GLAZING SPACER BAR

Abstract

 The invention relates to a spacer bar for a multiple glazed unit in which the spacer bar has a body having one or more cavities, wherein the body comprises a thermoplastic polymer and a blowing/foaming agent. The invention also relates to a method of manufacturing the spacer bar and its use in multiple pane glazing units.

Description

[0001] This invention relates to a novel spacer for use in a sealed multiple glazed unit, particularly a double glazed unit.

[0002] Although the invention will be described in terms of a double glazed unit, it could also be used for multiple glazed units e.g. triple glazed units.

[0003] Known double glazed units typically consist of two glazing panes, usually of glass, which are sealed to and separated by a self-supporting spacer, usually of bar of metal or a plastics extrusion, around the outer edges of the glazing panes. The spacer bar may be hollow and may be formed into any shape by bending and/or by joining (e.g. using corner keys) as is well known in the industry. The spacer bar is sandwiched and sealed between the two glazing panes to form a unit, defining a cavity (interspace) between the glazing panes. The sealing against the glazing panes may be by way of a sealant and/or adhesive e.g. butyl rubber, polysulphide or polyurethane, again as is known in the industry. In order to improve the heat insulation performance of the glazed unit, it is desirable although not essential to introduce an inert gas such as argon and/or xenon or similar gas into the cavity, in which case if the spacer bar is not constructed of 100% metal it is usual to have a composite hollow spacer bar with a gas barrier of metal tape (e.g. of steel or aluminium) around its outer edge i.e. facing away from the cavity (interspace). However the present invention provides for greater heat insulation still. In addition, a thermoplastic spacer bar eliminates the problem of static electricity build-up. This problem is well known in the industry. When a conventional metal spacer bar is substituted for an energy efficient polymer spacer bar, there is static electricity build-up because of the non-metallic spacer bar material. The static build-up may reduce moisture absorption capacity of the sealed unit, the said spacer system provides solution to this problem.

[0004] The present invention relates to a spacer bar for a multiple glazed unit in which the spacer bar has a body having one or more cavities, wherein the body comprises a thermoplastic polymer and a blowing/foaming agent.

[0005] In one embodiment, the spacer bar body is hollow.

[0006] Presence of a foamed structure in the spacer bar body reduces the thermal conductivity of the spacer bar. The reduction in thermal conductivity can be significant, for example up to 40% when compared with a non-foamed spacer bar.

[0007] The spacer bar body may be porous.

[0008] The spacer bar body may be formed of a thermoplastic polymer comprising polypropylene (PP), polyethylene (PE), polycarbonate (PC), polyamide (PA) commonly known as Nylon, polyvinyl chloride (PVC), polystyrene (PS) and or styrenic polymers and co-polymers, or any combination thereof. In one embodiment the thermoplastic polymer comprises or is polypropylene (PP).

[0009] The blowing/foaming agent may be endothermic or exothermic.

[0010] The blowing/foaming agent may comprise 4, 4'-Oxybis-benzenesulfonylhydrazide (OBSH), azodicarbonamide (ADA), bicarbonates or biurets.

[0011] In one embodiment, the spacer bar body may comprise a desiccant.

[0012] The desiccant may be in the form of a powder. The desiccant may comprise an aluminosilicate, silica gel, calcium sulphate, a montmorillonite clay, calcium chloride, molecular sieve desiccants, activated charcoal or combinations thereof.

[0013] The desiccant may be a 3Å or 4Å desiccant.

[0014] Presence of a desiccant in the spacer bar body aids in absorbing moisture inside a glazing unit when the spacer bar is in use in a glazing unit and increases the lifetime of the product. The presence of desiccant in the spacer bar body may also save time and energy of a sealed unit manufacturer by reducing the amount of desiccant which may need to be inserted into any cavity within the spacer bar.

[0015] One or more of the cavities of the spacer bar body may contain desiccant. The desiccant may be 3Å or 4Å desiccant beads.

[0016] In one embodiment, the spacer bar body further comprises a reinforcing material. The reinforcing material may be any suitable material, for example chopped glass fibres, milled glass fibres, glass beads, glass bubbles, polymer fibres, ceramic fibres and natural fibres or any combination thereof. The proportion of reinforcing material within the spacer bar body may be in a range from 5 to 50% by weight or more preferably from 25 to 50% by weight. Reinforcing material is added to improve the mechanical strength/stiffness, dimensional stability and thermal resistance.

[0017] In one embodiment, the spacer bar body may further comprise a coupling agent in combination with the reinforcing material. The coupling agent may be polypropylene functionalised with maleic anhydride or SCONA TPPP 9112.

