Abstract
An insulating glass unit suitable for a refrigeration unit is presented. The insulating glass unit includes a first pane, a second pane spaced at a distance from the first pane, a peripheral spacer frame between the first pane and the second pane, and an inner interpane space. According to one aspect, the spacer frame includes four hollow-profile polymeric spacers, which are secured between the first pane and the second pane along one of the four sides of the insulating glass. According to another aspect, the two first hollow-profile polymeric spacers are arranged along two opposing first sides of the insulating glass unit and the two second hollow-profile polymeric spacers are arranged along two opposing second sides of the insulating glass unit. According to yet another aspect, the first polymeric hollow-profile spacers contain 5% to 50% and the second polymeric hollow-profile spacers contain 0% to 0.5% reinforcement fibers.
Claims
1. An insulating glass unit for a refrigeration unit, comprising: a first pane; a second pane spaced at a distance from the first pane; a peripheral spacer frame arranged between the first pane and the second pane; and an inner interpane space, the inner interpane space delimited by the peripheral spacer frame, the first pane and the second pane, wherein the peripheral spacer frame comprises four hollow-profile polymeric spacers, each of the four hollow-profile polymeric spacers secured between the first pane and the second pane along one of four sides of the insulating glass unit via a primary sealant, first two of the four hollow-profile polymeric spacers arranged along two opposing first sides of the insulating glass unit, and second two of the four hollow-profile polymeric spacers arranged along two opposing second sides of the insulating glass unit, the first two of the four hollow-profile polymeric spacers include 5% to 50% reinforcement fibers, the second two of the four hollow-profile polymeric spacers include 0% to 0.5% reinforcement fibers, the second two hollow-profile polymeric spacers include on their outer wall a gas-tight and vapor-tight transparent barrier, wherein the transparent barrier is in the form of a transparent barrier film or a transparent barrier coating, and the transparent barrier film is a multilayer film, the multilayer film comprising at least one polymeric layer and at least one ceramic layer.
2. The insulating glass unit according to claim 1, wherein the second two of the four hollow-profile polymeric spacers are implemented transparent.
3. The insulating glass unit according to claim 1, wherein the hollow-profile polymeric spacers include one polymeric main body, the polymeric main body comprising: a first side wall; a second side wall arranged parallel to the first side wall; a glazing interior wall arranged perpendicular to the first and second side walls, wherein the glazing interior wall connects the first and second side walls to one another; an outer wall, the outer wall arranged substantially parallel to the glazing interior wall, wherein the outer wall connects the first and second side walls to one another; and a cavity, the cavity enclosed by the first and second side walls, the glazing interior wall, and the outer wall, wherein the cavity delimited by the first two of the four hollow-profile polymeric spacers contains a desiccant and the cavity delimited by the second two of the four hollow-profile polymeric spacers contains no desiccant.
4. The insulating glass unit according to claim 1, wherein the first two hollow-profile polymeric spacers include, as reinforcement fibers, 15% to 40% glass fibers.
5. The insulating glass unit according to claim 1, wherein the first two hollow-profile polymeric spacers include, as reinforcement fibers, 20% to 35% glass fibers.
6. The insulating glass unit according to claim 1, wherein the compressive strength of the second two hollow-profile polymeric spacers is lower by 20% to 40% than that of the first two hollow-profile polymeric spacers.
7. The insulating glass unit for a refrigeration unit according to claim 1, wherein the first two hollow-profile polymeric spacers and the second two hollow-profile polymeric spacers are secured on the first pane and the second pane via a transparent primary sealant, and wherein the outer interpane space facing the external surroundings is filled with a transparent secondary sealant.
8. The insulating glass unit according to claim 1, wherein the multilayer film includes one polymeric layer and two ceramic layers, the two ceramic layers arranged alternatingly with the one polymeric layer.
