Anti-vandalism and cut resistant fabric
Field of the invention
The present invention relates to a fabric, e.g. to be used to provide reinforcement or cut-resistance to protective textiles, such as e.g. clothing, canvasses, tents, tarpaulins, cases, sailing clothes and shelters.
The present invention relates more in particular to fabrics comprising steel cords or filaments or other cutting proof yarns.
The present invention further relates to the use of such a fabric to provide cut- resistance to protective textiles such as e.g. covers, clothing, canvasses, tents or shelters. It further relates to canvasses, composites and clothing, comprising such fabric.
Background of the invention
Fabrics with steel cords are widely known, as stab-resistant inserts comprising steel cords from WO 97/27769.
Further, canvas reinforcements comprising metal elements are also known from WO 98/55682. This document teaches that several metal elements, separated from each other and being embedded in a polymer strip, may be adhered to the inner side of canvasses to provide reinforcement. In order to prevent thefts, recently researches have been done to obtain cut resistant materials and constructions. This has already a lot of applications, especially in thermoharding materials. There are also known types of reinforcements for thermoplastic materials as e.g. a knitted "loop" fabric based on a knitted metal loop reinforcement. Also a woven tarpaulin reinforcement is already known comprising woven and knitted steel constructions. These last constructions have as major difficulty, i.e. the stiffness and the weight. The first "loop" knit construction has as major difficulty when it is used as "anti- hooligan" fabric in seats of trains, trams, busses, it may, upon damage pierce and stick through the fabric. So even if it helps a lot to improve cut resistance in the fabric, the seat can no more be used as the metal will pinch through the skin of the user as well. As mentioned the woven fabrics, as the knitted as well, have to be too heavy and too stiff in order to give enough cut resistance. US Pat. No. 5,883,018 - Bourgois et al. discloses steel cords which are woven or knitted and have a warp and a filling under 90°.
WO 98/55682 of Van de Walle et al. also discloses a woven fabric with warp and weft as basic reinforcement under 90°.
WO 01/86046 of Leman et al. also discloses warp and weft elements connected to each other by weaving.
WO 98/45516 also discloses a fabric under 90° with metal strands.
DE 3101003 of Wolf Reutlinger also discloses steel wire ropes and strands but which are also interwoven.
In order to improve flexibility Dr. Dieter Schuster and Dr. Achim Fels used in patent
DE 4441842 multilayered fabrics based on aramid and/or gelspun polyethylene. All these fabrics have a common parameter: the warp and the weft are interconnected so that one end in warp or in weft will have to absorb the full cutting load, which will be oriented transversal on the yarn.
Summary of the invention
It is an object of the invention to improve the resistance against the cutting action of a knife or cutter of protective textile, which comprises a fabric as subject of the invention preferably comprising steel elements.
According to the present invention, a fabric comprises at least two layers and/or directions of individual elements, which might be laid upon each woven, stitched interlink. These fabrics might contain a warp and/or a weft. The difference between multi-layered fabric and multi-axial directions is only in the fact that the individual elements with multi-axial directions are woven, stitched or knitted together lengthwise while for a multi-layered fabric they are kept together by chemical or mechanical, such as fusion means or by stitching or knitting or a combination thereof.
The term bias implies a direction diagonally across a piece of fabric at preferably 45 degrees to the warp and fill. In the present invention the degrees to the warp and fill may differ from 45, in a range of from 1 to 89 degrees, for example 10, 20, 30, 40, 50, 60, 70 or 80 degrees.
Non-woven implies material obtained by assembling fibers with other chemical, mechanical, thermal or physical processes than weaving or knitting.
Knitting means implies a method for forming a fabric or textile surface produced by interlacing stitches (loops).
The warp comprises different warp elements, laying in a same direction, the so-called warp direction. The weft comprises different weft elements, laying in a same direction, the so- called weft direction. Each warp and weft element follows a certain path through the fabric, being respectively a warp path or a weft path. According to the invention, at least one warp
element or one weft element, or both, comprise two or more elongated steel elements, which are in contact relationship with each other.
