DE69106985T2 - Thermally insulating spacer assembly for double glazing and its manufacturing process. - Google Patents

Abstract

An insulating unit (150) has a pair of glass sheets (12,14) about an edge assembly (152) to provide a compartment (18) between the sheets. The edge assembly has a U-shaped spacer (158) made of metal, metal coated plastic, gas and moisture impervious polymer, or gas and moisture impervious film coated polymer. The outer legs (156) of the spacer (158) and the glass (12,14) provide a long diffusion path to limit the diffusion of argon gas out of the compartment (18). The edge assembly (152) has materials selected and sized to provide edge assembly having an RES-value of at least 75. A spacer (158) for use in insulating units includes a plastic core having a gas impervious film e.g. a metal film or a halogenated polymer film. Also taught herein are techniques for making the unit (150) and spacer (158). The unit (150) has a long diffusion path to increase the time period in which insulating glass e.g. Argon gas may be retained in the compartment (18). The increased RES-value provides a unit (150) that has a low thermal conducting edge (152). In this manner heat loss through the marginal edge (152) of the unit (150) is reduced. <IMAGE>

Description

The present invention relates to components of an insulating glazing unit and a method of making a spacer frame. The invention relates in particular to an insulating glazing unit having an edge unit for providing the unit with an edge having low thermal conductivity, i.e. a high resistance to heat transfer at the edge of the unit.

Insulated glazing units are known to reduce heat transfer between the outside and inside of a house or other structure. A measure of insulation value that is commonly used is the "U-value". The U-value represents a unit of measurement of the heat energy in joules (British Thermal Unit (BTU)) passing through the unit per hour (Hr) - m² (square foot) - degrees Kelvin ºF).

As can be seen, the lower the U-value, the better the thermal insulation value of the unit, ie a higher resistance to heat transfer leads results in less heat being conducted through the unit. Another measure of insulation value is the "R-value", which is the inverse of the U-value. Yet another measure is the resistance (RES) to heat transfer, which is expressed in Hr-ºK (ºF) per joule (BTU) per m (inch) of circumference of the unit:

In the past, the insulation properties, i.e. the U-value of an insulation unit, were characterized by the U-value measured at the center of the unit. More recently, it has been found that the U-value of the edge of the unit must be considered separately to determine the overall thermal performance of the unit. For example, units that have a low U-value in the center and a high U-value at the edge during the winter season will not experience moisture condensation in the center of the unit, but may experience condensation or even a thin layer of ice on the edge of the unit near the frame. Condensation or ice on the edge of the unit indicates that heat loss is occurring through the unit and/or frame, i.e. the edge has a high U-value. If the condensate or water from the melted ice runs down the unit onto the wooden frames, the wood will rot if it has not been properly conditioned. In addition, larger temperature differences between the warm center and the cold edge can cause larger edge stresses and glass breakage. The U-values of units with or without frames and the methods for determining the U-values are explained in more detail in the chapter "Description of the Invention".

Over the years, the designs and materials used to manufacture insulated glazing units and frames have been improved to produce framed units with low U-values. Various types of units currently available and the U-values at the centre and edge of selected units are examined in the discussion below.

US-A-4 807 439 describes an insulation unit sold by PPG Industries, Inc., USA under the trademark SUNSEAL. The unit has a pair of glass panes spaced about (0.45 inches) 1.14 cm apart around an organic material edge unit. Air is contained in the compartment between the panes. A unit constructed in this manner is expected to have a U-value measured at the center of about 0.35 and a U-value measured at the edge of about 0.59. Although an insulating gas, i.e. argon, in the unit lowers the U-values at the center and edge, over time the argon diffuses through the organic material edge unit, causing the U-values at the center and edge to rise back to their previous values.

The unit known from US-A-4 831 799 has a peripheral unit made of organic material and a gas barrier coating, film or equivalent layer on the peripheral edge of the unit to retain argon in the unit. The thermal behavior of this unit is explained in column 5 of the corresponding publication.

US-A-4 431 691 and US-A-4 873 803 describe a unit comprising a pair of glass panes separated by a rim unit comprising a bead of organic material in which a thin rigid element is embedded. Although the units of these patents have acceptable U-values, they have disadvantages. More specifically, the units have a short length, high resistance diffusion path. The diffusion path is the distance that gas, ie argon, air or moisture, must travel to enter or leave the compartment between the panes. The resistance of the diffusion path is determined by the permeability, thickness and length of the material. The units described in US-A-4,831,799, 4,431,691 and 4,873,803 have a short, high resistance diffusion path between the metal strip or spacer and the glass panes, but the remainder of the edge unit has a long length, low resistance diffusion path.

US-A-3 919 023 describes an edge unit for an insulation unit which provides a high resistance and long length diffusion path which can be used to minimise argon losses. However, a limitation of the edge unit described in the patent is the use of a metal strip around the outer boundary edges of the unit. This metal strip conducts heat around the edge of the unit and the unit therefore has a high U-value at the edge.

IBM Technical Disclosure Bulletin, Volume 11, No. 2, July 1968, pages 127 and 128, describes a reinforced sheet metal corner that is made by forming a single flat piece from sheet metal. No joining or cutting is required.

From US-A-3 478 483 a plate filter construction is known which has two sections which allow folding of the filter. The frame contains two triangular cutouts in the upper, opposite sections. Their vertices form the fold line of the filter.

From DE-A-29 23 769 a method for producing an insulating glazing unit is known. The unit comprises a spacer frame on which a pair of glass panes are arranged. The frame is bent from standard spacer material, with at least two spacer materials being used to produce the frame.

The aim of the present invention is to provide an insulating glazing unit which has low U-values at the centre and at the edge, is simple to manufacture, does not have the limitations or disadvantages of the currently available insulating glazing units and can be used in conjunction with any frame construction.

This object is achieved by a spacer frame for an insulating glazing unit having a pair of glass panes, the frame being bent from U-shaped spacer profile material consisting of a substrate of a moisture and gas impermeable material having structural integrity and elasticity to hold the glass panes in a spaced relationship to one another, a plurality of the corners of the spacer frame being continuous, characterized in that the frame is bent from a profile of U-shaped spacer profile material, the outer legs of the U-shaped spacer profile material each having two folds and a notch at the location of each corner, the folds being arranged in a V-shape prior to bending and extending from the free edge of the outer leg to a common apex on the central leg, the notch between the two folds extends along the free edge of the outer leg, and the portions between the folds of each outer leg are bent inward while the portions outside each pair of folds are pressed towards each other to form the continuous corner.

The solution further comprises a method of manufacturing the spacer frame by providing a substrate of a moisture and gas impermeable material having structural integrity and elasticity to maintain the glass panes in spaced relationship to one another, forming the substrate into U-shaped spacer profile material, severing the spacer profile material and providing spacer profile material sufficient to produce a frame of a predetermined size, and bending the spacer profile material into the frame by pressing the outer legs of the spacer profile material against one another, wherein a plurality of the corners of the spacer frame are formed continuously, characterized by the following steps:

Providing a profile of a length sufficient to produce the frame, providing two folds and a notch at each corner location in each outer leg of the U-shaped spacer profile material, the folds being arranged in a V-shape and extending from the free edge of the outer leg to a common apex on the middle leg and the notch between the two folds running along the free edge of the outer leg, depressing the area between the folds and moving the depressed portions of the outer legs inwards at the notch, while the portions outside of each Pair of folds are pressed against each other to form the continuous corner.

