AU2012100847A4 - Methods of forming non-woven insulation products - Google Patents

Abstract

Abstract Methods of forming non-woven insulation products using textile fibres, as a relatively cheap source of glass fibre material, preferably using waste textile materials. / (9 2- r~

Description

METHODS OF FORMING NON-WOVEN INSULATION PRODUCTS 5 FIELD OF THE INVENTION This invention relates to methods of forming non-woven insulation products using glass fibres. 0 BACKGROUND TO THE INVENTION Glass fibre insulation is an important building material for thermal and acoustic insulation of residential, commercial and industrial buildings. Increasing awareness of the environment and the need to reduce green house gas emissions has raised the importance of insulation as a 5 building material which can help reduce the energy loads placed upon electricity generators by heating and cooling. Glass fibre insulation is available with a range of quality and cost, and has not previously made use of textile fibres. SUMMARY OF THE INVENTION 0 It is an object of the invention to provide for improved non-woven insulation products, or at least to provide a useful alternative to existing insulation products. In one aspect the invention resides in a method of forming a high-loft non-woven insulation 25 product including: providing a source of textile glass fibres, providing a source of binder fibres, combining the textile fibres and the binder fibres into a mat, curing the mat so that the binder fibres bond the textile fibres, and cutting the mat into product portions. In another aspect the invention resides in a method of forming a high-loft non-woven 30 insulation product including: providing a source of textile glass fibres, providing a source of fibre binder, forming the textile fibres into a mat, adding the fibre binder to the mat, curing the mat so that the binder bonds the textile fibres, and cutting the mat into product portions. 1/4 Preferably the textile fibres are provided as short stranded waste having lengths of about 60mm, within 10-20%. Preferably the textile fibres are resin-coated Eglass fibres with an average diameter of about 12 microns. 5 Preferably the mat has a thickness greater than about 50mm and is formed by an airlaying process or a cross-lapping process. In a further aspect the invention resides in an insulation product formed from short strand textile glass fibres having a loft greater than about 50mm. 0 LIST OF FIGURES Preferred embodiments of the invention will be described with respect to the accompanying drawings, in which: 5 Figure 1 shows a process for forming a non woven insulation product, Figure 2 shows an alternative process for forming a non woven insulation product, and Figures 3, 4 provide test data for a range of trial products. 0 DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawings it will be appreciated that the invention may be performed in a range of different processes using a range of textile fibres. The embodiments described here are given by way of example only. It will also be appreciated that the air-laying and cross 25 lapping processes need not be described in detail. Figures 1 and 2 schematically show the main components of an insulation manufacturing process in which fibres from a number of sources are blended and formed into a relatively high lofted mat, which can then be cured and cut into a product such as batts or rolls, for 30 example. In each case at least one of the sources includes textile fibres. These are typically glass fibres coated with a resin which reduces irritation when the products are handled and allows recovery of the product shape when compression due to packaging is removed. They can sometimes be obtained cheaply as waste from textile manufacturing processes. Other fibres or substances may also be added depending on the required product. 2/4 Textile fibres are themselves usually manufactured by a direct melt process in which melted glass flows into a forming section having moulded outlet bushings which form the fibres. These are drawn over a coating device which applies a resin finish before they are wound 5 onto a forming tube. The tube is placed in an oven where the resin is dried resulting in fibres which may be processed into rovings or chopped strand webs, for example. For the purposes of Figures 1 and 2, the textile fibres are preferably formed from chopped strands of Eglass having an average diameter of about 12 microns and an average length of 0 about 60mm. A range of up to about 10-20% in either of these parameters is currently acceptable. The resin which coats these fibres may have several components and several functions. These poly resins generally lubricate the fibre, reduce fibre rigidity, reduce