US3606914A

US3606914A - Webbing

Info

Publication number: US3606914A
Application number: US821454A
Authority: US
Inventors: Wolfgang Maiwald; Helmut Rohser
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1968-05-08
Filing date: 1969-05-02
Publication date: 1971-09-21
Anticipated expiration: 1988-09-21
Also published as: FR2009867A1; DE1760360B1; GB1229123A; SE375343B; NL6906674A; FI49527C; CH532668A; CH693569A4; ES366887A1; FI49527B; IE33071B1; HU163705B; IE33071L; AT302072B; BR6908564D0; BE732749A; NO125688B

Abstract

THE PRESENT INVENTION PROVIDES A WEBBING WHOSE WARP THREADS CONSIST OF MULTIFILAMENTS OFSYNTHETIC MATERIALS AND WHOSE WEFT THREADS CONSIST OF MONOFILAMENTS OF SYNTHETIC LINEAR POLYESTER MATERIAL.

Description

United States Patent Office 3,606,914 WEBBING Wolfgang Maiwald, Frankfurt am Main, and Helmut Rollser, Hofheim, Taunus, Germany, assignors to Farbwerke Hoechst Aktiengesellschaft vormals Meister Lucius & Bruning, Frankfurt am Main, Germany No Drawing. Filed May 2, 1969, Ser. No. 821,454 Claims priority, application Germany, May 8, 1968,

Int. Cl. D03d 15/00 US. Cl. 139-420 8 Claims ABSTRACT OF THE DISCLOSURE The present invention provides a webbing whose warp threads consist of multifilaments of synthetic materials and whose weft threads consist of monofilaments of synthetic linear polyester material.

It is the object of the present invention to provide a webbing.

Webbings such, for example, as safety belts for motor cars and webbings for lifting heavy loads have hitherto been made from fabrics of multifil synthetic warp and weft threads. To attain a certain essential lateral stability of these webbings, they are generally made of double or compound fabrics. However, with the use of these double or compound fabrics the thickness of the webbings is often increased to an undesirable degree. Single fabrics tend to roll up, they acquire the form of a knitted fabric and thus no longer have the necessary bearing or contact surface. This tendency to roll up is highly prejudicial to the safety factor, for example in the case of safety belts.

Attempts have, therefore, been made to fabricate webbings which are equal in regard to their strength and safety properties to the conventional webbings made of double or compound fabrics, but which have a lesser thickness and do not tend to roll up. A minor thickness of the webbings without impairment of their strength properties is desirable, for example, for accommodating the safety belts in small wind-up devices.

It is the object of the present invention to provide a webbing which fulfills the desiderata for such a webbing, i.e. a lesser thickness than that of the conventional webbings made of a double or compound fabric without the strength and safety properties thereof being impaired. The webbing according to the invention consists of a fabric constructed of synthetic warp and weft threads, which is characterized in that the warp threads are multifilaments of synthetic linear material, selected from the group consisting of nylon 3, nylon 6, nylon 66, nylon 12, polyacrylonitrile and polyester material and the weft threads are monofilaments of synthetic linear polyester material.

It is advantageous when not only the warp threads but also the weft threads consist of synthetic linear polyester material, preferably polyethylene terephthalate. As synthetic linear polyester material there may be used any of the conventional filament-forming polyesters and copolyesters such, for example, as poly-1,4-cyclohexanedimethanol-terephthalate and the copolyester of terephthalic acid/isophthalic acid and ethylene glycol. As synthetic linear polyamide material for the multifil warp threads there may be used mainly polyamide 6 and polyamide 66, however, there may also be used all other filament-forming polyamides and copolyamides.

The thickness of the warp and weft threads in the webbing according to the invention should correspond to the strength and safety requirements necessary in each 3,606,914 Patented Sept. 21, 1971 case. The thickness of the monofil weft threads preferably lies within the range of from 0.15 mm. to 0.4 mm.

It must also be mentioned that the multifil warp threads run in the longitudinal direction of the webbing and the monofil weft threads run transversely of this direction.

