Fibers which we used for asbestos substitutive materials are poly-vinyl-alcohol (Vinylon) fiber, poly-acrylo-nitorile (acrylic) fiber, and alkali-resistant glass fiber. We used mini-Hatschek machine to make test products. We used cellulose fiber to hold cement particles and mineral materials such as mica, cepiolite, wollastonite, silica fume, and bentonite, to prevent cracking and excessive length change. We have done five tests for asbestos substitutive materials, which are on bending strength, freezing and thawing resistance, impulse resistance, Incombustibility, and fiber contents. As a result, bending strength of asbestos alternative is a little low, but other properties of those are equal or better than asbestos slates. Addition of 2 % or 4 % asbestos to alternatives did not make proprieties better compared to non asbestos alternatives exept product cost.
