GB2565821A - Fire retardant upholstered article and method - Google Patents

Abstract

A fire-resistant upholstered article 100 comprises a resilient unit 110, a cover or ticking 140 and a filler layer 150 between the resilient unit and the cover, wherein the cover comprises a woven material of viscose and modified viscose, and wherein the filler layer comprises nonwoven fire resistant modified viscose. The upholstered article may comprise a mattress. The resilient unit may comprise a sprung unit such as a pocketed spring unit.

Description

Fire Retardant Upholstered Article and Method

The present invention relates to a fire-retardant upholstered article and to a method of manufacturing the same.

UK Furniture Flammability Regulations and Standards have remained largely unchanged for the past three decades, since the publication of the Furniture and Furnishings (Fire) (Safety) Regulations were introduced in 1988 in response to a number of large scale fires caused by foam-based mattresses. Since this time, although no legal compliance structure has existed for mattresses specifically, conformity to the F&F '88 regulations and general product safety regulations has been widely demonstrated through passing the requirements of BS 7177:2008 & Al :2011 (specification for resistance to ignition of mattresses, mattress pads, divans and bed bases) when tested in accordance with BS EN 597-1, BS EN 597-2 and BS 6807.

Historically, the stringent requirements of BS 7177 have led to almost all UK mattress manufacturers using chemically treated mattress ticking (cover fabric) to pass the match and cigarette test. Chemical treatments are typically applied post-ticking manufacture using either the submersion method, in which the woven ticking is submerged in a fireretardant chemical, or else the back coating method, in which the ticking is sprayed or otherwise coated with the chemical.

However, recent academic studies have suggested that there may be negative potential health implications of having such chemicals in large quantities in domestic environments.

There is also the issue of these chemical treatments being water soluble. When used for a product such as a mattress ticking, which is subjected to significant amounts of sweat on a nightly basis, it is sensible to predict that the flame resistant properties of the product will decrease over time.

Embodiments of the present invention aim to provide an upholstered article, and a method of manufacturing an upholstered article, that has fire retardant qualities, and in which the above problems are addressed.

The present invention is defined in the attached independent claims, to which reference should now be made. Further, preferred features may be found in the sub-claims appended thereto.

According to one aspect of the present invention, there is provided a fire-resistant upholstered article, comprising a resilient unit, a cover and a filler layer between the resilient unit and the cover, wherein the cover comprises a woven material of viscose and modified viscose, and wherein the filler layer comprises nonwoven fire resistant modified viscose.

The invention also comprises a method of making a fire resistant upholstered article, the method comprising covering a resilient unit and a filler layer with a cover sheet comprising a woven material of viscose and modified viscose, wherein the filler layer comprises nonwoven fire resistant modified viscose.

The invention also includes a fire resistant filler layer for an upholstered article, the filler layer comprising fire resistant modified viscose.

The invention also includes a fire resistant cover sheet for an upholstered article, the cover sheet comprising a woven material of viscose and modified viscose.

The filler layer preferably comprises a blend of fire resistant modified viscose and other fibres.

Preferably the cover sheet comprises a combination of unmodified/natural viscose and modified viscose in the range 50-70% natural viscose and 30-50% modified viscose, more preferably 60-65% natural viscose and 35-40% modified viscose.

The woven cover sheet may have a range of 35-45 ends (warp threads) and 20-30 picks (weft threads), More preferably the sheet may have 46 ends or 36 ends and 24 picks.

The filler layer may comprise a pad of nonwoven fibres. The filler layer preferably comprises a blend of fire resistant modified viscose and other fibres in approximately equal quantities .

The other fibres may comprise modified viscose. Alternatively or in addition, the other fibres may comprise natural fibres, more preferably wool.

In a preferred arrangement the natural fibres of the filler layer comprise wool.

Preferably the filler layer has a weight in the range 150350, more preferably approximately 200, grammes per square metre (gsm).

The upholstered article may comprise a mattress. The resilient unit may comprise a sprung unit, and may more preferably comprise a pocketed spring unit.

The invention may include any combination of the features or limitations referred to herein, except such a combination of features as are mutually exclusive, or mutually inconsistent.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawing, in which:

Figure 1 shows in schematic sectional view an upholstered article according to an embodiment of the present invention.

Turning to Figure 1, this shows generally at 100 an upholstered article, which in this case is a mattress, in accordance with an embodiment of the present invention. The mattress 100 comprises a pocketed spring core 110 comprising a plurality of linear strings 120 of pocketed springs 130 that are joined together in an array. Each of the springs 130 is encapsulated in an individual pocket within the string 120.

