Wire reinforced synthetic spacer profile

Abstract

The invention relates to a spacer profile having a spacer body of polypropylene, at least four wires and a diffusion barrier provided at least on an outer wall, wherein the polypropylene comprises from 5 – 30 weight% fillers. The wires are positioned in a first corner section, a second corner section, within a certain distance from a first contact line and within a certain distance from a second contact line.

Description

[0001] Wire reinforced

[0002] Field of the Invention

[0003] The present invention relates to a spacer profile for forming a spacing between glass panes with improved thermal expansion parameters.

[0004] Background of the Invention

[0005] It is well known to provide spacers in order to define the spacing between the panes of insulating glazing consisting of a plurality of parallel glass panes spaced apart by an insulating cavity.

[0006] A variety of such spacer profiles made of various materials and of various shapes is well known in the art. Spacer profiles made by roll forming of a thin metal foil are widely used and considered one of the preferred solutions because of their stability and their low gas diffusion properties. An even better thermically performance is achieved when combining stainless steel and plastic. There, the 100% vapor tightness of the steel brings full advantage on the back of the spacer, and the plastic with low conductivity is used as spacer top. These combined spacers are named Hybrid spacers.

[0007] However, the heat conductivity of such metallic based spacers makes them unsuitable for certain types of high performance IG units with low U-values. Therefore, spacer profiles with a spacer body of synthetic materials have been provided. Such spacers are combined with gas and watertight foils often in form of multilayer foils and, often “non- metallic”. Those foils typically are being named a diffusion barrier. EP2802726 B1 is an example of a synthetic spacer profile, where a multilayer foil has been proposed as a replacement for metal foils. EP3162999B1 is another example of a synthetic spacer profile with a non-metal diffusion barrier layer. There, EVOH is used as a barrier material. In both cases it is attempted to get the good properties from metal foil, i.e. good diffusion barrier properties while trying to get rid of the high heat conductivity of the metal.

[0008] The most promising synthetic spacer materials could be for example wise polypropylene or PVC having low heat conductivity but also having the disadvantage of a large thermal expansion coefficient in it's pure form. Such large thermically expansion results in risk of the spacer profile getting out of position during high summer temperatures. The stress generated by such movements are not allowed and will have negative effect on the service time of the IGU. In worst case, a direct leak in the sealants will be the result. Further, a pure synthetic spacer profile is too soft and flexible to be handled fast and efficient in a production line. Too much work is needed to keep the spacer profile in the right place and form during the manufacturing of IGU’s, when there are no stabilizing components incorporated in the spacer profile.

[0009] Previously, this problem of thermal expansion has been solved by adding one or more fillers to the synthetic material as have been done in EP2802726 B1 . But fillers increase the heat conductivity so that when the synthetic material ash a proper modified / controlled thermal expansion coefficient, the material as a whole reaches too high thermal conductivity. Further, the flexibility across the cavity, due to IGU pumping during temperature variation, is very limited due to the filler stiffened material. This gives extra stress to the IGU edge sealing.

[0010] Spacer profiles made of mainly synthetic materials containing mineral fillers and / or glass fibres further have the challenge that they need heating in order for the spacer profile to be bent into a window frame, i.e. they are no longer cold-bendable. The heating inter alia has the drawback that it results in the spacer frames being soft and difficult to handle due to soft corners still being warm. This overall makes frame handling delicate and critical and has negative influence on the IGU production efficiency.

[0011] Particularly spacers with a high content of filler and / or GF must be heated thoroughly or else they will crack up during bending.

[0012] Hence, there is a need for a solution where thermal expansion coefficient of low heat conductive synthetic material can be controlled so that such materials can be used in spacers and so that in case of heating during bending, the softness in the corner regions can be controlled. Or most preferred to find a solution where heating can be fully avoided, so that the spacer profile remains cold-bendable

[0013] Summary of the Invention

[0014] According to the invention there is provided a spacer profile for use as part of a spacer profile frame, which is suitable for being mounted in and / or along an edged area of an insulating glazing unit so as to surround an intervening space between glazing panes, the spacer profile comprising a spacer body made of a synthetic material and extending in a longitudinal direction (Z), said spacer body comprising: an inner wall facing the intervening space between and extending in a transverse direction (X), an outer wall separated from the inner wall by a first distance d1 , two side walls having a height h and extending in a height direction (Y) and separated by a second distance d2, two connection walls extending between the side walls and the outer wall,

[0015] - where the inner wall, the two side walls, the two connection walls and the outer wall define a chamber suitable for desiccants, the spacer profile further comprises at least two wires and a diffusion barrier provided at least on the outer wall, wherein the synthetic material is selected from synthetic materials with a heat conductivity below 0.4 W / (m K) measured at 25°C and that the synthetic material comprises from 0 - 40 weight% fillers.

[0016] It is to be understood that the value below 0.4 W / (m K) measured at 25°C is for the synthetic material without added fillers. As an example, Polypropylene (PP) unfilled is around 0.19 W / (m K) and PVC is around 0.17 W / (m K).

[0017] Preferably, the diffusion barrier is provided on both the outer wall and at least partially on the two side walls.

