WO2005088056A1

WO2005088056A1 - Moulded plastic door

Info

Publication number: WO2005088056A1
Application number: PCT/GB2005/000931
Authority: WO
Inventors: Trevor Booth
Original assignee: Trevor Booth
Priority date: 2004-03-12
Filing date: 2005-03-11
Publication date: 2005-09-22

Abstract

The present invention relates to a moulded plastics door (1) comprising first (2) and second (4) opposing panels separated by a spacer, wherein the panels and the spacer together define a void adapted to be filled with an insulating material (16) and characterised in that the spacer is integral with at least one of the panels.

Description

MOULDED PLASTIC DOOR

This invention relates to a moulded plastic door and uses thereof.

Background to the invention.

Conventional, PNC external doors are assembled from a number of components. These components include a panel either of a plastics material or glass, which is set within a extruded PNC sash, by the use of packing material and beading. This sash is then secured, generally via hinges to a door frame. Gaskets are used to provide a seal between the panel and the sash and also between the sash and the outer frame.

There are a number of problems associated with this conventional approach. The packing material and the plastic or glass panel move over a period of time, due to thermal expansion together with shock loadings and vibration generated during use.

The door sash relies upon the packing material and panel to maintain the correct dimensions and "square-ness" within the fixed outer frame. Any alteration in the dimensional relationship between sash and outer frame will create a poor fit, and make the door difficult or impossible to open and close. The expected life of fittings used can be much reduced due to the increased stress on them. This type of sash is also costly to produce due to the number of parts used, namely four mitred cut lengths of PNC sash extrusion, four cut lengths of steel reinforcing tube, four mitred cut lengths of PNC bead extrusion and one PNC or glass panel. This assembly has to be both welded and screwed together to produce the finished sash. The frame within a frame design of the modern PNC door also creates a rather unattractive looking door, in relation to the traditional timber door.

GB 2,133,069 attempts to address some these problems particularly the aesthetics, by fixing a pair of moulded door faces or "skins" to a timber sub-frame by means of adhesive, with a foamed core in the centre. In this way a spacer is created between the two faces. There are obvious potential problems using a timber sub-frame in what can be a very damp environment, namely warping and rotting of the sub-frame, leading to poor adhesion of the skins to the sub-frame. The sash in GB 2,133,069 is still difficult and labour intensive to produce, and mechanical stress related problems in the form of cracking around the mould detail can occur, caused by the dissimilar thermal expansion of the sub-frame and the "skins", as the timber sub-frame is very rigid if made correctly.

US 6,389,768 likewise uses a similar approach but using solid foamed PNC instead of timber to create the sub-frame spacer.

GB 2,183,706A removes the problems inherent to using timber in an external door by locating a PNC extruded sash frame with steel reinforcement as a spacer between two sheets of GRP or PNC material, fixed by means of adhesive. The central space is filled with PNC foam material. Use of the extruded PNC sash enables incorporation of a standard "euro-groove" feature for location of door lock fitments, rather than routing out the timber sub-frame in the previous GB 2,133,069.

Whilst the sash assembly in GB 2,183,706A also improves the aesthetic appearance of this type of door sash, whilst preventing the need for glass or PNC panels to be retained within the sash and therefore the need for packers and beading, it still needs for the conventional PNC extrusion/steel reinforcing sash to be manufactured as a sub-frame spacer prior to fixing of the two outer GRP or PNC faces. The problems inherent with the approach used in GB 2, 183, 706 A, still centre around the use of a sub-frame to hold the assembly together. Namely the door sash sub-frame spacer is still costly and difficult to produce, with additional problems created by rigidly fixing the two facing sheets to the PNC sub-frame. Thermal expansion of door sash face is prevented by fixation to the PNC/steel sub-frame, causing the whole assembly to bow away from the face receiving energy from the sun, in turn leading to poor sealing at the top and the bottom of the door. The dissimilar expansion of the external facing sheet, together with the less rigid but more bendable PNC/steel sub-frame causes this problem, which is precisely why the conventional frame within a frame design used floating packers, and subsequently why the packers moved leading to problems in service.

Surprisingly, we have found a plastic door in which two sheets of thermoforming plastic are pressure moulded in such a way that they interlock, and when filled with Polyurethane foam, form a high quality door, free from any sign of join. We have further found this door has great production advantages, with improved reliability and aesthetics.

