IE43649B1

IE43649B1 - Multiple panes

Info

Publication number: IE43649B1
Application number: IE2678/75A
Authority: IE
Original assignee: Saint Gobain
Priority date: 1974-12-11
Filing date: 1975-12-09
Publication date: 1981-04-22
Also published as: JPS5754456B2; IE43649L; ATA943275A; ZA757740B; BR7508176A; JPS5415924A; DK560875A; NL7514379A; DE2555383B2; CA1068097A; NL178804C; NO140004C; JPS5442367B2; FI58384C; DK151222C; AU497966B2; FR2294313A1; ES443306A1; NZ179493A; SE7513799L

Abstract

1524849 Extrusion device for multiple pane SAINT-GOBAIN INDUSTRIES 10 Dec 1975 [11 Dec 1974] 09923/78 Divided out of 1524848 Heading C1M An apparatus for extruding a spacer on to a glass sheet (e.g. in the formation of a double glazing pane) comprises an extrusion head rotatably mounted in relation to the moveable sheet so that the angle subtended by the extrusion axis and the surface of the sheet is 15-45 degrees. In Fig. 4 of the drawings the extrusion nozzle 12 subtends an angle α with the glass sheet 14 and the cutter 17 cuts the mass when all four sides of the sheet has been coated. The process and the product are claimed in Specification 1,524,848.

Description

The present invention relates to spacers f'or a multiple pane comprising two or more translucid or transparent sheets, for example of glass, separated hy the spacer which is of plastics material placed at their periphery and which isolates from the exterior atmosphere the air space between the sheets forming the pane.

In the description which follows reference will be made to glass sheets but it will be understood that other transparent or translucent materials may be used for the sheets of a pane.

There are known joints for such panes which have a double role: on the one hand of ensuring airtightness of the infernal air spaces situated between the glass sheets thus preventing migration of vapour and dust from the external atmosphere and, on the other hand to maintain the glass sheets firmly in place one with respect to the others at the desired separation.

These joints, when they are of plastics material, are usually formed of an interior band or spacer” of a first plastics material of the polyisobutylene type and by an exterior mastic of a second plastics material which is elastomeric, of the silicone or polysulphide type. This mastic is injected between the ^spacer and the edges of the glass sheets and, owing to its excellent adhesive properties it maintains the sheets in a correct position while also contributing to the airtightness of the assembly. The interior band itself playa, among others, the role-of a thickness spacer and allows separation of the sheets in order to maintain between them the desired air space. -2<3648 In order to ensure absorption of humidity contained in the air layer· separating the two 3li.es sheets, there is introduced into this spacer a desiccating substance, such as silica gel, levilite or a substance of the molecular sieve type.

The spacers of multiple insulating panes may be made starting from lengths of thermofusible and auto-adhesive material of the hot melt type and with such spacers it ia possible to obtain relatively large spacings between the glass sheets. On the other hand this process of manufacture has not ao far been fully automated satisfactorily.

Bands obtained hy extrusion are suited especially well to automatic manufacture of multiple panes. Devices intended for positioning the interior spacer and the exterior mastic layer have been described in British Patent Specifications Nos. 1, 500,416, 1,418,565, 1,455,588 and 1,441,798 and French Patent Publications 74.34334 and 74.34640.

During automatic deposition of spacers of large thickness, for example using the machines described in British Patent Specification No. 1,441,798 it is necessary that the . plastics material have specific characteristics with regard to viscosity to allow its extrusion and to ensure good adhesion qualities to the glass.

Plastics spacers made hy these methods have given good results for layers of air having a thickness of about 5 to 6 mm hut above these thicknesses the spacers may deform and no longer ensure the functions of spacing and airtightness in a satisfactory manner. For a given -3S6 4S thickness of a layer of air between the sheets the required thickness of the spacer is its dimension measured in the direction perpendicular to the faces of the sheets of the pane.

The Applicants have found that it is possible to avoid these disadvantages and in particular to manufacture multiple panes having a spacer of large thickness by using for the spacers , a material having certain viscosity characteristics.

Taking account of the physical characteristics of the band - viscosity and adhesion to the sheet - it is necessary however to feed the band at an angle within certain limits with respect to the plane of the pane.