[0018] The inventor has found that two or more wires in combination with an adapted filler content in the range 0 - 40 weight % are sufficient to control the thermal expansion of synthetic material with a heat conductivity. The result is a soft and more flexible spacer profile with very low heat conductivity while still having a proper thermal expansion. The wires further support the corners during and after a bending procedure involving heating. This support depends on wire shape and placement. As such wires are placed in longitudinal spacer direction, the effect on the spacer conductivity measures and stiffness across the spacer is limited.

[0019] Another object of the invention is controlling the bending properties when reducing the amount of fillers in the spacer profile while at the same time reducing the amount of metal. This is important both during cold bending and during heat assisted bending. It is important that the outer wall “falls” into the spacer profile in such a manner that wrinkles are minimized, and so that a stabile structure that is easy to handle in the manufacturing process is obtained. The inventor has found that by positioning four wires in a certain manner in the spacer body; less fillers and less material for wires are needed and thereby a reduced heat transmission is obtained while the bending properties are still controlled. This is done by having a first wire in a corner region between a first side wall and the inner wall and a second wire in a corner region between a second side wall and the inner wall, a third wire within a certain first distance from a contact line between a first connection wall and the outer wall, a fourth wire region defined within a certain second distance from a contact line between a second connection wall and the outer wall.

[0020] In a particularly suited embodiment there is provided a cold-bendable spacer profile for use as part of a spacer profile frame, which is suitable for being mounted in and / or along an edged area of an insulating glazing unit so as to surround an intervening space between glazing panes, the spacer profile comprising a spacer body made of polypropylene and extending in a longitudinal direction (Z), said spacer body comprising: an inner wall having a width w1 and facing the intervening space between and extending in a transverse direction (X), an outer wall separated from the inner wall by a first distance d1 , a first side wall and a second side wall having a height h, a width w2 and extending in a height direction (Y) and separated by a second distance d2, a first connection wall extending between the first side wall and the outer wall, a second connection wall extending between the second side wall and the outer wall,

[0021] - where the inner wall, the first side wall, the second side wall, the first connection wall, the second connection wall and the outer wall define a chamber suitable for desiccants, and

[0022] - where the inner wall has a first corner section defined by the width w1 of the inner wall and the width w2 of the first side wall,

[0023] - where the inner wall has a second corner section defined by the width w1 of the inner wall and the width w2 of the second side wall, the spacer profile further comprises at least four wires and a diffusion barrier provided at least on the outer wall said diffusion barrier comprising a polymeric material and said at least four wires comprising a first wire, a second wire, a third wire and a fourth wire each wire having a centre of gravity, wherein the centre of gravity of the first wire is positioned in the first corner section, the centre of gravity of the second wire is positioned second corner section, the centre of gravity of the third wire is positioned at a distance d6from a first contact line between the first connection wall and the outer wall, said distance d6being no more than 2 mm, the centre of gravity of the fourth wire is positioned at a distance d5from a second contact line between the second connection wall and the outer wall, said distance ds being no more than 2 mm, and wherein the polypropylene comprises between 5 - 30 weight% fillers.

[0024] The advantage of positioning the at least four wires as specified is that it is possible to reduce the content of fillers while still having a sufficiently ridged spacer profile for easy handling during the manufacturing of IGUs. However, at certain amount of fillers are still required to keep the spacer profile torsion resistant.

[0025] The contact line is the straight line running along the line, where the connection wall meets with the outer wall, i.e. the straight line that runs from the outer contact corner between the connection wall and the outer wall to the inner Conner between the same two walls. In case there is a rounded corner, the contact line runs from the middle point of the rounded part to the middle point of the other rounded part or to the corner in case there is a rounded corner and a sharp corner.

[0026] Preferably, the polypropylene comprises between 6 and 19 weight% fillers, particularly preferred is between 7 and 9 weight% fillers.

[0027] In a preferred embodiment the centre of gravity of the first and second wires is positioned at a distance da from the inner wall being no more than 2 mm and a distance d4 from the outer surface of the first or second side walls, respectively, being no more than 2 mm.

[0028] In a more preferred embodiment the centre of gravity of the first and second wires is positioned at a distance da from the inner wall being no more than 1 mm and a distance d4 from the first or second side walls, respectively, being no more than 1 mm.

[0029] By positioning the wires with a centre of gravity as described, it is possible to reduce the amount of metal to the wires so that there is a reduced raw material consumption during production. Further, the less metal the less heat conducting the spacer profile is. In general, the lower the amount of filler the more metal is needed to control the thermal expansion during hot bending of the spacer profile or to ensure it is still cold bendable. But by positioning the wires as specified, less material is needed for the wires to obtain the same stability.

[0030] Suitable fillers for the invention can be mineral fillers such as calcium carbonate, calcium sulphate, calcium silicates, magnesium silicates, glass , glass fibres (GF), silicium oxides, talc, wollastonite, mica, carbon black, barium sulphate, magnetite zinc oxides, alumina oxides, kaolin, silica and sodium sulphate.

[0031] Further organic fillers such as tree bark flour, nut flour, chicken feathers, and rice hulls are also suitable fillers.

[0032] Preferably, the synthetic material comprises from 1-35 weight% fillers, more preferred is 2 - 30 weight% fillers and most preferred is 3 - 25 weight% fillers and even more preferred is 3 - 20 weight%.

[0033] For all embodiments the wires suitable for the invention can be made of metals in different shapes, different fibre materials and / or being carbon-based.