The invention comprises an insulating glazing unit comprising a pair of glass panes separated by an edge unit to form a sealed compartment in which a gas is contained, the edge unit having an RES value of at least 10 as determined using the ANSYS program and comprising a spacer frame as described above and a moisture impermeable sealant on outer legs of the spacer to secure the glass panes to the spacer and to provide a diffusion path such that the loss of gas in the compartment is less than 5% per year as measured according to DIN 52293, and yet to allow for a certain degree of thermal expansion and contraction typically occurring in the various components of the insulating glazing unit. A diffusion path which provides resistance to the gas in the compartment, i.e. a long thin diffusion path is provided between the spacer and the glass panes, and the edge unit has a high RES value, determined using the ANSYS program, at the edge of the unit.

A method of making an insulation unit includes the steps of disposing an edge unit between a pair of glass panes to provide a compartment therebetween. The edge unit is made by providing a pair of glass panes, selecting a structurally resilient spacer material, sealant material and a moisture permeable desiccant containing material to provide an edge unit determining a high RES value using the ANSYS program, and a long thin diffusion path. The glass panes, spacer, gasket material and desiccant containing material are assembled to provide an insulation unit having a high RES value at the edge as measured using the ANSYS program.

The preferred insulation unit of the invention has a protective coating, i.e. a coating with a low E value, on at least one pane surface. An adhesive on each outer surface of the spacer, which has a U-shaped cross section, serves to attach the panes to the spacer. A strip of a moisture-permeable adhesive comprising a desiccant is provided on the inner surface of the spacer.

The spacer that can be used in the insulation unit has an elastic core, i.e. a plastic core having a moisture/gas impermeable film, i.e. a metal film or a film of a halogenated polymer such as polyvinylidene chloride or fluoride or polyvinyl chloride or polytrichlorofluoroethylene.

Furthermore, the spacer may be made entirely of a polymeric material having both elasticity and moisture/gas impermeability properties, such as a halogenated polymeric material including polyvinylidene chloride or fluoride or polyvinyl chloride or polytrichlorofluoroethylene.

To produce the insulation units, a strip is formed into a spacer profile. The strip comprises a metal substrate having a bead of moisture and/or gas permeable adhesive secured to a surface of the substrate. After forming the metal substrate into the spacer profile, ie the U-shaped spacer profile, the metal substrate can withstand higher compressive forces than the bead.

A method of manufacturing a U-shaped spacer profile for use in a spacer frame for insulation units comprises the following steps: passing a metal substrate having a bead of moisture and/or gas permeable adhesive disposed on a surface between spaced pairs of rollers forming wheels shaped to gradually bend the metal substrate around the bead into a spacer profile having a predetermined cross-sectional shape, i.e. a U-shaped cross-section.

The invention further relates to a spacer frame for an insulation unit having a groove for forming opposing outer sides and a plurality of continuous corners, and a method for producing the same. The method comprises the steps of arranging a profile of spacer profile material sufficiently large to produce a frame of a predetermined size. Opposite surfaces of the spacer profile are pressed inwardly while the spacer profile is bent about the recesses thereof to form a continuous corner. The step of forming a continuous corner is repeated until the opposing ends have been brought together and joined together, for example by welding.

What follows is a brief description of the drawings.

The figures

1 to 4 show sectional views of edge units of prior art insulation units;

Figure 5 is a plan view of an insulation unit having a spacer unit of the kind in question;

Figure 6 is a view taken along lines 6-6 of Figure 5;

Figure 7 shows the left half of the view of Figure 6, showing the heat flow lines through the unit;

Figure 8 is a view similar to Figure 7 with the heat flow lines removed;

Figure 9 is a graph showing the edge temperature distribution for units with different types of edge units;

Figure 10 is a sectional view of an edge unit incorporating features of the present invention;

Figure 11 shows a section through another embodiment of a spacer of the present invention;

Figure 12 is a view of an edge strip incorporating features of the invention and having a bead of moisture and/or gas-permeable adhesive provided with a desiccant;

Figure 13 shows a side view of a roll forming station for forming the edge strip of Figure 12 into a spacer profile incorporating features of the present invention;

the figures

14 to 16 are views taken along lines 14 to 16 in Figure 13;

Figure 17 is a view of a continuous corner of a spacer frame of the present invention made using the spacer profile shown in Figure 18;

Figure 18 is a partial side view of a spacer profile that has been notched and folded prior to bending to form the continuous corner of the spacer frame shown in Figure 17 in accordance with the teachings and features of the present invention;

Figure 19 is a view similar to Figure 18 showing another continuous corner of a spacer frame incorporating features of the invention; and

Figure 20 is a view similar to Figure 10 showing another embodiment of the invention.

In the following description, like reference numerals refer to like elements. Units are described, which have two glass panes. However, it will be understood by those skilled in the art that the invention also covers units with more than two panes, as shown in Figure 20.

Figures 1 to 4 show four general types of prior art units used in the construction of insulating glazing units. The unit 10 of Figure 1 comprises a pair of glass panes 12 and 14 spaced apart by an edge unit 16 to form a compartment 18 between the panes. The edge unit 16 comprises a hollow metal spacer 20 having a desiccant 22 incorporated therein to absorb any moisture in the compartment. Holes 23 (only one of which is shown in Figure 1) form a connection between the desiccant and the compartment. The edge unit 16 further comprises an adhesive sealant 24, i.e. silicone, on the lower portion of the spacer 20 as shown in Figure 1, to secure the spacer 20 and the glass panes together, and a sealant 25, i.e. a butyl sealant, on the upper portion of the spacer 20 to prevent the escape of the insulating gas from the compartment 18. The edge unit 16 of the unit 10 corresponds to the type of units sold by Cardinal Glass and to the insulating units described in US-A-2,768,475, 3,919,023, 3,974,823, 4,520,611 and 4,780,164.

The unit shown in Figure 2 comprises glass panes 12 and 14, the edges of which are welded together at 32 to form compartment 18. One of the glass panes, pane 12, has a low emissivity coating 34. The unit 30 shown in Figure 2 corresponds to the isolation units sold by PPG Industries, Inc. under the trademark OptimEdge. and the units described in US-A-4 132 539 and 4 350 515.

Figure 3 shows the unit 50 described in US-A-4 831 799.

The unit 50 has glass panes 12 and 14 separated by a rim unit 52 to provide a compartment 18. The rim unit 52 includes a moisture permeable foam material 54 with a desiccant 56 therein to absorb moisture in the compartment 18, a moisture impermeable sealant 58 to prevent airborne moisture from moving into the compartment 18, and a gas barrier coating, sheet or film 60 between the foam material 54 and the sealant 58 to prevent leakage of the insulating gas in the compartment 18.

