DESC:FIELD OF INVENTION:
The present invention generally relates to doors, frames, architraves and shutters as such. More particularly, the present invention relates to a non-hygroscopic, water resistant, weather resistant, termite resistant and sound insulated door assembly made up of cement bonded particle board which are used in producing skins, skeleton and frame of the door. The present invention further relates to a process of manufacturing said door assembly with supporting structure.

BACKGROUND AND PRIOR ART:
Doors are important in any construction as they are used to divide a space into smaller parts and give each of them a different purpose. The main function of door is to maintain privacy and safety in any construction. The doors are generally made of wood, and wood being hygroscopic in nature, is subject to humidity and change in environmental temperature. As humidity increases, the moisture content increases, and causes the wood to expand; on the other hand, as humidity decreases, the moisture content decreases, and the wood shrinks. Accordingly, the door losses or gains moisture and consequently shrinks or swells depending on the environmental conditions. Further for the doors to be long lasting, it needs to be prevented from contact with water, termite attack and extreme environmental conditions. As such the doors need to be maintained regularly. Thus, to avoid such inconvenience, there is a need of a door which is resistant to said conditions.

Particle boards have been used as an alternative for conventional wooden doors. Particleboards are composite board made of pieces of wood bonded together. They are commonly used in producing cabinets, tabletops, speaker boxes, sliding doors, kitchen worktops, and various furniture. However, there are several factors which affect the features and quality of the particleboards, foremost among them are fiber structure of the wood, species of wood, size and type of particles, hardness, density compressibility and method of drying the particles.

A cement bonded particle board (CBPB) panels provides a better alternative to materials such as plasterboard, Eraclit, Celenit, Calcium Sulphate, magnesite wood, MDF, OSB, plywood and chipboards. The cement bonded particle boards (CBPB) are traditionally made of wood fibres / particles, cement and water, along with additives to speed up the bonding process by hydration of cement. More specifically, the cement bonded particle board are made out of 62% cement and 28% wood and 10% of other additives. The said wood is selected from fast-growing species like eucalyptus and poplar. Further, said CBPB has only 28% wood particle which is mineralised wood that does not expand, contract, cause warpage and is dimensionally stable. The CBPB construction panel combines the advantageous properties of rigidity and strength of cement, with the insulating properties of wood fibers / particles and wood workability. Cement being strong and durable and is not affected by fire, weather, termites, etc., and wood being light and strong and is easily machinable. As the wood particles in the board are mineralised with chemicals during the manufacturing process, the particle becomes termite and vermin resistant, and also does not support fungal growth, and has excellent resistance to weather.

Further, cement bonded particle board adapts to many uses in construction. It is environmentally friendly and bio-compatible, opposed to other panels as the OSB panels having high amount of formaldehyde which is released into the environment as volatile aldehydes (VOC), highly carcinogenic emissions. Various prior arts related to use of cement-wood composite for manufacturing doors have been disclosed.

IN201941012954 discloses a method for manufacturing cement-wood composite door, cupboard door, cement backed decorative laminate and cement faced plywood board without requiring high temperature and high pressure. However, the said patent application uses layers of cement slurry and glass fiber mat or coconut fiber mat to make core infill of timber chips and adhesives, particle board, wood plastic composite or light weight cement board. The said patent application uses layers of slurry which involves a tedious and time-consuming process for the slurry to harden and cure. Further, the shutter frames are made with timber, wood plastic composite or plywood.

PCT/US1998/007003 discloses a method for manufacturing a moulded door skin in which a solid wood composite blank is heated in a press to a temperature sufficient to soften the blank. Further, on applying sufficient pressure on the blank, it gets deformed into a moulded shape of the platen. The said patent application uses a solid wood composite blank to make door skins. The shutter frame skeleton is also made with solid waste. Also, PVA (polyvinyl acetate) is used for adhesively securing skin to the door frame.

US20080016820 discloses a composite door and method for making the core of a door through the process of autoclaved aerated concrete (AAC). The said patent application uses two slabs of automated aerated concrete and a fire-resistant reinforcing panel sandwiched between the two slabs. Further, cement bonded particle board is used as a reinforcing band, reinforcing panel and decorative strip in the said application.

The present invention thus provides a process and structure for manufacturing strong and durable door shutters, architraves and frames using cement bonded particle board.