abrasion and skin irritation, protect the fibre from attack by moisture, and provide strand and packaging integrity. Typical resins include one or more of: polyvinyl, epoxy, vinyl-tris 5 salane, polyethylene glycol, polyethylene ethanol, methacryloxy silane, gamma aminopropyltriethoxysilane, for example. In Figure 1, the fibre sources include two bins of textile fibres 10 and a bin of polymer binder fibres 11, such as polyester or bicomponent melt fibres. The fibres from these sources fall 0 onto a conveyor 12 to form a bed 13. The bed generally contains clumps of fibres which must be opened and mixed. Two coarse opening stages 14 are provided in this example. These initial opening stages have been required in some cases to ensure that clumps of fibres are thoroughly worked and opened prior to the relatively fine stage which follows. Static electricity created by the inorganic fibres must usually be reduced after the first opening 25 stage, and an antistatic system such as a water sprayer (not shown) may be required. The fine opening stage 15 is typically either an air-lay process or a cross-lap process, and forms a mat 16 in which the fibres are thoroughly combined. The mat is then cured in an oven 17 which partially melts the binder fibres so that the mat becomes a robust non-woven product 18. 30 In Figure 2 shows are generally similar process for forming a non-woven product 28. Textile fibres from bins 20 are blended alone, with a binder being added in powder form by an applicator 21 before the mat enters the oven 27. The initial fibre bed 23 is formed on a conveyer 22 and passes through two coarse opening stages 24. A fine mixing stage 25, such as an air-laying process or cross-lapping process is again used to form a mat 26. The 11/4 components in this figure are typically the same as the components in Figure 1, although either may be varied depending on the product. It might only be necessary of have a single coarse opening stage for example. The cross lapper could be a textile card and cross lapper, or a camel back cross lapper, for example. The mat preferably has a thickness or loft of at 5 least 50mm. Products 18 and 28 which are suitable for thermal or acoustic insulation in buildings typically have a loft of 50-220mm and a weight of 10-20 kg/m 3 . Heavy acoustic insulation may have a loft of 50-100mm and a weight of 20-32 kg/m 3 . 0 A typical test product used the method of Figure 1 and a blend of fibres including 20% by weight of polyester low melt fibre (4 denier, 20mm length) and 80% Eglass fibre coated with polyvinyl (12 micron diameter, 60mm length). A range of 15-25% melt fibre and 75-85% textile fibre is currently considered acceptable. 5 Figure 3 shows test results for batt products formed using the method of Figure 1. The most suitable products were formed by blending textile fibres with melt fibres in an 80/20 ratio, where the textile fibres were Eglass with a diameter of about 12 microns. These were coated with low or no irritant resin to provide good handling integrity, and required no protective '0 clothing. They also provided consistently high thermal ratings in comparison to products using finer fibres. Products involving 7-9 micron Eglass were relatively abrasive, for example. Figure 4 shows the characteristics of thermal resistance and thickness recovery against weight 25 per unit area for the test products listed in Figure 3. These are useful for determining suitable weight and therefore cost of proposed commercial products. 4/4

Claims (5)

1. A method of forming a high-loft non-woven insulation product including: providing a source of textile glass fibres, 5 providing a source of binder fibres, combining the textile fibres and the binder fibres into a mat, curing the mat so that the binder fibres bond the textile fibres, and cutting the mat into product portions. 0 2. A method of forming a high-loft non-woven insulation product including: providing a source of textile glass fibres, providing a source of fibre binder, forming the textile fibres into a mat, adding the fibre binder to the mat, 5 curing the mat so that the binder bonds the textile fibres, and cutting the mat into product portions.

2. A method according to claim 1 wherein the textile fibres are provided as short stranded waste having lengths of about 60mm, within 10-20%. 0

3. A method according to claim 1 wherein the textile fibres are resin-coated Eglass fibres with an average diameter of about 12 microns.

4. A method according to claim 1 wherein the mat has a thickness greater than about 25 50mm and is formed by an air-laying process or a cross-lapping process.

5. An insulation product formed from short strand textile glass fibres having a loft greater than about 50mm. 30 1 /1