According to one aspect of the invention, there is provided a multiple pane comprising at least two transparent or translucid sheets, separated by a spacer adjacent their periphery, the spacer being of a composition which has a viscosity at 40°C of at least 115° Mooney measured at the end of an eight minute test as measured by a Mooney consistometer.

The organic material forming the spacer may advantageously be formed of a mixture of polyisobutylene and of butyl rubber (a co-polymer of isobutylene and isoprene) the weight ratio of polyisobutylene to butyl rubber being from 4:1 to 8:1, preferably 6:1.

According to another aspect of the invention, there is provided a method of depositing a spacer on a transparent or translucid sheet for a multiple pane according to the second preceding paragraph, which comprises extruding through an extrusion nozzle on to the sheet a plastics composition which has a Mooney viscosity not less than 115° measured at 40°C at the end of an 8 minute test by a Mooney consistometer, the axis of extrusion forming an angle from 15 to 45° with the surface of the sheet.

According to a further aspect of the invention, there is provided an apparatus for making a multiple pane according to the invention,which comprises an extrusion device having an extrusion head mounted for rotation on a body of the extrusion device and means for supporting the sheet adjacent the head, the sheet being movable relative to the head to allow deposition of a band of plastics material on the sheet surface while the angle subtended by the axis of extrusion and the surface is from 15 to 45°, the distance between the body and the sheet being variable, the rotation of the head relative to the body and said means causing variation of the angle subtended by the axis of extrusion and said surface. @48 In one embodiment of such apparatus, the head and the body of the extrusion device each have a flange having conical sides, the respective flanges being held together by a collar of which the internal profile is complementary to that of the conical sides of the flanges.

Preferred embodiments of the invention will be described by way of example with reference to the accompanying drawings. In these drawings: Figure 1 is a section of part of a double pane of relatively large thickness, Figure 2 is a curve illustrating the variation at 40°C as a function of time of the Mooney viscosity of the material forming the spacer of Figure 1, Figure 3 is a curve showing the variation as a function of temperature of the Mooney viscosity measured at the end of an 8 minute test of the material forming the spacer of Figure 1, Figure 4 is an elevation in partial section of the head of an extrusion machine and an extrusion nozzle used for applying the spacer, Figure 5 is an axial section of the extrusion head and of the body of the machine shown in Figure 4, Figure 6 is a transverse soctica along the line VI-VI of Figure 5, and Figure 7 i« an elevation of a device for adjusting the height of the machine of Figure 4.

Reference is first made to Figure 1 which shows a double pane comprising glass sheets 1 and 2 between which is interposed a spacer 3 and which are separated by air space 4» The glass sheets 1 and 2 are maintained in place by an external layer 5 of polysulphide.

The double pane intended for ensuring good thermal insulation should have an air layer 4 of large thickness and, because of this, the spacer 3 has to have a large thickness £ with respect to its height h.

In the automatic process of manufacture which is the subject of the above-mentioned Patent Applications the spacer 3 1® deposited by an injection machine directly from the exit of an injection nozzle onto one of the glass sheets, for example the sheet 1. The second glass sheet 2 ls then placed on the spacer 3 and the assembly is pressed in a continuous manner to apply the glass sheets 1 and 2 closely against the spacer 3 to make an airtight joint. The external layer 5 is then deposited in situ between the two glass sheets 1 and 2 in the space between the-spacer-3 and the edges 6 and 7 of the sheets. It will be appreciated that for automatic deposition of the spacer 3 on the sheet to be possible, it is necessary that the material forming the spacer has accurately determined characteristics of viscosity and adhesion to the glass.

In fact if this spacer adheres badly to the glass 7649 automatic assembly of the pane would be impossible because the spacer material would slide on the surface of the glass as the glass sheet passed below the injection nozzle.

Moreover, if the spacer material does not have the required viscosity characteristics it will, given its thickness, deform, collapse or bend when the second glass sheet is placed on it and it is impossible, by pressing, to ensure an airtight joint.

The applicants have found that automatic deposition of a spacer of thickness greater than 4 mm which can go to 19 mm or more is possible with compositions having a viscosity, expressed in degrees Mooney, greater than 115° measured at the end of an eight minute test at 40°C according to French Industrial Standard 43005 by means of a Mooney consistometer.

