Title of Invention

"A PROCESS FOR THE MANUFACTURE OF ASBESTOS FIBRE CEMENT AND FLYASH PRODUCTS"

Abstract

A process for the manufacture of asbestos fibre cement products comprising of flyash, fibre, water and cement, charactersied in that flyash is mixed with water thoroughly with centrifugal force, to form a slurry, said slurry is added into the fiber cone mixed with well open fibers, the slurry so obtained in the cone is mixed with cement to obtain a homogenous slurry, subjecting said slurry to the step of corrugating (moulding) in a manner to get the required product.

Full Text

This invention relates to a process for the manufacture of asbestos fibre cement products. Corrugated roofing sheets, plain boards/ flat sheets, roofing fittings and accessories, pipes and pipe fittings and water storage tanks are prepared from a suitable composition consisting of 40-50% cement, 8-11% asbestos fibre, 25-35% flyash with or without 0-5% wood/paper pulp. This composition is converted in the form of a slurry for use for the preparation of the above items. The composition is prepared by mixing all the components with each other in a beater tank and the flyash is fed in the dry form with cement into the beater to be mixed with the other ingredients of the composition. There are some disadvantages associated with the prior art. One of the main disadvantage is that as the flyash is mixed with the cement in the dry form it does not mix uniformly and therefore the slurry formed is not so homogenous and which causes thickness variation in the finished A.C. sheet. Another disadvantage is that the distribution of flyash, fibre and cement matrix also not found proper and thus variation observed in the raw material distribution in the sheet. Therefore it affect process running and quality of the sheet. Therefore the main object of this invention is to provide a novel wet process for the manufacture of asbestos-fiber-cement products and which obviates the disadvantages associated with the prior art. Another object of this invention is to provide a novel composition for use for the manufacture of asbestos-fiber-cement products. A process for the manufacture of asbestos fibre cement products comprising of flyash, fibre, water and cement, charactersied in that flyash is mixed with water thoroughly with centrifugal force, to form a slurry, said slurry is added into the fiber cone mixed with well open fibers, the slurry so obtained in the cone is mixed with cement to obtain a homogenous slurry, subjecting said slurry to the step of corrugating (moulding) in a manner to get the required product. Further according to this invention there is provided a composition for use for the manufacture of asbestos-fibre-cement products comprising 8-11% by weight of asbestos fibre, 40-50% by Height of cement, 25-35% by weight of flyash and 0.1-0.2% by weight of an additive or binder with or without 0-5% by weight of wood/paper pulp mixed with each other in the form ofahomogenous slurry. In accordance with this invention 25—35% by weight of flyash is first fed into a flyash hopper wherein it is thoroughly mixed with centrifugal force. The flyash mixture is then fed through a pipe line into a fibre cone wherein the wet flyash is mixed well with 8-11% by weight of fibres present therein in the fully open condition. The mixture of flyash and fibre is then fed into a beater mixer to be mixed with 40-50% by weight of cement in order to get a homogenous slurry. 0.1—0.2% by weight of an additive or binder (for example CCS6 chemical) is added into the beater mixer to be mixed with the slurry. The homogenous slurry so obtained is then processed in a conventional manner to get the finished product. According to an option 0-5% by weight of wood/paper pulp is mixed with the asbestos fibre cement mixture so as to get the composition for use for the manufacture of asbestos fibre cement product. The process and the composition of this invention is herein illustrated in the following example Example1 30 kg flyash was fed into a flyash hopper to be mixed with water thoroughly with centrifugal force. The wet flyash was conveyed to a fibre cone containing 10.5 kg asbestos fibres in the well open position wherein the wet flyash was mixed with the fibres. The mixture of flyash and asbestos fibre was then fed into a beater mixer containing 48 kg cement therein. The contents were then moved into the beater mixer in the form of a homogenous mixture. 0.2 kg chemical was added into the beater mixer to be mixed with the composition mixture homogeneously to obtain the composition which was then subjected to the step of moulding in a conventional manner in order to manufacture the desired product. WE CLAIM 1. A process for the manufacture of asbestos fibre cement products comprising of flyash, fibre, water and cement, charactersied in that flyash is mixed with water thoroughly with centrifugal force, to form a slurry, said slurry is added into the fiber cone mixed with well open fibers, the slurry so obtained in the cone is mixed with cement to obtain a homogenous slurry, subjecting said slurry to the step of corrugating (moulding) in a manner to get the required product. 2. A process for the manufacture of asbestos-fiber-cement products substantially as herein described and illustrated.

Documents:

1389-del-1999-abstract.pdf

1389-del-1999-claims.pdf

1389-del-1999-correspondence-others.pdf

1389-del-1999-correspondence-po.pdf

1389-del-1999-description (complete).pdf

1389-del-1999-form-1.pdf

1389-del-1999-form-19.pdf

1389-del-1999-form-2.pdf

1389-DEL-1999-Form-3.pdf

1389-del-1999-gpa.pdf