Figure 4 shows a unit 70 described in US-A-4 431 691 and 4 873 803.

In the unit 70, the glass panes 12 and 14 are separated by a rim unit 72 to provide the compartment 18. The rim unit 72 includes a moisture permeable adhesive 74 with a desiccant 76 and a metal element 78 therein.

Before describing the construction of the insulation unit, particularly the edge unit of the present invention, heat transfer across an insulated unit will be explained for a better understanding of the present invention. In the following description, the U-value is used to describe heat transfer, ie the resistance to heat flow through a glazing unit, to reduce heat losses. As the expert knows, the lower the U-value, the lower the heat transfer and vice versa. The U-value for an insulation unit can be determined from the following equation:

(1) Ut = (Ac/At) Uc + (Ae/At) Ue + (Af/At) Uf

where U is the unit of measurement for heat transfer in 0.02043 Joule/h-m²-ºK (British Thermal Unit h-foot²-ºF (BTU/h-ft²- ºF)).

A the corresponding area in m² (square feet)

c the center of unity

e the edge of unity

f the frame

t is the total unit value of the parameter in question.

Figures 5 and 6 show a generic insulation unit 90 in which the glass panes 12 and 14 are separated by an edge unit 92 to form the compartment 18. The edge unit 92 is intended to be a generic edge unit and is not limited in its construction. As can be seen in Figure 5, the unit 90 shown for illustrative purposes has an edge region 94, which is the region between the peripheral edge 95 of the unit and a location approximately 7.62 cm (3.0 inches) from the peripheral edge, and a central region 96. The interface between the edge region 94 and the central region 96 of the unit 90 is shown in Figure 5 by dashed lines 98.

The left half of the unit 90 shown in Figure 6 is shown in Figure 7. For clarity, reference numerals have been omitted in the following discussion of heat transfer through the unit. Reference is now made to Figures 5, 6 and 7. During the winter, heat energy moves from the interior of a enclosure, for example of a house, through the peripheral region 94 and central region 96 of the unit 90 to the outside. As can be seen in Figure 7, in the central region 96 of the unit the heat flow pattern is generally perpendicular to the isotherm which is the major surfaces of the glass panes 12 and 14 as indicated by the arrowed lines 100 in Figure 7. The direction of the heat flow pattern changes as one approaches the peripheral edge 95 of the unit as indicated by the arrowed lines 102 until at the peripheral edge 95 of the unit the heat flow pattern is again perpendicular to the major surface of the glass panes as indicated by the arrowed lines 104.

As will be appreciated by those skilled in the art, a frame mounted around the periphery of the unit will affect the flow patterns, particularly flow patterns 102 and 104. For the purposes of the present discussion, the effect of the frame on flow patterns 102 and 104 will be omitted. The foregoing discussion is considered sufficient to provide a background for the present invention.

The heat flow through the central region 96 of the unit 90 can be modified by changes in the thermal properties of the disks 12 and 14, the spacing between the disks and the gas in the compartment 18. Consider now the spacing between the disks, i.e. the spacing of the compartment 18. Compartments with a spacing of 0.63 to 1.27 cm (0.250 to 0.500 inches) are considered acceptable to provide an insulating gas layer with preferred spacing depending on the insulating gases used. Krypton is preferred in the lower region while air and argon are preferred in the upper region. Typically, the spacing below 0.63 cm (0.250 inches) is not wide enough, i.e. for air or argon to provide a significant insulating gas layer. Over 1.27 cm (0.500 inches) gas flows, ie using krypton, have sufficient mobility in the compartment to allow convection and thus move heat between the glass panes, ie the glass surface facing the interior of the house and the glass surface facing the exterior of the house.

As explained above, the heat flow through the unit can also be modified by the type of gas used in the compartment. For example, using a gas with a high thermal insulation value will improve the performance of the unit, i.e. reduce the U-value in the central and peripheral areas of the unit. For example, argon has a higher thermal insulation value than air, but this is not a limitation of the invention. The U-value of the unit will also be reduced by any other measure equivalent to the use of argon.

Another technique for modifying the thermal insulation value of the central region is to use panes having high thermal insulation values and/or panes having low emissivity coatings. Such low emissivity coatings which can be used in connection with the present invention are described in US-A-4,610,771, 4,806,220 and 4,853,256. In addition, by increasing the number of panes of glass, the number of compartments and thus the insulation effect in the central region and in the peripheral regions of the unit is increased. The heat losses at the peripheral region of the unit will now be discussed. Figure 8 shows a peripheral region of the unit 90 shown in Figures 5 and 6. The letters A and E indicate the points at which the heat flow is generally perpendicular to the glass surfaces. As the edge of the unit is approached, the glass begins to act as an extended surface relative to the edge and causes the heat flow paths 100 at the edge of the unit to bend or warp as shown in Figure 7 at reference numeral 102. The bending occurs in the edge region 94 shown in Figures 6 and 7. Between letters B and D, the heat flow is primarily opposed by the edge unit 92 rather than the disk at the edge of the unit. Curves 120, 130 and 140 shown in Figure 9 show the edge heat losses for different types of edge units. Figure 9 should not be interpreted as an absolute relationship, but merely as a general guide to better understand heat flow through the edge unit. Curve 120 shows the heat loss pattern for an edge unit which is highly thermally conductive, i.e., an aluminum spacer which is normally used in the construction of edge units of the type shown in Figure 1. Curve 130 shows the heat loss pattern for an edge unit which is less thermally conductive than an edge unit provided with an aluminum spacer, ie, an edge unit having a plastic spacer and conforming to the construction shown in Figure 3. Line 140 shows the edge heat loss pattern for a disc edge unit of the type shown in Figure 2. Although not a limitation of the invention, it is believed that the edge unit constructed in accordance with the invention will provide a heat loss pattern corresponding to curve 140, as well as heat loss patterns within the shaded areas between curves 130 and 140.

As can be seen from Figure 9, the profile for an aluminum spacer, represented by curve 120, shows that the aluminum spacer at the edge of the unit (between points A and C) offers a low resistance to heat flow, thus allowing a cooler edge to the face of the unit within the house. The profile for a spacer made of organic, i.e. polymeric, material, represented by curve 130, shows that the spacer has a high resistance to heat flow, thus allowing a warmer glass panel face within the house, resulting in reduced heat loss at the edge of the unit. This is particularly evident by curve 130 between points A and C. The edges of the welded glass panels according to Figure 2 have a greater resistance than the metal spacer unit, but a lower resistance than the plastic spacer unit. The temperature distribution of the welded edge units between points A and C is represented by line 140 which lies between points A and C in the diagram of Figure 9 between lines 120 and 130.

