GB2280467A - Doors and a method of manufacturing same - Google Patents

Doors and a method of manufacturing same Download PDF

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Publication number
GB2280467A
GB2280467A GB9315599A GB9315599A GB2280467A GB 2280467 A GB2280467 A GB 2280467A GB 9315599 A GB9315599 A GB 9315599A GB 9315599 A GB9315599 A GB 9315599A GB 2280467 A GB2280467 A GB 2280467A
Authority
GB
United Kingdom
Prior art keywords
door
frame
strands
plastics material
reinforcing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9315599A
Other versions
GB9315599D0 (en
GB2280467B (en
Inventor
Christopher George
James Christopher Warri George
Richard Warrington George
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PERMADOOR PLC
Original Assignee
PERMADOOR PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by PERMADOOR PLC filed Critical PERMADOOR PLC
Priority to GB9315599A priority Critical patent/GB2280467B/en
Publication of GB9315599D0 publication Critical patent/GB9315599D0/en
Publication of GB2280467A publication Critical patent/GB2280467A/en
Application granted granted Critical
Publication of GB2280467B publication Critical patent/GB2280467B/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/02Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
    • B29C44/12Incorporating or moulding on preformed parts, e.g. inserts or reinforcements
    • B29C44/18Filling preformed cavities
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/68Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
    • B29C70/74Moulding material on a relatively small portion of the preformed part, e.g. outsert moulding
    • B29C70/745Filling cavities in the preformed part
    • EFIXED CONSTRUCTIONS
    • E06DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06BFIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
    • E06B5/00Doors, windows, or like closures for special purposes; Border constructions therefor
    • E06B5/10Doors, windows, or like closures for special purposes; Border constructions therefor for protection against air-raid or other war-like action; for other protective purposes
    • E06B5/11Doors, windows, or like closures for special purposes; Border constructions therefor for protection against air-raid or other war-like action; for other protective purposes against burglary
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/06Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
    • B29K2105/08Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns
    • B29K2105/10Cords, strands or rovings, e.g. oriented cords, strands or rovings
    • EFIXED CONSTRUCTIONS
    • E06DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06BFIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
    • E06B3/00Window sashes, door leaves, or like elements for closing wall or like openings; Layout of fixed or moving closures, e.g. windows in wall or like openings; Features of rigidly-mounted outer frames relating to the mounting of wing frames
    • E06B3/70Door leaves
    • E06B3/7015Door leaves characterised by the filling between two external panels
    • E06B2003/703Door leaves characterised by the filling between two external panels containing a metallic layer

Abstract

A door comprises a rigid frame 10 between two outer skins 12 and 13. An inner core 14 of thermally insulating material is provided within the frame and between the skins. The core is made of foam plastics material and contains reinforcing material, preferably in the form of a plurality of discrete strands 15, typically of metal, plastics material, wood, glass fibre or any combination thereof, which are preferably substantially evenly distributed and randomly orientated in the foam plastics material in order to provide resistance to knife attack and hence make the door more secure. The reinforcement may be a mesh structure. <IMAGE>

