GB2245861A - Edge encapsulation of different sized panels - Google Patents

Abstract

A separate mold or jig for each size of panel e.g. a double glazing unit to be encapsulated is avoided by providing a low pressure modular mold or jig is composed of at least one mold or jig structure (52(A), 52(B), 52(C), 52(D)) for each side of the panel; and optionally at least one discrete mold or jig structure for each corner (54(A), 54(B), 54(C), 54(D)). A table (50) may be provided for supporting the discrete mold or jig structure assemblies together as a mold or jig. The modular mold is assembled around the marginal periphery of a panel to be edge encapsulated to define a closed volume around said periphery, and a settable encapsulating material injected into the closed volume at a pressure of up to 15 atmospheres and set. <IMAGE>

Description

EDGE ENCAPSULATION This invention relates to edge encapsulation.

Over recent years the process of edge encapsulation, wherein a polymeric material is set in situ around the marginal periphery of a panel, especially a glass pane, to be encapsulated, has been used increasingly for the production of edge encapsulated automotive glazings, see for instance the following: GB 1 001 853, GB 675 147, US 4 072 340, EP 76924, WO 85/01468, GB 2 167 337 and GB 2 115 049.

More recently this technology has also been utilised in architectural applications, see, for instance, WO 89/01398.

To produce these edge encapsulated panels a mold is typically used to surround at least the marginal periphery of the object into which the polymeric material may be injected and subsequently hardened. These molds have previously been made up of complete upper and lower mold parts. The panel is placed in the lower mold part, the upper mold part is located on top of the lower mold part to form a closed volume about the panel and the assembly is held in position during the injection and subsequent hardening of the edge encapsulation material.

Using complete upper and lower mold parts has the disadvantage that a slight alteration in the dimensions of the panel to be edge encapsulated will often mean that a new mold must be used, requiring time and expense in the manufacture thereof. A further disadvantage is that if just one part of a mold part is damaged the whole mold part may have to be replaced. These disadvantages may also apply to a jig used to hold or position an edge encapsulation mold in place.

One reason for the design of the known encapsulation molds (discussed above) is the high pressures they are required to withstand, for instance, in automotive applications the polymeric edge encapsulating material is generally introduced at a pressure of several hundred atmospheres. However, for certain applications such high pressures are not required; for instance in architectural glazings or in prototypes for automotive applications.

Thus it has been found that a modular mold may be used for low pressure edge encapsulation to alleviate the disadvantages of the prior art molds and jigs. The term "low pressure edge encapsulation" is used herein to refer to edge encapsulation using an injection pressure of not more than 15 atmospheres, and the term low pressure, used with reference to molds or jigs refers to molds or jigs for use in such a low pressure edge encapsulation process.

Accordingly the present invention provides a low pressure modular mold or jig for the edge encapsulation of a panel composed of at least one discrete mold or jig structure for each side of the panel.

Normally the modular mold or jig is of generally rectangular form. The modular mold or jig may additionally be composed of at least one discrete mold or jig structure for each corner. However, if discrete corners are not used then the side structures are normally mitred at their ends for assembly in to a rectangular form.

Preferably the modular mold or jig comprises, for at least one side of the panel, at least two discrete mold or jig structures constituted by upper and lower sections which are clamped together in use.

In some embodiments of the present invention upper and lower molds, pre-fabricated to circumferentially overlap an upper or lower part of the panel, may be used. These upper and lower molds still have the advantages of the present invention when they are composed of at least one discrete mold structure for each side of the panel.

The present invention further provides a kit of parts for assembly of a modular mold or jig for edge encapsulation of a panel, said kit comprising a set of discrete mold or jig side structures of different length adapted to be secured together whereby a rectangular mold or jig of selected dimensions, as described above, may be assembled.

Additionally, the present invention provides a method of edge encapsulating a panel comprising assembling a modular mold composed of at least one discrete mold structure for each side of the panel around the marginal periphery of the panel, injecting a settable encapsulating material in to the closed volume at a pressure up to 15 atmospheres and setting the encapsulating material.

Preferably the polymeric encapsulating material is injected in to the closed volume at a pressure of not more than 3 atmospheres.

The invention will now be described, by way of example only, with reference to the following drawings, of which: Figure 1 is a schematic plan view of an encapsulated double glazing unit made using tne present invention.

Figure 2 is a cross section through the line Il-Il in Figure 1.

Figure 3 is a plan view of a first embodiment showing a modular mold according to present invention comprising discrete mold structures arranged in the form of a rectangle.