The heat loss for an edge unit using a metallic spacer, particularly an aluminum spacer, is greater than for glass because the aluminum spacer has a higher thermal conductivity (aluminum is a better conductor of heat than glass or organic materials). The effect of the higher thermal conductivity of the aluminum spacer is also evident from point D, which shows that curve 120 for the aluminum spacer has a higher temperature on the outside surface of the unit than curve 140 or curve 130. The heat to maintain the higher temperature at D for the aluminum spacer is derived from the interior of the house, resulting in a heat loss at the edge of the unit that is greater than the edge heat loss for units using glass or aluminum spacers. organic material, and larger than the edge unit of the present invention, which will be explained in detail below.

The heat loss for an edge unit with an organic spacer is less than the heat loss for edge units having metal or welded glass spacers because the organic spacer has a lower thermal conductivity. This effect of the lower thermal conductivity of the organic spacer is shown by line 130 at point D, which is at a lower temperature than the glass and metal spacers. This shows that the conductive heat loss through the organic spacer is less than that for the glass and metal spacers.

A phenomenon of units that have high edge heat loss is that on very cold days, a thin layer of condensation or ice forms on the inside of the unit on the frame. This ice or condensation may be present even if the center of the unit is free of moisture.

As explained above, units having argon in the compartment and polymeric material edge units may have an initial low U-value. However, over time the U-value increases because polymeric material spacers are not normally able to retain argon. To avoid loss of argon, an additional film must be provided as described in US-A-4 831 799. The disadvantage of the unit of this US-A-4 831 799 is that the film has a short diffusion path as explained above. The retention capacity of argon can be increased by selecting suitable materials, ie hot melt adhesives such as HB Fuller 1191, HB Fuller 1081A and PPG Industries, Inc. 4442 butyl sealants, which have better argon retention than most polyurethane adhesives.

In Figure 10, an insulation unit 150 is shown having a rim unit 152 embodying features of the present invention for spacing the glass panes 12 and 14 and providing the compartment 18. The rim unit 152 includes a moisture and/or gas impermeable layer 154 of an adhesive for securing the glass panes 12 and 14 to the legs 156 of a metallic spacer 158. The layers 154 of adhesive or sealant act as a barrier to moisture entering the unit and/or as a barrier to the insulation gas, such as argon, leaving the compartment 18. As regards the loss of the charged gas from the unit, in practice the length of the diffusion path and the thickness of the sealant bead in combination with the gas permeability of the sealing material are selected so that the loss of the charged gas is adapted to the desired useful life of the unit. The ability of the unit to retain the charged gas is measured by a European method according to DIN 52293. Preferably the loss of the charged gas should be less than 5% per year, more preferably less than 1% per year.

Regarding moisture ingress into the unit, the geometry of the sealing bead is selected so that the amount of moisture penetrating through the peripheral parts (sealing bead and spacer) can be absorbed by the amount of desiccant within the unit over the desired life of the unit.

The preferred adhesive or sealant used with the spacer of Figures 10 and 11 should have a moisture permeability of less than 20 gm mm/M² day according to ASTM F 372-73. More preferably, the permeability should be less than 5 gm mm/M² day.

The relationship between the amount of desiccant in the unit and the permeability of the sealant (and its geometry) can be varied depending on the desired overall life of the unit.

An additional layer 155 of a sealant or an adhesive, but not limited to silicone adhesive and/or hot melt adhesive, may be provided in the perimeter groove of the unit formed by the central leg 157 of the spacer and the edges of the glass panes. The sealant does not represent a limitation on the invention and may be any of the known types, for example as described in US-A-4 109 431.

A thin layer 160 of a moisture-permeable adhesive having a desiccant 162 disposed therein to absorb moisture within the compartment 18 is provided on the inner surface of the central leg 157 of the spacer 158, as shown in Figure 10. The desiccant may be disposed on the inner surface of the legs 156 in addition to the inner surface of the central leg 157. The permeability of the adhesive layer 160 does not represent a limitation on the invention. However, there should be sufficient permeability to the moisture within the compartment 18 so that the desiccant therein can absorb moisture within the compartment. In carrying out the invention adhesives having a permeability greater than 2 gm mm/M² day as determined by ASTM F 373-73 may be used. The edge unit 152 functions to provide the unit 150 with a low thermal conductivity path through the edge, ie, high resistance to heat loss, a long diffusion path and structural integrity with sufficient structural resilience to allow for a certain amount of thermal expansion and contraction normally occurring in the various parts of the insulating glazing unit.

To understand why the edge unit of the present invention has such a high resistance to heat loss, the mechanism of heat conduction through the edge of an insulation unit is described below.

The heat loss through the edge of a unit depends on the thermal conductivity of the materials used, their physical arrangement, the thermal conductivity of the frame and the surface film coefficient. The surface film coefficient corresponds to the heat transfer from the air to the pane on the warm side of the unit and the heat transfer from the pane to the air on the cold side of the unit. This surface coefficient depends on the weather and the environment. Since the weather and the environment are dependent on nature and not on the design of the unit, no further explanation is necessary. The frame effect is discussed below, while the present explanation refers to the thermal conductivity of the materials at the edge of the unit and their physical arrangement.

The resistance of the edge of the unit to heat loss in an insulation unit with panes that separated by a boundary unit corresponds to the following equation (2):

(2) RHL = G₁ + G₂+ ... + Gn + S₁ + S₂ + .... + Sn where: RHL is the resistance to heat loss at the edge of the unit in 13.37 h - ºK/Joule/m of the perimeter of the unit (Hr-ºF/BTU/in.)

G is the resistance to heat loss of a pane in 13.37 h - ºK/Joule/m (Hr-ºF/BTU/in.). S is the resistance to heat loss of the edge unit in 13.37 h - ºK/Joule/m (Hr-ºF/BTU/in.).

For an isolation unit with two disks separated by a single edge unit, equation (2) can be rewritten as equation (3):

(3) RHL = G1 + G₂+ S�1;

The thermal resistance of a material is given by equation (4):

(4) R = L/CA

where:

R is the thermal resistance in 13.37 h - ºK/Joule/m (Hr-ºF/BTU/in).

K is the thermal conductivity of the material in 74.8 Joules/h-m-ºK (BTU/h-inch-ºF).

L is the thickness of the material measured in m (inches) along an axis parallel to the heat flow.

A is the area of the material measured in square inches along an axis transverse to the heat flow in inches of circumference.

The thermal resistance of components of an edge unit arranged in a line substantially perpendicular to the main surface of the unit is given by equation (5):

(5) S = R₁ + R₂ + ... + Rn wherein S and R have the meanings given above.

In those cases where the components of a peripheral unit are located along an axis parallel to the main surface of the unit, the thermal resistance (S) is given by the following equation (6):

where R has the meaning given above.

Combining equations (3), (5) and (6), the resistance of the edge of the unit 150 shown in Figure 10 to heat loss can be determined by the following equation (7):

where RHL has the meaning given above:

R₁₂ and R₁₄ are the thermal resistance of the glass panes,

R₁₅₄ is the thermal resistance of the adhesive layer 154,

R₁₅₅ is the thermal resistance of the adhesive layer 155,

R₁₅₆ is the thermal resistance of the outer legs 156 of the spacer 158,

R₁₅₇ is the thermal resistance of the middle leg 157 of the spacer 158,

R₁₆₀₀ is the thermal resistance of the adhesive layer 160.