Description

"Doors and a Method of Manufacturins Same" This invention relates to doors and to a method of manufacturing same.
Conventionally, doors are of solid timber construction, or comprise a timber frame between two outer timber skins. These doors do not generally possess good thermal insulation and require regular maintenance.
Glazed doors having extruded aluminium frames are also known, but these are expensive.
It is also known from GB 2236346A to provide a door comprising a rigid hardwood frame between two outer plastics skins, and thermally insulating material within the frame and between the plastics skins. However, these doors and conventional timber framed doors suffer from the drawback that they are not very secure in that they can be cut fairly easily giving unauthorised access to premises.
According to a first aspect of the present invention there is provided a door comprising a rigid frame between two outer skins, and thermally insulating material within the frame and between the outer skins, wherein the thermally insulating material includes a reinforcing material therein.
Preferably, the reinforcing material is in the form of a plurality of discrete strands.
Preferably, the reinforcing strands are substantially evenly distributed and randomly orientated in the thermally insulating material.
Preferably, the reinforcing strands are of metal, plastics material, wood, glass fibre or any combination thereof.
Preferably, the reinforcing strands have a length of between 20mm and lOOmm and a mean crosssectional dimension of between 2mm and 8mm.
Preferably, the mass of the strands per square metre of the thermally insulating material as viewed in a direction normal to a major face of the door is in the range of 1.3D to 1.7D grams, where D is the density of the strand material in kg/M3.
As an alternative to reinforcing strands, the reinforcing material could be a mesh structure, such as a non-ferrous metal mesh.
Advantageously, the outer skins are of plastics material as this reduces maintenance costs.
The rigid frame is preferably a rigid hardwood frame or a frame having a plurality of frame members each comprising a plurality of timber strands which have been treated with resin and pressed together.
Preferably, each frame member of the frame has a minimum width of 80mm as measured in a plane parallel to the plastics skins.
According to a second aspect of the invention there is provided a method of manufacturing a door according to the first aspect of the invention, wherein the thermally insulating material is a foamable plastics material which is introduced within the frame in liquid form.
Preferably, reinforcing strands are positioned within the frame and the foamable plastics material is injected or otherwise introduced into the space within the frame and between the outer skins.
Preferably, the strands are laid within the frame in a randomly orientated manner in a strip extending along the centre of the door and the foamable plastics material is then injected or otherwise distributed along the centre line of the strip, such as by a lance inserted through an aperture in the end of the door frame, to ensure substantially even distribution of the reinforcing strands in the thermally insulating material.
Alternatively, the reinforcing strands are substantially evenly distributed in a randomly orientated manner within the frame and foamable plastics material is sprayed over the reinforcing strands. In this case, the foamable plastics material can be sprayed over the reinforcing strands prior to securing one of the outer skins to the door. Alternatively, the foamable plastics material can be sprayed into the space within the frame and between the outer skins, such as by using a lance inserted through an aperture in the door frame. In this case, it is advantageous to support the door in a horizontal or substantially horizontal plane and to spray the foamable plastics material upwards onto the underside of the upper skin to obtain better distribution of the reinforcing strands.
The reinforcing strands could be fixed to one of the outer skins prior to introducing the foamable plastics material to ensure substantially even distribution.
The reinforcing strands could be introduced within the frame together with the foamable plastics material.
The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of one embodiment of a door according to the first aspect of the invention; and Figure 2 is a plan view showing the door at one stage of production.
Referring firstly to Figure 1 of the drawings, the door shown therein comprises a rectangular frame 10 having four frame members 11, and two door skins 12 and 13, each of which is preferably in the form of a sheet of thermoplastics material, e.g. uPVC, secured by bonding to two opposite faces, respectively, of the frame 10.
The frame members 11 may be of hardwood or of engineered wood. In the latter case, they may be of Intrallam LSL Engineered Wood, supplied by Trus Joist Macmillan, of Deerwood, Minnesota, USA and may be connected together by corrugated metal fasteners at the corners of the frame, leaving contraction gaps of 0.5mm to lmm between adjacent members. Intrallam LSL is made from strands of aspen, which are dried and treated with polyurethane resin. The treated strands are arranged in a plurality of parallel layers each of which comprises a plurality of randomly orientated strands, and the strands are then pressed into solid billets of wood in the presence of steam before being cut to size.
When using engineered wood for the frame 10, the adhesive used to bond the plastics skins 12 and 13 to the frame 10 is preferably a moisture curing polyurethane adhesive having a viscosity preferably in the range of 150 to 250 centipoids, and typically 200 centipoids. This is a relatively low viscosity adhesive and ensures a high degree of penetration into the engineered wood frame members.
An inner core 14 of thermally insulating material is provided within the frame 10 and between the skins 12 and 13. The core 14 is made of foam plastics material, typically polyurethane foam, and contains reinforcing material preferably in the form of a plurality of discrete strands 15, typically of metal, plastics material, wood, glass fibre or any combination thereof, which are preferably substantially evenly distributed and randomly orientated in the foam plastics material in order to provide resistance to knife attack and hence make the door more secure.
