Abstract
Compressive creep tests were carried out using some injection molded cylindrical specimens of polycarbonate filled with 30wt% glass-fiber and unfilled. Creep properties under various conditions of temperature and compressive stress were discussed.
The results obtained are as follows:
(1) At the condition of temperature under about 60°C, the maximum stress below which creep compliance does not depend on stress is 3∼6kg/mm2 on filled polycarbonate and 1kg/mm2 on unfilled.
(2) Creep compliance D(t) is shown in the following equation, when the conditions are not very severe.
logD(t)=alogt+b (1)
where t is time. Creep compliance D(t) after a long time is able to be estimated by using the values of a and b obtained from short period creep tests under conditions being considered.
(3) The value of a in equation (1) increases with temperature, and b is constant. The reinforcement with glass-fiber brings so low values of a and b as to be effective for an increase of dimensional stability under load.