Although equation (7) shows the relationship of components for determining the edge resistance to heat loss, equation 7 is only an approximate procedure used in standard calculations. Computer programs are available to determine the exact relationships related to heat flow through the edge of the unit or the resistance to the flow of heat through the edge of the unit.

One computer program available for thermal analysis is the ANSYS program supplied by Swanson Analysis Systems Inc., Houston, PA. USA. This ANSYS program was used to determine the resistance to edge heat loss or U-value for units as shown in Figures 1 - 4.

Although the U-value defined above is a measure of the overall effect achieved by the invention, it is nevertheless highly dependent on certain phenomena which are not limiting to the invention, such as film coefficients, glass thickness and frame construction. The edge resistance of the edge unit (excluding the glass panes) will now be explained. This edge resistance of the edge unit is defined as the inverse heat flow which exists from the interface of the pane and the sealant layer 154 on the inside of the unit to the interface between the pane and the sealant layer 154 on the outside of the unit per temperature increment per unit length of the perimeter of the edge unit. The interfaces of the pane sealants are assumed to be isothermal in order to simplify the explanation. Among other things, the definition given above is given by the publication "Thermal Resistance Measurements of Glazing System Edge-Seals and Seal Materials Using a Guarded Heater Plate Apparatus", by JL Wright and HF Sullivan, ASHRAE TRANSACTIONS 1989, V.95, page 2.

In the following description and in the claims, the resistance in terms of the heat flow of the edge unit per unit length of the circumference ("RES") is a parameter of interest.

As explained above, the ANSYS finite element code was used to determine the RES value. The result of the ANSYS calculation depends on the assumed geometry of the edge unit cross section and the assumed thermal conductivity of its constituents. The geometry of such a cross section can be easily measured by examining the edge unit. The thermal conductivity of the constituents of the edge unit, or the RES value thereof, can be measured in the manner described in the ASHRAE TRANSACTIONS publication. The following thermal conductivity values for edge unit materials are given in this article. Additional values can be found in the publication "Principles of Heat Transfer" by Frank Kreith, 3rd edition. Material thermal conductivity Butyl Silicone Polyurethane 304 stainless steel Aluminium

Consider now the RES calculated for the edge units of the units of Figures 1-4. The design of the edge unit 16 of unit 10 of Figure 1 included a hollow aluminum spacer 22 between the glass panes. The spacer had a wall thickness of about 0.06 cm (0.025 inches), a side length perpendicular to the major surface of the glass panes 12 and 14 of about 1.5 cm (0.415 inches), and a side length generally parallel to the major surface of the glass panes 12 and 14 of about 0.76 cm (0.3 inches). Butyl adhesive layers 24 having a thickness of about 0.008 cm (0.003 inches) were provided, and a silicone gasket 16 filled the cavity formed by the spacer 20 and the glass panes 12 and 14. The RES value of the edge unit of Unit 10 of the above-described design was calculated using the ANSYS program as 62.2 h-ºK/Joule per m of circumference (4.65 h-ºF/BTU per inch of circumference).

The edge unit 32 design of unit 30 of Figure 2 had a pair of glass panels spaced about 0.432 inches apart. An end wall 32 had a thickness of about 0.090 inches. The RES value of the edge unit of unit 30 of the above-described design was calculated using the ANSYS program to be 1390 h-ºK/Joule per meter of circumference (104 h- ºF/BTU per inch of circumference).

The edge unit 52 construction of unit 50 of Figure 3 had a pair of glass panes 12 and 14 spaced approximately 1.27 cm (0.50 inches) apart. A desiccant-filled foam element approximately 0.64 cm (0.25 inches) thick was adhered to the glass surfaces. An aluminum coated plastic diffusion barrier and a butyl edge seal approximately 0.64 cm (0.25 inches) thick were provided. The Aluminum coating between the foam element and the gasket was too thin for accurate measurement. The edge unit RES value of Unit 50 of the above design was calculated using the ANSYS program to be 1390 h-ºK/Joule per m circumference (104.0 h-ºF/BTU per inch circumference).

A similar unit to unit 50 of Figure 3, having a pair of glass panes 12 and 14 spaced 1.14 cm (0.45 inches) apart, a silicone adhesive layer 54 having a thickness of about 0.475 cm (0.187 inches) with a desiccant therein, and a butyl moisture impermeable sealant 58 having a thickness of about 0.475 cm (0.187 inches), had an edge unit RES of about 1132 h-ºK/Joule/m perimeter (84.7 h-ºF/BTU per inch perimeter) calculated using the ANSYS program. To demonstrate the effect that material and dimensional changes have on the wall unit RES, the edge unit RES of different designs of the type of units shown in Figure 3 were compared.

The edge unit construction of unit 70 of Figure 4 included a pair of glass panes spaced 1.143 cm (0.45 inches) apart, an edge seal made of a butyl adhesive about 0.767 cm (0.312 inches) wide with a desiccant therein, and an aluminum spacer about 0.025 cm (0.010 inches) thick embedded therein. The edge unit RES of unit 70 constructed as described above was calculated using the ANSYS program to be 62.2 h-ºK/Joule per m circumference (4.50 h-ºF/BTU per inch circumference).

The construction of the edge unit 150 of the invention shown in Figure 10 comprised a pair of glass panes arranged in a spaced 1.20 cm (0.47 inches) apart, a polyisobutylene layer 154 which was impermeable to moisture and argon and had a thickness of about 0.0254 cm (0.010 inches) and a height according to Figure 10 of about 0.64 cm (0.250 inches), a U-shaped channel 156 made of 304 stainless steel with a thickness of about 0.018 cm (0.007 inches), the middle leg of which had a width according to Figure 10 of about 1.09 cm (0.430 inches) and outer legs of which had a height according to Figure 10 of about 0.64 cm (0.250 inches), and a polyurethane layer 160 which was impregnated with a desiccant and had a height of about 0.32 cm (0.125 inches) and a width according to Figure 10 of about 1.05 cm (0.416 inches) and a polyurethane secondary seal 155 having a width of about 1.143 cm (0.450 inches) and a height of about 0.32 cm (0.125 inches) as shown in Figure 10. The RES value of the edge unit of the unit 150 constructed in the manner described above was calculated using the ANSYS program to be 1057.5 h-ºK/Joule per m circumference (79.1 h-ºF/BTU per inch circumference).

Figure 11 shows a sectional view of another embodiment of a spacer according to the invention. This spacer 163 has an elastic core 164. In carrying out the invention, the core can be made of a non-metal. It is preferably a polymer core, ie U-shaped element 164 made of glass fiber reinforced plastic, which has a thin film 165 made of a gas-impermeable insulating material. For example, if air, argon or krypton is used in the compartment, the thin film 165 can be metal. The construction of the spacer and the gas barrier film is selected so that the unit retains the filled gas over the desired service life of the unit. In a spacer according to Figure 11, in which argon is used as the filling gas and polyvinylidene chloride is used as the barrier film. A preferred thickness of the polyvinylidene chloride is at least 0.127 mm (5 mils), more preferably greater than 0.254 mm (10 mils).

