| 摘要 |
An improved moulding method and device which will ensure an accurate, constant shot weight of the dosage of molten plastic material being injected into the mould cavity, thereby to obtain substrate discs having a non-varying thickness. The method of the present invention comprises the step of sensing an actual, secondary rear end position of a moveable wall obtained shortly after the interruption of the supply of molten plastic material to a metering chamber, and then performing a forward stroke of said wall with a predetermined length, whereby an accurately metered constant dosage of molten plastic material will always be injected during each shot. The device includes a means for sensing an actual, secondary rear end position of the moveable wall, and a means for obtaining a predetermined length of the forward stroke of the moveable wall, thereby to inject an accurately metered constant dosage of molten plastic material during each shot. <IMAGE> |
