Clay reinforced with paper fibre is an
excellent material for large pieces, sculptures and slabs because of its
remarkable green strength and light fired weight. In paperclay, the clay
particles glue the paper fibres into a network and thus form a supporting
structure for an unfired object and prevent cracking. The paper fibres
burn away from the clay in firing, leaving the object porous.
The
aim of this research has been to improve the handling properties of large
objects at the green stage. It was financed by the Ministry of Education
in 1993 and the Academy of Finland in 1993 - 1994. Results of the research
have been published in the proceedings of the 8th Cimtec conference, Florence
Italy, 1994 and will be presented as a licenciate thesis by Leena Juvonen
in 1996.
Essential tests in the research have been bending
resistance, water absorption, linear shrinkage and efflorescence. Material
tests have been carried out on different kinds of fibres like cellulose,
waste paper and sludges from a paper mill in co-operation with the University
of Technology.
Along with material tests there has been an artistic
project testing paperclay in practise. Large, thin bowls and slabs have
been made by pressing on plaster moulds and painting with ceramic pigments.
This project is part of Varde the Nordic design programme, which was exhibited
in London, Rome, Budapest, Berlin and Vienna during 1994 - 1995.
The use of paperclay is economical. Instead of
requiring new paper, all kinds of waste paper, recycled paper and pulp
are good material to be mixed with clay. Material and energy costs are
cut down as paper fibre added to the clay body fills up the clay mass.
Paperclay also withstands rapid temperature changes, which shortens the
firing time and saves energy.
Working with paperclay is more spontaneous than
with conventional clay bodies. Paperclay withstands quick drying and firing
without cracking or warping. Large, thin paperclay objects can be raw glazed
and firing can be started even when the object is still wet. Paperclay
questions the traditional restrictions prevailing in ceramics and gives
more creative freedom.