9. A door for a refrigeration unit, comprising: i) an insulating glass unit comprising: a first pane; a second pane spaced at a distance from the first pane; a peripheral spacer frame arranged between the first pane and the second pane; and an inner interpane space, the inner interpane space delimited by the peripheral spacer frame, the first pane and the second pane, wherein the peripheral spacer frame comprises four hollow-profile polymeric spacers, each of the four hollow-profile polymeric spacers secured between the first pane and the second pane along one of four sides of the insulating glass unit via a primary sealant, first two of the four hollow-profile polymeric spacers arranged along two opposing first sides of the insulating glass unit, and second two of the four hollow-profile polymeric spacers arranged along two opposing second sides of the insulating glass unit, the first two of the four hollow-profile polymeric spacers include 5% to 50% reinforcement fibers, and the second two of the four hollow-profile polymeric spacers include 0% to 0.5% reinforcement fibers; and ii) two horizontal frame elements, wherein the horizontal frame elements are arranged along the first sides of the insulating glass unit such that the first two hollow-profile polymeric spacers are concealed, the second two hollow-profile polymeric spacers are implemented transparent, the second two hollow-profile polymeric spacers are secured via a transparent primary sealant, and a transparent secondary sealant is arranged along the second sides of the insulating glass unit in the outer interpane space.
10. A method for producing an insulating glass unit for a refrigeration unit, the insulating glass unit comprising: a first pane; a second pane spaced at a distance from the first pane; a peripheral spacer frame arranged between the first pane and the second pane; and an inner interpane space, the inner interpane space delimited by the peripheral spacer frame, the first pane and the second pane, wherein the peripheral spacer frame comprises four hollow-profile polymeric spacers, each of the four hollow-profile polymeric spacers secured between the first pane and the second pane along one of four sides of the insulating glass unit via a primary sealant, first two of the four hollow-profile polymeric spacers arranged along two opposing first sides of the insulating glass unit, and second two of the four hollow-profile polymeric spacers arranged along two opposing second sides of the insulating glass unit, the first two of the four hollow-profile polymeric spacers include 5% to 50% reinforcement fibers, the second two of the four hollow-profile polymeric spacers include 0% to 0.5% reinforcement fibers, the second two hollow-profile polymeric spacers include on their outer wall a gas-tight and vapor-tight transparent barrier, wherein the transparent barrier is in the form of a transparent barrier film or a transparent barrier coating, and the transparent barrier film is a multilayer film, the multilayer film comprising at least one polymeric layer and at least one ceramic layer, the method comprising: mounting the first pane and the second pane on the peripheral spacer frame via the primary sealant, wherein the inner interpane space and an outer interpane space are created; and filling the outer interpane space with a secondary sealant, wherein a transparent primary sealant and a transparent secondary sealant are applied along the two opposing first sides.
Description
(1) The invention is explained in detail in the following with reference to drawings. The drawings are purely schematic representations and are not true to scale. They in no way restrict the invention. They depict:
(2) FIG. 1 a cross-section through an insulating glass unit according to the invention through the plane of the spacer frame,
(3) FIG. 2 a plan view of a possible embodiment of a door according to the invention for a refrigeration unit,
(4) FIG. 3 a cross-section through an insulating glass unit according to the invention in the edge region,
(5) FIG. 4 a perspective cross-section through a polymeric hollow-profile spacer for an insulating glass unit according to the invention,
(6) FIG. 5 a cross-section through a suitable transparent barrier film,
(7) FIG. 6 a cross-section through another suitable transparent barrier film,
(8) FIG. 7 a perspective cross-section through a polymeric hollow-profile spacer.