[0034] The metals for the wires can be stainless steel, galvanized steel, aluminium, or for that matter any other type of steel suitable for bending.

[0035] The different fibre materials can be fibreglass or mineral fibres.

[0036] The carbon-based material can be Kevlar or carbon fiber wires, where carbon fibers refer to fibers which contain at least 90 weight % and up to 100 weight % carbon. They can be produced from polymeric precursor materials, such as polyacrylonitrile (PAN), cellulose, pitch and polyvinylchloride.

[0037] In certain embodiments, it can be advantageous that the wires are made of different materials so that a first pair of the at least two wires is made of a first material and a second pair of the at least two wires is made of a second material, where the second material is different from the first material. In another embodiment, where a similar effect can be obtained, is when a first pair of the at least two wires has a first shape, and a second pair of the at least two wires has a second shape, where the second shape is different from the first shape.

[0038] It is especially advantageously that the members of a pair are positioned at the same height in the height direction (Y). By having a first pair of the at least two wires being made of a first material and / or having first shape with each member positioned at the same height in the height direction (Y) while at the same time having a second pair of the at least two wires being made of a second material and / or having a second shape with each member positioned at the same height in the height direction (Y), it is possible to improve control of the bending properties of a synthetic spacer profile.

[0039] When there is a first pair of the at least two wires and a second pair of the at least two wires, then preferably the thermal expansion coefficient of the first pair differs from the thermal expansion coefficient of the second pair with no more than 40%, preferably no more than 30% and even more preferred no more than 20%. In a particularly preferred embodiment, they are the same.

[0040] In another preferred embodiment with a first pair of the at least two wires and a second pair of the at least two wires, then the thermal expansion coefficient of the first pair differs from the thermal expansion coefficient of the second pair with at least 5%, preferably at least 15% and even more preferred at least with 20%.

[0041] Preferably, the pair of the at least two wires with the highest thermal expansion coefficient is positioned closer to the outer wall than the pair with the lowest thermal expansion coefficient. The advantage of such a positioning is that the wires support the bending process when heat is used leading to less wrinkle formation during bending.

[0042] Preferably, the synthetic materials are selected from synthetic materials with a heat conductivity below 0.3 W / (m K), more preferred are materials with a heat conductivity below 0.2 W / (m K) and most preferred are synthetic material with a heat conductivity below 0.15 W / (m K). It is to be understood that the heat conductivity is for the synthetic material before fillers are added i.e. for the synthetic material as such.

[0043] Examples of synthetic materials with a heat conductivity below 0.2 W / (m K) are polypropylene (PP) and Polyethylene terephtalate (PET). For instance PVC has a heat conductivity around 0.17 W / (m K), SAN has a heat conductivity around 0.15 W / (m K); PP has a heat conductivity around 0.19 W / (m K). When e.g. 35% mineral fillers are added to PP, its heat conductivity increases to approximately 0.5 W / (m K).

[0044] The values for the heat conductivity is measured at 25°C using the classical steady state method (SS).

[0045] In a preferred embodiment, the at least two wires are positioned in the inner wall and the distance between them is at least 40% of the height h of the sidewalls. Preferably, the distance between them is at least 50% of the height h of the sidewalls and most preferred at least 60% of the height h of the sidewalls

[0046] In a preferred embodiment, no wire is closer to another wire than 40% of the height of the sidewall, preferably no wire is closer to another wire than 50% of the height h of the sidewalls and most preferred no wire is closer to another wire 60% of the height h of the sidewalls.

[0047] In a preferred embodiment, there are four wires, and the four wires are positioned such that no wire is closer to another one of the four that 40% of the height of the sidewall - preferably not less than 60% of the height of the side wall, and most preferred not less than 80% of the side wall.

[0048] The advantage of such a distribution is that no portion of the spacer body has an elongation different than the other.

[0049] Additional wires can be present and provide additional support, and those additional wires are allowed to be closer to other wires than the primary and secondary.

[0050] In another aspect of the invention, it relates to a spacer profile of any of the above described kind, where the inner wall comprises at least one groove positioned on the side of the inner wall facing away from the chamber.

[0051] The advantage of having at least one groove positioned on the side of the inner wall facing away from the chamber is that it forms a flexible zone at a predetermined spot that can absorb the forces from the pumping actions of the panes caused by wind and sun.

[0052] In a preferred embodiment, the at least one groove positioned on the side of the inner wall facing away from the chamber is in the form of either a pair of grooves consisting of a first grove and a second groove, or alternatively it is in the form of a central groove overlapping the middle of the inner wall.

[0053] In a particularly preferred embodiment, the inner wall comprises at least one groove positioned on the side of the inner wall facing away from the chamber being in the form of a pair of grooves consisting of a first grove and a second groove, and the inner wall further comprises a central groove positioned on the side of the inner wall facing towards the chamber and overlapping the middle of the inner wall. The central groove is positioned between the first groove and the second groove. This combination is particularly good for absorbing pumping action and it can be used in all spacers profiles with a spacer body made of a synthetic material.

[0054] Suitable diffusion barriers for the invention is known by the person skilled in the art. The diffusion barrier can be made of metal or it can be made of a polymeric material. The diffusion barrier can be a single sheet, or it can be of multiple overlapping sheets. Preferably, there is at least one sheet made of a polymeric material.