[0018] The spacer bar body may further comprise one or more pigment masterbatches. Each pigment masterbatch may comprise polypropylene (PP), polyethylene (PE), polyamide (PA), ethylene vinyl acetate, ethylene copolymers or other polymer and or copolymers.

[0019] The ability to include a pigment masterbatch allows sealed unit manufacturers to match the colour of the spacer bar to the glazing system.

[0020] The spacer bar body may comprise a UV stabiliser. The UV stabiliser may be Tinuvin 213. Presence of UV stabiliser eliminates the problem of UV/thermal degradation and or cracking as well as colour change during the work life.

[0021] The spacer bar body may comprise a thermoplastic polymer content in range of 10 to 80%, a reinforcing filler content in range of 5 to 60%, a moisture absorbing desiccant powder in range of 10 to 70%, a foaming agent in range of 0.1 to 7%, a UV stabiliser in range of 0.1 to 5%, an anti-static agent/additive in range of 0.1 to 5%, a coupling agent in range of 0.1 to 3% and a pigment masterbatch in range of 0.1 to 10%.

[0022] The spacer bar body of the present invention may be backed or coated with a moisture, moisture vapour and/or gas barrier. The moisture, moisture vapour and/or gas barrier may be metalized polymeric, polyester, multilayered polyethylene or a metallised polyester film/tape. The barrier may be a film/tape with a thickness that is in the range of 1 to 1000 microns.

[0023] The spacer bar may be vacuum sealed in a suitable metalized polymeric packaging and boxed for storage.

[0024] The spacer bar body may be elongate. The spacer bar body may be self-supporting.

[0025] The spacer bar body may have a thermal conductivity in the range of 0.11 to 0.18, preferably in a range of 0.12 to 0.16 W/(m.K).

[0026] The spacer bar body may have a continuous cross section. The cross section of the spacer bar body may alternatively be provided with apertures and/or breaks around or in its perimeter, which may extend along all or part of its length.

[0027] The spacer bar body may comprise any of the following three compositions:

Example composition 1:

[0028] 

1. Polypropylene - 39.5 %

2. Glass fibres - 20%

3. 3Å desiccant powder - 30%

4. Blowing agent - 0.5 %

5. UV stabiliser - 1.5 %

6. Anti-static agent - 1.7 %

7. Coupling agent - 0.8 %

8. Pigment masterbatch - 6 %

Example composition 2:

[0029] 

1. Polypropylene - 46 %

2. Milled glass fibres - 12%

3. Hollow glass bubbles - 12%

4. 3Å desiccant powder - 20%

5. Blowing agent - 4 %

6. UV stabiliser - 1 %

7. Anti-static agent - 0.6%

8. Coupling agent - 1.4 %

9. Pigment masterbatch - 3 %

Example composition 3:

[0030] 

1. Polypropylene - 39.3 %

2. Milled glass fibres - 18 %

3. Solid glass beads - 8 %

4. 3Å desiccant powder - 26%

5. Blowing agent - 2.7 %

6. UV stabiliser - 0.5 %

7. Anti-static agent - 0.7%

8. Coupling agent - 0.8 %

9. Pigment masterbatch - 4 %

[0031] Another aspect of the present invention relates to a method of manufacture of a spacer bar of the present invention, wherein thermoplastic polymer is foamed and extruded to form a spacer bar body. This method may comprise compounding/blending the thermoplastic polymer, and extruding the thermoplastic polymer, wherein, a foaming/blowing agent is introduced to the thermoplastic polymer during the polymer compounding/blending process or during a profile extrusion process.

[0032] Another aspect of the present invention relates to a method of assembling a spacer bar of the present invention into a pre-determined shape for making a sealed unit, for example a rectangular, square or other shape, wherein the method comprises heat welding, blending and/or by using corner keys.

[0033] An additional aspect of the present invention relates to a method of manufacturing a multiple glazed unit from a spacer bar of the present invention, wherein the spacer bar is fitted between two glazing panes spaced apart to form a cavity.

[0034] Another aspect of the present invention relates to the use of the spacer bar of the present invention in the construction of an insulating glass unit consisting of two or more parallel sheets/panes of glass or polymer.

[0035] Embodiments of the invention will now be described by way of example only and with reference to the figures in which like parts are referred to by use of the same reference number and in which:

Figure 1 shows a cross section through a spacer bar of a first embodiment of the present invention;

Figure 2 shows a cross section through a spacer bar of a second embodiment of the present invention;

Figure 3 shows a cross section through a spacer bar of a third embodiment of the present invention;

Figure 4 shows a cross section through a spacer bar of a fourth embodiment of the present invention; and

Figure 5 shows a cross section through a spacer bar of an embodiment of the present invention in position in a multiple glazed unit.