The strands 15 preferably have a length of between 20mm and l00mm, typically 50mm, and a mean crosssectional dimension of between 2mm and 8mm, typically 6mm, and are preferably right cylindrical or jagged with no flat faces to allow the foam plastics to get between the strands 15 and the skin or skins 12, 13 and ensure maximum bond area between the foam plastics material and the plastics skins 12 and 13. Also, preferably, the mass of the strands 15 per square metre of insulating material as viewed in a direction normal to a major face of the door is in the range of 1.3D to 1.7D grams, where D is the density of the strand material in kg/m3. Typically, the density of the strand material is 600 kg/m3 and in this case, the mass of strands per square metre of thermally insulating material is, preferably, in the range of 780 to 1020 grams.
In order to give the frame adequate strength, each frame member 11 preferably has a width of at least 80mm, and typically a width of about 90mm, as measured in a plane parallel to the skins 12 and 13, although in some doors the width of the frame members may be substantially smaller and typically 50mm. The frame members 11 and core 14 are each typically 40mm thick and the skins 12 and 13 are each typically 2mm thick.
The skins 12 and 13 can be provided with an integral, decorative pattern 15 to improve the aesthetic appearance of the door. The pattern is formed by heating the plastics sheets, which form the skins 12 and 13, and drawing them down by vacuum over a shaped former to provide a raised pattern on one side of the sheet and a recessed pattern on the other side of the sheet.
The core 14 serves not only to give the door good thermally insulating properties, but it also serves to give support to the skins 12 and 13 and prevent significant flexing thereof. For this reason it is desirable that the core 14 should be well packed between the skins 12 and 13 and should, if possible, also fill any large recesses which may be formed if either skin is provided with a decorative pattern.
The door described above can be made by a number of different methods. In each method, the frame 10 is first fabricated and one of the two skins, typically skin 12, is bonded to the frame.
In one method, the frame 10 and skin 12 are then supported in a horizontal or substantially horizontal plane with the skin 12 lowermost. The strands 15 are then laid within the frame 10 and on the upper surface of the skin 12 in a randomly orientated manner in a strip 16, typically 200mm wide, extending along the centre of the door, as shown in Figure 2. The other skin 13 is then bonded to the upper face of the frame 10 and a lance 17 is inserted through a hole in one end of the frame to inject or otherwise distribute foamable plastics material in liquid form, e.g. a two part polyurethane foam, evenly along the centre line of the strip 16. The liquid expands in the cavity defined by the frame 10 and skins 12 and 13 and in so doing distributes the reinforcing strands 15 substantially evenly throughout the cavity. The plastics material then sets as a foam filling the cavity with the reinforcing strands 15 contained therein.
In another method, the frame 10 and skin 12 are again supported in a horizontal or substantially horizontal plane with the skin 12 lowermost. In this case, the strands 15 are then evenly distributed in a randomly orientated manner over the entire upper surface of the skin 12. Foamable liquid plastics material is then sprayed, typically by hand, over the reinforcing strands 15. The skin 13 is then immediately bonded to the upper face of the frame 10 before the liquid foam has an opportunity to expand significantly. Alternatively, the foamable liquid plastics material can be sprayed using a lance as shown in Figure 2 inserted through one or more holes in one end of the frame. In this case, the skin 13 can be bonded to the upper face of the frame 10 prior to spraying. Also, in this case, it has been found advantageous to direct the spray upwards against the inner face of the skin 13 as better distribution results.
In this latter method, the strands 15 could be fixed to at least the skin 12 prior to spraying.
In yet another method, both skins 12 and 13 are bonded to the frame 10 and the strands 15 are injected into the cavity defined by the frame 10 and skins 12 and 13 together with the foamable plastics material. In this case, however, the strands 15 need to be quite small and therefore offer less resistance to knife attack.
As an alternative to discrete strands as the reinforcing material, a mesh structure, such as a nonferrous metal mesh, could be used.
The skins 12 and 13 may be of any desired colour and may, if desired, have a woodgrain finish.
The door can be provided with factory fitted hinges and door furniture, such as a handle and/or a lock, a letterbox, a spy-hole, and a door knocker.
A door as described above, once installed, is virtually maintenance free. It is much more resistant to bow and warp than conventional timber doors and, if the frame is made of engineered wood, more resistant to bow and twist than known doors having plastics skins attached to a rigid hardwood frame. There is therefore less tendency for the plastics skins to crack. The door also has good thermally insulating properties. It is much cheaper than extruded aluminium doors, and by keeping the outer peripheral edge of the frame exposed, the door can be trimmed to size, on site, with a plane. It is also more secure than conventional timber framed doors or doors as described in GB 2236346A.
The door could be provided with a glazed panel, such as described in GB 2236346A. The glazed panel could be of any convenient shape and could be factory fitted or supplied as part of a kit. If factory fitted, it could be fitted prior to, or subsequent to, formation of the core 14.
The embodiments described above are given by way of example only and various modifications will be apparent to persons skilled in the art without departing from the scope of the invention.

