A process was developed for modification of the surface of poly(p-phenylene terephthalamide) fibres so that these fibres function as a reinforcing agent in a cold-molded cementitious composite at levels below 1% by weight. The surface modification treatment involves treatment of the fibres with aqueous alkaline hydroxide between 20.degree. C. and 95.degree. C. for between 20 minutes and 7 hours. The modified fibre is used to replace asbestos in the cementitious composite and it has been found that this improves both the green strength and the flexural strength of the autoclaved material.

A surface coating composition comprising, in combination, a fibrillated polymer matrix, at least one pigment, at least one binder, and at least one solvent, and a method for the manufacture thereof.

A process for maintaining or increasing the tensile strength of fibers of aromatic copolyamides which are formed from a major portion of para-monomers and are soluble in organic aprotic and polar solvents. The process involves storing the fibers in alkaline media after production by wet or dry spinning processes, after treatment of the dry or wet spun fibers, and storing the fibers in an aqueous environment having a pH of at least 10. The tensile strength of the fibers is retained or increased.

A method for recycling wood fiber products and particularly newspaper-type pulp, into a new and useful molded product is disclosed. A quantity of paper to be recycled is mixed with sufficient water to form a viscous pulp or slurry by beating the pulp to a desired consistency for a given texture of the product to be made. A pulp press is employed which has a molding chamber with interior sidewalls comprised of a rigid screen through which water can pass and a rigid plate outboard from the screen. The rigid plate has channels formed therein facing the screen through which channels water can flow. One of the sidewalls is movable into the molding chamber to serve as a piston. Some means to drive the movable sidewall, such as an hydraulic jack, completes the press. The beaten pulp is poured into the molding chamber. The chamber is then closed, and the press operated by moving the movable sidewall into the chamber to compress the beaten pulp to a desired pressure and pulp density. Water and air are forced out of the slurry through the screens and into the rigid plate channels to drain. The compressed pulp is then dried to thereby yield a new pulp paper product. In a preferred form, the foregoing method further includes the use of a template for making an image on the pulp product during compression.

A cement mortar is provided which is mixed with a liquid media, preferably either water or aqueous latex, for use as a thin-set mortar, medium bed mortar, underlayment mortar and/or grout (pointing mortar). The mortar or grout contains cement, sand and a water retaining agent and is improved by employing an aramid fiber in the mortar. A p-aramid fiber is preferred and it is highly preferred to use the polymer fiber in a pulp form which has a fibrillated structure. The overall performance properties of a cement-based mortar or grout such as a thin-set mortar are significantly improved including sag resistance, open time, bond strength, flexibility, heat aging and water immersion strength.