If a material other than polyvinylidene chloride is used as the barrier film, the correct thickness to retain the filling gas for the desired service life can be adjusted depending on the properties of the gas compartment material.

The retention properties for the filling gas of the unit according to the present invention are calculated according to the above mentioned DIN 52293.

For argon, the film 165 may be a 0.000254 cm (0.0001 inch) thick aluminum film or a 0.127 mm (0.005 inch) thick polyvinylidene chloride film. The argon impermeable material has a permeability to argon of less than 5%/yr. The invention contemplates that a core 164 and a thin film layer 165 or several layers 164 and 165 be provided to form a laminate. By using the spacer 163 with the aluminum film instead of the spacer 155 of the unit 150 of Figure 10, the edge unit RES value for the unit 150 of Figure 10 is about 120. This represents about a 50% increase in the RES value achieved by changing the spacer to a plastic spacer with a thin metal coating. By using the spacer 163 with a polyvinylidene chloride film of 0.127 mm (0.005 inch) thickness, the edge unit RES value of the unit 150 of Figure 10 is also about 120.

The invention further proposes to provide a spacer 163 according to Figure 11, the housing of which is made entirely of a polymeric material having moisture/gas impermeability properties. Such a spacer housing may be reinforced (e.g., by glass fibers) but does not include a film barrier (ie, film 163 does not have a thin film 165). Such a polymeric material is preferably a halogenated polymeric material including polyvinylidene chloride, polyvinyldene fluoride, polyvinyl chloride, or polytrichlorofluoroethylene. The edge unit of such a spacer 163 may be made entirely of a polymeric material having a high RES value for the edge unit compared to the spacer of Figure 11.

The spacer of the present invention acts as a barrier to the insulating gas in compartment 18 and is of a fail-safe design. The term "fail-safe design" means that the spacer maintains the glass panes at a distance from one another while allowing for local deflection of the panes due to changes in barometric pressure, temperature and wind loads. The feature of maintaining the glass panes in a fixed spaced relationship means that the spacer prevents the glass panes from moving substantially toward one another when the edges of the unit are secured in the glazing frame. It will be understood that lesser forces are applied to the edge units of apartment windows mounted in a wood frame than to the edge units of office buildings mounted by pressure glazing in metal suspended wall systems. Allowing local deflection means that the spacer allows rotation of the edge portions of the disc around its edge during loading of the types described, while not allowing any movement other than rotation, ie translational movement. Degree of freedom from defects The design depends on the type of material and its thickness. For example, metal may be thin, while plastic may need to be thicker or reinforced, for example with glass fibers, to achieve the same flawless design.

Embodiments of the present invention can be used to improve the performance of prior art units. For example, if the spacer of unit 10 of Figure 1 is replaced with a stainless steel spacer, the RES of the perimeter unit is increased from 62.2 to 243 h-ºK/Joule (4.65 to 18.2 h-ºF/BTU) per unit (m) of circumference. When the metal thickness is changed from 0.06 cm (0.025 in.) to 0.0127 cm (0.005 in.), the edge unit RES value of unit 10 of Figure 1, determined using the ANSYS program, increases from 62.2 to 1285.9 h- ºK/Joule (4.65 - 96.1 h-ºF/BTU per inch) per meter of circumference. When the aluminum strip of the Figure 4 unit is replaced with a stainless steel strip, the edge unit RES value increases from 60.2 to 593.6 h- ºK/Joule (4.5 - 44.4 h-ºF/BTU) per unit (meter) of circumference.

The unit 150 of the present invention, which has the spacer unit 152 shown in Figure 10, has an edge heat loss corresponding to that of line 140. The unit 150 designed according to the invention, which is provided with the spacer unit 163 shown in Figure 11, has an edge heat loss between line 130 and line 140, but which is close to line 130. Although the edge unit of the present invention has an RES value which is lower than the RES value for edge units with spacers made of organic material of the type shown in Figure 3, the unit according to the invention has formed edge unit offers various advantages. Since the spacer is made of metal, gas and moisture impermeable plastic, a metal coated plastic core, a metal coated reinforced plastic core, a plastic core coated with a gas and moisture impermeable film, or a reinforced plastic core coated with a gas and moisture impermeable film, it is much more durable. The diffusion path, ie the length and thickness of the gas and moisture impermeable sealing adhesive, is longer in the unit according to the invention and therefore with the same type of material filling the diffusion path, the longer and thinner diffusion value of the present invention reduces the loss of filler gas. The path of the argon gas is longer because it is restricted to the adhesive layers 154 (see Figure 10), whereas with spacers made of organic material the diffusion path runs through the entire width of the spacer surface. In the unit of Figure 3, a metal barrier is provided to reduce argon losses. The metal film provided on the plastic or PVDC coated plastic has a thickness in the range of about 0.00254 - 0.00762 cm (0.001 - 0.003 inches), which is a short diffusion path. The present invention has a long diffusion path greater than about 0.00762 cm (0.0003 inches) and a thin diffusion path less than about 0.32 cm (0.0125 inches). The unit shown in Figure 10 has a diffusion path length of about 0.64 cm (0.250 inches) and a diffusion path thickness of about 0.254 cm (0.010 inches). The diffusion path length can be increased by increasing the height of the spacer legs. The diffusion path thickness can be decreased by decreasing the distance between the spacer legs and the adjacent glass pane.

In actual testing, a unit having a rim unit incorporating the present invention and a unit having the rim unit shown in Figure 3 had substantially identical RES values. It is believed that the bead provided inside the spacer insulated the spacer from convection cooling by the gases in the compartment.

As discussed above, the teachings of the present invention can be used to improve the RES of the edge unit of a device by using the spacer shown in Figure 11. By forming a glass fiber reinforced plastic core 164 and then sputtering a thin film 165 of aluminum or bonding any gas/moisture impermeable film, such as a PVDC film, in a conventional manner, argon leakage is prevented and the leakage path is substantially limited to the sealant or adhesive between the spacer and the disk, as discussed in connection with the device 150 of Figure 10.

The unit designed according to the invention thus provides an edge unit with a metal spacer, a metal-coated plastic spacer or a plastic spacer or a multi-layer plastic spacer that retains an insulating gas other than air, for example argon, has a relatively high RES value or low U-value of the edge unit and is durable.

We will now discuss the U-value of the unit’s frame. The frame also conducts heat. In certain cases, metal frames conduct sufficiently more heat than the Edge unit of the unit so that edge heat loss through the frame will mask any increase in thermal resistance related to heat loss at the edge of the unit. Wooden frames, metal frames with thermal barriers or plastic frames have a high resistance to heat loss so therefore edge heat loss of the unit is more dominant.

The invention is not limited to units having two disks. It can also be used in units having two or more disks, such as the unit 250 shown in Figure 20.

A method for producing the insulating glazing unit according to the invention will now be described. The unit of the present invention can be produced in any manner.

