Insulating glazing unit

The present invention relates to components of an insulating glazing unit and a method for producing a spacer frame. The invention relates in particular to an insulating glazing unit with an edge unit in order to provide the unit with an edge with low thermal conductivity, ie a high resistance to heat transfer at the edge of the unit.

Insulating glazing units are known to reduce heat transfer between the outside and inside of a house or other constructions. A measure of the insulation value that is normally used is the "U value". The U-value represents a unit of measurement for thermal energy in joules (British Thermal Unit (BTU)) that passes through the unit per hour (Hr) - m² (square feet) - 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 means that less heat is conducted through the unit. Another unit of measurement for the insulation value is the "R value", which is the reverse U value. Yet another unit of measurement is the resistance (RES) to heat transfer, expressed in Hr -ºK (ºF) per joule (BTU) per m (inch) of unit circumference:

In the past, the insulation properties, ie the U-value of an insulation unit, were characterized by the U-value measured at the center of the unit. It has recently been found that the U-value of the edge of the unit must be considered separately in order to determine the overall thermal behavior of the unit. For example, units that have a low U-value in the middle and a high U-value at the edge during winter do not experience moisture condensation in the center of the unit, but may experience condensation or even a thin layer of ice near the unit of the frame. The condensation or ice on the edge of the unit indicates that heat is lost through the unit and / or the frame, ie 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 breakages. The U values ​​of units with or without a frame and the methods for determining the U values ​​are explained in greater detail in the chapter "Description of the Invention",

Over the years, the structures and materials used to manufacture double glazing units and frames have been improved to produce framed units with low U-values. Various types of units that are currently available and the U-values ​​at the center 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 that are spaced about a (0.45 inch) 1.14 cm apart around an edge unit of organic material. There is air in the compartment between the panes. It is assumed that a unit designed in this way has a U-value measured in the middle of approximately 0.35 and a U-value measured at the edge of approximately 0.59. Although an insulating gas, ie argon, in the unit lowers the U-values ​​in the middle and at the edge, the argon diffuses over time through the edge unit made of organic material, causing the U-values ​​in the center and at the edge to revert to previous values ​​increase.

The unit known from US-A-4,831,799 has an edge unit made of organic material and a gas barrier coating, film or a corresponding layer on the peripheral edge of the unit in order to keep 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 with a pair of glass panes separated by a rim unit which has 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 drawbacks. 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, has to travel in order 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 diffusion path with high resistance between the metal strip or the spacer and the glass panes, but the rest of the edge unit has a long length diffusion path with little Exhibits resistance.

US-A-3 919 023 describes an edge unit for an isolation unit which provides a high resistance, long length diffusion path which can be used to minimize argon losses. However, a limitation with respect to 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, so that the unit therefore has a high U-value at the edge.

In IBM Technical Disclosure Bulletin, Vol. 11, No. 2, July 1968, pages 127 and 128 describe a reinforced sheet metal corner that is made by molding a single flat piece of sheet material. No joining or cutting is required.

From US-A-3 478 483 a plate filter construction is known which has two sections which allow the filter to be folded. The frame contains two triangular cutouts in the upper, opposite sections. The 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 is arranged. The frame is bent from standard spacer material, with at least two spacer materials being used to manufacture the frame.

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

This goal is achieved by a spacer frame for an insulating glazing unit which has a pair of glass panes, the frame being bent from U-shaped spacer profile material, which consists of a substrate of a moisture and gas impermeable material which has structural integrity and elasticity, to keep the glass panes in a spaced relationship from each other, wherein a plurality of the corners of the spacer frame is formed continuously, characterized in that the frame is bent from a profile made 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 point of every corner, the folds are arranged in a V-shape before bending and extend from the free edge of the outer leg to a common apex on the middle leg, the notch between the two folds extends at the free edge of the outer leg and the sections between the folds of each outer leg are bent inward, while the sections outside each pair of folds are pressed towards each other to form the continuous corner.