[0055] Suitable polymeric diffusion barriers are made of materials such as ethylene-vinyl-alco- hol copolymers (EVOH).

[0056] Another suitable polymer-based diffusion barrier is made of polyethylene (PE) or polyethylene terephthalate (PET) preferably sputtered with a SiOx material where 0 < X < 2.

[0057] A particularly preferred diffusion barrier is in the form of a multilayer foil having as its outer most layer a layer of polymeric material having a roughness Ra of at least 0.25 pm, preferably at least 0.30 pm, more preferably at least 0.35 pm and even more preferred at least 0.40 pm and most preferred at least 0.7 pm. Preferably, said outermost layer is a TCA treated PET layer.

[0058] List of figures

[0059] Figure 1 is an illustration of a spacer profile with two wires. Figure 2 is an illustration of a spacer profile with four wires.

[0060] Figure 3 is an illustration of suitable shapes of wires.

[0061] Figure 4a is an overview of other commercially available wires.

[0062] Figure 4b is a continuation of the overview of other commercially available wires.

[0063] Figure 5 is an illustration of a spacer profile with a pair of wires with a first shape and a second pair of wires of a second shape.

[0064] Figure 6 is an illustration of the spacer in figure 5 with alternatively shaped wires.

[0065] Figure 7 is an illustration of a spacer profile with a pair of wires with a first shape and a second pair of wires of a second shape and a pair of groves.

[0066] Figure 8 is an illustration of a spacer profile with a pair of wires with a first shape and a second pair of wires of a second shape and a groove.

[0067] Figure 9 is an illustration of a spacer profile with a pair of wires with a first shape and a second pair of wires of a second shape with three grooves.

[0068] Figure 10 is an illustration of the pumping action of an IGU unit.

[0069] Figures 11A-C illustrate the position of the centre of gravity for different wires.

[0070] Figure 12 is an illustration of a spacer with four wires and marked areas being enlarged in other figures.

[0071] Figure 13 is an illustration of an enlarged connection wall showing the connection line between the connection wall and the outer surface.

[0072] Figure 14 is an illustration of an enlarged connection wall showing the centre of gravity of the wire being close to the connection line.

[0073] Figure 15 is an illustration of an enlarged connection wall showing the position of a centre of gravity of the wire being too far away from the connection line.

[0074] Figure 16 is an illustration of the corner section.

[0075] Figure 17 is an illustration of an enlarged corner section showing the position of a centre of gravity of the wire being inside the corner section.

[0076] Figure 18 is an illustration of an enlarged corner section showing the position of a centre of gravity of the wire being outside the corner section.

[0077] Figure 19 is an illustration of the various width and heights.

[0078] Detailed description

[0079] A spacer profile that is particularly suitable for both having a very low thermal conductivity while being mitigating the challenges during heat-assisted bending into a window frame being a spacer profile for use as part of a spacer profile frame, which is suitable for being mounted in and / or along an edged area of an insulating glazing unit so as to surround an intervening space between glazing panes, the spacer profile comprising a spacer body extending in a longitudinal direction (Z), said spacer body comprising: an inner wall facing the intervening space between and extending in a transverse direction (X), an outer wall separated from the inner wall by a first distance d1 , two side walls having a height h and extending in a height direction (Y) and separated by a second distance d2, two connection walls extending between the side walls and the outer wall,

[0080] - where the inner wall, the two side walls, the two connection walls and the outer wall define a chamber suitable for desiccants, the spacer profile further comprises: a first pair of wires made of a first material and / or having first shape with each member of said first pair positioned at the same height in the height direction (Y), a second pair of wires second pair wires being made of a second material and / or having a second shape with each member of said second pair positioned at the same height in the height direction (Y) and a diffusion barrier provided at least on the outer wall, wherein the synthetic material is selected from synthetic materials with a heat conductivity below 0.4 W / (m K) measured at 25°C and that the synthetic material comprises from 20 - 40 weight% fillers.

[0081] In this version of the spacer profile, it is preferred that the second material is different from the first material and / or the second shape is different from the first shape.

[0082] Preferably, the first pair has a thermal expansion coefficient which differs from the thermal expansion coefficient of the second pair with no more than 40%, preferably no more than 30% and even more preferred no more than 20%. In a particularly preferred embodiment, they are the same.

[0083] In another preferred embodiment the first pair has a thermal expansion coefficient which differs from the thermal expansion coefficient of the second pair with at least 5%, preferably at least 15% and even more preferred at least with 20%.

