PURPOSE: To improve properties of polypropylene PTP formed piecs such as tablet capsules etc. by heating a sheet on a sheet heating zone of a blister pack forming machine and forming it at a specific sheet temperature.
CONSTITUTION: On a sheet heating zone of a blister pack forming machine, a sheet is heated and formed at polypropylene sheet temperature of 130W160°C. When a PP sheet is formed at the forming temperature of 130°C or lower, a formed piece obtained is a defective one where the formed shape of PTP is not transferred from the mold with good fidelity. When it is formed at 160°C or higher, the sheet sticks to a platen or a heating roll, etc., incapable of being fed and formed. The forming temperature range of the sheet to obtain good PTP formed pieces from PP sheet is limited to 130W160°C and preferably 135W 155°C. When a preheating zone is added in front of the heating zone of the PTP forming machine, the total heating time of 5W15sec can perform steady production.
SHIRAKAWA KATSUSHI
KOBAYASHI HIROITSU