The webbing according to the invention possesses especially valuable properties when the fabric constructed of multifil warp threads and monofil weft threads has been subjected to a heat-setting process Within a temperature range of from about 200 to 230 C., preferably for a period of at least two minutes. In a webbing of this type the monofil cross threads readily rupture when greater strain is applied in the longitudinal direction so that the warp threads are no longer retained in the fabric and project from the surface of the fabric. Owing thereto it is possible immediately and easily to detect greater strains applied on the webbings, for example the strain which has acted on a safety belt for motor cars in the case of an accident. This is very important since, as is known, webbings elongate in the case of high strains until the point of their time-to-failure is attained, whereby the webbings become practically useless owing to the loss of their capacity of absorbing energy. The exterior surface of the webbings made of fabrics constructed of multifil warp and weft threads as used hitherto did not show signs when the stress had exceeded a point which is critical for the safety. The test as to whether the webbings known hitherto had already been subjected to high strain consists in observing the behavior of the webbing when subjected to renewed great strain. When the webbings had not previously been subjected to great strain they become unserviceable by the strain applied during the test. This drawback is overcome by the webbing according to the invention when used in the aforesaid preferred modification, viz when the webbing consists of a heat-set fabric since the exterior surface of this webbing immediately shows signs when the webbing has been subjected to strains beyond the critical point. The rupture of the heat-set monofil cross threads in the case of great strains acting in the longitudinal direction on the webbing according to the invention, can be explained by the fact that the monofils which have been set by the heat-setting process in the original bend given by the structure of the fabric, are compressed into a flatter bend. This forcible alteration of the set form then provokes an easy rupture of the monofil weft threads.

It need hardly be mentioned that the point of rupture may be varied within certain limits by altering the set of warp threads, the heat setting conditions, for instance in the dyeing and finishing processes, as well as by the use of monofil weft threads of different thickness.

We claim:

1. Webbing made of a fabric constructed of synthetic 'warp and weft threads, comprising a single woven fabric, in which the warp threads are multifilaments of a synthetic linear material, and said weft threads consist of monofilaments also of a synthetic linear material.

2. Webbing as claimed in claim 1, wherein both the warp threads and the weft consist of synthetic linear polyester material.

3. Webbing as claimed in claim 1, wherein the synthetic linear polyester material is polyethylene glycol terephthalate.

4. Webbing according to claim 1 wherein the warp threads are selected from the group consisting of polyamide 6, polyamide 66, polyacrylonitrile, polyethylene glycol terephthalate, poly-l, 4-cyclohexanedimethanol terephthalate, a copolyester of terephthalic acid/isophthalic acid and ethylene glycol, or polyacrylonitrile.

5. Webbing according to claim 4 wherein the weft threads are of a polyester material.

6. Webbing as claimed in claim 5, wherein the monofil weft threads have a diameter within the range of from 0.15 mm. to 0.4 mm.

7. Webbing as claimed in claim 1 wherein the fabric constructed of multifilament warp threads and monofilament weft threads is subjected to a heat setting process within the range of 200 to 230 C. to render said weft threads in a condition to be easily ruptured when the warp threads are overstressed, whereby said weft threads after being ruptured no longer retain the warp threads which project from the surface of the fabric providing a visual indication of the webbing having been overstressed.

8. A method of manufacturing a webbing to provide a visual indication of overstress after the Webbing has been overstressed, comprising the steps of weaving a single fabric webbing with multifilament warp threads and consisting of monofilament weft threads, and then heat setting said fabric in a temperature ranging from 200 C. to 230 C. to render said weft threads in an original bent given by the structure of the fabric and thus in a condition to be compressed into a flatter bent and ruptured when the warp threads are overstressed, whereby said weft threads after being ruptured no longer retain the warp threads which project from the surface of the fabric 25 4 References Cited UNITED STATES PATENTS 2,788,023 4/1957 Renaud 139420X 2,794,450 6/1957 Gatzke 139 411 2,812,782 11/1957 Stevens 139- 120 2,903,021 9/1959 Holden et a1. 139426X 3,205,119 9/1965 Paul 161 91 3,296,062 1/1967 Truslow 161 91 3,322,163 5/1967 Hughes 139383 3,463,202 8/1969 Wildi et al. 139383 3,464,459 9/1969 Ballard 139-383 FOREIGN PATENTS 609,946 10/1948 Great Britain 28Dacron Digest OTHER REFERENCES Federal specification Belt; seat passenger type, automotive; JJB-B 1 85A, Jan. 19, 1960 (pp. 1-3).

JAMES KEE CHI, Primary Examiner US. Cl. X.R. 2872