According to the invention an individual element implies a warp element, preferably a yarn. A warp element is to be understood as one or more individual elements such as e.g. yarns, filaments, bundles of fibers, wires or cords, which follow the same path through the fabric in warp direction. Preferably, but not necessarily, all individual elements of a warp element cross the weft elements of the fabric in an identical way. Weft element is to be understood as one or more individual elements such as e.g. yarns, filaments, bundles of fibers, wires or cords, which follow the same path through the fabric in weft direction. Preferably, but not necessarily, all individual elements of a weft element cross the warp elements of the fabric in an identical way.
The innovation consists in the fact to have a textile construction which gives a maximum cutting resistance. Care needs to be taken so that the reinforcement yarns do not take the cutting loads as individual ends, but that the first warp or weft or other end will receive help in load bearing by a second, if needed a third end and so on before being destructed. The textile construction will thereto preferably not be interwoven or interconnected by the reinforcement yarns by themselves, but being connected by other means as relatively weak textiles under shape of stitches, ends, non-wovens, chemicals or all kinds of combinations. These chemicals can be provided also as a matrix or a part of the matrix as well. As an example reinforcement yarns can be used, which can be whatever natural, synthetical or natural yarns including herein steel, glass, LCP, PEW, aramid, PA's, PET's, PP's, PE's and so on with a dtex of 200 and more and a tensile strength of more than 2 grams per dtex and a connection textile of whatever nature with a tensile strength preferably but not necessarily lower than 5 grams per dtex. The elongation of the connection yarn will be preferably less than the modulus of the reinforcement yarn.
The present invention relates to a fabric comprising at least two layers and/or two directions of individual elements of which at least one individual element is a reinforced element comprising a metal component, preferable a steel component, which elements can be interwoven but can have also only an indirect connection created by chemicals, plastics, rubbers or by a connection elements which are weaker than the reinforced element.
In a preferred embodiment the angle between the individual elements differs from 90°. In another preferred embodiment the fabric according to the invention has at least three different layers and/or directions of individual elements.
In another preferred embodiment the fabric according to the invention comprises individual elements which are connected by knitting and/or by stitching.
In another preferred embodiment the individual elements are connected by plastic, chemicals or rubber. In another preferred embodiment the individual elements are connected by another textile means such as non-woven.
In another preferred embodiment the fabric according to the invention comprises a combination of one or more of the connection means.
In another preferred embodiment the fabric contains at least one direction and/or layer which differs to another in an angle other than 90°.
In another preferred embodiment at least one of the individual elements is partly or wholly conductive (electro-conductive) and at least partly insulated.
In another preferred embodiment the different individual elements have at least two different compositions of material. In another preferred embodiment the individual elements are covered by a material by spinning, winding, twisting or any other way to have fibers or filaments around the elements.
In another preferred embodiment at least some of the individual elements are covered by plastic and/or rubber.
In another preferred embodiment the fabric is woven or knitted or any other textile construction wherein the connection or interweaving takes at least partly place by means of non reinforcement individual elements, as e.g. normal textile yarns, while the major reinforcement individual elements do not have a major part of the woven or knitted connection to each other.
In another preferred embodiment the main reinforcement individual elements are only interwoven, interknit or interconnected at a distance of at least 3 mm, preferably 5 mm and more preferably more than 10 mm.
In another preferred embodiment the fabric is a multi-axial insertion fabric comprising four main directions, being one warp, one weft and two bias directions and a longitudinal knitted connection thread. In another preferred embodiment the fabric is a multi-axial weft insertion fabric comprising three main directions being two bias directions and one weft direction and a longitudinal knitted connection thread or yarn.
In another preferred embodiment the fabric is a laid fabric comprising two bias directions and one horizontal weft direction.
In another preferred embodiment the fabric is a laid fabric comprising four reinforcement directions being one weft direction, one warp direction and two bias directions.