Claims (21)

1. A door comprising a rigid frame between two outer skins, and thermally insulating material within the frame and between the outer skins, wherein the thermally insulating material includes a reinforcing material therein.
2. A door as claimed in claim 1, wherein the reinforcing material is in the form of a plurality of discrete strands.
3. A door as claimed in claim 2, wherein the reinforcing strands are substantially evenly distributed and randomly orientated in the thermally insulating material.
4. A door as claimed in claim 2 or claim 3, wherein the reinforcing strands are of metal, plastics material, wood, glass fibre or any combination thereof.
5. A door as claimed in any one of claims 2 to 4, wherein the reinforcing strands have a length of between 20mm and 100mm and a mean cross-sectional dimension of between 2mm and 8mm.
6. A door as claimed in any one of claims 2 to 5, wherein the mass of the strands per square metre of the thermally insulating material as viewed in a direction normal to a major face of the door is in the range of 1.3D to l.7D grams, where D is the density of the strand material in Kg/m3.
7. A door as claimed in claim 1, wherein the reinforcing material is a mesh structure.
8. A door as claimed in any one of the preceding claims, wherein the outer skins are of plastics material.
9. A door as claimed in any one of the preceding claims, wherein the rigid frame is a rigid hardwood frame.
10. A door as claimed in any one of claims 1 to 8, wherein the rigid frame comprises a plurality of frame members each comprising a plurality of timber strands which have been treated with resin and pressed together.
11. A door as claimed in any one of the preceding claims, wherein each frame member of the rigid frame has a minimum width of 80mm as measured in a plane parallel to the plastics skins.
12. A door substantially as hereinbefore described with reference to the accompanying drawings.
13. A method of manufacturing a door according to any one of the preceding claims, wherein the thermally insulating material is a foamable plastics material which is introduced within the frame in liquid form.
14. A method as claimed in claim 13, wherein reinforcing strands are positioned within the frame and the foamable plastics material is injected or otherwise introduced into the space within the frame and between the outer skins.
15. A method as claimed in claim 14, wherein the strands are laid within the frame in a randomly orientated manner in a strip extending along the longitudinal centre of the door and the foamable plastics material is then injected or otherwise distributed along the centre line of the strip to ensure substantially even distribution of the reinforcing strands in the thermally insulating material.
16. A method as claimed- in claim 14, wherein the reinforcing strands are substantially evenly distributed in a randomly orientated manner within the frame and foamable plastics material is sprayed over the reinforcing strands.
17. A method as claimed in claim 16, wherein the foamable plastics material is sprayed over the reinforcing strands prior to securing one of the outer skins to the frame.
18. A method as claimed in claim 16, wherein the foamable plastics material is sprayed into the space within the frame and between the outer skins.
19. A method as claimed in claim 18, wherein the door is supported in a horizontal or substantially horizontal plane and the foamable plastics material is sprayed upwards onto the underside of the upper skin to obtain better distribution of the reinforcing strands.
20. A method as claimed in claim 13, wherein the reinforcing strands are introduced within the frame together with the foamable plastics material.
21. A method of manufacturing a door, substantially as hereinbefore described with reference to the accompanying drawings.
GB9315599A 1993-07-28 1993-07-28 Doors and a method of manufacturing same Expired - Lifetime GB2280467B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9315599A GB2280467B (en) 1993-07-28 1993-07-28 Doors and a method of manufacturing same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9315599A GB2280467B (en) 1993-07-28 1993-07-28 Doors and a method of manufacturing same