Such compositions may comprise, for example, a mixture of polyisobutylene and butyl rubber the ratio by weight of ' polyisobutylene to the butyl rubber being from 4 to 8. The concentrations of the constituents of these compositions may be as follows expressed in percentage by weight. polyisobutylene : from 40 to 70% butyl rubber : from 5 to 17-5% carbon black : from 10 to 40% levilite ' ~ ' : from Oto 20% molecular sieve : from 0 to 5% The molecular sieve used as a desiccant is preferably formed of a mixture of molecular sieves of. which the dimensions of the absorption pores are 4 8 and 10 8 I and of which the weight proportions are the following: -843649 X sieve 5 0, co 4% of the total weight of the composition.

X sieve s 0. to 1% hy total weight of the composition.

By way of example, a spacer having the following compositions: Polyisobutylene : 5θ% butyl rubber : 10% carbon black : 17.5% levilite : 20% molecular sieve : 2.5% subjected to shearing tests according to French Industrial Standard NFT 43005 by means of a Mooney consistometer, has given the viscosity curves as a function of temperature and time, shown in Figures 2 and 3· It is seen that at 40°C measured at the end of an eight minute test, the viscosity of this composition is greater than 115° Mooney.

Such a spacer may be deposited automatically on a sheet of glass at a speed of at least 30 cm/s as it has sufficient adherence to glass and it does not exhibit deformation up to thicknesses which are equal to or even greater than. 19 mm.

The thickness of the spacer may be greater than 4 mm., preferably greater than 12 mm.

The deposition of this spacer may be effected.by a process which comprises extruding the spacer on to one of the glass sheets, in such a manner that its axis of extrusion forms with the line of deposition an angle from 15° to 45° and most advantageously from 25° to 35°.

Figure 4 is an elevation in partial section of the head of an extrusion machine and of an extrusion nozzle illustrating their position with respect to the sheet of - 9 !4S glass on which is extruded the spacer. The head 11 of the machine comprises, on its side, an extrusion nozzle 12 of which the axis ZZ* which is also the axis of the extended mass of material 13, forms with the plane of the sheet of glass 14 an angle OL from 15° io 45° · θη the same side of the head of the machine a support 15 carries a jack 16 which activates a cutter 17 intended to cut the mass when the latter has been deposited on the four edges of the glass sheet 14. The latter, carried by a transport device, not shown in this figure, passes below the extrusion nozzle 12 in the direction of the arrow f.

A pivoting device, not shown, allows the four edges of a rectangular glass sheet to be presented below the nozzle one after the other.

The angle ot. may vary from 15° to 45° in order to ensure a correct positioning and adherence of the spacer on the glass sheet; the optimum angle is a function of numerous parameters such as temperature, state of the surface of the glass and speed of passage.

In one embodiment of the device the extrusion head 11 may be turned about its longitudinal axis.

In Figure 5 it is seen that the extrusion head 11 and the body of the extrusion machine 18, each have a flange having conical sides respectively 19 and 20. Inside the head 11 and the body l8 is situated the extrusion screw 21 which compresses the plastics material forming the spacer and feeds the extrusion channel 22 at the outlet of which is fixed (but not shown in this figure) the extrusion nozzle 12. The extrusion head 11 and the body of the machine 18 are -10maintained in contact ’ey a collar 23 which engages the flanges.

In Figure 6, which is a section of the assembly along plane VT of Figure 5» it is shown that the collar 23 is formed by two half collars 24 and 25 each mounted on an axis respectively 26 and 27 connected by a rib 28. A bolt 29 allows tightening of the two half collars one against the other. As is shown in Figure 5« each of the half collars has an internal section defining a double flange corresponding to the flanges of the ring 19 and 20.

It will be understood that by releasing the bolt 29« it is possible to adjust the angular position of the extrusion head 11 and thus the angle θύ and that by tightening the bolt 29 this head is immobilised in position so effecting an airtight seal between the extrusion head 11 and the body l8 of the machine.

However, on adjusting the angle oC the distance between the glass sheet 14 and the end of the extrusion nozzle 12 is altered.

In order to retain optimum conditions for working, it is desirable to be able to adjust and fix this distance to return it to the desired value. This is possible with the arrangement shown in Figure 7.

As shown in this Figure an extrusion machine housing 30 is supported by a platform 31 mounted to tilt about axle 32 by a beam 33· The axle 32 is supported by the fixed frame 32'. The motor 34 drives the extrusion machine which comprises, among other things, at l8 the body of the machine and at 11 the extrusion head carrying at its end the - 11 _ extrusion nozzle at 12.