The solution also includes a method of making the spacer frame by providing a substrate made of a moisture and gas impermeable material that has structural integrity and elasticity to keep the glass sheets in spaced relationship, forming the substrate into a U-shaped spacer profile material, Cutting through the spacer profile material and providing spacer profile material, that is sufficient to produce a frame of a predetermined size, and bending the spacer profile material to the frame by pressing the outer legs of the spacer profile material against each other, a plurality of the corners of the spacer frame being continuously formed, characterized by the following steps:

Providing a profile of sufficient length 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 V-shaped and extending from the free edge of the outer leg extend to a common apex on the middle leg and the notch runs between the two folds on the free edge of the outer leg, Depressing the area between the folds and moving the depressed portions of the outer legs inward at the notch while pressing the portions outside of each pair of the folds against one another to form the continuous corner.

The invention includes an insulating glazing unit having a pair of panes of glass separated by an edge unit to form a sealed compartment in which there is a gas, the edge unit having a RES value of at least 10, determined using the ANSYS program , and comprises a spacer frame, as described above, and a moisture-impermeable sealant on outer legs of the spacer, in order to attach the glass panes to the spacer and to provide such a diffusion path that the gas loss in the compartment is less than 5% per year measured according to DIN 52293, and still a certain degree of thermal expansion and contraction that typically occurs in the various components of the double glazing unit, to enable. A diffusion path that opposes the gas in the compartment, ie 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.

One method of manufacturing an insulation unit includes the steps of placing an edge unit between a pair of glass sheets to provide a compartment therebetween. The rim unit is made by providing a pair of glass panes, selecting a structurally elastic spacer material, sealant material and a material containing a moisture permeable desiccant to provide a rim unit that determines a high RES value using the ANSYS program as well has a long thin diffusion path. The glass panes, the spacer, the sealing material and the desiccant-containing material are assembled to provide an insulation unit that has a high edge RES value measured using the ANSYS program.

The preferred insulation unit of the invention has a protective coating, ie 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, is used to attach the washers to the spacer. A strip of a moisture permeable adhesive having 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, ie a plastic core, which has a moisture / gas impermeable film, ie a metal film or a film made of a halogenated polymer such as polyvinylidene chloride or fluoride or polyvinyl chloride or polytrichlorofluoroethylene.

Furthermore, the spacer can be made entirely of a polymeric material that has 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 with a bead of moisture and / or gas permeable adhesive attached to one surface of the substrate. After the metal substrate has been shaped into the spacer profile, ie the U-shaped spacer profile, the metal substrate can withstand higher compressive forces than the bead.

A method for producing 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 that form wheels that are shaped so that the metal substrate gradually wraps around the bead into a spacer profile is bent, which has a predetermined cross-sectional shape, ie a U-shaped cross section.

The invention further relates to a spacer frame for an insulation unit, which has a groove for forming opposite outer sides and a plurality of continuous corners, and a method for producing the same. The method comprises the steps of arranging a profile made of spacer profile material that is large enough to produce a frame of a predetermined size. Opposing surfaces of the spacer profile are pressed in while the spacer profile is bent around its recesses to form a continuous corner. The step of forming a continuous corner is repeated until the opposite ends have been brought together and joined together, for example by welding.

There now follows a brief description of the drawings.

The figures

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

Figure 5 is a top plan view of an isolation unit having a spacer unit of the type 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 with the heat flow lines represented by 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 having features of the present invention;

FIG. 11 shows a section through a further embodiment of a spacer of the present invention;

Figure 12 is a view of an edge strip having 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 having features of the present invention;

the figures

14 through 16 are views taken along lines 14 through 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 scored 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 having features of the invention; and

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

In the following description, the same reference symbols relate to the same elements. Units are described which have two glass panes. However, it is understood by those skilled in the art that the invention also covers units with more than two disks, as shown in Figure 20.

Figures 1 to 4 show 4 general types of prior art units used in the construction of double glazing units. The unit 10 of Figure 1 comprises a pair of glass panes 12 and 14 which are spaced apart by an edge unit 16 so that a compartment 18 is formed between the panes. The rim unit 16 includes a hollow metal spacer 20 into which a desiccant 22 is incorporated 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 includes an adhesive sealant 24, ie 1, to secure the spacer 20 and the glass panes to one another, and a sealant 25, ie a butyl sealant, on the upper section of the spacer 20, in order 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 the insulation units described in US-A-2,768,475, 3,919,023, 3,974,823, 4,520,611 and 4,780 164 are described.

