Abstract: A band of bags of plastic material connected with each other by perforation lines. In the two end parts of each perforation line the number of perforations and/or the width of the perforations per unit of width is greater than in the central part of the perforation line. A device for manufacturing said band of bags comprises a perforating member with equidistantly spaced first perforating pins and second perforating pins are present on either side of a central area between the first perforating pins.
Abstract: An extruder for synthetic material with at least two mixing and conveying worms, comprising an extruder housing, an extruder inlet, a driving member for driving one of the worms and a gearing for driving the second worm, said gearing comprising two gear wheels with inclined toothings. These gear wheels are mounted on either side of the mixing and conveying worm and cooperate therewith.
Abstract: Extruder, especially a multi-worm extruder with a housing and one or more mixing worms with associated shaft, as well as at least one hydrostatic bearing for absorbing the axial load of the conveying and mixing worm. A slit between a bearing disc on the worm shaft and a counter bearing ring can be filled with oil via a pipe connected to a pump, radial sealings preventing the oil from escaping between the gliding faces of the bearing, whereas the said counter bearing ring is rotatably supported in the extruder housing.
Type:
Grant
Filed:
February 15, 1974
Date of Patent:
March 23, 1976
Assignee:
Wavin B.V.
Inventors:
Willem Cornelis den Hertog, Geert Rolleman
Abstract: A conducting plastic pipe system comprising a male plastic pipe part and a female plastic pipe part with conducting covering layers which are interconnected by means of a conducting sealing ring between the male and female part. In case of outer covering layers on the pipe part the covering layer extends onto the inner side of the muff end of the female pipe part.
Abstract: Pipe connection for plastic pipes comprising two penetrating pipe parts and a receiving pipe part, which is provided with corrugations at each end. The radius of curvature or the height of the corrugations decrease from each end to the centre part of the receiving pipe part.
Abstract: Device for the supply and discharge of cooling liquid in the worms of an extruder press, the worm or worms being situated at some distance from the housing, being provided with a stationary sleeve with a stationary centering ring near both ends thereof and rotatable adjusting rings on each of its sides. The sleeve is furnished with at least two circular chambers, which are delimited by sealing rings, these chambers being in open communication with cooling liquid channels in the worm shaft and which are each connected with an external supply and discharge pipe for the cooling liquid, while part of the sleeve comprises oil holes and overflow openings.