(9) FIG. 1 depicts a schematic cross-section through an insulating glass unit according to the invention through the plane of the spacer frame. The insulating glass unit I has a first pane 11 and a parallel and congruently arranged second pane 12 (seen in FIG. 3). A peripheral spacer frame 10 that delimits an inner interpane space 8 is arranged between the first pane 11 and the second pane 12. The spacer frame 10 comprises four hollow-profile polymeric spacers 13.1, 13.2, 13.3, and 13.4, which are in each case arranged along one of the four sides 14.1, 14.2, 14.3, and 14.4 of the insulating glass unit I. The four polymeric hollow-profile spacers 13.1, 13.2, 13.3, and 13.4 are plugged together at the corners of the insulating glass unit by corner connector 25. Connecting by plug-in connectors has the advantage that it is possible to easily combine different types of hollow-profile spacers with one another in a spacer frame 10. Also, the corner connectors 25 can be implemented such that with filling of one of the four hollow-profile spacers with a desiccant 21, the desiccant 21 is prevented from penetrating into the next hollow-profile spacer. The insulating glass unit I is implemented rectangular and has two opposing first sides 14.1, 14.2 and two opposing second sides 14.3 and 14.4. Two first hollow-profile polymeric spacers 13.1 and 13.2 are mounted along the two first sides 14.1 and 14.2. Two second hollow-profile polymeric spacers 13.3 and 13.4 are arranged along the two second sides. The two first polymeric hollow-profile spacers 13.1 and 13.2 are hollow-profile polymeric spacers according to the prior art with a polymeric main body 1 substantially made of styrene acrylonitrile (SAN) with 35% glass fibers as reinforcement fibers. These reinforcement fibers increase the mechanical stability of the polymeric hollow-profile spacer and have proven themselves as reinforcement fibers for polymeric spacers. The first polymeric hollow-profile spacers 13.1 and 13.2 are provided, on the outer wall, with a gas- and vapor-tight barrier, which seals the inner interpane space. Suitable for this is, for example, a multilayer film comprising three layers made of polyethylene terephthalate (PET) with a thickness in each case of 12 m and two aluminum layers with a thickness in each case of 150 nm. The aluminum layers are alternatingly arranged with the PET layers. Openings 29 are made in the glazing interior surface 3 of the of the first polymeric hollow-profile spacer, via which openings any moisture present in the inner interpane space 8 can be absorbed by the molecular sieve that is filled as desiccant 21 into the cavity 5 of the first polymeric hollow-profile spacers 13.1 and 13.2. The second polymeric hollow-profile spacers 13.3 and 13.4 comprise a polymeric main body 1, which is made substantially of styrene acrylonitrile (SAN) and includes 0% reinforcement fibers. The absence of the reinforcement fibers results in hollow-profile spacers 13.3 and 13.4, which have lower mechanical stability than those with reinforcement fibers. Surprisingly, the stability of the entire insulating glass unit I is not adversely affected thereby and a stable insulating glass unit I is obtained. The second polymeric hollow-profile spacers 13.3 and 13.4 are implemented transparent and include no filling with desiccant. The filling of the two first polymeric hollow-profile spacers 13.1 and 13.2 suffices to absorb the moisture from the inner interpane space 8. The second polymeric hollow-profile spacers 13.3 and 13.4 include a transparent barrier film 6. The details of a suitable transparent barrier film 6 are depicted, for example, in FIG. 5. A transparent silicone is installed in the outer interpane space 7 as a transparent secondary sealant 28.1. The transparent silicone 28.1 is arranged peripherally such that no material incompatibilities between different secondary sealants occur. This embodiment is also simpler to realize in production than combining different secondary sealants 28. The transparent silicone along the second sides 14.3 and 14.4 in combination with the transparently implemented polymeric hollow-profile spacers 13.3 and 13.4 results in an insulating glass unit I with two sides 14.3 and 14.4, along which an unobstructed view of the items situated behind the insulating glass unit I is possible, even in the edge region. Thus, the insulating glass unit I has a maximal through-vision area. Only along the first sides 14.1 and 14.2 does an edge seal with the first polymeric hollow-profile spacers 13.1, 13.2, in each case, block the view through the edge region of the insulating glass unit I.
(10) FIG. 2 depicts a door II according to the invention for a refrigerator display case. The door II comprises two horizontal frame elements 30.1 and 30.2 and an insulating glass unit I, the structure of which is depicted schematically in cross-section in FIG. 1. The horizontal frame elements 30.1 and 30.2 are arranged along the first sides 14.1 and 14.2 of the insulating glass unit I. The two horizontal frame elements 30.1 and 30.2 obscure the view of the first polymeric hollow-profile spacers 13.1 and 13.2 and the edge seal with primary and secondary sealants. The corner connectors 25 are also hidden by the edge seal. The horizontal frame elements 30.1 and 30.2 are formed from a 0.3-mm-thick stainless steel sheet. The frame elements 30.1 and 30.2 increase the stability of the door II. The horizontal frame element 30.2, is at the top with vertical installation of the door II in a refrigerator display case or at the rear with horizontal installation in a freezer display case. The horizontal stainless steel sheet 30.2 wraps around the first and second panes 11 and 12 and thus protects the edges of the panes against damage. The horizontal frame element 30.1, which, after installation in a refrigerator display case, would be arranged at the bottom or, with installation in a freezer display case, would be arranged in the front, is structured exactly like the upper or rear frame element 30.2. The horizontal frame elements 30.1 and 30.2 are glued to the insulating glass unit I. Securing means, such as, for instance, hinges in the case of installation in a refrigerator display case, can be mounted on the horizontal frame elements 30.1 and 30.2 or rails in the case of use as a sliding door in a freezer display case. A door handle 31 that is glued onto the first pane 11 enables simple opening and closing of the door II. Thanks to the combination of first and second polymeric hollow-profile spacers, the insulating glass unit I is so stable that the forces acting on the insulating glass unit I during opening of the door II do not adversely affect the insulating glass unit I.