Some of the benefits of using cement bonded particle boards as skins, skeleton and frame of doors are listed below:
• Superior water resistance: Cement bonded particle boards have excellent resistance to weather
• Termite Resistance: It is resistant to termite and vermin attack and also does not support fungal growth.
• Excellent sound insulation: Airborne sound reduction varies according to the thickness of cement bonded particle board panels.
• Non-hygroscopic in nature: CBPB has only 28 % wood particle which is mineralized wood, thus it does not expand, contract or warp and is dimensionally stable.

The present invention thus aims to provide an improved, sustainable, efficient, eco-friendly, long-lasting door assembly with its supporting structures.

SUMMARY OF THE INVENTION:
It is an object of the present invention to provide a superior water resistant, weather resistant, termite proof, soundproof and non-hygroscopic door shutters, architraves and frames.

It is another object of the present invention to provide an environment friendly and bio-compatible door assembly.

It is another object of the present invention to provide sound insulation by reducing air borne sound up to 37db.

It is an object of the present invention to provide energy efficient door assembly which can reduce heat flow thermal break by preventing entry of heat or cold from outside.

Accordingly, the present invention discloses a sustainable, efficient, eco-friendly and long-lasting door assembly with its supporting structures. The present invention provides a cement bonded particle board door assembly comprising a laminated door frame, a laminated architrave and a laminated shutter.

The said laminated door frame comprises, two or more cement bonded particle board pressed on a foam board using a first adhesive, and laminated with a PVC foil using a second adhesive.

The said laminated architrave comprises two or more cement bonded particle board perpendicularly joined using a second adhesive, and laminated with a PVC foil using said second adhesive.

The said laminated shutter comprises thin strips of a foam board and a cement bonded particle board glued using a third adhesive, and sandwiched between two or more pre-laminated cement bonded particle board filled with honeycomb infill and joined using a first adhesive. The said pre-laminated cement bonded particle board is pre-laminated with a layer of craft paper and a layer of barrier paper along with hot melt adhesives for efficiency and sustainability.

The said cement bonded particle board door manufacturing process according to the present invention enables the panels to acquire strength and durability of cement and easy workability of wood.

The present invention further discloses a process for manufacturing a superior water resistant, weather resistant, termite proof, soundproof and non-hygroscopic door shutters, architraves and frames.

BRIEF DESCRIPTION OF DRAWINGS:
The figures below show an exemplary embodiment:
Figure 1 discloses a schematic view of a skeleton panel of door shutter with honeycomb infill.
Figure 2 discloses a schematic view of the door frame.

List of reference numerals
Part ref Description
100 Door assembly
10 Door frame
20 Architrave
30 Shutter
40 Shutter skeleton
50 Honeycomb infill
60 Cement bonded particle board
70 Foam board

DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in detail with reference to optional and preferred embodiments so that various aspects of the invention will be more clearly understood, however, should not be construed to limit the scope of the invention. The following embodiments clearly and completely describes various technical features and advantageous of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. The examples used herein are intended merely to facilitate an understanding of the ways in which the embodiments herein may be practices and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The present invention relates to a non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) and supporting structure.

As illustrated in figures 1-2, the present invention discloses a schematic view of a skeleton panel (40) of door shutter with honeycomb infill (50); and a door frame (10) having two or more cement bonded particle board (60) pressed on a foam board (70).

In a preferred embodiment according to the present invention, the non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) comprises, a laminated door frame (10), by pressing two or more cement bonded particle board (60) on a foam board (70) using a first adhesive; a laminated architrave (20), by perpendicularly joining two or more cement bonded particle board (60) using a second adhesive; and a laminated shutter (30) by sandwiching thin strips of a glued foam board (70) and a cement bonded particle board (60), between two or more pre-laminated cement bonded particle board (60) using a first adhesive, along with honeycomb infill (50), wherein said thin strips are glued using a third adhesive.

In a same preferred embodiment according to the present invention, said laminated door frame (10) comprises, two or more cement bonded particle board (60) pressed on a foam board (70) using a first adhesive, and laminated with a PVC foil using a second adhesive.

In a same preferred embodiment according to the present invention, said laminated architrave (20) comprises two or more cement bonded particle board (60) perpendicularly joined using a second adhesive, and laminated with a PVC foil using said second adhesive.

In a same preferred embodiment according to the present invention, laminated shutter (30) comprises thin strips of a foam board (70) and a cement bonded particle board (60) glued using a third adhesive, and sandwiched between two or more pre-laminated cement bonded particle board (60) filled with honeycomb infill (50) and joined using a first adhesive; wherein said pre-laminated cement bonded particle board (60) is pre-laminated with a layer of craft paper and a layer of barrier paper using second adhesives.