Figure 4 is a cross-section through the line IV-IV in figure 3, with a panel to be encapsulated also shown to facilitate the explanation of the invention.

Figure 5 is a horizontally exploded plan view in diagrammatic form of a second embodiment according to the present invention mounted on a table.

Figure 6 is a cross-sectional representation through the line VI-VI in figure 5.

Figure 7 is a cross-sectional representation through the line VII-VII in figure 5 showing a corner structure; the table is omitted for clarity.

Figure 8 is a schematic plan view of an architectural panel made using the present invention.

Figure 9 is a cross section on the line IX-IX of figure 8 drawn on an expanded scale.

Figure 10 is a schematic plan view of modular mold and jig assemblies in accordance with the invention for producing architectural panels as shown in figures 8 and 9.

Figure 11 is a cross section on the line XI-XI in figure 10 drawn on an expanded scale.

Figure 12 is a schematic cross-sectional view of the corner area marked XII in figure 10 at the level of the line marked XII'-XII' in figure 11 with the double glazing module omitted for clarity.

Figure 13 is a cross section corresponding to Figure 11, of a sub-assembly produced in the process for building up the assembly shown in Figure 10.

Figures 1 and 2 show a rectangular edge encapsulated unit 2. The unit 2 comprises a double glazing module 4 the marginal periphery of which is surrounded by an edge encapsulating polymeric material 6. The material 6 may be chosen from a range of encapsulating agents such as polyurethane or polyvinyl chloride. The double glazing module 4 is of known design made up of two spaced glass sheets 8 separated by a spacer 10 which is inset from the peripheral edges of the glass sheets 8. Many other panels may be edge encapsulated for differing applications such as single monolithic sheets, single laminated sheets or three sheets constituting a triple glazing unit; if desired glass sheets may be used, plain, decorated or opacified: further alternative sheet materials may be encapsulated in place of glass, for example marble, plastics, stonework, stone laminates, metal or coated metal. The variety of materials suitable for the various components of the present invention allow the invention to be used in a wide range of applications such as glazings, spandrels, wall panels, shower screens etc. Normally the panel will be a plane, i.e. flat, panel, but the invention is not limited to plane panels; for example a curved shower screen may be produced in accordance with the present invention. It will be appreciated that this is most conveniently done when the edges of the panel are substantially co-planar.

Figures 3 and 4 show an assembly 12 for producing the unit 2 shown in figures 1 and 2. The periphery of the known double glazing module 4 is surrounded by a modular mold 14 of generally rectangular form. The mold 14 is made up of four discrete mold structures 16 (A-D), one along each side of the double glazing module 4. Each discrete mold structure 16 (A-D) is of substantially C-shaped section and extends longitudinally along the length of the respective side of the module 4 and extends to overlap the outer faces of the module on both sides thereof. The discrete mold structures 16 (A-D) are mitred at their ends and held in a generally rectangular form corresponding approximately to the shape of the double glazing module 4. Known corner keys (not shown) such as corner brackets pop rivetted to the structures 16 (A-D) may be used to hold the mold 14 together.The discrete mold structures 16 (A-D) may conveniently be extruded from suitable materials such as aluminium, aluminium alloys or uPVC (unplasticised polyvinyl chloride).

The discrete mold structures 16 (A-D) are each made up of an upper element 18 and lower element 20 as shown in figure 4. The upper and lower elements 18 and 20 are approximately symmetrical along a plane parallel to the plane of the double glazing module 4, a lower surface 22 of upper element 18 abutting against an upper surface 24 of lower element 20. The lower surface 22 of upper element 18 has a longitudinal projection 26 along its length which co-operates with and engages a longitudinal channel 28 in the upper surface 24 of lower element 20 in order to locate the upper and lower elements 18 and 20 in relation to each other.

The upper element 18 has an upper arm 30 which projects inwardly towards the centre, and extends past the periphery of the module 4. A similar lower arm 32 on the lower element 20 completes the C-section shape of the discrete mold structure 16 (A-D).

Near the ends of each of the arms 30 and 32 there is provided a longitudinal slot 34. The slots 34 carry silicone seals 36. The slots 34 are co-extensive and both the silicone seals 36 are contiguous around the mold 14 when it is assembled together. The silicone seals 36 serve two primary functions; they prevent the glass sheets 8 of the module 4 from being damaged by contact with the upper and lower mold elements 18 and 20, and they bridge and seal the gap between the module 4 and the elements 18 and 20.

Silicone is used as it does not adhere to the encapsulating material 6.