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

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

The unit 50 has glass panes 12 and 14 which are separated from one another by an edge unit 52 in order 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 impervious sealant 58 to prevent airborne moisture from moving into the compartment 18, and a gas barrier coating, corresponding Layer or film 60 between foam material 54 and sealant 58 to prevent insulation gas from leaking into 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 from one another by an edge unit 72 in order to provide the compartment 18. The edge unit 72 includes a moisture permeable adhesive 74 with a desiccant 76 and a metal element 78 therein.

Before the construction of the insulation unit, in particular the edge unit of the present invention, is described, the heat transfer via an insulated unit should be explained for a better understanding of the present invention. In the following description, the U-value is used to compare or classify the heat transfer, ie the resistance to heat flow through a glazing unit, to reduce heat losses. As the person skilled in the art 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)). Mean here

A the corresponding area in m² (square feet)

c the center of unity

e the edge of the unit

f the frame

t the total unit value of the parameter in question.

FIGS. 5 and 6 show a generic insulation unit 90, in which the glass panes 12 and 14 are separated from one another by an edge unit 92 in order to form the compartment 18. The edge unit 92 is intended to represent a generic edge unit and is not restricted in its construction. As can be seen in Figure 5, the unit 90 shown for purposes of illustration 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 acts, and a central area 96. The interface between the edge area 94 and the central area 96 of the unit 90 is shown in FIG. 5 with broken lines 98.

The left half of the unit 90 shown in FIG. 6 is shown in FIG. For clarity, the reference numerals have been omitted in the following explanation of the heat transfer through the unit. Reference is now made to FIGS. 5, 6 and 7. During the winter, thermal energy moves from the inside of an enclosure, for example a house, through the edge area 94 and the central area 96 of the unit 90 to the outside. As can be seen in FIG. 7, in the central area 96 of the unit the heat flow pattern is generally perpendicular to the isotherm, which is the main surface of the glass panes 12 and 14, as indicated in FIG. 7 by the lines 100 with arrows. 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 the heat flow pattern on the peripheral edge 95 of the unit is again perpendicular to the major surface of the glass sheets, as shown by the arrows Lines 104 is indicated.

As those skilled in the art know, a frame mounted around the perimeter of the unit has an impact on 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 is omitted. The foregoing discussion is believed to be sufficient to provide a background for the present invention.

The heat flow through central area 96 of unit 90 can be modified by changing the thermal properties of disks 12 and 14, the distance between the disks, and the gas in compartment 18. The distance between the panes, ie the distance of the compartment 18, is now considered. 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 a preferred spacing depending on the insulating gases used. Krypton is preferred in the lower range, while air and argon are preferred in the upper range. Typically, the distance below 0.250 inches is not wide enough for air or argon to provide a significant layer of insulation gas. Above 1.27 cm (0.500 inches), gas flows, i.e. using krypton, have sufficient mobility in the compartment to enable convection and in this way heat between the glass panes, ie the glass surface facing the interior and the glass surface facing the exterior , to move.

As explained above, the heat flow through the unit can also be modified by the type of gas used in the compartment. For example, by using a gas with a high thermal insulation value, the behavior of the unit is improved, ie the U-value in the central area and in the peripheral areas of the unit is reduced. 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 is also reduced by any other measure that corresponds to the use of argon.