Statements of the invention

Thus according to a first aspect of the invention there is provided a moulded plastics door comprising first and second opposing panels separated by a spacer, wherein the panels and the spacer together define a void adapted to be filled with an insulating material and characterised in that the spacer is integral with at least one of the panels.

Preferably the insulating material is a thermal insulator. Even more preferably the insulating material is a foam, for example Polyurethane expanding foam

The first and second opposing panels are moulded in such a way that they interlock and create the required spacer, whilst providing location for a moulded rubber gasket. In this manner a seal is created to enable the injection of an insulating material, such as a foam, for example, a medium density Polyurethane foam, into the void created between the two panels and spacer, whilst concealing the join beneath the rubber gasket. The foam typically consists of two chemicals, Polyol and Isocyanate pre- mixed by machine and injected through a hole cut in the spacer in such a specific quantity that the two chemicals react inside the void to create an expanding foam which fills and packs the void completely and acts as both adhesive and insulation. The foam bonds the assembly together to provide necessary structural integral strength for the door, whilst the foam is sufficiently flexible to allow thermal expansion/contraction of the door sash in service.

Preferably the insulating material is injected into the void via a hole cut in what will be the bottom of the door, after the door has been assembled and placed in a restraining press. After injection of two pre-mixed chemicals, a plug is used to seal this hole, prior to the foaming of the polyurethane mix, to prevent escape of the chemical foam and enable a small amount of pressure to build within the door assembly, hence the need for a mechanical restraining press during this process which takes approximately 20 minutes. After this time the foam has set and the door assembly is now rigidly bonded into a finished door and can be removed from the press.

Each opposing panel is formed in such a way as to interlock whilst creating a spacer between the two, which can vary to suit the dimensions and profile of the door outer frame. This foam filled void also provides excellent insulation properties to the finished door, without the "thermal bridge" at the edge of the finished door sash, associated with a sub-frame filled door sash. Metal or glass-fibre reinforced polyester (GRP) reinforcement may be inserted into the void during assembly, prior to foam injection to provide additional support and screw fixing for door fittings as required and can vary widely to suit the specific applications and fitments. The foam once set will fix any such reinforcement in place. Glass units and sealing gaskets are fitted in a like manner during assembly of the two sides of the door shell, and are again secured and supported by the Polyurethane foam.

In a preferred embodiment of the invention wherein the spacer comprises a first lip which extends substantially perpendicularly from a peripheral edge of the first panel towards, when in use, the second panel.

Even more preferably the peripheral edge of the first panel is a longitudinal edge of the panel. This longitudinal edge is the upright edge when the door is in situ.

The dimensions of the spacer may be modified at the point of manufacture in order to correspond substantially to the dimensions of the door frame.

A means of retaining the first panel in an abutting relationship with the second panel is required. Preferably this is achieved by the provision of a retaining means on one of the panels. Whilst it would be known to one skilled in the art that such retaining means may be selected from the group consisting of, adhesives, nails, tacks, staples or screws, in a preferred embodiment of the invention the retaining means is integral with a panel, and even more preferably still it is integral with the second panel. Preferably an adhesive is applied to the contacting edges of the two door panels to form a further bond. Thus in a further preferred embodiment of the invention the retaining means on the second panel comprises a second lip which is provided on a second longitudinal edge, this second longitudinal edge corresponding to the first longitudinal edge with the second lip extending substantially perpendicularly from the second panel and being adapted to provide a recess for receiving the first lip.

Any joins within a moulded plastics door need to be sealed with a fluid-tight seal in order to prevent, for example, water or air entering the interior of the door, condensing and causing structural damage. Gaskets which are conventionally made of synthetic rubber are used to seal the joins, and are of a type suitable to ensure the synthetic rubber does not deteriorate over time or become less effective and require replacement.

We have found that by the further moulding of the first and second lips, a gasket retaining socket may be formed which mechanically retains the gasket in place whilst further acting as a substantially fluid-tight seal behind the gasket. A rubber sealing gasket may be fitted into the gasket retaining socket to form a seal between the two parts of the spacer whilst at the same time hiding the join between the two faces of the door sash. A second or third seal may be further provided by rubber gaskets fitted to the door outer frame.

Preferably the moulded plastics door comprises un-plasticized polyvinylchloride (UVPC) or a composite material such as glass-fibre reinforced polyester (GRP).