Thus a closed volume 42 is formed defined by the upper and lower mold elements 18 and 20, the silicone seals 36 and the double glazing module 4. This closed volume 42 is the volume in which the encapsulation is to be formed by the polymeric material 6. It is to be noted that the closed volume 42 extends past the marginal periphery of the module 4 so that in the finished unit 2 the spacer 10 may be hidden by the encapsulating material 6; this is one of the advantages of edge encapsulation.

The upper element 18 of discrete mold structure 16 (D) has a fill hole 38 constituted by an internally threaded bore through it. Discrete mold structure 16 (B) has a similar hole (not shown) through its upper element 18, which acts as a vent hole. Attached to the fill hole 38 on the side of the upper element 18 distant from the module 4 is a fill pipe 40 screwed into the fill hole 38 and sealed with a silicone '0' ring 41 between the face of upper element 18 and a step in the wall of pipe 40. The pipe 40 is connected to a pressurised source of encapsulating material (not shown).

To encapsulate the glazing module 4 the upper and lower elements 18 and 20 are clamped together, for instance using G-clamps, so that the glazing module 4 is compressively held between the silicone seals 36. To assist in the final removal of the mold 14 a release agent may be applied to the interior surface of the mold 14. Sufficient pressure is exerted to substantially prevent the egress of any encapsulating material past the seals 36 during the encapsulation stage. This 'clamping' pressure need not be great as only low pressures are used when injecting the encapsulating material 6. Any small egress of encapsulating material 6 past the seals 36 (known as "flashing") may be removed with a sharp blade.An encapsulating material 6 is then pumped into the closed volume 42 at an injection pressure of up to 15 atmospheres; the atmosphere within the closed volume 42 is displaced out of the vent hole (not shown). The vent hole is then closed, material 6 set and the resultant encapsulated double glazing unit removed from mold 14. After removing any flashing the unit 2 may be washed and is then ready for use. Because the discrete side structures 16 (A-D) may be made up of extruded elements they can be produced simply and cheaply. Various combinations of opposing pairs of side structures of differing lengths may be used to produce a variety of molds of selected dimensions and generally rectangular form.

Although it is preferred that the discrete mold structures 16 (A-D) have separate upper and lower sections 18 and 20 as shown, this is not essential. Each discrete mold structure 16 A-D may be of unitary construction, with the discrete mold structures being pressed over the edges of the module 4 with the resilient silicone seals 36 engaging the faces of the module.

A further embodiment of the present invention which avoids the engineering problems associated with producing mitred corners, such as the problem of forming effective seals of the corners, is shown in figures 5, 6 and 7. This assembly may be used to produce units similar to that shown in figures 1 and 2.

Referring to figures 5 to 7 (in which the panel to be encapsulated has been omitted) a table 50 (omitted from figure 7 for clarity) is shown supporting a modular mold 51 composed of four discrete side structures 52 (A-D) each made up of upper and lower elements 58 and 60 respectively, and four discrete corner structures 54 (A-D). The table 50 is a flat, rectangular table with two perpendicular channels or grooves 66 therein. The grooves 66 run the entire lengths of adjacent sides of the table and are situated towards the periphery of the table 50 so that the discrete side structures 52 (A and D) and the discrete corner structures 54 (A, B and D) can be conveniently mounted on the table 50 locating in the grooves 66. The side structures 52 (A-D) are similar to the side structures shown in figures 3 and 4 except that they do not have mitred ends; instead they have squared off corners so they are of generally rectangular form when viewed in plan section. Additionally two of the side structures 52 (A and D) have longitudinal ridges 56 on the undersides of their lower elements 60 which enable them to be located in the channels 66 and which are discussed below.

The four corner structures 54 (A-D) are also made up of upper and lower corner elements 62 and 64 respectively (figure 7) forming C-shaped sections extending from the corners. In plan view the corner structures 54 (A-D) are of generally L-shaped form (figure 5). The corner structures may typically be produced by casting or molding and are usually then machined to a final tolerance, all using known methods. The upper and lower corner elements 62 and 64 are maintained in relation to one another in a similar manner to the upper and lower side elements 58 (A-D) and 60 (A-D), i.e. using mating projections 68 and channels 70 which, in this case, are L-shaped in plan. The side structures 52 (A-D) and the corner structures 54 (A-D) each define cavities 74 within the arms of the C-shaped sections.

The lower corner elements 64 of discrete corner structures 54 (B and D) have longitudinal ridges 72 on their undersides that are similar to the ridges 56 in the lower side elements 60. The longitudinal ridges 72 locate the corner structures 54 (B and D) in the channels 66. The lower corner element 64 of discrete corner structure 54 (A) which is located over the intersections of the channels 66 has two ridges 73 on its underside extending at right angles to each other which locate the lower corner element 64 of corner structure 54 (A) in the channels 66, see figure 7.