Another technique for modifying the central region's thermal insulation value is to use panes that have high thermal insulation values ​​and / or panes that have coatings for low emissivity. Such low emissivity coatings that 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, increasing the number of glass panes increases the number of compartments and thus the insulation effect in the central area and in the peripheral areas of the unit. The heat losses at the edge area of ​​the unit will now be explained. FIG. 8 shows an edge region of the unit 90 shown in FIGS. 5 and 6. The letters A and E denote the points at which the heat flow is generally perpendicular to the glass surfaces. As one approaches the edge of the unit, the glass begins to act as an enlarged surface relative to the edge and causes the paths 100 of heat flow to bend or bend at the edge of the unit, as shown in Figure 7 by reference number 102. The curvature occurs in the edge region 94 shown in FIGS. 6 and 7. Between the letters B and D, the edge flow 92 primarily counteracts the heat flow instead of the disk at the edge of the unit. The curves 120, 130 and 140 shown in FIG. 9 show the marginal heat losses for different types of marginal units. Figure 9 should not be interpreted as an absolute relationship, but only as a general guide for a better understanding of the heat flow through the edge unit. Curve 120 shows the heat loss pattern for an edge unit that is highly heat conductive, ie an aluminum spacer that is normally used for 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 which has a plastic spacer and corresponds to the construction shown in FIG. 3. Line 140 shows the edge heat loss pattern for a disc edge unit of the type shown in Figure 2. Although this is not a limitation of the invention, it is believed that the edge unit constructed in accordance with the invention provides a heat loss pattern that corresponds to curve 140 and heat loss patterns within the hatched areas between curves 130 and 140.

As can be seen in 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 little resistance to heat flow, so a cooler edge on the area of ​​the unit within the house. The profile for a spacer made of organic, ie Polymeric material, which is represented by curve 130, shows that the spacer has a high resistance to the heat flow, so that a warmer glass pane surface is made possible within the house, which leads to a reduced heat loss at the edge of the unit. This is particularly evident from curve 130 between points A and C. The edges of the welded glass panes according to FIG. 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 in FIG. 9 between lines 120 and 130.

The heat loss for an edge unit using a metallic spacer, especially an aluminum spacer, is greater than for glass because the aluminum spacer has a higher thermal conductivity (aluminum is a better heat conductor 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 outer surface of the unit than curve 140 or curve 130. The heat to maintain the higher temperature at D for the aluminum spacer is dissipated from the interior of the house so that there is greater heat loss at the edge of the unit than the edge heat loss for units having glass or organic material spacers than the edge unit of the present invention, which is explained in detail below.

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

One phenomenon of units that have high marginal 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 condensed water can be present even if the center of the unit is free of moisture.

As discussed above, units containing argon in the compartment and peripheral units made of polymeric material can have an initial low U-value. However, the U-value increases over time, since spacers made of polymeric material cannot normally hold argon. To avoid loss of argon, an additional film such as that described in US-A-4,831,799 must be provided. 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 of argon can be improved 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 a better retention with respect to argon than most polyurethane. Glue.

An insulation unit 150 is shown in FIG. 10 which has an edge unit 152 which embodies features of the present invention in order to space the glass panes 12 and 14 and to provide the compartment 18. The edge unit 152 includes a moisture and / or gas impermeable layer 154 of an adhesive to secure the glass panes 12 and 14 to the legs 156 of a metal spacer 158. The layers 154 made of the adhesive or Sealants act as a barrier to moisture entering the unit and / or a barrier to insulation gas exiting compartment 18, such as argon. As far as the loss of the filled gas from the unit is concerned, 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 filled gas is adapted to the desired useful life of the unit , The unit's ability to hold back the filled 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.

With regard to the penetration of moisture 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 service life of the unit.

The preferred adhesive or sealant used in conjunction with the spacer of Figures 10 and 11 should have a moisture permeability that is less than 20 gm mm / M 2 day according to ASTM F 372-73. Even 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, can be provided in the peripheral groove of the unit formed by the middle leg 157 of the spacer and the edges of the glass panes. The sealant is not a limitation on the invention and can be any of the known types, such as described in US-A-4,109,431.

A thin layer 160 of moisture-permeable adhesive, in which a desiccant 162 is placed to absorb moisture in the compartment 18, is provided on the inner surface of the middle leg 157 of the spacer 158, as shown in FIG. In addition to the inner surface of the middle leg 157, the drying agent can also be arranged on the inner surface of the leg 156. The permeability of the adhesive layer 160 is not a limitation for the invention. However, there should be sufficient moisture permeability within compartment 18 so that the desiccant therein can absorb moisture within the compartment. Adhesives with a permeability greater than 2 gm mm / M 2 day as determined by ASTM F 373-73 can be used in the practice of the invention. The edge unit 152 causes the unit 150 to travel a path with low thermal conductivity through the edge, ie maintains a high resistance to heat loss, a long diffusion path and structural integrity with sufficient structural elasticity to allow for some degree of thermal expansion and contraction that normally occurs in the various parts of the double glazing unit.

