Improved Rice Husk Particle Board

INTRODUCTION: Increasing demand for wood and wood based panel materials cannot be met from forest resources alone. The Rice Husk Particle Board manufactured using abundantly available rice husk can successfully substitute the demand for panel materials. Also these boards enable utilization of waste material and can be produced at low costs. Manufacture of Boards from Rice Husk by using suitable binding agents is a unique method developed by the Indian Plywood Industries Research & Training Institute (IPIR&TI), Bengaluru, India both from the point of view of value addition and complete utilization of the husk without stringent chemical composition requirements.

GENERAL CHARACTERISTICS: The improved rice husk particle boards have the following distinctly advantageous properties when compared to wood particle boards and other similar panel materials:

• Termite Resistance
• Decay Resistance
• Fire Resistance
• Rodent Resistance

TECHNICAL CHARACTERISTICS

1. Internal Bond Strength: The most important technical property of a particle board is its internal bond strength, i.e. the tenacity with which adjacent particles are held together by the adhesive used. In fact most of the other important properties of particle board depend on the internal bond strength. Depending on the density, rice husk boards exhibit a range of internal bond strength values. Low density boards give internal bond strength values of about 1.5-3.0 kg/cm2, whereas medium and high density boards give values of 8 to 12 kg/cm2.

2. Screw and Nail Holding Capacity: Rice husk boards possess adequate resistance to withdrawal of screws and nails. The relevant values are of the order of 40 kg and 15 kg of direct screw and nail withdrawal, respectively. These values compare well with those for wood particle boards.

3. Dimensional Stability: Rice husk boards exposed to various humidity and temperature conditions show very little changes in their dimensions. These changes do not affect seriously any of the proposed applications of the board.

PROCESS: The husk as received from Rice Mills and charged into a dust separator, then sieved to separate dust from husk. The rice husk is then dried and powdered. The powdered rice husk is then segregated according the size. Cleaned husk and the powdered husk is charged into a blender separately and then mixed and coated with a propriety resin on to the Husk which is called furnish. The “Furnish” is spread over a carrier sheet to a pre-determined thickness manually, layer by layer to form a sandwich (fines-coarse-fines) and charged on to a loading cage. The loading cage shall load all the 7 sets into a 7 day light opening Hydraulic Hot Press. After pressing to a specific pressure, the furnish is heated for the thermo setting of resin by thermic fluid heated in Diesel fired thermic fluid heater. On completion of reaction the Boards are unloaded on to unloading cage one after another. Carrier plates are removed and sent back by merry go round to mat former. The Boards are loaded into seasoning chamber and on seasoning the boards are cut and trimmed to size. Cut and trimmed boards are passed through a sander for thickness plaining and the plain Rice Husk Boards are stacked.

RESIN PLANT: The resin is manufactured in a resin kettle, resin kettle is provided with a steam jacket and paddle to mix chemicals driven by a motor and gear box, the system is fitted with a cooling arrangement and vacuum pump to suck in excess water in the resin and as well as to facilitate charging of chemicals, the steam required is produced by a Baby Boiler fired by the cutting and trimming waste of Husk Board.

USES: Rice Husk boards are manufactured in various densities, thickness, types and grades to suit a wide range of applications. The manufacturing process based on highly innovative technology ensures quality in the total sense. Few product applications are Wall Panelling, Doors, Windows, Furniture, Table Tops, False Ceilings, Roofing Panels, Insulation, Partitions, Stage Setting, Industrial and Domestic Floorings, etc.

COMPARISON OF THE IMPROVEMENTS MADE ON RHPB:

IPIR & TI, Bengaluru has further improved and refined the technology for the manufacturing of rice husk particle board using the modified resin binding technology to obtain multi layers. The strength of the RHBP panels meet the requirement as per the relevant specifications and standards. The below table provides the improvements made on RHPB over the years:

Sl #

RHPB Technology in 1985

RHPB Technology Post 2010

1

Single layered rice husk particle board

Multi layered rice husk particle board

2

Coarse particles used and had rough surface finish

Segregation of face and core particles resulting in smooth surface finish

3

The internal bond integrity was less than the prescribed value of IS3087-1985: specification for medium density particle board

The physical and mechanical properties conforms to the requirement of IS3087-1985: specification for medium density particle board type 2 flat pressed three layered boards

4

The board possess high termite, decay and fire resistance

The board possess high termite, decay and fire resistance

5

Overlaying was not possible on the surface of the RHPB due to rough surface

The overlaying with any kind of film sheets possible due to smooth finish of the surface

6

The working / cutting of boards was found to be difficult by the Carpenters using normal hand tools

Working with the improved RHPB is easy as the size of the particles is reduced

PLANT & MACHINERY: Husk Feeder Blower, Dust Separator, Cyclone Husk Cleaning/Dust Extractor, Grinder, Sieving Machine, Electrical Control Panel Cleaning Section, Feed Blower, Blender, Glue Spreader, Carrier Sheet (Fabricated and Polished M.S. sheet with push Space Bar), Resin Kettle, Weighing Scales, Drum Jacket, Thermic Fluid Heater, Hydraulic Press, Material Handling Equipment (For Hydraulic Press), etc.

PROCESS KNOW HOW: IPIR&TI, Bengaluru will provide the complete technical know-how with training and demonstration of the process on pilot plant scale. Industries interested in commercializing the product in India or other countries may kindly get in touch with NRDC.

Shri.N.G.Lakshminarayan, Chief-Business Development, National Research Development Corporation, 20-22, Zamrudpur Community Centre, Kailash Colony Extension, New Delhi 110048;?Mobile: +91 9945204755;?E-Mail: [email protected].