[0084] Preferably, the pair of the first pair and the second pair being positioned closest to the outer wall has the largest thermal expansion coefficient. In an aspect that is suitable to minimize the amount of fillers and the amount of material needed for the wire is the embodiment where there is provided a cold-bendable spacer profile for use as part of a spacer profile frame, which is suitable for being mounted in and / or along an edged area of an insulating glazing unit so as to surround an intervening space between glazing panes, the spacer profile comprising a spacer body made of polypropylene and extending in a longitudinal direction (Z), said spacer body comprising: an inner wall having a width w1 and facing the intervening space between and extending in a transverse direction (X), an outer wall separated from the inner wall by a first distance d1 , a first side wall and a second side wall having a height h, a width w2 and extending in a height direction (Y) and separated by a second distance d2, a first connection wall extending between the first side wall and the outer wall, a second connection wall extending between the second side wall and the outer wall,

[0085] - where the inner wall, the first side wall, the second side wall, the first connection wall, the second connection wall and the outer wall define a chamber suitable for desiccants, and

[0086] - where the inner wall has a first corner section defined by the width w1 of the inner wall and the width w2 of the first side wall,

[0087] - where the inner wall has a second corner section defined by the width w1 of the inner wall and the width w2 of the second side wall, the spacer profile further comprises at least four wires and a diffusion barrier provided at least on the outer wall said diffusion barrier comprising a polymeric material and said at least four wires comprising a first wire, a second wire, a third wire and a fourth wire each wire having a centre of gravity, wherein the centre of gravity of the first wire is positioned in the first corner section, the centre of gravity of the second wire is positioned second corner section, the centre of gravity of the third wire is positioned at a distance de from a first contact line between the first connection wall and the outer wall, said distance de being no more than 2 mm the centre of gravity of the fourth wire is positioned at a distance ds from a second contact line between the second connection wall and the outer wall, said distance ds being no more than 2 mm, and wherein the polypropylene comprises between 5 - 30 weight% fillers. In a preferred embodiment, the distance from the first contact line and the distance from the second contact line is no more than 1 mm respectively and most preferred no more than 0.5 mm.

[0088] The distance of the centre of gravity of the third wire to the first contact line and the distance to the centre of gravity of the fourth wire to the second contact line can be identical, but they can also be different. In certain variants of the spacer, the centre of gravity can also be positioned on opposite sides of the contact lines, i.e. one of the centres of gravity is located towards the outer wall while the other centre of gravity is located towards the side wall.

[0089] In a certain aspect, the invention relates to a spacer profile for use as part of a spacer profile frame, which is suitable for being mounted in and / or along an edged area of an insulating glazing unit so as to surround an intervening space between glazing panes, the spacer profile comprising a spacer body extending in a longitudinal direction (Z), said spacer body comprising: an inner wall facing the intervening space between and extending in a transverse direction (X), an outer wall separated from the inner wall by a first distance d1 , two side walls having a height h and extending in a height direction (Y) and separated by a second distance d2, two connection walls extending between the side walls and the outer wall,

[0090] - where the inner wall, the two side walls, the two connection walls and the outer wall define a chamber suitable for desiccants, the spacer profile further comprises: a first pair of wires made of a first material and / or having first shape with each member of said first pair positioned at the same height in the height direction (Y), a second pair of wires second pair wires being made of a second material and / or having a second shape with each member of said second pair positioned at the same height in the height direction (Y) and a diffusion barrier provided at least on the outer wall, wherein the synthetic material is selected from synthetic materials with a heat conductivity below 0.4 W / (m K) measured at 25°C and that the synthetic material comprises from 20 - 40 weight% fillers, where the one of the first pair and the second pair, which is positioned closest to the outer wall, has a thermal expansion coefficient that is larger than the one being closer to the inner wall. The advantage of this arrangement of thermal expansion coefficients is that the heat- assisted bending is supported by the materials of the spacer profile.

[0091] Suitable diffusion barriers for those embodiments are still diffusion barrier which can be made of metal or it can be made of a polymeric material. The diffusion barrier can be a single sheet, or it can be of multiple overlapping sheets. Preferably, there is at least one sheet made of a polymeric material.

[0092] Suitable polymeric diffusion barriers for all embodiments are made of materials such as ethylene-vinyl-alcohol copolymers (EVOH).

[0093] Another suitable polymer-based diffusion barrier is made of polyethylene (PE) or polyethylene terephthalate (PET) preferably sputtered with a SiOx material where 0 < X < 2.

[0094] A particularly preferred diffusion barrier is in the form of a multilayer foil having as its outer most layer a layer of polymeric material having a roughness Ra of at least 0.25 pm, preferably at least 0.30 pm, more preferably at least 0.35 pm and even more preferred at least 0.40 pm and most preferred at least 0.7 pm. Preferably, said outermost layer is a TCA-treated PET layer.

[0095] The advantage of a foil with the outermost layers having the above specified roughness is that the spacer profile is compatible with almost all sealing materials both primary and secondary sealing materials as is known by the person skilled in the art.

[0096] The invention will be described in further detail with reference to the figures.

[0097] In figure 1 , a spacer profile 1 suitable for the invention is illustrated. The spacer profile 1 comprises a spacer body 10, where the spacer body comprises an inner wall 11 and an outer wall 12 being separated from the inner wall 11 by a first distance d! When mounted between the panes in an IG unit, the inner wall is facing towards the interior of the IG unit, i.e. the intervening space formed between the panes and the spacer. The spacer body in figure 1 further comprises a first sidewall 13 and a second sidewall 14. The sidewalls 13, 14 can be parallel to each other, or they can be slightly slanted. The first sidewall 13 is separated from the second sidewall 14 by a second distance d2. In figure 2, the inner wall and the outer wall are illustrated as being parallel, but that does not have to be the case. Solutions exist, where the inner wall and the outer wall are separated by a first distance d1 , and where they are slanted, curved etc. relative to each other. A first connection element 15 and a second connection element 16 connect the sidewall with the outer wall 12. The inner wall 11 , the outer wall 12, the first sidewall 13, the second side wall 14, the first connection element 15, the second connection element 16 and the outer wall 12 define a chamber 50, the chamber being suitable for containing a desiccant. The spacer profile 1 further comprises as first wire 21 and a second wire 22 being positioned in the corners between the inner wall 11 and the sidewalls 13, 14, one in each corner.

