Netstal-maschinen Ag

Bock, Stefan

Stefan Bock

Britta Scheunemann

A method and an apparatus for rapid and efficient heating of polymer pellets in preparation for processing in a plastifier. For introduction of heat energy, a gas, preferably dried air, is introduced into the polymer pellets flow so as not to be in direct countercurrent thereto. The gas is preferably introduced in its still hottest state in a targeted fashion, for the purpose of rapid energy input, at a freely selectable location. This preferably takes place at the material output of the booster hopper. The gas is preferably conducted by way of cascades, which can be of a variable design, and flows through the bulk material at least twice. The speed of the flow can be influenced.

Method and device for the fast and efficient heating of plastic granulates for preparing for the processing in a plasticization

Preforms with a neck region and a preform body and having an enlarged geometry in comparison with the cavity of the injection mold are produced by injecting a polymer melt into the mold with a geometry of the cavity in the mold such that the radial extent of an inner space in the preform body thereby produced is not greater than the radial extent of the inner space in the neck region, the preforms are removed from the open mold by a removal gripper, and the preforms in the removal gripper are inflated using positive pressure such that the geometry of the inflated preform body is larger than the cavity in the injection mold.

Method and device for producing preforms with special geometries

The invention relates to a device and a method for producing preforms () with a special geometry, wherein the finished preforms have a neck region with a thread and a preform body, which adjoins the neck region and has an enlarged geometry in comparison with the cavity of the injection mould. The method is characterized in that preforms are produced by injecting a polymer melt into an injection mould, in which the geometry of the impressions forming the cavity in the mould is designed in such a way that the radial extent of the inner space in the preform body thereby produced is not greater than the radial extent of the inner space in the neck region, the preforms are removed from the open mould by a removal gripper, transfer pins of a transfer gripper are introduced into the associated inner space of a preform, the preforms are removed from the removal gripper by means of the transfer gripper and are transferred into a post-cooling device, and the preforms in the removal gripper and/or in the post-cooling device are inflated using positive pressure in such a way that the geometry of the inflated preform body is larger than the cavity in the injecti on mould.

An auxiliary device and a method for finishing and calibrating preforms that are removed from a multiple tool in an unstable shape, the calibration process being performed with compressed air immediately after removing and withdrawing the preforms from the multiple tool. Nipples that can be inserted into the preforms are provided with expandable press rings or sealing rings in order to seal the interior of the blow-molded part of the preforms. The compressed air is introduced via the nipples, the sealing process being performed by radially expanding the press rings or sealing rings in analogy to the closing process of thermoses, thus protecting the preforms from adverse forces. The sealing point can be randomly selected in the transition zone from the threaded part to the blow-molded part of the preforms. The interior of the blow-molded part is optimally sealed without affecting the form stability and dimensional stability of the preforms.

Growing community of inventors

Glarus, Switzerland

Stefan Bock