GB2521853A

GB2521853A - High security blanket

Info

Publication number: GB2521853A
Application number: GB1400135.8A
Authority: GB
Inventors: Fiona Bennington
Original assignee: FAST ENGINEERING Ltd
Current assignee: FAST ENGINEERING Ltd
Priority date: 2014-01-06
Filing date: 2014-01-06
Publication date: 2015-07-08
Anticipated expiration: 2034-01-06
Also published as: GB2521853B; GB201400135D0

Abstract

A high security blanket comprises first and second composite layers, each composite layer comprising a layer of tear-resistant material 16,18 fused to a layer of wadding 24,26. The composite layers are bonded to one another so that the respective tear-resistant layers provide the obverse and reverse outer faces of the blanket. The blanket may comprise an ultrasonically bonded, quilted and laminated structure with an inwardly folded double hem 36,38. The blanket, which is adapted for use in institutions by those at risk of self-harm or of causing harm to others offers, improved user safety by the reduction of thread, improved tear resistance and life expectancy from repeated wash cycles, as well as reduced shrinkage when washed at high temperatures.

Description

High Security Blanket

Field of the Invention

This invention relates to blankets, in particular high security fire resistant blankets for use with for example persons at risk of self harm or causing harm to others.

Background to the Invention

Historically high security (or anti-suicide) blankets are used in situations where a patient or detainee is at risk of self-harm or causing harm to others. Anti-suicide blankets have remained similar in design since the 1 900s. Typically the design uses bulky material to prevent rolling or folding in such a way as to form a noose. The design is intended to be difficult to tear as garrottes can be formed from strips of fabric torn from a blanket. The material is usually quilted by sewing in typically 50mm grids; this use of sewing introduces needle holes, perforating the fabric and offering a natural tear line. Needle holes also allow for quick ingress of liquids into the centre of the blanket which can lead to hygiene problems and degradation of the materials. It would be desirable to provide an improved high security blanket.

Summary of the Invention

A first aspect of the invention provides a blanket having an obverse face and a reverse face, the blanket comprising first and second composite layers, each of said first and second composite layers comprising a layer of tear-resistant material fixed to a layer of wadding, and being fixed to one another so that the respective tear-resistant layers provide a respective one of the obverse and reverse face of the blanket and the respective wadding layers are located between the tear-resistant layers.

A second aspect of the invention provides a blanket comprising at least one composite layer comprising a layer of tear-resistant material sonically bonded, preferably ultrasonically bonded, to a respective layer of wadding.

A third aspect of the invention provides a method of manufacturing a blanket having an obverse face and a reverse face, the method comprising providing first and second composite layers, each of said first and second composite layers comprising a layer of tear-resistant material fixed to a layer of wadding, and fixing said composite layers to one another so that the respective tear-resistant layers provide a respective one of the obverse and reverse face of the blanket and the respective wadding layers are located between the tear-resistant layers.

A fourth aspect of the invention provides a method of manufacturing a blanket, said method comprising forming at least one composite layer by sonically bonding a layer of tear-resistant material to a respective layer of wadding.

Preferred features are recited in the dependent claims.

The preferred blanket comprises an ultrasonically bonded, quilted and laminated (multi-layer) structure, advantageously with an inwardly folded double hem. Preferred embodiments exhibit improved user safety by the reduction of thread, improving tear resistance and life expectancy from repeated wash cycles, as well as reduced shrinkage when washed at high temperatures. The hem results in reduced water retention which speeds drying time and reduces energy costs.

Brief Description of the Drawings

Other advantageous aspects of the invention will be apparent to those ordinarily skilled in the art upon review of the following description of a specific embodiment and with reference to the accompanying drawings in which: Figure 1 is a perspective view of a blanket embodying the invention, shown in a folded state; Figure 2 is a perspective view of part of the blanket of Figure 1; Figure 3 is a plan view of a preferred welding pattern for use with blankets embodying the invention; and Figure 4 is a perspective cross-sectioned view of part of the blanket of Figure 1.

