EP1369509B1

EP1369509B1 - Acrylic chenille yarn for use in fire-retardent upholstery fabrics, and fabrics made with such yarns

Info

Publication number: EP1369509B1
Application number: EP03447141A
Authority: EP
Inventors: Jean-Marie c/o NV Ragolle Ragolle
Original assignee: Nv Ragolle
Current assignee: Nv Ragolle
Priority date: 2002-06-05
Filing date: 2003-06-05
Publication date: 2006-01-04
Anticipated expiration: 2023-06-05
Also published as: EP1369509A1; ATE315116T1; DE60303115D1; BE1014866A5

Abstract

The invention relates to chenille yarns, for use in fire-resistant upholstery fabrics or furnishing fabrics, the pile of which yarn contains mainly acrylic, while over 25% of the chenille core is composed of raw materials other than standard acrylic and can be dyed with the same dyes and/or dye bath as standard acrylic. <??>The chenille core is preferably composed fully or partially of cationic dyeable polyester (with chenille pile of more than 50% standard or fire-resistant modified acrylic), or of fire-resistant modified acrylic (with chenille pile of more than 50% standard acrylic). <??>The invention also relates to acrylic chenille fabrics at least partially made of such chenille yarns.

Description

The present invention relates to a chenille yarn that contains mainly acrylic (in particular more than 50% acrylic) in the pile, and the use of such a yarn in a fabric, in particular in an upholstery fabric or furnishing fabric.
Chenille yarn is composed of a chenille core and a chenille pile. The chenille core is composed of at least 2 threads that are twisted (twined) around each other, and between which the pile fibres are retained. The pile fibres, which form the chenille pile, may be composed of either cut or uncut pile. It is particularly preferable for the chenille core to be fully or partially in the form of a spun yarn (staple yarn) because this improves the strength of the pile.
In the present invention a distinction is made between the following terms:

"Standard acrylic" refers to a fibre that contains at least 85% of acrylonitrile co-monomer and therefore does not have any fire-resistant properties. It is known that standard acrylic melts and burns when exposed to a flame.
"Fire-retardant acrylic" or "fire-resistant acrylic" means acrylic that is chemically modified in order to obtain fire-resistant properties, and contains between 85 and 35% of acrylonitrile co-monomer. These materials typically contain substantial quantities of halogen-containing co-monomers, which gives them self-extinguishing properties when they are exposed to a flame.
"Acrylic" means standard and fire-resistant acrylic.
"Standard polyester" means polyester that is dyed with disperse dyes in an acid or possibly a basic agent.
"Anionic modified polyester" or "cationic dyeable polyester" means polyester that is chemically modified by, for example, sulphonic acid groups and can be dyed with disperse dyes, but also with cationic dyes. Such anionic polyester is used in the art as a raw material for products with reduced pilling properties.
"Interliner" means a material, in the form of a woven fabric, knitted fabric or non-woven fabric, which lies between the foam of the chair or sofa and the outer fabric in a manufactured upholstery fabric.
"Laminate" means a material, in particular an upholstery material, against which a second layer is fixed. This second layer can be either a non-woven or a polymer layer, or can be another woven fabric.