[0098] The position is only for illustrative purposes; the first wire 21 and the second wire 22 could be at alternative positions. Preferably, the first wire 21 and the second wire 22 are positioned at the same height position, one at each side.

[0099] A diffusion barrier 50 is provided at least on the outer wall. The diffusion barrier can be extended up on the outer side on the sidewalls 13, 14.

[0100] Figure 2 illustrates the spacer profile in figure 1 but with a third wire and fourth wire. The third wire 23 and the fourth wire 24 are positioned in the first and second connection element, respectively. The position of the third wire and the fourth wire can be at alternative positions, preferably they are positioned at the same height position in the height direction (Y) and one at each side. In a preferred embodiment, where the wires 21 and

[0101] 22 constitute a first pair of wires, and as can be seen in the figure, they are positioned at the same height. The wires 23 and 24 constitute a second pair of wires, and the wires

[0102] 23 and 24 are also positioned at the same height but at a different height than the wires 21 and 22.

[0103] Optionally, the spacer profile can comprise additional reinforcement elements (not shown) such as a third and a fourth reinforcement element in the form of a wire.

[0104] Figure 3 illustrates four common shapes of wires that are particularly suited for the invention. The shapes are a squared wire 30, a hexagonal wire 31 , a flattened wire 32 and a round wire 33. The round wire 33 does not have to have a circular cross section, oval and ellipsoidal cross sections will also work. Figure 4a and b illustrate various shape of commercially available wires which can be bought from e.g. Alloy Wire International. The walls of the channel-shaped wire can have 90 degree angles as shown, but they can also have angles between 45 and 150 degrees, especially angles between 110 and 150 degrees are preferred. In such a configuration, the walls open outwardly so that the wires fit with e.g. a connection wall as illustrated in figure 6.

[0105] Figure 5 illustrates a version of the spacer profile 1 that comprises a spacer body 10, where the spacer body comprises an inner wall 11 and an outer wall 12 being separated from the inner wall 11 by a first distance d1. When mounted between the panes in an IG unit, the inner wall is facing towards the interior of the IG unit, i.e. the intervening space formed between the panes and the spacer. The spacer body in figure 1 further comprises a first sidewall 13 and a second sidewall 14. The sidewalls 13, 14 can be parallel to each other, or they can be slightly slanted. The first sidewall 13 is separated from the second sidewall 14 by a second distance d2. In figure 2, the inner wall and the outer wall are illustrated as being parallel, but that does not have to be the case. Solutions exist, where the inner wall and the outer wall are separated by a first distance d1 , and where they are slanted, curved etc. relative to each other. A first connection element 15 and a second connection element 16 connect the sidewall with the outer wall 12. The inner wall 11 , the outer wall 12, the first sidewall 13, the second side wall 14, the first connection element 15, the second connection element 16 and the outer wall 12 define a chamber 50, the chamber being suitable for containing a desiccant. A diffusion barrier 50 is provided at least on the outer wall. The diffusion barrier can be extended up on the outer side on the sidewalls 13, 14.

[0106] The spacer profile 1 further comprises a first pair of wires consisting of a first wire 21 and a second wire 22. The wires being positioned in the corners between the inner wall 11 and the sidewalls 13, 14, one in each corner and they are positioned at the same height. In the illustrated embodiment the wires are of squared shape.

[0107] The spacer profile 1 further comprises a second pair of wires consisting of a third wire 23 and a fourth wire 24. The third wire 23 and the fourth 24 wire are positioned in the first and second connection element, respectively, and they are positioned at the same height. The second pair of wires could also have been positioned in the lower part of the sidewall 13, 14 or in the outer wall 12. In the illustrated embodiment, the wires of the second pair are of a round shape. The wires can be made of different materials as well. The advantage of having different shape and / or materials for the pair of wires is that the thermal expansion of the spacer profile can be controlled e.g. by having a portion with a larger thermal expansion coefficient than a different portion. Alternatively, the wires can be adjusted so that the wires compensate for the contribution to thermal expansion from e.g. a diffusion barrier. In case of a diffusion barrier made of metal or a synthetic material limiting the thermal expansion of the outer wall, different shapes of the wires can compensate for that so as to obtain a spacer profile with roughly the same thermal expansion coefficient in all regions.

[0108] Figure 6 illustrates a spacer profile 1 of the kind described for figure 5 above, where the first pair of wires consists of a first wire 21 and a second wire 22 being of angled shape, and where a second pair of wires consists of a third wire 23 and a fourth wire 24 being of channel shape, where the angles are roughly 135 degrees. The position of the wires are as described for figure 5.

[0109] Figure 7 illustrates a spacer profile 1 comprising a first pair of wires consisting of a first wire 21 and a second wire 22 being of a first shape and a second pair of wires consisting of a third wire 23 and a fourth wire 24 being of a second shape. The inner wall 11 of the spacer body comprises a first groove 81 and a second groove 82 both positioned on the side of the inner wall 11 facing away from the chamber 70.