In a same preferred embodiment according to the present invention, said first adhesive is selected from D3 glue.

In a same preferred embodiment according to the present invention, said second adhesive is selected from PUR hot melt glue.

In a same preferred embodiment according to the present invention, said third adhesive is selected from high initial tack glue.

In a same preferred embodiment according to the present invention, the non-hygroscopic, water resistant, weather resistant, termite proof and soundproof laminated door frame (10) comprises, two or more cement bonded particle boards (60); a foam board (70) pressed on said two or more cement bonded particle boards (60); a first adhesive for bonding said two or more cement bonded particle board (60) to said foam board (70); a PVC laminating foil for laminating the panel after moulding; and a second adhesive for bonding said laminate on the moulded panel.

In a same preferred embodiment according to the present invention, the non-hygroscopic, water resistant, weather resistant, termite proof and soundproof laminated architrave (20) comprises, two or more cement bonded particle boards (60); a third adhesive for bonding said two or more cement bonded particle boards (60) together; a PVC laminating foil for laminating the bonded panel after moulding; and a second adhesive for bonding said laminate on the moulded panel.

In a same preferred embodiment according to the present invention, the non-hygroscopic, water resistant, weather resistant, termite proof and soundproof laminated shutter (30) comprises, a cement bonded particle board (60); a foam board (70); a first adhesive for bonding said cement bonded particle board (60) and said foam board (70) together to form a panel for skeleton; a third adhesive for joining thin strips of said panel to form a shutter skeleton; two or more pre-laminated cement bonded particle board (60), wherein said pre-laminated cement bonded (60) particle board is pre-laminated with a layer of craft paper and a layer of barrier paper using hot melt adhesives; a honeycomb infill (50) for filling the shutter skeleton; a first adhesive for joining or bonding said pre-laminated cement bonded particle boards (60) and shutter skeleton filled with honeycomb infill, to obtain a raw shutter; a PVC laminating foil for laminating the raw shutter after moulding; an edge band tape for covering the sides of said laminated shutter using second adhesive.

In a same preferred embodiment according to the present invention, the process for preparing a frame (10) for a non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) comprises the steps of, placing a foam board (70) on two or more cement bonded particle board (60) applied with a first adhesive on contact surface; pressing the board to form a thick panel; cutting the panel to desired size; passing the cut panel through a moulder machine for trimming the sides of said panel for shutter rebate and wick groove provisions; laminating the moulded frames with PVC foils on a foil wrapping machine using a second adhesive; machining the laminated frames in a CNC machine for miter joints along with provisions for architrave (20), hinge slots, lock receiving plates and dowel screw holes.

In a same preferred embodiment according to the present invention, the process for preparing an architrave (20) for a non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) comprises the steps of, cutting two or more cement bonded particle board (60) to a desired size on a beam saw cutting machine; joining the cut two or more cement bonded particle board (60) perpendicularly on a case joining machine using a third adhesive; trimming and moulding the panel using blades for desired design; laminating the trimmed-moulded architrave with PVC foils on a foil wrapping machine using a second adhesive.

In a same preferred embodiment according to the present invention, the process for preparing a shutter (30) for a non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) comprises the steps of, placing a foam board (70) on a cement bonded particle board (60) applied with first adhesive on contact surface; pressing together said foam board (70) and said cement bonded particle board (60) to form a panel; cutting the panel to obtain thin strips; joining the strips using a third adhesive to form a shutter-skeleton (40); filling the area within the shutter-skeleton (40) with an infill (50); pre-laminating two or more cement bonded particle board (60) with a layer of craft paper and a layer of barrier paper; applying a first adhesive on said two or more pre-laminated cement bonded particle board (60) and placing it on the shutter-skeleton (40) filled with infill (50); placing the shutter panel on a hot-pressing machine and pressing together to obtain a raw shutter; trimming and sizing the raw shutter on a tenoner machine; laminating the raw shutter with PVC foils on a foil wrapping machine using a second adhesive; covering the sides of the laminated shutter with edge banding tape using a second adhesive; machining the laminated and edge-banded shutter in a CNC machine for lock body and hinge slots.

In a same preferred embodiment according to the present invention, said infill (50) is an eco-friendly infill selected from high density craft paper honeycomb.

In a same preferred embodiment according to the present invention, said tenoner machine is a double end tenoner.

In a same preferred embodiment according to the present invention, said frame (10), architrave (20) and shutter (30) are laminated with a thick PVC foil on a foil wrapping machine using a second adhesive at a temperature of about 120ºC to 150ºC.