For chenille yarns that in particular contain more than 50% of acrylic in the pile it is customary in the art to use a core of the raw material most used in the pile. The reason for this lies in the dyeing of the yarn or the fabric containing these yarns. Various methods of dyeing chenille yarns or fabrics are known in the art. A first method starts off with plain ecru chenille yarn, the core and the pile of which in particular are made of 100% acrylic. Everything can then be dyed in one dyeing operation, and using the same dyes. A second method is to start from a chenille core that is only partly made of ecru acrylic. The pile consists, for example, of two different raw materials, namely acrylic and viscose. The core of this yarn is then composed of the same raw material as the material most used in the pile. In the dyeing process only acrylic is then dyed. In another process a chenille yarn composed of coloured pile yarns is used. This chenille is no longer dyed, which has the advantage that it has a good appearance and is not flattened by the effect of the dyeing process. The chenille pile can also consist of two (or more) raw materials. These raw materials can be in several different colours. In the art an effort is always made to have a chenille core that is not visible through the chenille pile, because a visible core would give a poor appearance. For that reason, an effort is always made to ensure that the core is the same colour as the pile, and that the pile covers the core sufficiently.
It is known in practice that, on account of the high quantity of oxygen between the pile fibres, it is not easy to obtain good fire-retardant properties, and that a backcoating with a large quantity of bromine-containing fire retardants is required. If the core and the pile of the chenille yarn in particular are composed of standard acrylic fibres, it is known that it is very difficult to bring this fire behaviour under control.
British patent GB 988072 relates to a fire-resistant fabric made of chenille yarns in which the pile consists substantially of polyvinyl chloride (PVC) and/or polyvinylidene chloride, and which have a core consisting of normal textile fibre such as, for example, cotton, wool, rayon or synthetic fibres. The special application of such a yarn in an upholstery fabric is not known from this patent, not to mention the standards that have to be met for such an application. Furthermore, a disadvantage of a chenille yarn in which the pile consists substantially of PVC is that the material has an unpleasant feel and imposes limitations in available colours. It is also known that such materials have great heat sensitivity and that during heat treatments such as ironing, washing or dyeing great shrinkage occurs. Besides, PVC is dyed with disperse dyes, which cannot be used for acrylic.
"US patent 6.107.218 relates to chenille yarns which can be used on high speed machines such as air-jet or water-jet looms. The chenille core is therefor composed of at least one low melting binder core yarn and at least one other core yarn. The chenille yarn is subjected to a heath treatment so that the low melting component melts and fixes the chenille pile in the yarn, and to a subsequent cooling step before winding the yarn on bobbins. The obtained yarns show improved weaving performance, but involve the drawback of increased combustibility of the fabric, due to the presence of the low melting binder core yarn."
There is a need for fabrics made of chenille yarn consisting of mainly pile fibres in acrylic which also have adequate fire-resistant properties and can be dyed in a one-step process, and which further require a minimal quantity of fire-resistant latex, so that the feel of the fabric does not change.
It is known in the art that fabrics can be made fire-retardant with chemicals, the application of a backcoating and the use of a laminate. If fire-retardant properties are sought by way of water-soluble chemicals such as, for example, phosphates or ammonium compounds, the disadvantage is that these chemicals are not permanent and disappear during cleaning, so that the fire-retardant properties are lost. Furthermore, the feel of such materials that have been given full bath treatment is hard and unpleasant. In the case of use of a backcoating, which is a coating applied to the back of the fabric, bromine-containing chemicals, which are harmful to man and the environment, are generally used. It is also known in the art that a large quantity of fire-retardant backcoating gives rise to a stiff fabric with a not very pleasant and sticky feel. Where an interliner is used, it is known that interactions between the fabric and the interliner occur, so that, although the constituents are fire-retardant, the whole combination does not necessarily have fire-retardant properties.
It is known in the art that if a flame is held against a chenille fabric in particular composed of standard acrylic, the chenille fabric will start to burn. After a short time, it is found that the core of the chenille yarn has burned through and the standard acrylic chenille starts to curl up into intertwined spikes. Owing to the fact that the chenille yarn has this curling effect, the fire-retardant chemicals, which are often applied to the back of the fabric, cannot work effectively, so that the flame does not go out. These chemicals, which are in the coating and are designed to stop the fire reaction, are not sufficiently involved in the reaction in particular because the fire reaction is taking place too far away from the back of the fabric. The spikes simply go on burning. If a full bath treatment is used to apply a fire-retardant chemical, which in particular has the disadvantage that the treatment is not permanent, it is found that here too the fire requirements are difficult to achieve. It is known from the art that the fire behaviour of acrylic chenille fabrics is difficult to predict. It is only after the end product has been tested that it can be said how the material reacts in a fire test. This behaviour is even determined by the design of said textile material.
One object of the present invention is to provide a yarn, in particular a chenille yarn, in which the pile is composed mainly of acrylic, and by means of which it is possible to produce fabrics that have fire-retardant properties irrespective of the design, and for which a fire-retardant backcoating with only a small quantity of fire-resistant product is required, so that the pleasant feel is retained.
Another object of the present invention is to provide a chenille yarn that is to be used in particular in an upholstery fabric or furnishing fabric, which fabric can be treated with a minimal quantity of fire-resistant agent, which means an advantage for the environment and further gives a supple, non-sticky feel.
To that end, the present invention provides a chenille yarn in which over 50% in weight of the chenille pile is composed of acrylic (standard acrylic or fire-resistant modified acrylic), characterized in that over 25% of the core of the yarn is composed of other raw materials that can be dyed with the same dyes and/or with the same dye bath as standard acrylic.
According to a preferred embodiment of the invention, the core of the yarn consists fully or partially of an anionic modified polyester, while the pile is constituted fully or partially of standard acrylic, and the whole combination can be dyed in one dyeing operation.
The fact that this material in combination with acrylic is a way of obtaining improved fire-resistant properties is unexpected per se and is certainly not known in the art.
A possible explanation could be that on exposure to higher temperature the modifying chemical group causes a rapid degradation, so that the fibre quickly becomes carbonized. Compared with standard polyester, the hydrolysis does in fact take place much more quickly.
Anionic modified polyester is known for its great susceptibility to hydrolysis on exposure to a higher temperature or pH. This is caused by the presence of, for example, the sulphonic acid groups.
In the case of standard polyester exposure to a higher temperature leads to melting, which results in loss of strength and degradation.
According to another preferred embodiment of the invention, the core of the yarn consists fully or partially of a fire-retardant acrylic.
It is a special feature of the present invention that the use of anionic modified polyester or fire-retardant acrylic in the core and standard acrylic in the pile produces a synergistic effect, so that fire-resistant backcoating with a smaller quantity of fire-resistant chemicals is required.
Further features and particulars of the invention will be explained by way of example below with reference to a number of specific embodiments of chenille yarns according to the invention.
It should, however, be emphasized that the details of those specific embodiments do not imply any limitation of the scope of protection of the invention as described in the above text of the description and as indicated in the patent claims below.