In another preferred embodiment the fabric is a bias laid fabric comprising two directions. In another preferred embodiment the fabric is a bias laid fabric comprising a longitudinal carrier yarn up and/or under the two main directions.
In another preferred embodiment the fabric is a three layer laid fabric.
In another preferred embodiment the fabric is a four layer laid fabric.
The present invention also relates to the use of a fabric as an anti-vandalism and/or cutting resistant fabric.
In a preferred embodiment the invention relates to a cutting-resistant tarpaulin or cover based on a fabric according to the invention.
In another preferred embodiment the invention relates to a cutting-resistant "convertible" for cars or other transport vehicle based on a fabric according to the invention. In another preferred embodiment the invention relates to a cutting-resistant luggage or parcel or other packing material based on a fabric according to the invention.
In another preferred embodiment the invention relates to a cutting-resistant upholstery fabric reinforced in the form of seats, chairs based on a fabric according to the invention.
In another preferred embodiment the invention relates to a cutting-resistant flexible in preference but also non-flexible door, gate based on a fabric according to the invention.
In another preferred embodiment the invention relates to a cutting-resistant composite which contains plastics based on a fabric according to the invention.
In another preferred embodiment the invention relates to a cutting-resistant composite which contains rubber based on a fabric according to the invention. In another preferred embodiment the invention relates to a cutting-resistant shelter and/or tent based on a fabric according to the invention.
In another preferred embodiment the invention relates to a cutting-resistant temporary wall or fence as used for exhibition rooms based on a fabric according to the invention.
In another preferred embodiment the invention relates to a cutting-resistant composite containing at least one fabric based on a fabric according to the invention.
In another preferred embodiment the invention relates to a cutting-resistant composite containing at least one of the previously mentioned cutting-resistant elements based on a fabric according to the invention.
In another preferred embodiment the invention relates to cutting resistant fabrics which have an alarm possibility through conductive yarns and/or conductive polymers.
In another preferred embodiment the invention relates to cutting resistant fabrics which contain yarns which can be used to heat up the fabric to a well-determined temperature.
In another preferred embodiment the invention relates to cutting resistant fabrics which contain aramid as a whole or as a part of the reinforcement.
In another preferred embodiment the invention relates to cutting resistant fabrics which contain gel-spun polyethylene as a whole or a part of the cutting resistant reinforcement.
In another preferred embodiment the invention relates to cutting resistant fabrics which contain electro-conductive yarns and/or electro-conductive polymers which can heat up the protection fabric and/or composite.
As a supplemental feature we can make the reinforcement under an angle different of 90° than of normal woven and knit and other fabrics, also having two or more reinforcement directions. Doing so the knife or other weapon can not cut through all the ends under 90°. In this way even the full force can not be used on these ends.
Taking the above-mentioned features into account the preferred textile constructions will be "weft inserted" knits, laid fabrics, multi-axial fabrics in shape of multi-axial laid fabrics or as multi-axial weft insertion (type Liba and Karl Mayer Malimo) and also stitched materials including the use of non-wovens and all other.
The invention is further elucidated with reference to the drawings wherein several fabrics according to the invention are depicted.
Figures 1 b, 2b and 2c, 3b, 3c, 3a depict the force vectors in the plane of force elucidating the enhanced cutting resistance aspect of the fabrics of the present invention.
Figure 1b elucidates the force vector of a prior art fabric while the other figures depict the force vectors acting upon fabrics according to the invention. The active (downward) force vector, for example the result of a vandalism action by a cutting knife on the yarns of the present invention (figures 2-10) will be resolved in the plane of force into a cutting force vector acting perpendicular on the individual yarn and a rest force vector. It is clear that the rest force vector is zero on a fabric according to the present invention (figure 1 a), while on a fabric according to the invention (figures 2-10) a positive rest force vector will be present and therefore reducing the active downward force vector into a smaller cutting force vector acting
perpendicular on the individual yarns. It is clear that due to the bias directions and/or bias layers, there is a considerable loss of the cutting force (perpendicular on the yarns).