Publications (3)

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GB9315599D0 GB9315599D0 (en) 1993-09-08
GB2280467A true GB2280467A (en) 1995-02-01
GB2280467B GB2280467B (en) 1997-01-08

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GB9315599A Expired - Lifetime GB2280467B (en) 1993-07-28 1993-07-28 Doors and a method of manufacturing same

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999045226A1 (en) * 1998-03-06 1999-09-10 F.E.K.-Haustürfüllungen Gmbh Va armoring
GB2357111A (en) * 1999-12-10 2001-06-13 Environmental Seals Ltd Polyurethane twin-walled fireproof structure

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4271649A (en) * 1979-04-09 1981-06-09 Bombardier Limited Structural panel
GB2088452A (en) * 1980-03-27 1982-06-09 Neary Terence Edward Thief Resistant insulated Window Shutter
DE3723924A1 (en) * 1986-09-23 1988-03-31 Heinrich Romberg Ohg Door with reinforced filling
EP0294265A1 (en) * 1987-05-22 1988-12-07 Electricite De France Fireproof doors
DE3728093A1 (en) * 1987-08-22 1989-03-02 Klaus Dieter Winkler Door element
EP0411457A1 (en) * 1989-08-03 1991-02-06 Leo Wassner Door wing
WO1992010634A1 (en) * 1990-12-15 1992-06-25 Duraflex Limited Door construction and kit therefor
GB2258683A (en) * 1991-08-14 1993-02-17 Hseih Wu Chang Door panel incorporating a strengthening perforated steel plate

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4271649A (en) * 1979-04-09 1981-06-09 Bombardier Limited Structural panel
GB2088452A (en) * 1980-03-27 1982-06-09 Neary Terence Edward Thief Resistant insulated Window Shutter
DE3723924A1 (en) * 1986-09-23 1988-03-31 Heinrich Romberg Ohg Door with reinforced filling
EP0294265A1 (en) * 1987-05-22 1988-12-07 Electricite De France Fireproof doors
DE3728093A1 (en) * 1987-08-22 1989-03-02 Klaus Dieter Winkler Door element
EP0411457A1 (en) * 1989-08-03 1991-02-06 Leo Wassner Door wing
WO1992010634A1 (en) * 1990-12-15 1992-06-25 Duraflex Limited Door construction and kit therefor
GB2258683A (en) * 1991-08-14 1993-02-17 Hseih Wu Chang Door panel incorporating a strengthening perforated steel plate

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999045226A1 (en) * 1998-03-06 1999-09-10 F.E.K.-Haustürfüllungen Gmbh Va armoring
GB2357111A (en) * 1999-12-10 2001-06-13 Environmental Seals Ltd Polyurethane twin-walled fireproof structure
GB2357111B (en) * 1999-12-10 2003-04-23 Environmental Seals Ltd Fire resistant structures

Also Published As

Publication number Publication date
GB9315599D0 (en) 1993-09-08
GB2280467B (en) 1997-01-08

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746 Register noted 'licences of right' (sect. 46/1977)

Effective date: 19990428

PE20 Patent expired after termination of 20 years

Expiry date: 20130727