| 摘要 |
The die is of the spiral feed-groove type, in which the annulus of liquid resin emerging from the groove chamber has bands of unequal temperature. The die is provided with a flow-dividing and re-combining facility, which takes the form of two series of open channels, one cut into the outer wall, and one cut into the inner wall, just below the die nozzle. One series of channels is inclined or offset to the right, the other to the left. The effect is that liquid from the hot band may be recombined with a matched quantity of liquid from the cool band. This leads to a marked improvement in temperature equalization band to band. As a result, the gauge thickness of the as-manufactured plastic film is more consistent. |