Thus the corner structure 54 (A) is located in three dimensions on the table 50. The side structures 52 (A and D) and the corner structures 54 (B and D) are located in two dimensions on the table 50. The side structures 52 (A and D) can be abutted against the corner structure 54 (A) by sliding them along the channels 66. The corner structures 54 (B and D) can be similarly abutted against the side structures 52 (A and D). By using the table 50 in this manner two sides of the mold may be located positively and accurately in a simple manner.

The upper and lower side elements 58 and 60 (Figure 6) each have longitudinal slots 76 carrying silicone seals 78.

The upper and lower corner elements 62 and 64 also each have slots 80 extending longitudinally from the apex of the corner carrying silicone seals 79. The silicone seals 78 and 79 are contiguous and form continuous upper and lower seals when the mold is assembled, performing the same function as the silicone seals 36 in the embodiment illustrated in figures 3 and 4.

Using the table 50 as described above the mold may be assembled and used for encapsulating a panel in a process similar to that outlined above in relation to figures 1 to 4. Neither the table 50 nor the channels 66 are essential to the present invention, they merely provide a convenient means for locating the discrete mold structures.

If discrete corner structures are formed at non-perpendicular angles, for instance corners over an angle of 600, then other shapes, such as equilateral triangles for corners at 60 , may be produced using the same discrete side structures. These other corner structures may be formed in the same way as the perpendicular corner structures. Thus the present invention provides for a wide variety of shapes to be produced.

Moreover, by using discrete corner structures with square ends to abut the discrete side structures a wide variety of sizes may be formed without the need to provide side structures with ends mitred to form corners. Further the cost of replacing one of the structures is far lower than the cost of replacing a mold, especially for the side structures which can be formed of extruded sections.

Figures 1 to 7, as described above, are concerned with the use of modular molds in accordance with the invention.

Figures 8 onwards relate to the use of both modular molds (separate "inner" and "outer" molds, referred to in the following description as "sub-frames", each being made up from discrete side structures) and modular jigs.

Figure 8 shows an architectural unit 102 having a plane panel 104 and a frame 106.

Figure 9 shows the plane panel 104 which is a double glazing module made up of two sheets of glass 108 and 109 separated by a spacer frame 110. In use the glass sheet 108 will be the interior sheet. This double glazing module is of the well known design with the spacer frame 110 inset from the peripheral edges 111 of the glass sheets 108 and 109.

Around the marginal periphery of the double glazing unit is an encapsulating material 112.

The frame 106 comprises a rectangular interior sub-frame 114 and a rectangular exterior sub-frame 116, the exterior sub-frame 116 having an exterior face 117. The two sub-frames 114 and 116 are separated by a thermal break 118 to avoid a high thermal conductivity pathway from the exterior to the interior of the unit 102. The interior sub-frame 114 is made up of four rigid frame elements 114(A), 114(B), 114(C) and 114(D); similarly the exterior sub-frame 116 is made up of four rigid frame elements 116(A), 116(B), 116(C) and 116(D). Each of the individual frame elements 114 (A-D) and 116 (A-D) extends along one side of the plane panel 104 and extends to overlap the outer faces of the panel 104 on both sides thereof. Thus there are a total of eight frame elements, four in each sub-frame.In this embodiment each of the four rigid frame elements 114 (A-D) constitutes a discrete side structure.

Similarly, each rigid frame element 116 (A-D) constitutes a discrete side structure.

Each of the frame elements 114 (A-D) and 116 (A-D) needs to be rigid i.e. self supporting prior to the edge encapsulation stage.

Among the suitably rigid materials which may be used are aluminium, aluminium alloys and uPVC.

The sub-frames 114 and 116 extend inwardly past the peripheral edges of the glass sheets 108 and 109 to provide them with support, so that the frame elements extend to overlap the outer faces of the panel 4 on both sides thereof, providing protection for the edges of the panel. The edge encapsulating material extends under the frame elements to overlap the outer faces of the panel on both sides thereof and supports the sub-frames from the glass sheets 108 and 109 to avoid their damaging the glass sheets 108 and 109. The position of the sub-frames 114 and 116 may also ensure that the spacer 110 is suostantially hidden from view; if necessary the spacer 110 can be coloured so that even when it is observed it does not detract from the overall appearance of the unit 102.

