JPH04362049A - Treatment of reinforcing fiber for inorganic building material - Google Patents

Abstract

PURPOSE:To enable the use of the pulp of waste fine paper as reinforcing fibers for a cement product. CONSTITUTION:Water is added to waste fine paper so as to regulate the concn. of solid matter to <10% and they are stirred to a slurried state. This slurry is allowed to stand for >=6hr in an autoclave at >=110 deg.C and dehydration is carried out. Harmful starch, etc., are removed by dissolution.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of treating inorganic reinforcing fibers for building materials, and more particularly to a method of treating waste paper pulp that makes effective use of it.

0002

[Prior Art] Traditionally, it has been considered essential to add reinforcing fibers to inorganic products whose main component is cement, etc., in order to give them strength.In recent years, the use of pulp fibers has become very popular in place of asbestos fibers as reinforcing fibers. It is widely practiced. By the way, pulp fibers are a cause of large consumption of wood, and their use is gradually being restricted due to forest protection issues, and various attempts have been made to effectively utilize waste paper pulp, which is an industrial waste.

0003

[Problems with the Prior Art] Among the waste papers mentioned above that are used as recycled resources for pulp fibers, wood-free paper has good pulp quality and is considered suitable for use as reinforcing fibers. Starch is often added as a paper strength enhancer or sizing agent, and since these additives become substances that inhibit cement hardening, there is a problem that they cannot be used as pulp fibers as they are.
When used, it was only used as an extender for green pulp.

0004

[Problems to be Solved by the Invention] In view of the above-mentioned problems, the present invention provides a method for processing reinforcing fibers for inorganic building materials so that the entire amount of wood-free paper containing cement hardening inhibitors can be used as pulp fibers as reinforcing fibers. This was done for the purpose of providing a method.

[0005]

[Means for Solving the Problems] That is, the method of treating inorganic reinforcing fibers for building materials of the present invention involves adding water to waste wood-free paper and stirring it to a solid content of less than 10% to form a slurry. , the slurry is left in an autoclave at 110° C. or higher for 6 hours or more, and then dehydrated.

[0006]

[Operation] The high quality paper used in this invention is waste such as office paper. This high-quality paper contains a paper strength enhancer and a starch sizing agent, and as mentioned above, it cannot be used as is as a reinforcing fiber for cement compounding. Therefore, water is added to the above-mentioned high-quality waste paper so that the solid content concentration is less than 10%, preferably 4% or less, stirred to form a slurry, and this is left in an autoclave at a temperature of 110°C or more for 6 hours or more. As a result, these curing-inhibiting substances are eluted into water to which a large amount has been added. Therefore, after this treatment, almost no substances that cause curing inhibition remain in the high-quality waste paper, and therefore, even if the entire amount is used as pulp fibers, curing inhibition will not occur. In the above, the solid content concentration of the waste paper is set to less than 10%.If the concentration is higher than this, the concentration of the substance that causes curing inhibition after elution becomes relatively high, and the concentration in the waste paper is not sufficiently reduced. This is because it cannot be planned. Further, the purpose of performing autoclave treatment is to promote elution.

[0007]

[Example] Next, an example of the present invention will be described. Water was added to waste office paper to give a solid content concentration of 4%, and the mixture was forcibly stirred with a mixer to decompose the waste paper and form a slurry. Next, this waste paper slurry was placed in an autoclave at 120°C for 8 hours, and then dehydrated to reduce the water content to 10.
% waste paper pulp was obtained. This treated pulp was used as a reinforcing fiber, and 8% by weight of the treated pulp was added to a mixture of 40% by weight of cement, 42% by weight of fly ash, and 10% by weight of perlite, mixed uniformly, and then water was added to form a mixture with a thickness of 5 mm and a width of 45 cm.
A plate-shaped body having a length of 90 cm was molded and cured in an autoclave. As a comparative example, a test plate was molded in the same manner as in the above example except that waste paper pulp that was merely ground without any treatment was used. The bending strength of the above Examples and Comparative Examples was measured and the results are shown in Table 1.

[0008]

[Table 1] In Table 1, pulp COD indicates a substitute characteristic for the amount of starch contained in the pulp after treatment, and is the COD measured in the supernatant liquid of a 1% pulp solution.

As is clear from Table 1, it was found that the products treated according to the present invention had excellent strength even though the entire amount was waste paper pulp.

0010

[Effects of the Invention] As explained above, this invention makes it possible to effectively utilize high-quality waste paper, which conventionally was impossible to add as is, contributing to resource conservation and processing in an autoclave. This method has various effects such as less wasted energy because it can be performed simultaneously and in parallel during autoclave curing of cement products.

Claims (1)

[Claims] [Claim 1] Water is added to high-quality waste paper so that the solid content concentration is less than 10%, stirred to form a slurry, and the slurry is left in an autoclave at 110°C or higher for 6 hours or more, and then A method for processing reinforcing fibers for inorganic building materials, which includes dehydration.