In order 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 disc on the warm side of the unit and the heat transfer from the disc 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 construction of the unit, no further explanation is required. The frame effect is dealt with below, while the present explanation relates 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 with respect to heat loss in an insulation unit with panes separated by an edge unit corresponds to the following equation (2):

(2) RHL = G & sub1; + G 2 + ... + Gn + S 1; + S & sub2; + .... + Sn where: RHL is the resistance to heat loss at the edge of the unit in 13.37 h - ºK / Joule / m of the circumference of the unit (Hr-ºF / BTU / in.)

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

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

(3) RHL = G & sub1; + G 2 + S 1;

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

(4) R = L / KA

in which mean:

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 / hm -ºK (BTU / h-inch -ºF).

L 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 the circumference.

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

(5) S = R & sub1; + R? + ... + Rn wherein S and R have the meanings given above.

In those cases where the components of an edge unit are located along an axis parallel to the main surface of the unit, the thermal resistance (S) is represented 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 FIG. 10 to heat losses can be determined by the following equation (7):

where RHL has the meaning given above:

R 1 2; and R & sub1; & sub4; the thermal resistance of the glass panes are

R 1 5 4 the thermal resistance of the adhesive layer 154 is

R 1 5 5 the thermal resistance of the adhesive layer 155 is

R1 5 & 6 is the thermal resistance of the outer legs 156 of the spacer 158,

R 1 5 7 is the thermal resistance of the middle leg 157 of the spacer 158,

R1 6 0 is the thermal resistance of the adhesive layer 160.

Although equation (7) shows the relationship of the components used to determine edge resistance to heat loss, equation 7 only corresponds to an approximation method used in standard calculations. Computer programs are available that determine the exact relationships in terms of heat flow through the edge of the unit or resistance to the outflow of heat through the edge of the unit.

A computer program available with respect to thermal analysis is that of Swanson Analysis Systems Inc., Houston, PA. USA-supplied ANSYS program. This ANSYS program was used to determine the resistance to edge heat loss or the U-value for units in accordance with FIGS. 1-4.

Although the U-value defined above is a measure of the overall effect achieved by the invention, it is highly dependent on certain phenomena that do not limit the invention, such as film coefficients, glass thickness and frame construction. The edge resistance of the edge unit (without the glass panes) will now be explained. This edge resistance of the edge unit is defined as the inverse heat flow that is present from the interface of the disc and the sealant layer 154 on the inside of the unit to the interface between the disc and the sealant layer 154 on the outside of the unit per temperature increment per unit length of the circumference of the edge unit , It is believed that the interfaces of the washer sealants are isothermal to simplify the explanation. Among other things, the definition given above is supported by the publication "Thermal Resistance Measurements of Glazing System Edge-Seals and Seal Materials Using a Guarded Heater Plate Apparatus" by JL Wrigth and HF Sullivan, ASHRAE TRANSACTIONS 1989, V.95, page 2.

In the following description and in the claims, the resistance with respect to 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 cross section of the edge unit and the assumed thermal conductivity of its components. The geometry of such a cross section can be measured simply by examining the edge unit. The thermal conductivity of the components of the peripheral unit or the RES value thereof can be measured in the manner described in the publication ASHRAE TRANSACTIONS. 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 aluminum

The RES value calculated for the edge units of the units in FIGS. 1-4 is now considered. The construction of the edge unit 16 of the unit 10 of Figure 1 had 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 approximately 1.5 cm (0.415 inches) and a lateral length generally parallel to the major surface of the glass panes 12 and 14 of approximately 0.76 cm (0.3 inch). Adhesive layers 24 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 edge unit RES value of unit 10 of the construction described above was calculated using the ANSYS program as 62.2 h-° K / joules per meter (4.65 h-° F / BTU per inch circumference).