Over the mattress is a layer of ticking 140, which is a woven sheet of fabric providing protection for the mattress and also comfort for the user. The ticking is sewn and bound to the mattress. In the drawing, the thickness of the ticking sheet is exaggerated for illustrative purposes. Between the ticking 140 and the joined strings 120 is a layer of nonwoven support filling material in the form of a pad 150.

In practice, the mattress may be constructed with several layers of pocketed springs, which may be of different sizes and/or characteristics. Also, there may be several layers of filler beneath the ticking 140. However, in this example the mattress structure has been simplified for the purposes of illustration.

Fire resistant modified viscose is a cellulosic fibre that helps to provide heat and flame resistance. The raw material for the viscose fibres used in the example below is beech wood, which is a natural material.

The ticking 140 and filling pad 150 work together to provide the necessary resistance to fire. Preferably the cover and filling are in direct contact.

The first element of flammability resistance is the woven fabric of the ticking 140, which has a composition of 60-65% regular viscose with 35-40% fire resistant modified viscose (such as sold under the registered trade mark Lenzing) . A preferred example specification is of 46 ends (warp)/24 picks 10 (weft), preferably with the warp threads being unmodified viscose and the weft threads being fire resistant modified viscose .

The second element of flame resistance is the filling 150 in 15 the form of a natural fibre pad, which is a blend of 50% wool and 50% fire resistant modified viscose (e.g. Lenzing RTM), used in any weight between 150g and 350g, with a 200g weight being optimal in one embodiment.

In tests, it was found that the combination of the woven fabric cover in direct contact with the natural fibre pad comfortably passed all BS 7177 requirements for mattresses.

This method of conformity to BS 7177 not only eliminates the need for chemical treatments but also has the added benefit of allowing the mattress ticking to retain its flammability protection in use, offering a long term fire resistance solution.

The inventor has developed a method which has been found to offer the necessary level of flammability resistance to satisfy the requirements of BS 7177 without the need for any added chemicals . This is achieved through a combination of nonwoven and woven materials.

It will be understood by the skilled person that other combinations of percentages, weights and end (warp)/pick (weft) counts could be employed whist remaining within the scope of the present invention.

Indeed, it has been found that a version of the cover sheet with 36 ends and 24 picks beneficially results in a higher proportion of modified fire resistant viscose, as there is a similar weight in the weft, but a relative reduction in the unmodified viscose in the warp, when compared to the example described earlier.

In the mattress shown in Figure 1, the pocketed springs are of a conventional type. However, it will be understood by the skilled person that other types of resilient unit could be used, such as the pocketed spring structure described in our European Patent Number EP 1 993 947 B.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or combination of features referred to herein, and/or shown in the drawings, whether or not particular emphasis has been placed thereon.

Claims (16)

1 . A fire-resistant upholstered article, comprising a resilient unit, a cover and a filler layer between the resilient unit and the cover, wherein the cover comprises a woven material of viscose and modified viscose, and wherein the filler layer comprises nonwoven fire resistant modified viscose.

2. An article according to Claim 1, wherein the cover

3.

sheet comprises a combination of viscose and modified viscose in unmodified/natural the range 50-70% natural viscose and 30-50% modified viscose.

An article according to Claim 2, wherein the cover sheet comprises a combination of unmodified/natural viscose and modified viscose in the range 60-65% natural viscose and 35-40% modified viscose.

4. An article according to any of Claims 1 to 3, wherein the woven cover sheet has a range of 35-45 ends (warp threads) and 20-30 picks (weft threads),

5. An article according to Claim 5, wherein the sheet has 46 ends or 36 ends and 24 picks.

6. An article according to any of the preceding claims, wherein the filler layer comprises a pad of nonwoven fibres.

7. An article according to any of the preceding claims, wherein the filler layer comprises a blend of fire resistant modified viscose and other fibres in approximately equal quantities.

8. An article according to Claim 7, wherein the other fibres comprise modified viscose.

9. An article according to Claim 7 or 8, wherein the other fibres comprise natural fibres, such as wool.

10. An article according to any of the preceding claims, wherein the filler layer has a weight in the range 150350 grammes per square metre (gsm).

11. An article according to Claim 10, wherein the filler layer has a weight of approximately 200 gsm.

12. An article according to any of the preceding claims, wherein the upholstered article comprises a mattress.

13. An article according to any of the preceding claims,

wherein the resilient unit comprises a such as a pocketed spring unit. sprung unit,

14. A method of making a fire resistant upholstered article, the method comprising covering a resilient

unit and a filler layer with a cover sheet comprising a woven material of viscose and modified viscose, wherein the filler layer comprises nonwoven fire resistant modified viscose.

15. A fire resistant filler layer for an upholstered article, the filler layer comprising a nonwoven blend of fire resistant modified viscose and other fibres.

10

16. A fire resistant cover sheet for an upholstered article, the cover sheet comprising a woven material of viscose and modified viscose.