The sub-frames 114 and 116 are secured to the edge encapsulating material 112, either by the edge encapsulating material 112 bonding to the frame elements 114 (A-D) and 116 (A-D) and/or by the set edge encapsulating material 112 being sufficiently rigid to hold the sub-frames 114 and 116 in place by engaging around projections 120, some of which are of re-entrant form, on the sections forming the frame elements. The edge encapsulating material 112 also secures the plane panel 104 in place. Thus the frame elements 114 (A-D) and 116 (A-D), the plane panel 104 and the edge encapsulating material 112 are all maintained in position relative to one another.

The section used for exterior frame elements 116 (A-D) is provided with a first channel 122 and a second channel 124 opening on the peripheral edge of the unit. The first channel 122 is shaped to allow a weatherseal (not shown) to be inserted therein.

In a typical architectural glazing structure the weatherseal will abut against a transom or a mullion. The second channel 124 is shaped to allow a hinge or a fixing such as a catch, strut or latch to be inserted thus providing the unit 102 with sufficient versatility to be used in a variety of applications. The second channel 124 may also be employed to link adjacent units together, or to link the unit to a building.

The frame 106 need not be of the design exemplified above; this design merely serves to illustrate some of the advantages which may be obtained with a modular mold according to the present invention which is incorporated in the finished product. The frame may be adapted to provide means for many other functions and applications.

A method of manufacturing the architectural unit illustrated in figures 8 and 9 will now be described by way of example only.

The method may be regarded as comprising four steps: (1) Providing a plane panel.

(2) Preparing interior and exterior sub-frames.

(3) Mounting the sub-frames and plane panel in a jig.

(4) Edge encapsulating the plane panel.

The method will be described with reference to these four steps.

(1) In the first step, a rectangular plane panel 104 comprising in this case two opposed spaced glass sheets 108 and 109, separated by and adhered to a spacer frame 110 is assembled in known manner.

(2) A rectangular interior sub-frame 114 is built up of four rigid aluminium frame elements 114 (A-D), each mitred at its ends, and held together in the form of a rectangle using known aluminium corner keys (not shown). A rectangular exterior sub-frame 116 is similarly built up of four rigid aluminium frame elements 116 (A-D), each mitred at its ends, held together in the form of a rectangle using known aluminium corner keys (not shown). Typically the corner keys used comprise aluminium corner brackets which may be either pop rivetted onto the frame elements or glued into place using an industrial adhesive. The rigid frame elements 114 (A-D) and 116 (A-D) are extruded lengths of aluminium section, although other sufficiently rigid materials such as aluminium alloys and certain plastics (e.g. uPVC) may also be used.Each, or any, of the rigid frame elements 114 (A-D) and 116 (A-D) may be pre-treated on the surfaces which are to contact the edge encapsulating material 112 to increase (or if desired to decrease) the bonding between the edge encapsulating material 112 and the frame elements 114 (A-D) and 116 (A-D).

Two holes 150 are drilled in elements 116(B) and 116(D) of the sub-frame 116 as near to two opposing corners as possible without weakening the mitres (see figure 12) to serve as fill and vent holes. The holes 150 are drilled in the portion of the frame elements between the two channels 122 and 124 as explained below.

(3) In the third step, the sub-frames and plane panel are mounted in a jig assembly with the peripheral edge of the panel extending into the hollow section of the frame constituted by the discrete side structures (see Figure 11). A flat table 128 mounted on a pivot (not shown) is used to support the assembly.

The pivot allows the flat table 128 to be set at a variety of angles to the horizontal e.g. to ensure the vent hole in sub-frame 116 is higher than the fill hole.

Referring to Figures 10, 11 and 12, four first jig elements 126 (A-D) of truncated U-section are fixably mounted on the flat table 128 to form a rectangle. At the corners of the rectangle the ends of the first jig elements 126 (A-D) are mitred where they abut against each other and further Cdt away at the corners where the fill and vent holes 150 will be located as further discussed below. A silicone seal 146 in the form of a strip is mounted in a slot in the upper face 147 of the inner limb of the U-section and extends the length of each jig element 126 (A-D) forming a continuous rectangular seal. A tapering projection 142 is provided on the upper face 149 of the outer limb of the U-section and similarly extends the length of each jig element 126 (A-D). The purpose of seal 146 and projection 142 are more fully described hereinafter.

The four first jig elements 126 (A-D) are each held in place on the table 128 by a spaced pair of similar fixing means 130. The fixing means 130 each comprise a metal tongue 132, a metal post 134 and a threaded bolt 136 which engages a threaded bore in the table 128. The tongues 132 extend into recesses 138 in the first jig elements 126 (A-D) and the bolts 136 are tightened so that the tongues engage against the lower surfaces of the recesses 138 and the upper surfaces of the posts 134.