The construction of the rim unit 32 of the unit 30 of Figure 2 had a pair of glass panes spaced approximately 1.07 cm (0.432 inches) apart. An end wall 32 was approximately 0.229 cm (0.090 inches) thick. The edge unit RES of unit 30 of the construction described above was calculated using the ANSYS program at 1390 ° C / joules per meter (104 ° F / BTU per inch size).

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

A unit similar to unit 50 of Figure 3 with a pair of glass panes 12 and 14 spaced 1.14 cm (0.45 inches) apart, an adhesive layer 54 of silicone approximately 0.475 cm (0.187 inches) thick and a desiccant therein and a moisture-proof butyl sealant 58 about 0.475 cm (0.187 inches) thick had an edge unit RES value of about 1132 h-° K / joules / m girth (84.7 h-° F / BTU per inch girth) ) which was calculated using the ANSYS program. In order to show the effect that material changes and dimensional changes have on the RES value of the wall unit, the RES values ​​of the edge units of different constructions of the type of units shown in FIG. 3 were compared with each other.

The construction of the edge unit of unit 70 of Figure 4 had a pair of glass panes spaced 1.143 cm (0.45 inches) apart, an edge seal made from a butyl adhesive approximately 0.767 cm (0.312 inches) wide and one Desiccant therein and an aluminum spacer that was about 0.025 cm (0.010 inches) thick and embedded therein. The marginal unit RES value of unit 70 constructed as described above was calculated using the ANSYS program at 62.2 h ° K / Joules per m circumference (4.50 h ° F / BTU per inch circumference).

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

FIG. 11 shows the sectional view of a further embodiment of a spacer designed according to the invention. This spacer 163 has an elastic core 164. In carrying out the invention, the core can consist 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 insulation material. For example, if air, argon, or krypton is used in the compartment, the thin film 165 may be metal. The construction of the spacer and the gas barrier film is selected so that the unit retains the filled gas for the desired life of the unit. For a spacer as shown in Figure 11 using argon as the fill gas and polyvinylidene chloride 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 for retaining the filling gas can be set over the desired service life depending on the properties of the material and the gas compartment.

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

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

The invention further proposes to provide a spacer 163 according to FIG. 11, the housing of which consists entirely of a polymeric material with moisture / gas impermeability properties. Such a spacer housing can be reinforced (e.g. by glass fibers) but does not include a film barrier (ie film 163 does not have thin film 165). Such a polymeric material is preferably a halogenated polymeric material including polyvinylidene chloride, polyvinyldenfluoride, polyvinyl chloride or polytrichlorofluoroethylene. The edge unit of such a spacer 163 can consist entirely of a polymeric material which has a high RES value for the edge unit in comparison to the spacer of FIG.

The spacer of the present invention acts as a barrier to the insulation gas in compartment 18 and has a flawless construction. The term "flawless design" means that the spacer keeps the glass sheets spaced from one another while allowing local deflection of the sheets due to changes in barometric pressure, temperature and wind loads. The feature of maintaining the glass sheets in a fixed spaced relationship means that the spacer prevents the glass sheets from moving substantially towards each other when the edges of the unit are secured in the glazing frame. It is understood that less forces are applied to the edge units of the windows of apartments, which are mounted in a wooden frame, than to the edge units of office buildings, which are mounted by pressure glazing in metal hanging wall systems. Allowing local deflection means that the spacer allows the edge portions of the disc to rotate about its edge during loading of the types described, while not permitting movement other than rotation, ie, translational movement. The degree of error-free construction depends on the type of material and the thickness. For example, metal can be made thin, while plastic must be thicker or reinforced, for example by glass fibers, to form the same flawless construction.

Embodiments of the present invention can be used to improve the performance of the prior art units. For example, if the spacer of unit 10 of Figure 1 is replaced with a stainless steel spacer, the RES value of the rim unit will be from 62.2-243 h-° K / Joule (4.65 to 18.2 h-° F / BTU) per Unit (m) of circumference raised. When the metal thickness is changed from 0.06 cm (0.025 inches) to 0.0127 cm (0.005 inches), the RES value of the edge unit of unit 10 of FIG. 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 m of circumference. When the aluminum strip of the unit of Figure 4 is replaced with a strip of stainless steel, the RES value of the rim unit increases from 60.2 to 593.6 h ° K / Joule (4.5-44.4 h ° F / BTU) per Unit (m) of circumference.