The door panel may comprise two 'skins' of material, typically plastic sheet or a plastic composite such as GRP moulded in such a way that the smaller skin fits inside the larger skin.

The door panel may be additionally moulded to form locations for fittings, such as a door lock and hinge mechanisms. Additional moulding can also provide the features necessary for creating a matching and interlocking pair of double French doors. Matching moulded sidelights can also be formed in this way. According to a further aspect of the invention there is provided the use of a moulded plastics in the manufacture of a door, the door comprising first and second opposing panels separated by a spacer, wherein the panels and the spacer together define a void adapted to be filled with an insulating material and characterised in that the spacer is integral with at least one of the panels. Preferably the moulded plastics comprise UPNC or GRP.

According to a still further aspect of the invention there is provided a moulded plastics door panel comprising a lip, wherein the lip extends substantially perpendicularly from a longitudinal edge of the panel.

Preferably the lip is substantially L-shaped and orientated outwardly relative to the longitudinal edge. In an alternative embodiment of the invention the lip is orientated inwardly relative to the longitudinal edge.

In a further preferred embodiment of the invention the lip comprises a stepped structure orientated outwardly relative to the longitudinal edge.

In a still further preferred embodiment of the invention there is provided a first panel which comprises a substantially L-shaped lip, the lip being orientated inwardly relative to the longitudinal edge and a second panel which comprises a lip which further comprises a stepped structure orientated outwardly relative to the longitudinal edge. The lips of the first and second panel we adapted to co-operate.

According to a further aspect of the invention there is provided the use of a moulded plastics door panel comprising a lip, wherein the lip extends perpendicularly from a longitudinal edge of the panel, in the manufacture of a door according to the invention.

According to a further aspect of the invention there is provided a kit comprising a door according to the invention. Preferably the kit further comprises a door frame.

According to a further aspect of the invention there is provided a method of manufacturing a moulded plastics door comprising the step of bringing together a first and second door panel, wherein the first door panel comprises an integral spacer, such that the integral spacer abuts the second door panel.

A moulded plastic door, a moulded plastic door panel, uses thereof, methods of manufacture or kits substantially as hereinbefore described with reference to the accompanying description and drawings.

Specific embodiment of the invention

Figure 1 illustrates a plan view in cross section of the moulded plastics door when disassembled.

Figure 2 illustrates a plan view in cross section of the moulded plastics door when assembled.

Figure 3 illustrates a plan view in cross section of the moulded plastics door when assembled and secured to a door frame.

Figure 1 illustrates a plan view in cross section of the moulded plastics door 1 when disassembled. The longitudinal edges of first panel 2 are provided with lips 3 a and 3b which extend substantially perpendicularly from the longitudinal edges towards, when in use, the second panel 4. A section of the lips 3 a and 3b which is distal from the longitudinal edge is moulded in a stepped arrangement 5a and 5b, with the steps extending outwardly relative to the longitudinal edge. This stepped arrangement 5a and 5b forms three side walls of a gasket retaining socket (not shown). The longitudinal edges of the second panel 4 is provided with substantially L-shaped lips 6a and 6b which extends substantially perpendicularly from the longitudinal edges towards, when in use, the first panel 2. The L-shape lips 6a and 6b we orientated inwardly relative to the longitudinal edges.

Figure 2 illustrates a plan view in cross section of the moulded plastics door 1 when assembled. The longitudinal edges of a first panel 2 are provided with a lips 3a and 3b which extend substantially perpendicularly from the longitudinal edges towards, when in use, the second panel 4. A section of the lips 3a and 3b which is distal from the longitudinal edge is moulded in a stepped arrangement 5 a and 5b comprising two steps, with the steps extending outwardly relative to the longitudinal edge. This stepped arrangement 5a and 5b forms three side walls of a gasket retaining socket (not shown). The longitudinal edges of the second panel 4 are provided with substantially L-shaped lips 6a and 6b which extends substantially perpendicularly from the panel towards, when in use, the first panel 2. The L-shape lips 6a and 6b we orientated inwardly relative to the panel and form a further portion of the gasket retaining sockets 7a and 7b.