Figure 12 shows an edge strip 169 having a substrate 170 provided with the bead 160 of moisture permeable adhesive having the desiccant 162 mixed therein. In the preferred embodiment of the invention, the substrate is made of a material, such as a metal or plastic composite material as described above, which is moisture and gas impermeable to retain the insulating gas in the compartment and prevent moisture from entering the compartment. It also has structural integrity and is resilient to maintain the glass panes spaced apart while still allowing for a certain degree of thermal expansion and contraction typically present in various components of the insulating glazing unit. In the practice of the invention, the substrate was made of 304 stainless steel having a thickness of about 0.0178 cm (0.007 inches), a width of about 1.588 cm (0.625 in.) and of sufficient length to accommodate the spacer between glass panes, ie, to provide a 0.6 m² (24 in.²) unit. The bead 160 is polyurethane with a drying agent mixed in. A bead having a height of about 0.32 cm (1/8 in.) and a width of about 0.96 cm (3/8 in.) is applied to the center of the substrate 170 in a conventional manner.

The desiccant bead can be any adhesive or polymeric material that is moisture permeable and can be mixed with a desiccant. In this way, the desiccant can be placed in the adhesive or polymeric material and fixed to the substrate while having access to the compartment. Recommended materials, but not limited to, are polyurethanes and silicones. In addition, the bead can be a spacer drainage element as described in U.S. Patent No. 3,919,023. The disclosure of this publication is hereby incorporated by reference.

Furthermore, one or both sides of one or more panes may have a coating for protection against environmental influences, as described, for example, in US-A- 4,610,771, 4,806,220, 4,853,256, 4,170,460, 4,239,816 and 4,719,127.

In the practice of the present invention, the metal substrate after forming the spacer profile and the bead have sufficient strength and resilience to hold the panes spaced apart from each other and yet allow for a certain amount of thermal expansion and contraction normally encountered in various components of the insulating glazing unit. In one embodiment of the invention, the spacer is more stable than the bead, that is, sufficiently stable or dimensionally stable to hold the disks apart from one another, which the bead cannot. In another embodiment of the invention, both the spacer and the bead can do this. For example, the bead can be formed by a desiccant in a preferred spacer, as disclosed in US-A-3,919,023. As those skilled in the art will appreciate, a metal spacer can be made through a series of bending and forming operations so that it can withstand appropriate compressive forces. With regard to the bead 160 disposed on the substrate 170, the substrate 170 is formed into a U-shaped spacer profile with a single wall, this U-shaped spacer profile being able to withstand appropriate compressive forces to hold the disks apart from one another, regardless of the stability of the bead. As those skilled in the art will appreciate, the extent of the compressive forces and the stability depend on the use of the unit. For example, if the unit is secured by clamping the edges of the unit, as in suspended wall systems, the spacer must be of sufficient strength to hold the glass panes apart while subjected to the compressive forces of the clamping action. If the unit is mounted in the joint of a timber frame and caulked to secure it, the spacer does not need to be particularly strong to hold the panes apart, unlike a spacer on a unit that is clamped.

The edges of the strip 150 are bent in a conventional manner to form outer legs 156 of the spacer 158 shown in Figure 10. For example, the strip 170 can be pressed between lower and upper rollers as shown in Figures 13-16.

As shown in Figure 13, the strip is moved from left to right between forming rolling stations 180 to 185. As will be appreciated by those skilled in the art, the invention is not limited to the number of forming rolling stations shown or to a specific number of forming rolls at the respective stations. As shown in Figure 14, the forming rolling station 180 includes a lower roll 190 having an annular groove 192 and an upper roll 194 having an annular groove 196 sufficient to receive the layer 160. The groove 192 is dimensioned to begin bending the strip 170 into a U-shaped spacer and is less deep than the groove 198 of the lower roll 200 of the pressing station 180 shown in Figure 15 and the remaining lower rolls of the downstream pressing stations 182 to 185.

As shown in Figure 16, the lower roller 202 of the forming rolling station 185 has a circumferential groove that is essentially U-shaped. The spacer profile leaving the forming rolling station 185 is the U-shaped spacer 158 shown in Figure 10.

The grooves of the upper rollers can be designed to form the bead of material on the substrate.

In the practice of the invention, the bead 160 was applied after the spacer profile had been formed, i.e., the substrate had been formed into the U-shaped spacer profile. This was done by pulling the substrate through a die of the known type to convert a flat strip into a U-shaped strip.

Loose desiccant provides better thermal insulation than desiccant in a moisture-permeable material. However, handling and placing loose desiccant in a spacer is in some cases more restrictive than handling a desiccant in a moisture permeable matrix. Furthermore, placing the desiccant in a moisture permeable matrix increases the lifetime because the desiccant requires a longer period of time to saturate when placed in a moisture and/or gas permeable material than if it were directly exposed to moisture. The length of time depends on the porosity of the material. The invention proposes both the use of loose desiccant and the use of the desiccant in a moisture permeable matrix.

The spacer profile 158 can be formed into a spacer frame for placement between the panes. The layers 154 and 155 shown in Figure 1.0 can be applied to the spacer profile or the spacer frame. The invention is not limited to the materials used for the layers 154 and 155. However, the layers 154 should offer a high resistance to the flow of the insulating gas in the compartment between the spacer 152 and the panes 12 and 14. The layer 155 can be made of the same material as the layers 154 or a corresponding adhesive, for example silicone. Before or after the layers 154 and/or 155 are applied to the spacer profile, a piece of the spacer profile is cut off and bent to form the spacer frame. Three corners can be formed, i.e. continuous corners, while the fourth corner is welded or sealed using a moisture and/or gas impermeable sealant. The continuous corners of the spacer frame designed according to the invention are shown in Figures 17 and 19.

According to Figure 18, a length of the spacer profile provided with the bead is severed and a notch 207 and grooves (folds) 208 are formed in the spacer profile at the corresponding bend lines in any conventional manner. The area between the grooves is recessed, i.e. the portion 212 of the outer legs 156 at the notch is bent inwards while the portions on each side of the groove are pressed against each other to form a continuous, overlapping corner 224 as shown in Figure 17. The non-continuous corner, i.e. the fourth corner of a rectangular frame, can be glued or welded with a moisture and/or gas impermeable material. The bead at the corner can be removed before the continuous corners are formed.

Referring to Figure 19, in the practice of the invention, the spacer frame 240 was made from a U-shaped spacer profile. A continuous corner 242 was formed by depressing the outer legs of the spacer profile against each other while bending sections of the spacer profile around the recess to form a corner having a 90° angle. As the sections of the spacer profile are bent, the depressed sections 244 of the outer legs move inwardly toward each other. After forming the spacer frame, layers of sealant were provided on the outer surface of the legs 156 of the spacer frame and the bead on the inner surface of the middle leg of the frame. The unit was assembled by bonding the glass panes together in a conventional manner. positioned and bonded to the sealant layers 154 of the spacer frame.