(11) FIG. 3 depicts a cross-section of an insulating glass unit I according to the invention in the edge region. The structure of the insulating glass unit I is, in principle, identical along all four sides. There are differences between the first and second polymeric hollow-profile spacers. The figure depicts a hollow-profile spacer filled with desiccant 21, which is arranged only along the first sides, as is depicted in FIG. 1. The description of the figure is generally not based on a particular polymeric hollow-profile spacer. The first pane 11 is connected to the first first side wall 2.1 of the polymeric hollow-profile spacers 13 via a transparent primary sealant 27.1, and the second pane 12 is mounted on the second side wall 2.2 via the transparent primary sealant 27.1. The transparent primary sealant 27.1 contains a transparent cross-linking polyisobutylene. The inner interpane space 8 is situated between the first pane 11 and the second pane 12 and is delimited by the glazing interior wall 3 of the spacer 13. The cavity 5 is, in the case of the first polymeric hollow-profile spacers 13.1 and 13.2, filled with a desiccant 21, for example, molecular sieve. The cavity 5 is connected to the inner interpane space 8 via openings in the glazing interior wall 29. A gas exchange occurs between the cavity 5 and the inner interpane space 8 through the openings 29, with the desiccant 21 absorbing the humidity from the inner interpane space 8. The first pane 11 and the second pane 12 protrude beyond the side walls 2.1 and 2.2 such that an outer interpane space 7 is created, which is situated between the first pane 11 and the second pane 12 and is delimited by the outer wall of the hollow-profile spacer 4. The outer interpane space 7 is filled with a transparent secondary sealant 28.1. The transparent secondary sealant 28.1 is, for example, a silicone. Silicones absorb the forces acting on the edge seal particularly well and thus contribute to high stability of the insulating glass unit I. The first pane 11 and the second pane 12 are made of soda lime glass with, in each case, a thickness of 3 mm.
(12) FIG. 4 depicts a cross-section of a polymeric hollow-profile spacer 13.1, 13.2 suitable for an insulating glass unit I according to the invention. The polymeric hollow-profile spacer 13 comprises a polymeric main body with a first side wall 2.1, a side wall 2.2 running parallel thereto, a glazing interior wall 3, and an outer wall 4. The glazing interior wall 3 runs perpendicular to the side walls 2.1 and 2.2 and connects the two side walls. The outer wall 4 is opposite the glazing interior wall 3 and connects the two side walls 2.1 and 2.2. The outer wall 4 runs substantially perpendicular to the side walls 2.1 and 2.2. The sections of the outer wall 4.1 and 4.2 next to side walls 2.1 and 2.2 are, however, inclined at an angle of approx. 45 relative to the outer wall 4 in the direction of the side walls 2.1 and 2.2. The angled geometry improves the stability of the hollow-profile spacer 13 and enables better bonding with a barrier film 6. The wall thickness d of the hollow profile is 1 mm. The hollow profile 1 has, for example, a total height h.sub.G of 6.5 mm and a width b of 16 mm. The outer wall 4, the glazing interior wall 3, and the two side walls 2.1 and 2.2 enclose the cavity 5. The cavity 5 can accommodate a desiccant 21. The polymeric main body 1 contains styrene acrylonitrile (SAN) and, additionally, in the case of the first polymeric hollow-profile spacer, approx. 35 wt.-% glass fibers. A gas- and vapor-tight barrier film 6, which improves the tightness of the spacer 13, is mounted on the outer wall 4 and approx. half of the side walls 2.1 and 2.2. The barrier film 6 can, for example, be secured on the polymeric main body 1 with a polyurethane hot melt adhesive. Alternatively to a barrier film 6, a barrier coating 9 can also be applied. This can be applied directly on the polymeric main body, for example, in a vacuum coating process.