The exterior sub-frame 116 is next located in the U-section openings in the first jig elements 126 (A-D) which are shaped to receive it and have a smooth surface to avoid damaging the exterior face 117 (Figure 9) of exterior sub-frame 116. Four similar second jig elements 140 (A-D), each of substantially rectangular cross-section, are then placed over the jig elements 126 (A-D) around the exterior sub-frame 116. The second jig elements 140 (A-D) have channels 144 in their lower faces 145 which extend the length of the second jig elements 140 (A-D) and corresponding projections 142' on their upper surfaces 145'. The projections 142 of first jig elements 126 (A-D) and the channels 144 of second jig elements 140 (A-D) cooperate to locate the second jig elements 140 (A-D) in position on first jig elements 126 (A-D) abutting against the exterior sub-frame 116.

Second jig elements 140 (A-D) are each mitred at one end and cut square at the other end so that, when assembled to form a rectangle, they produce closed mitred joins at one pair of opposite corners of the rectangle, but leave the sub-frame 116 exposed at the other pair of opposite corners for access to the fill and vent holes 150.

The plane panel 104 is then mounted over exterior sub-frame 116 as shown in Figure 11 with the peripheral edges of the panel 104 overlapping the sub-frame 116 on each side of the rectangle.

The panel 104 rests on the silicone seal 146 which is provided to prevent the exterior glass sheet 109 touching the sub-frame 116, and also to seal the gap between sheet 109 and the sub-frame 116 during formation of the edge encapsulation.

Referring again to Figure 11, a set of third jig elements 148 (A-D) is provided each of which is of truncated n-shaped hollow cross-section with a stepped upper face 149(1 and a channel 144' in its lower face 149' and mitred at both ends.

Each third jig element 148 (A-D) has two additional internal channels 151 in which are located silicone seals 153 and 155.

The three sets of jig elements 126 (A-D), 140 (A-D) and 148 (A-D) constitute, in their respective triplets, discrete side structures 141 (A-D); one on each side of the panel 104. Before the third jig elements 148 (A-D) are located over second jig elements 140 (A-D), they are inverted on a flat supporting surface in the form of a rectangle and the assembled interior sub-frame 114 fitted into the rectangular jig so formed to provide a sub-assembly of third jig elements and a sub-frame, one side of which is shown in cross section in Figure 13. The silicone seals 153 and 155 compressively hold the interior sub-frame 114 in place in the hollows of the third jig elements 148 (A-D).

The sub-assembly made up of third jig elements 148 (A-D) and interior sub-frame 114 is mounted over the second jig elements 140 (A-D) with projections 142' on second jig elements 140 (A-D) engaging in and locating channels 144' in third jig elements 148 (A-D). The silicone seal 153 rests on the interior pane 108 of the plane panel 104 to seal the gap between the panel and the interior sub-frame. The silicone seal 155 bridges and seals the gap between the interior sub-frame 114 and the exterior sub-frame 116; this gap will become the thermal break in the final architectural unit.

Figure 12 illustrates the arrangement of first and second jig elements 126 (A and B) and 140 (A and B) at the two opposing corners where the encapsulating material is to be injected and vented respectively (one corner is shown, the opposite corner is similar).

Figure 12 shows the second jig elements 140(A) and 140(B) cut square at their adjacent ends and exposing one corner of the sub-frame 116; the first jig elements 126(A) and 126(B) are mitred toward their inner edges at the corner and cut square toward their outer edges to similarly expose the corner of the sub-frame. The broken lines show the second jig elements 140 (A and B) extending beneath the exterior sub-frame 116. Thus, there is in effect only a partial mitre at the corners of the fill and vent holes to enable access to these holes. The silicone seals 146 must be continuous around the sub-frame 116, thus the first and second jig elements 126 (A and B) and 140 (A and B) are also continuous in the region of the seals 146. This arrangement allows access to the hole 150 which can be used as either a fill or vent hole.The hole 150 is drilled between the first and second channels 122 and 124 respectively, instead of in the exterior face 117, to avoid deleteriously affecting the exterior appearance of the unit 102.

Figure 12 also shows adjacent frame elements of exterior sub-frame 116 joined by a simple mitre, which is a convenient method of obtaining a perpendicular corner.

(4) It will be seen that frame 106 with planar panel 104 and seals 146, 153 and 155 together define a closed volume 157 with fill and vent holes 150. In this step, a settable edge encapsulating material is injected into the closed volume 157, and set.