Furthermore, due to the weak connections between the individual elements or yams and the downward directed active force vector, several individual elements will be loosened and will be collected together and form a resistant barrier presenting a high cutting resistance.
It is clear that the cutting resistant value increases surprisingly high with a fabric according to the present invention whereof the examples are depicted in figures 2-10.
Figure 1a shows a fabric as known in the prior art.
Figure 2a shows a bias laid fabric comprising a longitudinal reinforcement yarn up and two bias directions; three main inforcements bond together.
Figure 3a shows a four laid fabric.
Figure 4 shows a fabric according to invention comprising a weft reinforcement individual element (A) and a warp reinforcement individual element (B), a weft binding individual element (C) and a warp binding individual element (D) whereby the reinforcement individual elements A and B do not bind each other or if wanted only at wider distances, e.g. 3 mm, the way of binding can be changed and the number of ends or picks of as well individual elements and binding elements can be different than one on any row.
Figure 5 shows a multi-axial insertion fabric comprising four main directions, being one warp, one weft and two bias directions and a longitudinal knitted connection thread, stitching through the fabric and keeping all ends together by knitting.
Figure 6 shows a multi-axial weft insertion fabric comprising three main directions being two bias directions and one weft direction and a longitudinal knitted connection thread or yarn.
Figure 7 shows a laid fabric comprising two bias directions and one horizontal weft direction. The connections are made by chemical means, e.g. PVC, PVA, PP, PE or other means of chemical bonding.
Figure 8 shows a laid fabric comprising four directions being one weft direction, one warp direction and two bias directions.
Figure 9 shows a bias laid fabric comprising two directions. Figure 10 shows a bias laid fabric comprising a longitudinal carrier yarn up and under the two main directions.
All these laid fabrics are bond; this means the ends are kept together by chemical or fusion bonding.
Examples
A) A fabric was made consisting of no warp direction (no 0° direction) but having a weft under 90° and two bias directions, one under 60° and the other one under -60° on a multi-axial machine. The material was a high content carbon steel wire of 0,15 mm and knitted together by a 167 dtex polyester FTF, having two ranges of this stitching yarn per cm. The first was covered in two parts with a PVC cover on both sides. The second with PVC on both sides and each side laminated to a polyester textile upholstery type of fabric. The fabric has steel wires in each direction at a distance of 2 mm.
B) A fabric was made with a non-woven fabric of 30 gram/m2 on each side of the metal wire weft insertion product. These non-woven layers have been connected to the steel wire part by the 167dtex knitting yarn, stitching through the non-wovens. This type of fabric facilitates the knife coating and is further referred to as a complex.
C) A fabric was made with a covered steel wire in warp (0°) and weft (90°). The warp and the weft have a 0,15 mm wire covered with polyester. The distance between each wire is 2 mm and they are laid on each other. The connection has been done by a 70 dtex polyester knitting yarn on a weft insertion machine (as Karl Mayer or Liba).
D) A laid fabric was made with a warp (0°) and two directions of bias yarns under 60° (+60° and -60°) with the same yarns as example B. The yarns are imbedded in a PVC dip and connected with a non-woven polyester layer by pressure. The complex is dried at 160°C. Afterwards the complex is covered with PVC and laminated to an upholstery fabric for use in convertible cars.
E) A multi-axial fabric was made consisting of a warp (0°) and a bias reinforcement in two directions -50° and +50° and a weft in 90°. All these reinforcements are steel wires of 0,18 mm diameter with high carbon content. They are connected by a 70 dtex polyester knitting yarn which breaks or elongates easily when the steel wires are put under load. The number of reinforcement yarns were 2 per cm in each direction.
Tests
The cutting resistance of these fabrics according to the invention has been measured on an adapted tension meter type Zwick. The obtained values were surprisingly high, such as values above 600 N, which is considered to be higher than man's power. However, if needed this cutting resistance can be increased by the gange of the wire, the number of ends in each direction, the number of directions of the reinforcement layers or ends.