In a same preferred embodiment according to the present invention, said shutter (30) is edge banded with an edge banding tape using a second adhesive at a temperature of about 120ºC to 150ºC.

In an exemplary embodiment according to the present invention, the said door frame (10) is of 48mm thickness.

In a further exemplary embodiment according to the present invention, said door frame (10) of 48mm thickness is prepared by pressing together a 10mm and 20mm thick cement bonded particle board (60) with a 18mm foam board (70) using D3 glue. The panel thus obtained is cut to required sizes. The cut panel is then passed through a molding machine to trim the sides along with provisions for shutter rebate and wick groove. The molded frames are then laminated with 0.2mm thick PVC foils on a foil wrapping machine using PUR hot melt glues at a temperature of 120ºC to 150ºC. The foil wrapped frames thus obtained are appropriately machined in a CNC machine for miter joints along with provisions for architraves, hinge slots, lock receiver plates and for dowel screw holes.

In a further exemplary embodiment according to the present invention, an architrave (20) for the door is prepared by using a 12mm and 6mm cement bonded particle board (60), which are cut to desired sizes on a beam saw. The cut cement bonded particle board (60) are perpendicularly joined to each other on a case joining machine using high initial tack hot melt glues and then trimmed and moulded to required design using blades. The moulded architraves thus obtained are laminated with PVC foils on a foil wrapping machine using PUR hot melt glue at a temperature of 120ºC to 150ºC.

In a further preferred embodiment according to the present invention, a shutter (30) for the door is prepared by pressing together 18mm cement bonded particle board (60) and 18mm foam board (70) using D3 glue, to obtain a 36mm thick panel for door skeleton. Further, 30mm strips are cut from the thus obtained panel and joined using high initial tack glues to attain a skeleton for shutter (30). These skeletons are then sandwiched between two 5.5 mm thick pre-laminated cement bonded particle boards (60). The said pre-laminated cement bonded particle board (60) are pre-laminated with a layer of craft paper and a layer of barrier paper. The said pre-laminated cement bonded particle board (60) are placed with craft and barrier layer on the exposed sides and with craft only layer on the other sides. Further, honeycomb (50) is used as an infill for the shutter panel. Later, all these are pressed together to achieve a raw shutter, using D3 glues on a hot press unit. The thus obtained raw shutter is then squared to size on a Double-End Tenoner. The raw shutters thus obtained are then laminated with the PVC foils on a foil wrapping machine using PUR hot melt glues at a temperature of 120ºC to 150ºC. Further, the laminated shutters are edge banded on all four sides using 1mm edge banding tape using a PUR hot melt glue at a temperature of 120ºC to 150ºC. The laminated and edge banded shutters thus obtained are appropriately machined in a CNC machine for hinge slots and lock body.

The advantages of the present invention include superior water resistant; excellent weather resistant; superior vapour permeability; resistant to termite and vermin attack; excellent sound insulation; dimensionally stable.

The foregoing descriptions are merely specific embodiments of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
,CLAIMS:1. A non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) comprising,
a laminated door frame (10), by pressing two or more cement bonded particle boards (60) on a foam board (70) using a first adhesive;
a laminated architrave (20), by perpendicularly joining two or more cement bonded particle board (60) using a second adhesive; and
a laminated shutter (30) by sandwiching thin strips of a glued foam board (70) and a cement bonded particle board (60), between two or more pre-laminated cement bonded particle board (60) using a first adhesive, along with honeycomb infill (50), wherein said thin strips are glued using a third adhesive.

2. The door assembly (100) as claimed in claim 1, wherein said laminated door frame (10) comprises, two or more cement bonded particle board (60) pressed on a foam board (70) using a first adhesive, and laminated with a PVC foil using a second adhesive.

3. The door assembly (100) as claimed in claim 1, wherein said laminated architrave (20) comprises two or more cement bonded particle board (60) perpendicularly joined using a second adhesive, and laminated with a PVC foil using said second adhesive.

4. The door assembly (100) as claimed in claim 1, wherein laminated shutter (30) comprises thin strips of a foam board (70) and a cement bonded particle board (60) glued using a third adhesive, and sandwiched between two or more pre-laminated cement bonded particle board (60) filled with honeycomb infill (50) and joined using a first adhesive; wherein said pre-laminated cement bonded particle board (60) is pre-laminated with a layer of craft paper and a layer of barrier paper using second adhesives.