Figure 3 illustrates a plan view in cross section of the moulded plastics door 1 when assembled and seemed to a door frame 9a and 9b. The longitudinal edges of the first panel 2 is provided with a lips 3 a and 3b which extend substantially perpendicularly from the longitudinal edges towards, when in use, the second panel 4. A section of the lips 3 a and 3b which is distal from the panel is moulded in a stepped arrangement 5 a and 5b comprising two steps, with the steps extending outwardly relative to the longitudinal edge. This stepped arrangement 5a and 5b forms three side walls of a gasket retaining sockets 7a and 7b. The longitudinal edges of the second panel 4 is provided with substantially L-shaped lips 6a and 6b which extends substantially perpendicularly from the longitudinal edges towards, when in use, the first panel 2. The L-shape lips 6a and 6b are orientated inwardly relative to the longitudinal edges and form a further portion of the gasket retaining sockets 7a and 7b. Gaskets 10a and 10b we shown secured into gasket retaining sockets 7a and 7b respectively.

Optional reinforcement is shown at 11a and l ib, which in itself may interlock with the assembly at 12a and 12b. A panel 13 or a number of panels may be inserted into the door during assembly prior to foam injection, they may be of metal, GRP or glass glazing units, and may be fitted with gaskets 14a and 14b for sealing purposes. An adhesive 15a and 15b is optionally used to seal and secure the two shells of the door leaf together where they interlock, in addition to the bonding properties of the Polyurethane foam 16 or a foam with properties that may be preferable or suitable alternative. Door lock 17, lock keep 18 and hinge 19 are shown for location purposes.

Claims

1. A moulded plastics door comprising first and second opposing panels separated by a spacer, wherein the panels and the spacer together define a void adapted to be filled with an insulating material and characterised in that the spacer is integral with at least one of the panels.

2. A moulded plastics door according to Claim 1, wherein the spacer comprises a first lip which extends substantially perpendicularly from a peripheral edge of the first panel towards, when in use, the second panel.

3. A moulded plastics door according to Claim 2, wherein the peripheral edge is a first longitudinal edge.

4. A moulded plastics door according to any of Claims 1 to 3, wherein a retaining means is provided on a panel for retaining the first panel in an abutting relationship with the second panel.

5. A moulded plastics door according to Claim 4, wherein the retaining means is integral with the panel.

6. A moulded plastics door according to Claims 4 or 5, wherein the retaining means is provided on the second panel.

7. A moulded plastics door according to Claim 6, wherein the retaining means comprises a second lip provided on a second longitudinal edge and wherein the second longitudinal edge corresponds to the first longitudinal edge and the second lip extends perpendicularly from the second panel and is adapted to provide a recess for receiving the first lip.

8. A moulded plastics door according to any of Claims 2 to 7, wherein the first and second lips are adapted to form a gasket retaining socket.

9. A moulded plastics door according to Claim 8, wherein the gasket retaining socket forms a substantially fluid-tight seal.

10. A moulded plastics door according to any of Claim 1 to 9, wherein the door comprises UPNC.

11. The use of a moulded plastics in the manufacture of a door, the door comprising first and second opposing panels separated by a spacer, wherein the panels and the spacer together define a void adapted to be filled with an insulating material and characterised in that the spacer is integral with at least one of the panels.

12. The use of moulded plastics in the manufacture of a door according to Claim 11, wherein the moulded plastics comprises UPVC.

13. A moulded plastics door panel comprising a lip, wherein the lip extends perpendicularly from a longitudinal edge of the panel.

14. A moulded plastics door panel according to Claim 13, wherein the lip is substantially L-shaped and orientated outwardly relative to the longitudinal edge.

15. A moulded plastics door panel according to Claim 13, wherein the lip is substantially L-shaped and orientated inwardly relative to the longitudinal edge.

16. A moulded plastics door panel according to Claim 13, wherein the lip comprises a stepped structure orientated outwardly relative to the longitudinal edge.

17. A moulded plastics door panel according to any of Claims 13 to 16, wherein the moulded plastics comprises UPNC.

18. A moulded plastics door panel according to Claim 13, wherein the panel is suitable for a door according to Claim 1.

19. The use of a moulded plastics door panel according to claim 13 in the manufacture of a door according to Claim 1.

20. A kit comprising a door according to any of Claims 1 to 10.

21. A kit according to Claim 13, wherein the kit further comprises a door frame.

22. A method of manufacturing a moulded plastics door comprising the step of bringing together a first and second door panel, wherein the first door panel comprises an integral spacer, such that the integral spacer abuts the second door panel.

23. A moulded plastics door, a moulded plastics door panel, uses thereof, methods of manufacture or kits substantially as hereinbefore described with reference to the accompanying description and drawings.