| 摘要 |
Additive for plastic material and others being screw extruded, such as colorant, anti-oxidant and the like, is auger fed through the sidewall of the feed hopper just above the screw with the auger feed tube hooded by the upper side extending beyond the lower side and with the lower side terminating at a point in a range of distance along an approximately horizontal line extending from the in-feed sidewall, i.e., the sidewall where the auger feed tube penetrates, and substantially passing through the vertical axis of the feed hopper, and, at a distance from said axis towards said in-feed sidewall equal to about one-seventh the diameter of the hopper at that level to a distance from said axis away from said in-feed sidewall equal to about one-tenth diameter, but preferably within a distance from about one-ninth diameter from the axis towards the in-feed sidewall to about one-fifteenth diameter beyond said axis, and most preferably between the said axis and about one-twelfth diameter therefrom toward the in-feed sidewall. Two or three auger tubes that substantially meet at a common point may be used to add a like number of additives simultaneously. Each hooded end may have any of various shapes from flat bevelled to arcuate to stepped. The motor drive for the screw extruder and the variable speed motor drive of the auger tube or tubes are controlled from a common electrical or other control device switch for coordinate proportional addition of additive.
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