The assembly 35 comprises a transporter intended to transport a body of glass below the extrusion nozzle and also to rotate it through 90° each time the spacer has been deposited along ona edge. This assembly is of a type which is known in the glass manufacturing industry and will not be described in detail.' To the left of the framework 36 of the transporter 35« as shown in Fig. 7 is positioned a screwed shaft 37 comprising an abutment 38 which is adjustable in height, immobilised in position by two screws 39 and 40.

On this abutment 38 there rests an abutment 41 integral with the housing 3θ» the platform 31 tending to tilt in the direction of the arrow £ under the action of the compression spring 42. It will be seen that to adjust the distance separating the extrusion nozzle 12 from the glass sheet 14 carried by the transporter 35 it ia sufficient to screw or to unscrew the screws 39 and 40, in order to increase or decrease the height of the abutment 38·

Claims

1. CLAIMS i1. A multiple pane comprising at least two transparent or translucid sheets, separated hy a spacer adjacent their periphery, the spacer being of a composition which has a viscosity at 4O°C of at least 115° Mooney measured at the end 5 of an eight minute test and as measured by a Mooney consistomer.

2. A pane according to claim 1, in which said composition comprises a mixture of polyisobutylene and butyl rubber.

3. A pane according to claim 2, in which the ratio by weight of polyisobutylene to butyl rubber in said composition is from 10 4:1 to 8:1.

4. A pane according to claim 3, in which said ratio is about 6:1.

5. A pane according to any one of claims 1 to 4 in which said composition has the following components by weight: 15 polyisobutylene: from 40 to 70% butyl rubber: from 5 to 17.5% carbon black: from 10 to 40% levilite: from 0 to 20% molecular sieve: from 0 to 55 20

6. A pane according to claim 5, in which the composition has the following components by weight: polyisobutylene: 50% butyl rubber: 10% carbon black: 17.5% 25 levilite: 20% molecular sieve: 2.5%

7. A pane according to claims 5 and 6, in which the molecular sieve comprises a mixture of molecular sieves, one having absorption pores of 4 A, the other absorption pores of 10 A in 30 the following proportion: 43S4S molecular sieve of 4 K: 0 to 4% of the total weight of the spacer o molecular sieve of 10 A: 0 to 1% of the total weight of the spacer.

8. A pane according to any one of claims 1 to 7, in which the spacer has a thickness greater than 4 mm.

9. A pane according to claim 8, in which the spacer has a thickness greater than 12 mm.

10. A method of depositing a spacer on a transparent or translucid sheet for a multiple pane according to any one of claims 1 to 9 comprising extruding through an extrusion nozzle on to the sheet a plastics composition which has a Mooney viscosity not less than 115° measured at 40°C at the end of an 8 minute test by a Mooney consistometer, the axis of extrusion forming an angle from 15 to 45° with the surface of the sheet.

11. A method according to claim 10, in which said angle is from 25 to 35° .

12. A method according to claims 10 or 11, in which the composition comprises a mixture of polyisobutylene and butyl rubber.

13. A method according to claim 12, in which the weight ratio of polyisobutylene to butyl rubber in the mixture is from 4:1 to 8:1.

14. A method according to claim 13, in which said ratio is about 5:1.

15. A method according to claim 10, substantially as hereinbefore described with reference to the accompanying drawings.

16. Apparatus for making a pane according to Claim 1, which comprises an extrusion device having an extrusion head mounted for rotation on a body of the extrusion device and means for supporting the sheet adjacent the head, the sheet being movable _ 14 β S' 6 4 9 relative to the head to allow deposition of a band of plastics material on the sheet surface while the angle subtended by the axis of extrusion and the surface is from 15 to 45°, the distance between the body and the sheet being variable, the 5 rotation of the head relative to the body and said means causing variation of the angle subtended by the axis of extrusion and said surface.

17. Apparatus according to claim 16, in which said angle is from 25 to 35°. 10

18. Apparatus according to claim 17, in which the head and body are connected by conical flanges clamped together by a clamping ring.

19. Apparatus according to claim 16, substantially as hereinbefore described with reference to and as shown in 15 the accompanying drawings.