(13) FIG. 5 depicts a cross-section through a transparent barrier film 6 that is suitable to be mounted on a transparent first polymeric hollow-profile spacer 13.1, 13.2. The transparent barrier film 6 is a multilayer film composed of polymeric layers 19 and ceramic layers 20. The polymeric layers consist substantially of 12-m-thick polyethylene films, and the ceramic layers consist of a 40-nm-thick SiO.sub.x layer. Two polymeric layers 19 are arranged alternatingly with two ceramic layers 20. The alternating arrangement has the advantage that defects in one of the ceramic layers 20 can be compensated by the other layers. In all, three ceramic layers 20 and three polymeric layers 19 are part of the barrier film. Two of the ceramic layers 20 are directly connected via an adhesive layer 18, for example, a 3-m-thick layer of polyurethane adhesive. By means of this arrangement, all ceramic layers 20 are protected by polymeric layers 19 against mechanical damage from the outside. The transparent barrier film 6 depicted can be produced particularly easily by bonding three polyethylene films, each of which has been coated with a SiO.sub.x layer, via two adhesive layers 18.
(14) FIG. 6 depicts a cross-section through another embodiment of a transparent barrier film 6 that is suitable to be mounted on a transparent first polymeric hollow-profile spacer 13.1, 13.2. The transparent barrier film 6 is a multilayer film with two polymeric layers 19, substantially consisting of polyethylene terephthalate (PET) and two ceramic layers 20, consisting in each case of 30-nm-thick silicon oxide (SiO.sub.x) layers. The production of the barrier film 6 can advantageously be done by bonding two PET films coated with SiO.sub.x. The adhesive layer 18 is, for example, a 3-m-thick polyurethane adhesive layer. Preferably, such a barrier 6 with an outward positioned ceramic layer 20 is glued on the hollow-profile spacers such that the polymeric layer 19 faces the hollow-profile spacers and the ceramic layer 20 faces the external environment or the secondary sealant. In this arrangement, the ceramic layer can serve as an adhesion promoter since the adhesion of the customary secondary sealant to a ceramic layer is improved compared with the adhesion to a polymeric layer.
(15) Measurement of Compressive Strength
(16) FIG. 7 depicts a perspective cross-section of a polymeric main body 1 and essential parameters for measurement of the compressive strength of a polymeric hollow-profile spacer. Additionally sketched in are the height of the side wall h.sub.S, the length L of a piece of the hollow-profile spacer and the direction of the force F, which acts during the measurement of the compressive strength. The compressive strength describes the stability of the polymeric hollow-profile spacer in the transverse direction. For the measurement of the compressive strength, a polymeric main body 1 is arranged with the first side wall 2.1 on an immovable pressing surface 40. This can be in the orientation depicted in FIG. 6, or the polymeric main body 1 can be placed with the first side wall 2.1 on the pressing surface 40 such that the arrangement depicted in FIG. 6 is rotated counterclockwise by 90. For the measurement, a piece of polymeric main body 1 of the length L is selected. In the example depicted, the sections 4.1 and 4.2 of the outer wall 4 next to the side walls are angled. Accordingly, the area with which the polymeric main body 1 is in contact with the pressing surface 40 is defined by the length L and the height h.sub.S of a side wall 2. The area Lh.sub.S on the second side wall 2.2 is characterized by a fine checkered pattern. In the measurement of the compressive strength, the polymeric main body 1 to be measured is clamped and then pressed together at a defined test speed by exertion of a force F on the entire area Lh.sub.S of the second side wall. The maximum force F.sub.max that can be exerted on the polymeric main body 1 before the polymeric main body 1 breaks or collapses is measured. In a graphic plot of the force F exerted against the deformation during the measurement, the force F rises continuously up to a point F.sub.max, from which the curve suddenly drops. The measurement is terminated at this point.
EXAMPLE
(17) A door according to the invention is equipped with four polymeric hollow-profile spacers, as depicted in FIGS. 1 and 2. The door is rectangular, and the first and second panes are in each case 80 cm180 cm in size. A transparent butyl was used as a primary sealant, and a transparent silicone was used as a secondary sealant. The two first polymeric hollow-profile spacers are filled with molecular sieve; whereas the second polymeric hollow-profile spacers contain no desiccant. The inner interpane space was filled with a noble gas, in this case argon.