Example 1

Test 1 of Example 1 was carried out with a chenille yarn having in the pile a standard acrylic, and the core of which yarn consists of anionic modified polyester. The advantage of this construction is that the yarn can be dyed in one dye bath and with the same dyes. This gives the advantage that no additional dye treatment has to be carried out in order to dye the core, which means a saving in energy.
Test 2 of Example 1 was carried out with a chenille yarn composed of a pile made of standard acrylic and a core in fire-retardant acrylic. Here again, core and pile can be dyed in one and the same dye bath and with the same dyes. In Test 3 of Example 1 a chenille yarn consisting of a standard acrylic pile and with the chenille core consisting of fire-retardant acrylic and standard acrylic was used. Fabrics were made with these different yarns and a fire-resistant latex was applied. The fire tests were subsequently carried out in accordance with BS 5852, part 1, and the materials were always found satisfactory.

Example 2

In this example a fabric was made with chenille yarn consisting of a standard acrylic pile and a core consisting of cationic modified polyester yarn. This fabric (fabric 1) was treated with a fire-retardant latex with a weight of 80 g/m2.
A second fabric (fabric 2) was made with a chenille yarn consisting of standard acrylic in the pile and having standard acrylic yarn as the core. This fabric was treated with a fire-retardant latex with a weight of 140 g/m2.
These two products were tested in accordance with BS 5852, part 1.
In this test the fabric was stretched over a PU foam of 22 kg/m3, During this test a flame was held against the fabric for twenty seconds, and the flame must go out after two minutes.
In the case of fabric 2 it was found that the fire escalated and had to be extinguished.

In the case of fabric 1 the material did meet the standard. In this case it is easy to see that the yarns have actually become carbonized, but they have not curled up.
The details of this example are summarized in the table below.

Fabric 1	Fabric 2
Chenille pile: standard acrylic	Chenille pile: standard acrylic
Chenille core: anionic modified polyester	Chenille core: standard acrylic
Weight of fire-retardant latex: 80g/m2	Weight of fire-retardant latex: 140g/m2
Colour: ecru	Colour: yellow
Meets BS 5852-1	Fails BS 5852-1
Construction of the two fabrics (weave, density etc.) is identical, with the exception of the chenille core and the colour. The colour is not relevant in the fire tests.

The fire tests were carried out as follows and gave the following results:

Situation 1. Start of the fire test on fabric 1: the flame is held against the fabric for twenty seconds.
Situation 2. Fabric 1 shows a slight flame development fifteen seconds after the start of the test.
Situation 3. Fabric 1 shows no further flame forty seconds after the start of the test; it can be seen clearly that the chenille yarns in which the core is made of anionic modified polyester have not burned through and curled up. The fabric has passed the test: it has stopped burning before the end of the test.
Situation 4. Start of the fire test on fabric 2: the flame is held against the fabric for twenty seconds.
Situation 5. Fabric 2 shows a rapid flame development fifteen seconds after the start of the test.
Situation 6. Fabric 2 continues to burn; intertwined chenille yarns can be seen.
Situation 7. Fabric 2 goes on burning because the chenille yarn goes on curling up further.
Situation 8. The flame is blown out after over two minutes. It is easy to see that the chenille yarn is intertwined into spikes, which go on feeding the flame increasingly further.

Claims

Chenille yarn in which the pile comprises over 50 % of standard acrylic, for use in fire-resistant upholstery fabrics or furnishing fabrics, characterized in that over 25% of the chenille core is composed of anionic modified polyester and/or fire retardant acrylic, as a material that is different from standard acrylic and can be dyed with the same dyes and/or the same dye bath as standard acrylic.
Chenille yarn in which the pile comprises over 50 % of fire retardant acrylic, for use in fire-resistant upholstery fabrics or furnishing fabrics, characterized in that over 25% of the chenille core is composed of anionic modified polyester, as a material that is different from those of the chenille pile and can be dyed with the same dyes and/or the same dye bath as standard acrylic.
Chenille yarn according to one of the preceding claims, characterized in that the chenille core is fully or partially a staple yarn.
Acrylic chenille fabrics, characterized in that at least part of the chenille yarns used meets the description in one or more of Claims 1 - 3.
Acrylic chenille fabrics according to Claim 4, characterized in that the weight lies between 200 and 800 g/m2.