Hoechst Aktiengesellschaft

Eocom Corporation

Klaus-Peter Schoen

Klaus Schmitt

Engelbert Pliefke

Juergen Lingnau

Richard E Amtower

William Jeffers

Norman L McGowan

Josef Fritsch

Peter Riedel

Rudolf Urban

A device for filling a tubular casing with a pasty product comprising a stuffing horn, a brake which encircles the outside of the stuffing horn in the vicinity of the orifice thereof, and a coaxial, cylindrical support tube accommodating a tubular net, which support tube is arranged at a distance from the outside of the stuffing horn and extends over the length of the stuffing horn to an end in the vicinity of the orifice of the stuffing horn, the brake being located at said end of the support tube. The invention enables the tubular net to continuously applied to the tubular casing during the stuffing operation.

Process for filling tubular casings

The decoating device 21 comprises a spraying section 22, a heating zone 9, a cleaning station 23 and a gumming station 24. Containers 5a, 5b, 5c for various developing liquids are connected via a multiway valve 5 to one or more flat-jet nozzles 6 in the spraying section 22. A first sensor 4 registers the incoming printing plate 1 and actuates the multiway valve 5 in order to admit decoating liquid from one of connected containers 5a, 5b or 5c to the flat-jet nozzle(s) 6. The decoating liquid sprayed past the printing plate 1 is conveyed via a collecting trough 7 into a collecting container 8. The thin film of decoating liquid on the printing plate 1 is heated to the preselected temperature by means of the radiator 25 in the heating zone 9. A pair of squeezing rollers 11 cleans the printing plate surface. A second sensor 14 registers the front edge of the printing plate 1 and then switches on the cleaning station 23 and gumming station 24 known per se. The rear edge of the printing plate 1 switches the decoating device 21 off via the second sensor 14. Shortly before the switching off, the flat-jet nozzles 6 are rinsed via a water connection 20 and the multiway valve 5 in order to prevent a clogging of the nozzle orifices.

Decoating device

Printing forms or metallized images can be prepared electrophotographically by a process comprising the electrostatic chargeup, imagewise exposure and tonering of a photoconductor layer applied to an electroconductive base material, followed by fixing of the tonered image areas, removal of the photoconductive layer in the non-image areas by decoating and, where appropriate, etching of the bared base material surface. A recording material is used that comprises a photoconductive layer containing at least one organic n-conducting pigment in a concentration between 10 and 50 percent by weight and an organic p-conducting photoconductor in a concentration of 0 to 20 percent by weight, based on the layer weight, together with a binder which is soluble or dispersible in aqueous-alkaline solution. The decoating is carried out with an aqueous-alkaline decoater solution, which preferably contains alkali metal hydroxides and/or phosphates. The decoating is preferably carried out at an elevated temperature, for example, between about 30.degree. to 60.degree. C.

Electrophotographic process for preparing printing forms using alkaline

Disclosed is a device for the electrophotographic manufacture of printing forms, comprising a loading table, an exposure table and a developing table arranged in the device one after the other in the transport direction A of printing plates. The loading table is pivotable and is equipped with spring suction devices, by means of which the uppermost printing plate can be removed from a plate magazine. After the printing plate has been removed, the loading table is swung into its horizontal position, a corona is moved over the loading table and the photoconductive layer of the printing plate is loaded to the required voltage. The printing plate is transported from the loading table to the exposure table and from the latter to the developing table by means of compressed air which forms a cushion underneath the printing plate. The printing plate is guided on the cushion in suspension from processing station to procesing station. For this purpose, at least two rows of air nozzles are arranged in the tables of the processing stations. The air nozzles extend at an angle inside the tables and are charged with compressed air. The loading table, at its narrow sides, is equipped with pivotable flaps. The exposure table, at its narrow sides, has fixed guide plates, whereas the developing table is equipped on all four sides with pivotable flaps and, moreover, has two additional rows of air nozzles which are arranged at right anges to the air nozzles which extend along each of the tables in the transport direction.

Device for the electrophotographic manufacture of printing forms

Disclosed is a liquid developer device for a recording material which comprises at least one conveying device for applying a liquid developer to the recording material and a developer electrode attached to the conveying device in a manner such that the electrode floats on the developer layer at a constant distance from the recording material. In a further embodiment, the recording material, which has a latent electrostatic image on both its surfaces, is passed vertically between conveying devices. Also disclosed is a process for using both devices.

Liquid developer device

The present invention relates to a suction device for securely holding printing plates in a processing position by sub-atmospheric pressure. The suction device comprises a turnstile arrangement with four suction tables in two mutually perpendicular planes and is connected to a motor which rotates the turnstile arrangement in 90.degree. steps. Four suction chambers are located in a hub part of the turnstile arrangement, these chambers being connected, via pressure lines, to a vacuum source for generating sub-atmospheric pressure. The supporting surface of each suction table comprises suction slots, which communicate in pairs, each of these communicating pairs of suction slots being connected to the associated suction chamber via a common suction passage. Each suction chamber comprises a piston with its piston rod being guided outwardly through an end face of the hub part and carrying a circular plate. The inner surface of this plate bears partly against the outside surface and against the inner edge of a stationary radial cam-plate.

Suction device for holding plates

An original holder for a printing plate processing apparatus for rapid exchange of an original in a vacuum frame covered by a glass plate and exposed in the exposure device of a printing plate processing apparatus. The glass plate is held in its open position by a gas pressure element to facilitate insertion of the original. Two U-shaped metal sheets serve as supports for two vacuum frames which are each evacuated following insertion of an original and closing of the glass cover plate. Swivel joints are attached at the sides of the supports which enable the original holder to be pivoted through an angle of 360.degree. and which are additionally horizontally slidable in the guides of supporting and guiding arms. The vacuum frames are individually pivotably mounted in their supports by ball guides in guide tracks. When one of the vacuum frames is in the vertical exposure position in the exposure opening in the wall of the exposure device housing and its support is secured to the housing wall by locking devices, the second vacuum frame is pivoted into the horizontal position by means of a lever so that an original can be inserted therein. The second vacuum frame is thereafter folded back again to the vertical position in its support. After exposure of the original in the first vacuum frame, the entire original holder is drawn into the change position, pivoted through 180.degree., and the original in the second vacuum frame is moved into the exposure opening. In an alternate embodiment, the swivel joints are fixedly mounted adjacent the edges of the exposure opening, and the original holder pivots inside the exposure device.

Original holder for a printing plate processing apparatus

An electrophotographic apparatus for producing printing masters utilizing modulated laser light as the exposure source and a continuous process for producing such printing masters involving the steps of plate conveyance, synchronous charging and exposure, and electrostatic development and fusing of electrophotographic printing masters suitable for use in offset or lithographic printing processes. The apparatus comprises a transport system for sequentially conveying printing masters to the exposure platen which retains the masters in a fixed plane for synchronous charging and exposure, utilizing as a light source, a modulated laser beam. The optical and deflecting components of the exposure system are mounted in a moveable carriage member adapted to traverse a plane substantially parallel to the plane of the exposure platen such that the exposure laser will raster scan the platen area. The charging coratron is also preferably mounted on the moveable carriage such that the sequence of charging the electrophotographic master and exposure thereof to the raster scan of the exposure laser are synchronous. The apparatus employs an exposure laser having a power of about less than 1 watt, but sufficient power to provide a light energy on the photoconductive surface of the printing master of at least about 2.times.10.sup.-3 millijoules/cm.sup.2 under operating conditions.

Growing community of inventors

Wiesbaden, Germany

Klaus-Peter Schoen