(18) The polymeric main bodies of the first and second hollow-profile spacers have the following dimensions:
(19) Wall thickness d=1 mm; width b=16 mm; total height h.sub.G=6.5 mm; height of the side walls h.sub.S=4.5 mm
(20) The polymeric main bodies of the first polymeric hollow-profile spacers are made substantially of styrene acrylonitrile (SAN) with a glass fiber content of approx. 35%. The polymeric main bodies of the second polymeric hollow-profile spacers are made substantially of styrene acrylonitrile (SAN) and and have a reinforcement fiber content of 0%.
(21) The compressive strength of the polymeric bodies of the first and the second polymeric hollow-profile spacers was measured as described above and the following values were obtained for measurements on pieces of the length L=10 cm at a test speed in each case of 2 mm/min:
(22) TABLE-US-00001 F.sub.max/L Main body SAN with 35% glass fibers 410 N/cm Main body SAN 295 N/cm
(23) The compressive strength F.sub.max/L of the second polymeric hollow-profile spacers is, accordingly, lower by approx. 28% than that of the first polymeric hollow-profile spacers. The influence of the barrier layer or barrier film applied on the main body on the compressive strength values is negligible.
Comparative Example
(24) A door with four polymeric hollow-profile spacers, which include in each case a main body with SAN and 35% glass fiber content, was installed otherwise analogously to the door of the Example. In this case, the compressive strengths of all polymeric hollow-profile spacers are as high as those of the first polymeric hollow-profile spacers in the Example.
Comparison: Example Versus Comparative Example
(25) The two doors were each installed in a refrigerator display case with an internal temperature of 18 C. and and an external temperature of 20 C. The doors were automatically opened and closed again 10000 times on a test bench. After closing, the doors were kept closed for at least 90 seconds so that the temperature in the interior of the refrigerator display case did not heat up excessively during the test.
(26) Then, the insulating glass units of the example door and of the comparative example door were examined. The external appearance of both doors was undamaged. The edge seal was intact and the panes were not fogged up from the inner interpane space. In addition, a dewpoint analysis was performed, as described in DIN EN 1279. Both doors reached a dewpoint of below 60 C., which corresponds to the requirements for such an insulating glazing per DIN EN 1279. In addition, the argon content was determined by gas chromatography. It was, in both cases, approx. 90% which is in compliance with the requirements for a gas-filled insulating glass unit. The sealing and stability of the edge seal of the Example and the Comparative Example is, accordingly, excellent for both. Accordingly, the insulating glass unit with second polymeric hollow-profile spacers without reinforcement fibers has equally great stability as the embodiment according to the prior art with reinforcement fibers in all hollow-profile spaces.
LIST OF REFERENCE CHARACTERS
(27) I insulating glass unit II door for a refrigeration unit 1 polymeric main body 2 side walls 2.1 first side wall 2.2 second side wall 3 glazing interior wall 4 outer wall 4.1, 4.2 the sections of the outer wall nearest the side walls 5 cavity 6 transparent barrier film 7 outer interpane space 8 inner interpane space 9 barrier coating 10 peripheral spacer frame 11 first pane 12 second pane 13 polymeric hollow-profile spacer 13.1, 13.2 hollow-profile spacers along the first sides 14.1 and 14.2 13.3, 13.4 hollow-profile spacers along the second sides 14.3 and 14.4 14.1, 14.2 two opposing first sides of the insulating glass unit I 14.3, 14.4 two opposing second sides of the insulating glass unit I 18 adhesive layer 19 polymeric layer of the transparent barrier film 20 ceramic layer of the transparent barrier film 21 desiccant 25 corner connector 27 primary sealant 27.1 transparent primary sealant 28 secondary sealant 28.1 transparent secondary sealant 29 openings in the glazing interior wall 30.1, 30.2 horizontal frame elements 31 door handle 40 pressing surface b width of a hollow-profile spacer d wall thickness of a hollow-profile spacer h.sub.G total height of a hollow-profile spacer h.sub.S height of a side wall of a hollow-profile spacer L length of a piece of hollow-profile spacer F force acting in the direction of arrow
