To shorten the start-up time at the beginning of the operation and realize an automatic start-up by providing a volume-reduction molding machine with a unit for adjusting the feed rate of a molding feedstock based on values detected by a means of measuring the temperature of a die, a means of measuring the driving output, and a monitoring means for identifying the shape and quality of discharged products.

An adjusting unit is provided on a volume-reduction molding machine wherein a roller 4 is rolled on a die 2 having vertical through holes to grind a solid material to reduce its volume and mold it into cylindrical pellets. When the measurement by a device for measuring the temperature of the die reaches a certain temperature at the beginning of operation, the raw material is fed continuously. It is desirable to bring the machine into a stationary operation when the temperature on the surface of the die becomes 40°C or higher. When the machine begins to discharge products orderly in shape, the feed rate is increased. The shape monitoring may be done with an ultrasonic detector a laser detector or an image processor judging the shape of falling objects, or by sampling. It is suitable to provide a unit for heating the die, the rolling roller, or the raw material.