[0110] Figure 8 illustrates a spacer profile 1 comprising a first pair of wires consisting of a first wire 21 and a second wire 22 being of a first shape and a second pair of wires consisting of a third wire 23 and a fourth wire 24 being of a second shape. The inner wall 11 of the spacer body comprises a central groove 83 positioned on the side of the inner wall 11 facing away from the chamber 70. The groove in figure 8 is positioned essentially at the middle of the inner wall 1 . It does not have to be exactly at the middle, but a part of the central groove 83 overlaps with the middle of the inner wall 11.

[0111] Figure 9 illustrates a spacer profile 1 , where the spacer body 10 comprises a particularly preferred combination of grooves. This combination of grooves, though being illustrated for the spacer profiles described in figure 5, it can be used with all the spacer profiles described in this application. The spacer body 10 comprises a pair of grooves consisting of a first groove 81 and a second groove 82. The first pair of grooves is positioned in the inner wall 11 on the side facing away from the chamber 70. The spacer body 11 further comprises a central groove 83 positioned between the first groove 81 and the second groove 82 and on the side of the inner wall 11 facing towards the chamber 70. It is to be understood that e central groove 83 can have an overlap with the first groove 81 and the second groove 82, respectively. This combination is particularly suited for IGU, where a large pumping action can be expected. When the panes of the IGU pump, then the grooves provide flexible zones that can absorb the pumping action so that the life span of the spacer profile 1 is increased. Without the grooves, the other parts of the spacer body has to absorb the pumping forces, and this can lead to wear in undesired zones of the spacer profile 1.

[0112] Figure 10 illustrates the pumping action of an IGU. On the left side of the spacer profile 1 , the primary sealant 90 and a single window pane 91 are shown. When the wind blows and / or the IGU is exposed to heat from the sun, the panes 91 will move as illustrated by the arrow. This movement of the panes causes stress on the spacer body 10. By absorbing this stress in certain predetermined zones, the life span of the spacer profiles can be increased, and the tightness of the sealing provided by the primary sealant 90 is improved.

[0113] Figures 11 A-C illustrate that given that the spacer profile is identical along the Z axis, the centre of gravity can be looked on in two dimensions. For instance the centre of gravity for a wire having a circular cross section is at the centre of the circle.

[0114] In the figures 11A-11 C, there is illustrated couple of wires with different shapes and their centre of gravity. In figure 11A, a wire with a circular cross section 201 is illustrated. The centre of gravity for such a wire is at the centre of the wire. In figure 11 B, a rectangular shape wire 202 is illustrated with the centre of gravity being positioned where the two diagonals cross each other. In figure 11C, a wire with two legs 203 having an angle between them is illustrated. There is can be seen that the centre of gravity is actually located outside the material. The inventor has found that it is the position of the centre of gravity that has importance when the elongation of the spacer profile is to be controlled.

[0115] Figure 12 illustrates the spacer profile of figure 5, where the circles marked with A and B, respectively, are the areas that are expanded in the following figures.

[0116] Figure 13 is an illustration of the expanded area A of figure 12, and it illustrates the second contact line 175 between the second connection wall 16 and the outer wall 12. In this illustration, the second contact line 175 runs from the outer contact corner between the second connection wall 16 and the outer wall 12 to the inner Conner between the same two walls. In case there is a rounded corner, the second contact line 175 runs from the middle point of the rounded part to the middle point of the other rounded part or to the corner in case there is a rounded corner and a sharp corner.

[0117] Figure 14 is an illustration of the expanded area A of figure 12, where is can be seen that the fourth wire 24 has a centre of gravity 200 that is positioned at a distance ds being no more than 2 mm from the second contact line 175.

[0118] Figure 15 is an illustration of the expanded area A of figure 12, where the fourth wire 24 is positioned differently. The result is that the centre of gravity 200 is positioned at a distance ds being more than 2 mm from the second contact line 175 and hence not a part of the invention.

[0119] Figure 16 is an illustration of the corner section 150 of the spacer profile.

[0120] Figure 17 is an illustration of the expanded area B of figure 12. There it can be seen that the centre of gravity of the fourth wire is positioned in the second corner section 150.

[0121] Figure 18 is an illustration of the expanded area B of figure 12. There the fourth wire is replaced with a wire of a different shape. This results in the centre of gravity being positioned in the chamber and not in the second corner, i.e. the spacer profile is not in accordance with the invention.

[0122] Figure 19 is an illustration where distances, heights and width are illustrated. It can be seen that the outer wall is separated from the inner wall by a first distance di and that the first side wall and the second side wall are separated by a second distance d2. The inner wall has a first width wi and the side walls have a height h and a second width W2. Though being illustrated as having the same width, it is to be understood that the side walls can have different thicknesses. The first width wi and the second width W2 of the first side wall define a first corner region 149. The first width wi and the second width W2 of the second side wall define a second corner region 150. The first connection wall and the outer wall meet each other at a first contact line 174, and the second connection wall and the outer wall meet each other at a second contact line 175. The following distances are illustrated; da is the distance from the inner surface of the inner wall, d4 is the distance from the outer surface of the sidewall, d5is the distance from the first contact line, and d6is the distance from the second contact line.