Detailed Description of the Drawings

Referring now to the drawings there is shown, generally indicated as 10, a blanket embodying the invention and shown in a folded state. The blanket 10 has an obverse face 12 and a reverse face 14 and comprises first and second composite layers 16, 18. Each composite layer 16, 18 comprises a layer2O, 22 of tear-resistant material fixed to a layer24, 26 of wadding. The composite layers 16, 18 are fixed to one another so that the respective tear-resistant layers 20, 22 provide a respective one of the obverse and reverse face 12, 14 of the blanket 10. The respective wadding layers 24,26 are located, or sandwiched, between the tear-resistant layers 20, 22 to create a padded, or quilted, structure.

The tear-resistant material preferably comprises a woven material, for example a woven fabric.

Advantageously, the tear-resistant material is wholly or partly synthetic, and may for example comprise polyester or nylon, e.g. woven nylon. It is preferably a material of the type commonly known as ripstop material. The material typically includes a reinforcing grid (not shown), for example formed from nylon or other reinforcing strands, which may be incorporated by interweaving with other thinner strands, which may also comprise nylon. The spacing between strands of the grid is typically mm to 10 mm, and so the grid may for example comprise grid squares of approximately 10 mm x 10 mm. By way of example, the layers 20,22 may each be approximately 0.5 mm to 1.5 mm thick, preferably approximately 1 mm thick. The material is preferably fire-retardant. It is particularly preferred that the material comprises inherently fire-retardant fibres (as opposed to being coated with a fire-retardant substance).

In preferred embodiments, the wadding material comprises a non-woven material, typically a fibrous and/or spun material. The wadding may alternatively comprise a foam material. The wadding is preferably partly or wholly synthetic, for example comprising polyester. For example the wadding may comprise non-woven spun polyester or spun basalt. By way of example, the layers 24, 26 may each be approximately 3 mm to 5 mm thick, preferably approximately 4 mm thick. The wadding is preferably fire-retardant. It is particularly preferred that the wadding comprises inherently fire-retardant fibres (as opposed to being coated with a fire-retardant substance).

Advantageously, the layer 20, 22 of tear-resistant material is fixed to the respective layer 24, 26 of wadding by sonic bonding (which term is intended to include sonic welding), preferably ultrasonic bonding (which term is intended to include ultrasonic welding). More generally, the respective layers are preferably fixed together by non-stitching means, advantageously any convenient fusing method, typically involving the application of heat and/or pressure to the layers.

In preferred embodiments, for each of the composite layers 16, 18, a respective plurality of (e.g. ultrasonic) bonds 28 fix the tear-resistant layer 20,22 to the respective wadding layer 24, 26, the bonds 28 preferably being spaced apart and forming a lattice (or grid) pattern. The lattice pattern preferably extends across substantially the entire composite layer 16, 18, the pattern being disposed substantially in the major plane of the respective layer 16, 18 when the layer 16, 1 8 is substantially flat and unfolded. The illustrated bonds 28 are substantially linear when the blanket is unfolded and overlap to form the lattice pattern. In alternative embodiments, the bonds make take other shapes (e.g. zig-zag or wave-like) and need not necessarily overlap.

Figure 3 shows a preferred lattice pattern 30 in two dimensions. The pattern comprises a plurality of polygonal regions 32 defined between bonds 28. The regions 32 are preferably quadrilateral, for example rectangular or diamond-shaped, but are most preferably substantially square. Alternatively, the regions 32 may take other shapes and may be rounded rather than polygonal. The regions, particularly when polygonal, typically have an area of approximately 100 mm2 to 1600 mm2, preferably approximately 400 mm2 to 500 mm2. In the illustrated embodiment, the regions 32 are substantially square and have width / length of approximately 20 mm. This results in a relatively tight quilting grid which adds stability to the blanket shape and reduces shrinkage during washing.

In preferred embodiments, at at least some, and preferably all, of the intersections of the respective longitudinal axis of the bonds 28, the lattice pattern 30 defines rounded regions 34, which are preferably substantially circular. The regions 34 reduce the number of sharp edges in the bond pattern 30, which is desirable to reduce stress concentration points and improve longevity and adhesion of the ultrasonic weld.

In preferred embodiments, the first and second composite layers 16, 18 are bonded, typically adhesively bonded, to one another, using any suitable adhesive or other bonding means, preferably fire retardant adhesive or bonding means, to produce a multi-layer (in this case four layer) structure.

