly limited. For example, in the case of a braid used for a blind cord, the use results so far and the work of changing the blind cord are easy. It is preferable to use a polyester filament in consideration of properties and the like.

That is, in the blind cord, it is usually necessary to replace the blind cord for a reason other than deterioration of the aesthetic appearance due to secular contamination due to use when the yarn constituting the sheath part 2 is worn and cut. If the breaking strength and abrasion resistance of the portion 2 are mainly improved, it is considered that the performance required for the braid has been improved. Therefore, by forming the core portion 1 as a braid of a polyester filament alone and combining only the sheath portion 2, it is possible to improve the performance and maintain the ease of the changing operation.

The braid used for the blind cord is not only required to have a low cost, but also has a high knot strength retention rate and a low frictional resistance when passing through a hole provided in the slat. For this purpose, it is desirable that the braid should have a double blade structure and a cross-sectional shape closer to a perfect circle. Further, the diameter of the braid is desirably as small as possible in order to make the appearance less noticeable. In particular, considering the recent reduction in slat width and increase in the number of slats, how much the braid diameter can be reduced greatly affects the value of the final product called a blind, and is a very important point. It is no exaggeration to say that there is. Braids using only polyester filaments that have been commonly used so far, by increasing the weight of blinds and reducing the diameter of the braid,
The load applied to the yarn constituting the braid increases, and the strength becomes insufficient.Furthermore, with the increase in the load applied, the yarn is elongated, whereby the fiber diameter becomes smaller, The time required for abrasion cutting is reduced, and the abrasion resistance is necessarily significantly reduced.

On the other hand, a braid in which a high-strength fiber and a polyester filament are composited not only leads to an improvement in the breaking strength and dimensional stability of the braid, but also reduces the amount of elongation of the yarn constituting the braid. Can be suppressed,
As a result, abrasion resistance and durability are improved.

In view of the required characteristics of the braid used for the above-mentioned blind cord, as an example of a suitable braid structure, a yarn consisting of only ultra-high molecular weight polyethylene filaments and a yarn consisting of only polyester filaments are aligned. Alternatively, there is a braid having a sheath portion that is individually prepared without twisting and is braided into eight pieces by using four of the former and four of the latter. In this braid, even when a load is applied, the load stress concentrates only on the ultra-high molecular weight polyethylene filament, which is a low elongation fiber, and as a result, the elongation of the entire braid can be suppressed to a small value. It does not cause a decrease in the fiber diameter even when used in, and also maintains the perfect circular shape of the braid, and can keep the frictional resistance when passing through the holes provided in the slats small, and abrasion resistance It has the effect of improving the properties and suppressing the deterioration of the appearance, and can be said to be one of the structures suitable for the use.

An example of a suitable braided structure in the case where higher performance is required is a braid having a sheath formed of a thread in which high-strength polyethylene fibers and polyester filaments are aligned or twisted. This braid can maintain a uniform tension state of the yarn constituting the braid even when a large load is applied, and can exhibit uniform physical properties in the cross section of the braid.

[0023]

【Example】

[Example 1] Sample structure: double blade structure Core part: polyester filament (1600d-195)
f 2 twin strands) Sheath: Dyneema SK60 (trade name) (800d-78)
0f) 5 polyester filaments (750d-96f) 11 16 strokes [Example 2] Sample structure: double blade structure Core: polyester filament (1600d-195)
f 2 twin strands) Sheath: Dyneema SK60 (trade name) (800d-78)
0f) Eight polyester filaments (750d-96f) Eighteen hits [Example 3] Sample structure: Double blade structure Core: Polyester filament (1600d-195)
f 2 twin strands) Sheath: Dyneema SK60 (trade name) (800d-78)
0f) 11 polyester filaments (750d-96f) 5 16 strokes [Example 4] Sample structure: double blade structure Core part: polyester filament (1600d-195)
f twin strands) Sheath: Dyneema SK60 (trade name) (400d-39)
0f) Polyester filament (375d-48f) 16 double-punches

[0024]

[Table 1]

Comparative Example 1 Sample structure: Double blade structure Core: Polyester filament (1600d-195)
sheath of polyester filament (16 strokes of 750d-98f) [Comparative Example 2] Sample structure: double blade structure Core: Dyneema SK60 (trade name) (1600d-1)
Sheath part: Dyneema SK60 (trade name) (800d-78)
(Comparative Example 3) Sample structure: double blade structure Core: polyester filament (1600d-195)
f 2 twin strands) Sheath: Dyneema SK60 (trade name) (800d-78)
[Comparative Example 4] Sample structure: double blade structure Core part: polyester filament (1600d-195)
f 2 twin strands) Sheath: Dyneema SK60 (trade name) (800d-78)
0f) 12 polyester filaments (750d-96f) 4 x 16 hits [Comparative Example 5] Sample structure: double blade structure Core: polyester filament (1600d-195)
f 2 twin strands) Sheath: Dyneema SK60 (trade name) (800d-78)
0f) 3 polyester filaments (750d-96f) 13 x 16 hits

[0026]

[Table 2]

[0027]

According to the present invention, in comparison with a braid using a conventional polyester filament, the braid can be formed without a significant increase in cost and while maintaining the property of being able to be melted and fixed by heat. Required breaking strength,
Characteristics such as abrasion resistance, dimensional stability, and durability can be improved in a well-balanced manner, so that when this braid is used for a blind cord, for example, it is conventionally used in the work of changing the blind cord. It is possible to use the simple method as it is, and to achieve a remarkable effect that the blind cord can be designed to have a small diameter.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a braid for blind code according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core part 2 Sheath part 2a Yarn

Continuation of the front page (56) References JP-A-1-139849 (JP, A) JP-A-5-26512 (JP, U) New-function fiber utilization handbook Editing Committee, New-function fiber utilization handbook, Industrial survey Issued by the Society, June 6, 1888, 51-66 (58) Fields investigated (Int. Cl. ⁷ , DB name) D04C 1/12 D04C 1/02 D07B 1/02

Claims (1)

(57) [Claims] 1. A blind coat comprising a core and a sheath.
A braid for braiding, wherein the high-strength fiber is used in 25 to 75% by weight of the yarn constituting the sheath portion, wherein the high-strength fiber has an ultrahigh molecular weight polyolefin having a weight average molecular weight of 1,000,000 or more. blind co characterized in that the multifilament consisting of stretched material is used
Braid for braid.