[0123] Reference numbers

[0124] I spacer profile

[0125] 10 spacer body

[0126] I I inner wall

[0127] 12 outer wall

[0128] 13 first side wall

[0129] 14 second side wall

[0130] 15 first connection wall

[0131] 16 second connection wall

[0132] 21 first wire

[0133] 22 second wire

[0134] 23 third wire

[0135] 24 fourth wire

[0136] 50 barrier

[0137] 70 chamber

[0138] 81 first groove

[0139] 82 second groove

[0140] 83 central groove

[0141] 90 primary sealant

[0142] 91 window pane

[0143] 149 first corner section

[0144] 150 second corner section

[0145] 174 first connection line

[0146] 175 second connection line

[0147] 200 centre of gravity

[0148] 201 round wire

[0149] 202 rectangular wire

[0150] 203 wire with two legs

[0151] A expanded area with corner section

[0152] B expanded area with a contact line d1 distance between inner wall and outer wall d2 distance between the side walls d3 distance from inner surface d4 distance from the outer surface of the side wall d5 distance from the first contact line d6 distance from the second contact line w1 width of the inner wall w2 width of the side wall h height of the side wall

Claims

Claims1. A cold-bendable spacer profile (1) for use as part of a spacer profile frame, which is suitable for being mounted in and / or along an edged area of an insulating glazing unit so as to surround an intervening space between glazing panes, the spacer profile comprising a spacer body (10) made of polypropylene and extending in a longitudinal direction (Z), said spacer body (10) comprising: an inner wall (11) having a width w1 and facing the intervening space between and extending in a transverse direction (X), an outer wall (12) separated from the inner wall by a first distance d1 , a first side wall (13) and a second side wall (14) having a height h, a width w2 and extending in a height direction (Y) and separated by a second distance d2, a first connection wall (15) extending between the first side wall (13) and the outer wall (12), a second connection wall (16) extending between the second side wall (14) and the outer wall (12),- where the inner wall (11), the first side wall (13), the second side wall (14), the first connection wall (15), the second connection wall (16) and the outer wall (12) define a chamber (70) suitable for desiccants, and- where the inner wall (11) has a first corner section (149) defined by the width w1 of the inner wall (11) and the width w2 of the first side wall (13),- where the inner wall has a second corner section (150) defined by the width w1 of the inner wall (11) and the width w2 of the second side wall (14) the spacer profile further comprises at least four wires and a diffusion barrier (50) provided at least on the outer wall (12), said diffusion barrier comprising a polymeric material and said at least four wires comprising a first wire (21), a second wire (22), a third wire (23) and a fourth wire (24) each wire having a centre of gravity, wherein the centre of gravity (200) of the first wire (21) is positioned in the first corner section (149), the centre of gravity of the second wire (22) is positioned second corner section (150), the centre of gravity of the third wire (23) is positioned at a distance de from a first contact line (174) between the first connection wall (15) and the outer wall (12), said distance de being no more than 2 mm,the centre of gravity of the fourth wire (24) is positioned at a distance d5from a second contact line (175) between the second connection wall (16) and the outer wall (12), said distance d5being no more than 2 mm, and wherein the polypropylene comprises between 5 - 30 weight% fillers2. A spacer profile according to claim 1 , wherein the distance ds and the distance de are no more than 0.5 mm respectively.

3. A spacer profile according to claim 1 or 2, wherein the diffusion barrier is a TCA treated foil.

4. A spacer profile according to any one of the preceding claims, wherein the polypropylene comprises between 7 and 9 weight% fillers.

5. A spacer profile according to any one of the preceding claims, wherein the wires are made of stainless steel, galvanized steel, aluminium or mixtures thereof.

6. A spacer profile according to any one of the preceding claims, wherein the diffusion barrier (50) comprises a layer of polyethylene terephthalate (PET) sputtered with a SiOx material where 0 < X < 2.

7. A spacer profile according to any one of the preceding claims, wherein the diffusion barrier (50) is in the form of a multilayer foil having as its outer most layer a layer of polymeric material having a roughness Ra of at least 0.25 pm.

8. A spacer profile according to any one of the preceding claims, wherein the centre of gravity of the second wire (22) is positioned as a distance da from the inner wall (11) being no more than 2 mm and a distance d4 from the second side wall (14) being no more than 2 mm.

9. A spacer profile according to any one of the preceding claims, wherein the at least four wires comprise wires of at least two different shapes.

10. A spacer profile according to any one of the preceding claims, wherein the inner wall (11) comprises at least one groove (81 , 82, 83) positioned in the inner wall 11 on the side facing away from the chamber (70).

11. A spacer profile according to claim 10, wherein the at least one groove is either a pair of grooves consisting of a first grove (81) and a second groove (82), or is in form of a central groove (83) overlapping the middle of the inner wall.

12. A spacer profile according to any one of claims 1 - 9, wherein the inner wall (11) comprises a pair of grooves consisting of a first grove (81) and a second groove (82) positioned in the inner wall 11 on the side facing away from the chamber (70); and a central groove (83) positioned in the inner wall 11 on the side facing towards the chamber (70) said central groove (83) being positioned between the first groove (81) and the second groove (82).

13. A spacer profile according to any one of claims 1-10, wherein the diffusion barrier is provided on both the outer wall and at least partially on the two side walls.

14. Use of a spacer profile according to any one of claims 1-13 in window frames to IGU units.

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