In the preferred embodiment, adhesive (not shown) is applied to the exposed face of one or both of the wadding layers 24, 26. The exposed wadding faces are fixed together so that the respective tear-resistant layers 20, 22 form the outer faces of the blanket 10. The first and second composite layers 16, 18 may be fixed together using other means, especially non-stitching means, e.g. by lamination.

Advantageously, each of the composite layers 16, 18 is folded or rolled along at least part, and preferably all, of its peripheral edge to form a respective hem 36, 38 around at least part and preferably all of the blanket 10. The respective hems 36, 38 are fixed together to form a double hem.

In preferred embodiments, the edge of the composite layers 16, 18 are folded inwardly of the blanket such that the respective hems 36, 38 are located inwardly of the blanket 10.

The hems 36, 38 are preferably fixed together by at least one row, and preferably more than one row, of stitching 40 running around at least part and preferably all of the periphery of the blanket 10.

Three rows of stitching 40 are shown in the illustrated embodiment by way of example. The rows 40 may be substantially parallel with one another. Preferably the outmost row of stitching 40 is located relatively close to (for example between 1 mm and 5 mm, preferably approximately 3 mm) the edge of the blanket 10. The composite layers 16, 18 are preferably shaped such that the blanket 10 has rounded corners 39, although other shapes, e.g. mitred, may be used.

It will be seen that in preferred embodiments, stitching is only used around the hems 36, 28. The preferred use of bonding, or more generally non-stitching, leads to an up to 90% reduction in thread required for manufacture and so increases the security of the blanket (e.g. less stitching to be unpicked, plaited and formed into a garrotte.) During the bonding and/or stitching process, one face (typically the reverse face) of the composite layer 16, 18 tends to be poorer (in terms of quality and/or appearance) than the other (typically the obverse face). In preferred embodiments the bonding and stitching is performed such that the face comprising the tear-resistant layer 20,22 is the better (obverse) face. Since each of the blanket's exposed faces is comprised of a respective tear-resistant layer 20, 22, the poorer quality faces are hidden and the overall product consistency, appearance, and quality is improved.

The illustrated quilted construction comprises of a layer of tear resistant (e.g. ripstop) woven material ultrasonically fused to wadding infill to form a two layer composite. The ripstop' fabric has a reinforcing grid, e.g. 10mm centre to centre, to resist ripping. Torn fabric is a common way to form a garrotte and hence the safety of the blanket is improved.

The inverted, or inward, hems 36,38 locked with one or more rows of stitching 40 provide increased security at the most common point of access for destruction since it is harder to pull apart than a conventional rolled edge. The outer sewing line is close to the blanket edge to reduce the opportunity to grip the two layers and pull apart. Also, the inverted hem 36, 38 with stitching doubles the bulk of material and impedes tearing from the edge. It is also found that the inverted hem 36, 38 retains up to 40% less water during washing and so drying time is significantly decreased thereby reducing laundry costs.

The rounded corners 39, which are facilitated by the inverted hems 36, 38, improve washability and durability of the blanket 10. In contrast, conventional mitred corners tend to be the first area to show signs of wear through use and washing due as a result of increased thickness, stiffness and abrasion in this area. The rounded corners also improved security since stiff corner edges can be used to injure.

Preferred embodiments of the blanket 10 carry a directly printed, e.g. screen printed, label 42 for added security (it cannot be unpicked and removed). Such a label is also beneficial for permanent identification. Preferably the label 40 includes a region 44 suitable for writing on to enable, for example, custom references to be added by the user for traceability purposes.

Where possible, it is preferred to use permanently fire retardant fabrics (inherently fire retardant fibres) for the layers 20, 22, 24,26 to ensure constant levels of fire retardancy over the lifetime of the blanket even after many washes.

In alternative embodiments, one or more further layers of wadding, tear-resistant or other material may be provided between the composite layers 16, 18 and/or between any tear-resistant layer and wadding layer. In preferred embodiments the blanket comprises a multi-layer structure having at least four layers (layers 20, 22, 24, 26 or similar) and may include one or more additional layers, the or each additional layer comprising wadding, or tear-resistant material, or a composite layer, or layer of other material. In any case, the arrangement of the multi-layer structure is advantageously such that the obverse and reverse faces of the blanket are provided by an obverse face of a respective tear-resistant layer (which provides the obverse face of a composite structure) that has been positioned during a bonding and/or stitching process on the composite structure such that it is better in terms of quality and/or appearance than the reverse face of the composite structure.

