Hoechst Aktiengesellschaft

Agfa Gevaert Nv

Agfa-gervaert Ag

Uwe Gartmann

Hermann Idstein

Guenter Hultzsch

Klaus Joerg

Georg Haby

G&uuml;nter Hultzsch

J&ouml;rg Kaden

Raimund Haas

To avoid or minimize the occurrence of cross streaks or current streaks on a substrate that is transported through an electrolytic bath and roughened electrochemically in it, the current density is regulated in the electrolyte between a first alternating or three-phase current electrode and the substrate in such a way that at the beginning of a roughening zone, the current density has a lesser value than within the roughening zone, in the transport direction of the substrate. Downstream of the first alternating or three-phase current electrode, either a further alternating current electrode or a further three-phase current electrode acts on the substrate. In a preferred embodiment, the first alternating or three-phase current electrode has a rounded outline, which is composed of a curved portion and adjoining it a straight portion.

Method for electrochemical roughening of a substrate

A method and apparatus for electrochemically roughening a support is disclosed to minimize the occurrence of surface discharges or electrical discharges on the support. A DC voltage acts on the support at the start of the movement of the support through the electrolyte bath. Subsequently, a three-phase or single-phase current acts on the support in the roughening zone. Three-phase electrodes are arranged in the electrolyte bath and are connected to the secondary of a three-phase transformer. The primary of the three-phase transformer is connected, via control transformers to a three-phase power transformer. A DC electrode is located upstream of the three-phase electrodes in the direction in which the support is transported through the bath. The DC electrode may be connected to the positive pole of a DC source while the negative pole of this DC source makes contact with the support.

Method and apparatus for roughening a support for radiation-sensitive coatings

Apparatus and method for applying a coating solution to a running substrate using a slot die having two die lips forming a gap therebetween. The gap also defines an outlet for releasing the coating solution to the substrate. The lips have plurality of manifold chambers communicating with gas feeder and coating solution feeder provided in the die lips. The manifold chambers communicate with the outlet. The width of the coating solution is adjustable with the gas pressure applied to the gas feeder.

Method and apparatus for applying a coating solution

A device for generating a subatmospheric pressure at a coating layer on a web-shaped carrier material which is guided over a coating roll. The device is provided with a pressure chamber which is pressurized symmetrically with compressed air via two end-face inflow openings. The compressed air is fed symmetrically to the inflow openings via a manifold unit. From the pressure chamber, the compressed air emerges via a so-called Laval nozzle, thereby generating in a region above the nozzle a subatmospheric pressure which acts on the meniscus of the coating layer during the transition from the gap of the coating die onto the carrier material. Movable seals are provided to permit the width of the nozzle to be adapted to the coating width of the carrier material.

Device for generating a subatmospheric pressure

A directing apparatus for guiding, deflecting and/or diverting a web of material including a block which has a curved surface. The block is segmented, i.e. divided into sections, and in each section there is a certain number of bores, to which streams of medium are admitted at various velocities or with various quantities of medium. In each of the sections, a predetermined number of bores are connected to one another and are connected via a common line to a common medium supply device. The medium may be either compressed air or a liquid.

Growing community of inventors

Eltville, Germany

Uwe Gartmann