[0036] Figure 1 shows a cross section through a spacer bar of a first embodiment of the present invention. In this embodiment the spacer bar body 1 has been formed from polypropylene, a thermoplastic polymer, which has been foamed during manufacture of the spacer bar body 1 using, azodicarbonamide, a foaming/blowing agent, though other foaming/blowing agents may be used. Presence of a foamed structure in spacer bar body 1 may reduce the thermal conductivity up to 40% when compared with a non-foamed spacer bar body. The spacer bar includes a cavity 2 formed within the body 1 which can be filled with a desiccant. The spacer bar body 1 has perforations or a series of apertures 3 to allow desiccant within the cavity 2 to absorb moisture inside a glazing unit when the spacer bar is in use in a glazing unit.

[0037] Figure 2 shows a cross section through a spacer bar of a second embodiment of the present invention. In this embodiment the spacer bar body 1 possesses all of the properties of the spacer bar body 1 of figure 1. Also in this spacer bar body 1 is a desiccant 4, in this instance calcium sulphate though other desiccants may be used, which aids in absorbing moisture inside a glazing unit when the spacer bar is in use in a glazing unit and increases the lifetime of the product. Desiccant 4 in the spacer bar body 1 may also save time and energy of a sealed unit manufacturer by reducing the amount of desiccant which may need to be inserted into the cavity 2. The manufacturer may not be required to fill the spacer bar cavity 2 with desiccant as the spacer bar body 1 of present invention can absorb the moisture inside a glazing unit when the spacer bar is in use in a glazing unit, due to presence of desiccant 4 within the spacer bar body 1.

[0038] Figure 3 shows a cross section through a spacer bar of a third embodiment of the present invention. In this embodiment the spacer bar body 1 possesses all of the properties of the spacer bar body 1 of figure 1. Also in this spacer bar body 1 is a reinforcing material 5. In this instance the reinforcing material is chopped glass fibres, though other reinforcing materials may be used. Reinforcing material 5 is added to improve the mechanical strength/stiffness, dimensional stability and thermal resistance.

[0039] Figure 4 shows a cross section through a spacer bar of a fourth embodiment of the present invention. In this embodiment the spacer bar body 1 is as described in figure 2 and in addition contains a reinforcing material 5. In this instance the reinforcing material is chopped glass fibres, though other reinforcing materials may be used. Reinforcing material 5 is added to improve the mechanical strength/stiffness, dimensional stability and thermal resistance.

[0040] Figure 5 shows a cross section through a length of spacer bar in accordance the second embodiment of the present invention in position in a multiple glazed unit. The spacer bar comprises a cavity 2 formed within the body 1. The spacer bar body 1 is elongate and of a generally "D" cross section and has first and second long side walls 11a, 11b and first and second short side walls 7a, 7b giving rise to the width and depth of the spacer bar 1 respectively.

[0041] The spacer bar contains desiccant 12 within the cavity 2. The spacer bar is in use in a standard double glazed or multiple glazed unit as shown in Figure 9 wherein the glazing panes 8a, 8b are made of glass or polymeric material and/or any other transparent, translucent or opaque material, the cavity 6 between the glazing unit is sealed by using hot melt or warm melt sealants 10. A primary sealant such as layer/bead of polyisobutylene also can be applied on the sides 7a, 7b of the spacer bar 1 adjacent to glazing panes 8a, 8b. In order to improve the thermal insulation performance of glazing unit an inert gas such as argon/krypton/xenon may be introduced into the cavity 6 between the panes 8a, 8b.

[0042] The cavity 2 within the spacer bar body 1 contains Grace Davidson Sylosiv K 360 moisture adsorbing 3Å desiccant beads/granules 12, inserted in a conventional manner. The spacer bar 1 has perforations or series of apertures 3 extending through to the cavity 2 and positioned on long side 11a to allow desiccant 12 to adsorb moisture inside a glazing unit. The long side 11a bearing the apertures 3, is positioned to face into the cavity 6 between the glazing panes 8a, 8b while in use.

[0043] In this embodiment, the desiccant 12 fills the entire cavity 2 though it may fill only a portion of the cavity in other embodiments.

[0044] Whilst the embodiment of figure 2 is shown, any of the embodiments described could be used in the unit of Figure 5.

Claims

1. A spacer bar for a multiple glazed unit in which the spacer bar has a body having one or more cavities, wherein the body comprises a thermoplastic polymer and a blowing/foaming agent.