The invention is not limited to the embodiment(s) described herein but can be amended or modified without departing from the scope of the present invention.

Claims

CLAIMS: 1. A blanket having an obverse face and a reverse face, the blanket comprising first and second composite layers, each of said first and second composite layers comprising a layer of tear-resistant material fixed to a layer of wadding, and being fixed to one another so that the respective tear-resistant layers provide a respective one of the obverse and reverse face of the blanket and the respective wadding layers are located between the tear-resistant layers.
2. A blanket as claimed in claim 1, wherein for at least one of, and preferably each of, said first and second composite layers, said layer of tear-resistant material is fixed to the respective layer of wadding by non-stitching means, preferably by fusing, more preferably by ultrasonic bonding.
3. A blanket as claimed in claim 1 or2, wherein said first and second composite layers are fixed together by non-stitching means, preferably by bonding, more preferably by adhesive bonding.
4. A blanket as claimed in claim 3, wherein the respective wadding layers are fixed together by said non-stitching means.
5. A blanket as claimed in any one of claims 2 to 4, wherein a plurality of spaced apart bonds fix said layer of tear-resistant material to the respective layer of wadding, said bonds preferably overlapping to form a lattice pattern.
6. A blanket as claimed in claim 5, wherein said spaced-apart bonds and, when present said lattice pattern, extend across substantially the entire obverse and/or reverse face of said blanket.
7. A blanket as claimed in claim 5 or 6, wherein said lattice pattern defines a plurality of polygonal regions between said sonic bonds.
8. A blanket as claimed in claim 7, wherein said polygonal regions are quadrilateral, preferably substantially rectangular and more preferably substantially square.
9. A blanket as claimed in claim 7 orB, wherein said polygonal regions have an area of approximately 100 mm2 to 1600 mm2, preferably approximately 400 mm2.
10. A blanket as claimed in any one of claims 6 to 9, wherein at at least some of the intersections of the respective longitudinal axis of said bonds, said lattice pattern defines rounded regions, preferably substantially circular regions.
11. A blanket as claimed in any preceding claim, wherein each of said first and second composite layers is folded or rolled along at least part, and preferably all, of its peripheral edge to form a respective hem around at least part and preferably all of the blanket.
12. A blanket as claimed in claim II, wherein the respective hems are fixed together to form a double hem around at least part, and preferably all, of the peripheral edge of the blanket.
13. A blanket as claimed in claim 12, wherein the respective hems are fixed together by at least one row, and preferably more than one row, of stitching running around at least part and preferably all of the periphery of the blanket.
14. A blanket as claimed in any one of claims 11 to 13, wherein the or each hem is folded or rolled inwardly of the blanket.
15. A blanket as claimed in any preceding claim, having rounded corners or mitred.
16. A blanket as claimed in any preceding claim, wherein said tear-resistant material comprises a woven material, preferably a woven fabric.
17. A blanket as claimed in any preceding claim, wherein said tear-resistant material is at least partly, and preferably wholly, synthetic.
18. A blanket as claimed in any preceding claim, wherein said tear-resistant material comprises a ripstop material.
19. A blanket as claimed in any preceding claim, wherein said wadding material comprises a non-woven material.
20. A blanket as claimed in any preceding claim, wherein said wadding material comprises a fibrous material.
21. A blanket as claimed in any preceding claim, wherein said wadding is at least partly, and preferably wholly, synthetic, for example comprising polyester.
22. A blanket as claimed in any preceding claim, wherein said wadding comprises spun basalt.
23. A method of manufacturing a blanket having an obverse face and a reverse face, the method comprising: providing first and second composite layers, each of said first and second composite layers comprising a layer of tear-resistant material fixed to a layer of wadding; and fixing said composite layers to one another so that the respective tear-resistant layers provide a respective one of the obverse and reverse face of the blanket and the respective wadding layers are located between the tear-resistant layers.
24. A method as claimed in claim 23, further including forming each of said composite layers by a fusing and/or stitching process; and positioning the respective tear-resistant material such that its obverse face provides the obverse face of the respective layer during the fusing and/or stitching process.