The Composite of “Paper Clay”, Characterization of material properties, abilities and workability from an art perspective

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Abstract

The usage of Ceramic Composites in order to improve the workability and properties of clay already has past a long history behind. In spite of the fact that clay by its own is a flexible and appropriate material for sculpting and ceramic making, it also carries some problems, flaws and imperfections (such as cracking, heaviness and etc.) which make it somehow troublesome to work with. From the old-times it was common to add diversity of organic and mineral additives such as straw, cattail, wool of goat, ash, grog and etc. to improve the clay’s properties which are still on their way regarding the technological and scientific promotion beside the invention and discovery of new materials such as fiberglass, nylon and cellulose fibers. In this essay in addition to review of the background of the using additives to improve clay, some of the most common additives and their effect on the enhancement of ceramics properties have been surveyed. Common additives can be categorized by several different factors. For instance by their shape; as fibers or granules, or by their source; natural or synthetic and also by their usage; as flux, colorant and etc. The close study and observing of cellulose fibers (pulp) as an additive to clay is consisting the main part of this essay. Cellulose has a natural source in the shape of hollow tubes called fiber. Because of its structure, it can easily absorb and convey water through itself. Cellulose usually is obtained from most of trees and some other plants. Cellulose fibers due to their physical and chemical structure and properties improve variety of clay body’s properties. Among those we can mention the noticeable weight loss, enhancing the green stage strength, decreasing cracks and breakage of bodies, beside some other properties which have been considered in this essay.The process of pulp making and preparing Paper Clay beside the historical contents, properties, formulation, techniques, abilities and usage of this composite (Paper Clay) with emphasis on it’s artistic workability have been under meticulous observation. Finally some technical and scientific examinations have been accomplished to determine special characterization of paper clay such as green and fired stages strength, porosity and water absorption, density, thermal shock tolerability and shrinkage of clay bodies. The case studies prepared in different amount of pulp volumes in clay bodies from 10% up to 200% which was the maximum amount of pulp possible to add to clay slip. Finally, the result of scientific examinations reveled that existence of cellulose fiber in ceramic bodies in all percentages improves the green stage strength. Furthermore it has a great effect on reduction of the weight of bodies booth in the green and fired stages. It also proved that after firing, porosity and water absorption of bodies will noticeably increases which mean a better acceptance of glazes. The strength of bodies according to the results is reduced by increasing of pulp in them. However this reduction in comparison is also acceptable and will not be a problem especially in the field of artistic ceramics.

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