Unit 1 50 of the present invention, which has the spacer unit 152 shown in FIG. 10, has an edge heat loss which corresponds to that of the line 140. The unit 150 designed according to the invention, which is provided with the spacer unit 163 shown in FIG. 11, has an edge heat loss between the line 130 and the line 140, which is, however, close to the 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 FIG. 3, the edge unit designed according to the invention has 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 he 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, so that for the same type of material that fills the diffusion path, the longer and thinner diffusion value of the present invention reduces the loss of fill gas. The path of the argon gas is longer since it is limited to the adhesive layers 154 (see FIG. 10), while in the case of spacers made of organic material the diffusion path runs through the entire width of the spacer surface. A metal barrier is provided in the unit of FIG. 3 in order to reduce argon losses. The metal film provided on the plastic or the PVDC-coated plastic has a thickness in a 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 that is greater than about 0.00762 cm (0.0003 inches) and a thin diffusion path that is 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 legs of the spacer. The thickness of the diffusion path can be reduced by reducing the distance between the legs of the spacer and the adjacent glass pane.

In current tests, a unit with an edge unit with the present invention and a unit with the edge unit shown in FIG. 3 had essentially identical RES values. It is believed that the bead provided inside the spacer has insulated the spacer from convection cooling by the gases in the compartment.

As discussed above, the teaching of the present invention can be used to improve the RES value of the edge unit of a unit by using the spacer shown in FIG. By forming a glass fiber reinforced plastic core 164 and then sputtering a thin aluminum film 165 or gluing any gas / moisture impermeable film such as a PVDC film in a conventional manner, argon is prevented from escaping and the exit path is essentially open limits the sealant or adhesive between the spacer and the washer, as explained in connection with the unit 150 of FIG. 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 plastic spacer having multiple layers, which retains an insulating gas other than air, for example argon, a relatively high RES value or low U. -Value of the edge unit owns and is durable.

The U-value of the frame of the unit will now be explained. The frame also conducts heat. In certain cases, metal frames conduct sufficiently more heat than the edge unit of the unit so that the edge heat loss from the frame covers any increase in thermal resistance with respect to heat losses at the edge of the unit. Wooden frames, metal frames with thermal locks or plastic frames have a high resistance to heat loss, so that the edge heat loss of the unit is therefore more dominant.

The invention is not limited to units that have two disks. It can also be used in units that have two or more disks, such as unit 250 shown in FIG.

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

FIG. 12 shows an edge strip 169 with a substrate 170 which is provided with the bead 160 of the moisture-permeable adhesive, into which the drying agent 162 is mixed. In the preferred embodiment of the invention, the substrate is made of a material, such as a metal or plastic composite, as described above, which is moisture and gas impermeable to retain the insulating gas in the compartment and to prevent moisture from entering the compartment. It also has structural integrity and is resilient so that the glass panes are spaced from each other while still allowing some degree of thermal expansion and contraction that is typically present in various components of the double glazing unit. In practicing the invention, the 304 stainless steel substrate was made about 0.0178 cm (0.007 inches) thick, about 1.588 cm (0.625 inches) wide, and of sufficient length to place the spacer between panes of glass, ie to provide a 0.6 m² (24 inch²) unit. The bead 160 is polyurethane with a mixed in desiccant. A bead about 0.32 cm (1/8 inch) high and about 0.96 cm (3/8 inch) wide 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 the invention, are polyurethanes and silicones. Furthermore, the bead can be a spacer drainage element described in US Pat. 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, such as, for example, in US Pat. Nos. 4,610,771, 4,806,220, 4,853,256, 4,170,460, 4,239,816 and 4,719,127 described.