Referring again to figure 11, pressure is applied, using G-clamps (not shown), to the upper surfaces 149" of the third jig elements 148 (A-D) to hold jig elements 140 (A-D) and 148 (A-D) in place on jig elements 126 (A-D) during the edge encapsulation process. Thus the jig elements 126 (A-D), 140 (A-D) and 148 (A-D) are held in position by the force exerted by the G-clamps and by their co-operating projections and channels 142, 144 and 142',144' respectively. Additionally the first jig elements 126 (A-D) are held by tongues 132 as discussed above. The exterior sub-frame 116 is located on the suitably shaped lower interior surface of the first jig element 126 (A-D) and held in position by the force exerted through the second jig elements 140 (A-D) by the G-clamps.

The interior sub-frame 114 is compressively held between the silicone seals 153 and 155 and located against the interior surface of the third jig element 148 (A-D). The glazing module is compressively held between silicone seals 146 and 153.

The flat table 128 is rotated to be vertical in such a way that the corner of the frame 116 adjacent the fill hole is the lowest part of the frame, and so that the corner of the frame adjacent the vent hole is the highest part of the frame. Thus, when the edge encapsulating material 112 is introduced it can displace the air within the closed volume 157 through the vent hole with the minimum disruption to the flow of the encapsulating material 112.

At this stage the edge encapsulating material 112 is introduced to fill the closed volume 157. When the air has been displaced from closed volume 157, the vent hole is plugged.

Typically the material 112 is introduced at a pressure from 0.1 to 3 atmospheres, although the assembly may be suitable for pressures up to about 10 atmospheres if held in place with sufficient force. The material 112 is then set. Typically, when a two component edge encapsulating material 112 is used, such as a polyol:isocyanate system, the setting is a curing process. The curing is simply an exothermic reaction between the two components. For a polyol:isocyanate encapsulating material 112 the assembly is left for between 10 and 20 minutes to allow curing and then the pressure is released from the upper surface 149" of the third jig element 148 (A-D). The second and third jig elements, 140 (A-D) and 148 (A-D) respectively, are then removed and the edge encapsulated architectural unit 102 (in figures 8 and 9 and described above) extracted from the jig elements 126 (A-D).

If necessary the small amount of edge encapsulating material 112 remaining from the fill and vent holes may be removed and the unit 102 washed. The unit 102 is then ready for use.

The following Example describes, by way of illustration only, the use of the method described above to produce an architectural double glazing unit in accordance with the invention.

EXAMPLE A double glazing module comprising two sheets of 6 mm float glass separated by and adhered to a 20 mm wide Tremco (Trade Mark) swiggle spacer frame giving a 20 mm air gap was provided and its peripheral glass surfaces treated to enhance the adhesion between the glass and the encapsulating material by wiping Betawide (Trade Mark) VP 04604 and then priming with Betaprime (Trade Mark) 5001.

Interior and exterior sub-frames were then made up as described above, and the faces of the frame elements which would contact the edge encapsulating material were treated to enhance their adhesion to that material. The treatment comprised a two stage process which included a degreasing step and a priming step. The elements were wiped with a Betaclean 3100 (Trade Mark) degreaser and primed with Betaprime (Trade Mark) VP1706 (A & B) a two stage primer system.

All of the above treatment materials were obtained from Gurit-Essex (UK) Ltd. of 1B Gresham Road, Bermuda Ind. Estate, Nuneaton, Warwickshire, England. The materials were applied in accordance with the instructions supplied therewith.

Interior and exterior sub-frames 114, 116 were made up and mounted using jig elements 126 (A-D), 140 (A-D) and 148 (A-D) as described above with the table 128 horizontal.

The assembly was then secured using G-clamps acting against the underside of the table 128 and against the upper face 149 " of the stepped section on the third jig elements 149 (A-D).

Sufficient pressure was exerted to prevent escape of any encapsulating material past any of the silicone seals during the encapsulation process.

The jig elements were then heated by running hot water at 600C through water pipes (not shown) in contact with the jig elements. This heated the metal frame up sufficiently to avoid it inhibiting the exothermic reaction between the two components of the encapsulating material, thereby ensuring an even cure of the encapsulating components throughout the closed volume 157.

With the table pivotted at an angle to the horizontal as discussed above, an encapsulating material was injected into the closed volume 157 to edge encapsulate the double glazing module.