If not previously provided on the frame, a layer 155 of adhesive is provided in the peripheral channel of the unit (see Figure 10) or on the periphery of the unit. Argon gas is introduced into the compartment 18 in any convenient manner to provide an insulating unit with a low thermal conductivity edge.

Claims (30)

1. A spacer frame (210, 240) for an insulating glazing unit (150) having a pair of glass panes (12, 14), the frame (210, 240) being bent from U-shaped spacer profile material (158, 163) consisting of a substrate (170) of a moisture and gas impermeable material having structural integrity and elasticity to hold the glass panes (12, 14) apart from one another, a plurality of the corners (224, 242) of the spacer frame being continuous, characterized in that the frame is bent from a section of the U-shaped spacer profile (158, 163), the outer legs (156) of the U-shaped spacer profile (158, 163) each having two folds (208) and a notch (207) at the location of each corner, that the Folds (208) are V-shaped before bending and extend from the free edge of the outer leg (156) to a common apex on the middle leg (157), that the notch (207) runs between the two folds (208) on the free edge of the outer leg (156) and that the sections (212) between the folds (208) of each outer leg (156) are bent inwardly, while the portions outside of each pair of folds (208) are pressed towards each other to form the continuous corner (224, 5242). 2. Spacer frame according to claim 1, characterized in that a bead (160) made of a moisture-permeable adhesive, into which a desiccant (162) is mixed, is glued to the inner surface of the middle leg (157) of the U-shaped spacer profile (158, 163). 3. Spacer frame (210, 240) according to one of claims 1 or 2, characterized in that the frame (210, 240) has four corners, three corners (224, 242) being continuous. 4. Spacer frame (210, 240) according to one of claims 1 to 3, characterized in that the substrate (170) for the U-shaped spacer profile (158) consists of metal. 5. Spacer frame (210, 240) according to claim 4, characterized in that the substrate (170) consists of stainless steel. 6. Spacer frame (210, 240) according to one of claims 1 to 3, characterized in that the substrate (170) for the U-shaped spacer profile (163) consists of plastic which has a moisture- or gas-impermeable film (165). 7. Spacer frame (210, 240) according to claim 6, characterized in that the film (165) consists of a metal or a halogenated polymer. 8. Spacer frame (210, 240) according to one of claims 1 to 3, characterized in that the substrate (170) consists of a polymeric material with structural elasticity. 9. Spacer frame (210, 240) according to claim 8, characterized in that the polymeric material consists of halogenated polymeric material. 10. Spacer frame (210, 240) according to one of claims 2 to 9, characterized in that the adhesive for the bead (160) into which the desiccant (162) is mixed is selected from polyurethane and silicone. 11. A method of making the spacer frame (210, 240) of any one of claims 1 to 10 by providing a substrate (170) of a moisture and gas impermeable material having structural integrity and elasticity to hold the glass panes (12, 14) apart from each other, forming the substrate into a U-shaped spacer profile material, severing the spacer profile material and providing sufficient spacer profile material to make a frame (210, 240) of a predetermined size and bending the spacer profile material into the frame (210, 240) by pressing the outer legs (156) of the spacer profile material toward each other, wherein a plurality of the corners (224, 242) of the spacer frame are continuous, characterized by Providing a section of the profile (158, 163) of a length sufficient to produce the frame (210, 240), providing two folds (208) and a notch (207) at each intended corner location in each outer leg (156) of the U-shaped spacer profile (158, 163), the folds (208) being V-shaped and extending from the free edge of the outer leg (156) to a common apex on the middle leg (157) and the notch (207) between the two folds (208) running at the free edge of the outer leg (156), pressing down the area between the folds (208) and moving the pressed-down sections (244) of the outer legs (156) inward at the notch (207), while the sections outside of each pair of folds (208) are pressed against each other to form the continuous corner (224, 242). 12. Method according to claim 11, characterized in that a bead (160) made of a moisture-permeable adhesive into which a desiccant (162) is mixed is provided on the inner surface of the middle leg (157) of the spacer profile (158, 163). 13. Method according to claim 11, characterized in that a substrate (170) is used on which a bead (160) of a moisture-permeable adhesive into which a desiccant (162) is mixed is located, and that the substrate (170) is formed into a U-shaped spacer profile (158, 163) with a single wall and outer legs (156). 14. Method according to claim 11 to 13, characterized in that three corners are formed as continuous corners (212, 242) and the fourth corner is welded or sealed using a moisture and/or gas impermeable sealant. 15. Method according to one of claims 11 to 14, characterized in that the substrate (170) for the U-shaped spacer profile (158) consists of metal. 16. Method according to claim 15, characterized in that the substrate (170) consists of stainless steel. 17. Method according to one of claims 11 to 16, characterized in that the substrate (170) for the U-shaped spacer profile (163) consists of plastic with a moisture- or gas-impermeable film (165). 18. The method according to claim 17, characterized in that the film (165) is selected from a metal or a halogenated polymer. 19. Method according to one of claims 11 to 14, characterized in that the substrate (170) consists of a polymeric material with structural elasticity. 20. The method according to claim 19, characterized in that the polymeric material is a halogenated polymeric material. 21. Method according to one of claims 11 to 20, characterized in that the adhesive for the bead (160) into which the desiccant (162) is mixed is selected from polyurethane and silicone. 22. Method according to one of claims 11 to 16, characterized in that the forming step comprises the step of guiding the substrate (170) through roll forming wheels (190, 192, 194, 200, 202) which progressively form the substrate (170) into the U-shaped spacer profile (158). 23. Insulated glazing unit (150) comprising a pair of glass panes (12, 14) separated by an edge unit (152) to form a sealed compartment (18) with a gas therein, the edge unit (152) having an RES value of at least 10 (determined using the ANSYS program), and a spacer frame (210, 240) according to claims 1 to 10 and a moisture-impermeable sealant (154) on the outer legs (156) of the spacer (158, 163) for securing the glass panes (12, 14) to the spacer (158, 163) to provide a diffusion path such that the loss of the gas in the compartment (18) is less than 5% per year, measured according to DIN 52293. 24. Unit (150) according to claim 23, characterized in that the compartment (18) is provided with an insulating gas. 25. Unit (150) according to claim 23, characterized in that at least one glass pane (12, 14) has a coating for protection against environmental influences. 26. Unit (150) according to claim 23, characterized in that it further comprises a moisture-impermeable sealant (155) on the surface of the central leg (157) facing away from the compartment (18). 27. The unit (150) of claim 23, characterized in that the sealing means (154) securing the glass panes (12, 14) to the spacer (158, 163) provides a diffusion path having a thickness of less than 0.0508 cm (0.020 inches) and a length of at least 0.32 cm (0.125 inches). 28. Unit (150) according to claim 23, characterized in that the loss is less than 1% per year. 29. The unit (150) of claim 23, characterized in that the sealant (154) has a permeability of less than 20 gm mm/m² per day using ASTM F 372-73. 30. Unit (150) according to one of claims 23 to 29, characterized in that it comprises three or more glass panes (14), each of the glass panes (14) being separated by an edge unit.