In practicing the present invention, the metal substrate, after being formed into the spacer profile and the bead, has sufficient strength and elasticity to keep the panes apart while still allowing some degree of thermal expansion and contraction that is normally associated with various components of the double glazing unit occurs. In one embodiment of the invention, the spacer is more stable than the bead, ie sufficiently stable or dimensionally stable to keep the disks at a distance from each other, which the bead cannot. In another embodiment of the invention, both the spacer and the bead can do this. For example, the bead may be formed by a desiccant in a preferred spacer, as disclosed in US-A-3,919,023. As is known to those skilled in the art, a metal spacer can be made through a number of bending and molding operations so that it can withstand appropriate compressive forces. As for the bead 160 disposed on the substrate 170, the substrate 170 is formed into a U-shaped spacer profile with a single wall, which U-shaped spacer profile is able to withstand appropriate compressive forces to space the disks apart hold, regardless of the stability of the bead. As one skilled in the art knows, the magnitude of the compressive forces and the stability depend on the use of the unit. For example, if the unit is attached by clamping the edges of the unit, such as in wall systems, the spacer must have sufficient strength to keep the glass sheets at a distance while being impacted by the compressive forces of the clamping operation. When the unit is assembled and caulked in the joint of a wooden frame to secure it, the spacer, unlike a spacer of a unit that is clamped, does not have to be particularly stable to keep the panes apart.

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

As shown in Figure 13, the strip is moved from left to right between form rolling stations 180 to 185. As the person skilled in the art knows, the invention is not restricted to the number of molding roll stations shown or a specific number of molding rolls at the corresponding stations. According to FIG. 14, the form-rolling station 180 comprises a lower roller 190 with an annular groove 192 and an upper roller 194 with an annular groove 196, which is sufficient for receiving 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 roller 200 of the pressing station 180 according to FIG. 15 and of the other lower rollers of the pressing stations arranged downstream 182 to 185.

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

The grooves of the upper rollers can be designed so that they form the material bead on the substrate.

In practicing the invention, the bead 160 was applied after the spacer profile had been formed, ie 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 form a flat strip into a U-shaped strip.

Loose desiccant provides better thermal insulation than desiccant in a moisture permeable material. However, the handling and placement of loose desiccant in a spacer is, in some cases, a greater limitation than the handling of a desiccant in a moisture permeable matrix. Furthermore, the arrangement of the desiccant in a moisture-permeable matrix increases the service life, since the desiccant takes a longer time to saturation when it is arranged 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.

Spacer profile 158 can be formed into a spacer frame for placement between the panes. The layers 154 and 155 shown in FIG. 1.0 can be applied to the spacer profile or the spacer frame. The invention is not limited to the materials used for layers 154 and 155. However, layers 154 should provide high resistance to the flow of insulating gas in the compartment between spacer 152 and washers 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 layers 154 and / or 155 are applied to the spacer profile, a piece of the spacer profile is cut and bent to the spacer frame. Three corners can be formed, ie, continuous corners, while the fourth corner is sealed 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 FIGS. 17 and 19.

As shown in Figure 18, a length of the spacer profile provided with the bead is cut off, and a notch 207 and grooves (folds) 208 are formed in the spacer profile on the corresponding bend lines in any conventional manner. The area between the grooves is deepened, ie the section 212 of the outer legs 156 on the notch is bent inward as the sections on each side of the groove are pressed against each other to form a continuous, overlapping corner 224, as shown in FIG. The non-continuous corner, ie the fourth corner of a rectangular frame, can be glued or welded to a moisture and / or gas impermeable material. The bead on the corner can be removed before the continuous corners are formed.

According to FIG. 19, the spacer frame 240 was produced from a U-shaped spacer profile when the invention was carried out. A continuous corner 242 was formed by pressing the outer legs of the spacer profile against each other while portions of the spacer profile were bent around the recess to form a corner at 90 °. When the portions of the spacer profile are bent, the depressed portions 244 of the outer legs move inward 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 positioning the glass sheets in a conventional manner and gluing them 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 perimeter channel of the unit (see Figure 10) or on the perimeter of the unit. Argon gas is introduced into compartment 18 in any convenient manner to provide an insulating unit with a rim with low thermal conductivity.