For the encapsulating system a two component polyol:isocyanate system comprising Polyol Hyperlast (Trade Mark) 7850442 and Isocyanate Hyperlast (Trade Mark) 21875/009 was used. Both these components were obtained from Macpherson Polymers Limited of Station Road, Birch Vale, Stockport, Cheshire, England. The two components, at ambient temperature, were mixed in a weight ratio of 4.5 polyol:1 isocyanate just before being pumped into the assembly. The mixture was pumped in at about 2 atmospheres of pressure. Because such low pressures are used (in edge encapsulation of vehicle windows using Reactive Injection Moulding pressures up to about 100 atmospheres are used) the components of the system can be manufactured to less exacting tolerances than those used in vehicle edge encapsulation processes.

Once filled the vent hole was plugged and the assembly was left for about 13 minutes before the table 128 was brought to the horizontal, the G-clamps were removed, the second and third jig elements were then removed. The encapsulated panel was extracted, cleaned and surplus material at the fill and vent holes removed.

The panel was then ready for use.

Using the present invention, molds and jigs may be made up from interchangeable modular components of any required size. It thus enables panels of non standard size to be edge encapsulated without the expense of providing mold structures suitable only for edge encapsulation of that size of panel.

Claims (22)

1. A low pressure modular mold or jig for the edge encapsulation of a panel composed of at least one discrete mold or jig structure for each side of the panel.

2. A modular mold or jig according to claim 1 of generally rectangular form.

3. A modular mold or jig according to claim 1 or claim 2 which is additionally composed of at least one discrete mold or jig structure for each corner.

4. A modular mold or jig according to claim 2 wherein the side structures are mitred at their ends for assembly in to a rectangular form.

5. A modular mold or jig according to any of the preceding claims which comprises, for at least one side of the panel, at least two discrete mold or jig structures constituted by upper and lower sections which are clamped together in use.

6. A modular mold or jig according to claim 5 in which the upper and lower sections include cooperating means which engage to hold the upper and lower sections in position relative to each other.

7. A modular mold or jig according to any of the preceding claims wherein the discrete mold or jig structures for each side of the panel comprise at least one longitudinal sealing element whereby, when the structures are assembled together, a continuous seal is formed to seal a hollow cavity around the edge of the panel placed in the mold or jig for edge encapsulation thereof.

8. A modular mold or jig according to any of the preceding claims which additionally comprises means for securing said discrete mold or jig structures together.

9. A modular mold or jig according to claim 8 wherein said means includes a table for supporting the discrete mold or jig structures assembled together as a mold or jig.

10. A modular mold or jig according to claim 9 wherein said table is provided with at least one pair of locating means extending at right angles to each other for location of adjacent sides of a rectangular mold or jig.

11. A modular mold or jig according to claim 10 wherein said locating means comprise perpendicular channels in the surface of the table, and the mold or jig structure contacting the table on said two adjacent sides are provided with ridges on their undersides which engage in said channel for location of the mold or jig structures on the table.

12. A modular jig according to any of the preceding claims wherein the jig structures for each side of the panel are adapted to receive and secure one side of a rigid hollow section frame which serves as a mold for the edge encapsulation.

13. A modular jig according to any of the preceding claims in which discrete mold structures for each side of the panel are adapted to overlap the outer faces of the panel on both sides thereof.

14. A low pressure modular edge encapsulation mold substantially as hereinbefore described with reference to, and as illustrated in, Figures 3 and 4, Figures 5 to 7 or Figures 10 to 13 of the accompanying drawings.

15. A modular jig for supporting a hollow section frame to be used as a mold for the edge encapsulation of a panel substantially as hereinbefore described with reference to, and as illustrated in, Figures 10 to 13 of the accompanying drawings.

16. A kit of parts for assembly of a modular mold or jig for edge encapsulation of a panel said kit comprising a set of discrete mold or jig side structures of different length adapted to be secured together whereby a rectangular mold or jig of selected dimensions according to any of the preceding claims may be assembled.

17. A method of edge encapsulating a panel comprising assembling a modular mold composed of at least one discrete mold structure for each side of the panel around the marginal periphery of the panel to form a closed volume about the marginal periphery of the panel, injecting a settable encapsulating material in to the closed volume at a pressure up to 15 atmospheres and setting the encapsulating material.

18. A method according to claim 17 in which a modular jig composed of at least one discrete jig structure for each side of the panel is used to locate the modular mold structures in place.

19. A method according to claim 17 or 18 in which the encapsulating material is injected into the closed volume at a pressure of not more than 3 atmospheres.

20. A method according to any of claims 17 to 19 in which the modular mold is removed from the edge encapsulated panel after the encapsulating material has set.

21. A method according to any of claims 17 to 20 in which discrete mold structures extend to overlap the outer faces of the panel on both sides thereof.

22. A method of edge encapsulating a panel substantially as hereinbefore described in the Example.