2. The spacer bar of claim 1, wherein any one or more of the following applies,

a) the bar body is hollow;

b) the spacer bar body is porous;

c) the thermoplastic polymer comprises polypropylene (PP), polyethylene (PE), polycarbonate (PC), polyamide (PA) commonly known as Nylon, polyvinyl chloride (PVC) polystyrene (PS) and/or styrenic polymers and co-polymers, or any combination thereof;

d) the blowing/foaming agent is endothermic or exothermic; and

e) the blowing/foaming agent comprises 4, 4'-Oxybis-benzenesulfonylhydrazide (OBSH), azodicarbonamide (ADA), bicarbonates or biurets.

3. The spacer bar of any preceding claim, wherein any one or more of the following applies

a) the spacer bar body comprises a desiccant, wherein optionally any one or more of the following applies,

i) the desiccant is in the form of a powder,

ii) the desiccant comprises an aluminosilicate, silica gel, calcium sulphate, a montmorillonite clay, calcium chloride, molecular sieve desiccants, activated charcoal or a combination thereof, and

iii) the desiccant is a 3Å or 4Å desiccant;

b) one or more of the cavities contain desiccant, wherein optionally the desiccant is 3Å or 4Å desiccant beads.

4. The spacer bar of any preceding claim, wherein the spacer bar body further comprises a reinforced material, wherein optionally any one or more of the following applies,

i) the reinforcing material is chopped glass fibres, milled glass fibres, glass beads, glass bubbles, polymer fibres, ceramic fibres and natural fibres or any combination thereof,

ii) the proportion of reinforcing material within the spacer bar body is in the range from 5 to 50% by weight, and

iii) the proportion of reinforcing material within the spacer bar body is in the range from 25 to 50% by weight.

5. The spacer bar of claim 4, wherein the spacer bar body further comprises a coupling agent in combination with the reinforcing material, wherein optionally the coupling agent is

i) polypropylene functionalised with maleic anhydride or

ii) SCONA TPPP 9112.

6. The spacer bar of any preceding claim, wherein

a) the spacer bar body further comprises one or more pigment masterbatches, wherein optionally the pigment masterbatches comprise polypropylene (PP), polyethylene (PE), polyamide (PA), ethylene vinyl acetate, ethylene copolymers or other polymer and or copolymers; and/or

b) the spacer bar body comprises a UV stabiliser, wherein optionally the UV stabiliser is Tinuvin 213.

7. The spacer bar of claim 1, wherein the spacer bar body comprises a thermoplastic polymer content in range of 10 to 80%, a reinforcing filler content in range of 5 to 60%, a moisture absorbing desiccant powder in range of 10 to 70%, a foaming agent in range of 0.1 to 7%, a UV stabiliser in range of 0.1 to 5%, an anti-static agent/additive in range of 0.1 to 5%, a coupling agent in range of 0.1 to 3% and, a pigment masterbatch in range of 0.1 to 10%.

8. The spacer bar of any preceding claim, wherein the spacer bar body is backed with a moisture, moisture vapour and/or gas barrier, wherein optionally

i) the moisture, moisture vapour and gas barrier is metalized polymeric, polyester, multilayered polyethylene or a metallised polyester film/tape, and/or

ii) the barrier is a tape with a thickness that is in the range of 1 to 1000 microns.

9. The spacer bar of any preceding claim, wherein any one or more of the following applies,

a) the spacer bar is vacuum sealed in a suitable metalized polymeric packaging and boxed for storage;

b) the spacer bar body is elongate;

c) the spacer bar body is self-supporting;

d) the spacer bar body has a thermal conductivity in the range of 0.11 to 0.18 W/(m.K); and

e) the spacer bar body has a thermal conductivity in the range of 0.12 to 0.16 W/(m.K).

10. The spacer bar of any preceding claim, wherein

a) the cross section of the spacer bar body is continuous; or

b) the cross section of the spacer bar body is provided with apertures and/or breaks around or in its perimeter, which may extend along all or part of its length.

11. A method of manufacture of a spacer bar of any preceding claim, wherein thermoplastic polymer is foamed and extruded to form a spacer bar body.

12. The method of claim 11, wherein the manufacturing of the spacer bar comprises compounding/blending the thermoplastic polymer, and extruding the thermoplastic polymer, wherein, a foaming/blowing agent is introduced to the thermoplastic polymer during the polymer compounding/blending process or during a profile extrusion process.

13. A method of assembling a spacer bar of any of claims 1 to 10 into a pre-determined shape for making a sealed unit, for example a rectangular, square or other shape, wherein the method comprises heat welding, blending and/or by using corner keys.

14. A method of manufacturing a multiple pane glazing unit from a spacer bar of any of claims 1 to 10, wherein the spacer bar is fitted between two glazing panes spaced apart to form a cavity.

15. Use of the spacer bar of any of claims 1 to 10 in the construction of an insulating glass unit consisting of two or more parallel sheets/panes of glass or polymer.

Drawing