5. The door assembly (100) as claimed in claim 1, wherein said first adhesive is selected from D3 glue.

6. The door assembly (100) as claimed in claim 1, wherein said second adhesive is selected from PUR hot melt glue.

7. The door assembly (100) as claimed in claim 1, wherein said third adhesive is selected from high initial tack glue.

8. A non-hygroscopic, water resistant, weather resistant, termite proof and soundproof laminated door frame (10) comprising,
two or more cement bonded particle boards (60);
a foam board (70) pressed on said two or more cement bonded particle boards (60);
a first adhesive for bonding said two or more cement bonded particle board (60) and foam board (70) together;
a PVC laminating foil for laminating the panel after moulding; and
a second adhesive for bonding said laminate on the moulded panel.

9. A non-hygroscopic, water resistant, weather resistant, termite proof and soundproof laminated architrave (20) comprising,
two or more cement bonded particle boards (60);
a third adhesive for bonding said two or more cement bonded particle boards (60)
together;
a PVC laminating foil for laminating the bonded panel after moulding; and
a second adhesive for bonding said laminate on the moulded panel.

10. A non-hygroscopic, water resistant, weather resistant, termite proof and soundproof laminated shutter (30) comprising,
a cement bonded particle board (60);
a foam board (70);
a first adhesive for bonding said cement bonded particle board (60) and said foam board (70) together to form a panel for skeleton;
a third adhesive for joining thin strips of said panel to form a shutter skeleton;
two or more pre-laminated cement bonded particle board (60), wherein said pre-laminated cement bonded particle board (60) is pre-laminated with a layer of craft paper and a layer of barrier paper using hot melt adhesives;
a honeycomb infill (50) for filling the shutter skeleton;
a first adhesive for joining or bonding said pre-laminated cement bonded particle boards (60) and shutter skeleton filled with honeycomb infill, to obtain a raw shutter;
a PVC laminating foil for laminating the raw shutter after moulding;
an edge band tape for covering the sides of said laminated shutter using second adhesive.

11. A process for preparing a frame (10) for a non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) comprises the steps of,
placing a foam board (70) on two or more cement bonded particle board (60) applied with a first adhesive on contact surface;
pressing the board to form a thick panel;
cutting the panel to desired size;
passing the cut panel through a moulder machine for trimming the sides of said panel for shutter rebate and wick groove provisions;
laminating the moulded frames with PVC foils on a foil wrapping machine using a second adhesive;
machining the laminated frames in a CNC machine for miter joints along with provisions for architrave (20), hinge slots, lock receiving plates and dowel screw holes.

12. A process for preparing an architrave (20) for a non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) comprises the steps of,
cutting two or more cement bonded particle board (60) to a desired size on a beam saw cutting machine;
joining the cut two or more cement bonded particle board (60) perpendicularly on a case joining machine using a third adhesive;
trimming and moulding the panel using blades for desired design;
laminating the trimmed-moulded architrave with PVC foils on a foil wrapping machine using a second adhesive.

13. A process for preparing a shutter (30) for a non-hygroscopic, water resistant, weather resistant, termite proof and soundproof door assembly (100) comprises the steps of,
placing a foam board (70) on a cement bonded particle board (60) applied with first adhesive on contact surface;
pressing together said foam board (70) and said cement bonded particle board (60) to form a panel;
cutting the panel to obtain thin strips;
joining the strips using a third adhesive to form a shutter-skeleton (40);
filling the area within the shutter-skeleton (40) with an infill (50);
pre-laminating two or more cement bonded particle board (60) with a layer of craft paper and a layer of barrier paper;
applying a first adhesive on said two or more pre-laminated cement bonded particle board (60) and placing it on the shutter-skeleton (40) filled with infill (50);
placing the shutter panel on a hot-pressing machine and pressing together to obtain a raw shutter;
trimming and sizing the raw shutter on a tenoner machine;
laminating the raw shutter with PVC foils on a foil wrapping machine using a second adhesive;
covering the sides of the laminated shutter with edge banding tape using a second adhesive;
machining the laminated and edge-banded shutter in a CNC machine for lock body and hinge slots.

14. The process as claimed in claim 13, wherein said infill (50) is an eco-friendly infill selected from high density craft paper honeycomb.

15. The process as claimed in claim 13, wherein said tenoner machine is a double end tenoner.

16. The process as claimed in claim 11,12,13, wherein said frame (10), architrave (20) and shutter (30) are laminated with a thick PVC foil on a foil wrapping machine using a second adhesive at a temperature of about 120ºC to 150ºC.

17. The process as claimed in claim 13, wherein said shutter (30) is edge banded with an edge banding tape using a second adhesive at a temperature of about 120ºC to 150ºC.