DD216643A1 - APPLICATION METHOD FOR METAL PATCHES WITH ORGANIC COATINGS, ESPECIALLY PVC PLASTISOLS - Google Patents

Abstract

The application of the invention can be carried out on all coating systems for tapes and sheets, in particular broadband coating systems. The aim of the invention is to achieve quality when using coating materials with impurities, which meet the requirements. The object of the invention is to develop a process for the continuous application of organic coating materials, in particular of PVC plastisols, with hitherto insufficient purity. According to the invention, the object is achieved by d. be located in the nip particles are conveyed out of the nip by the synchronization of dipping and metering and thus the Laengsriefenbildung is avoided. A certain speed of all rollers must be observed.

Description

a) Title of the invention

Application process for metal strips with organic coating materials, in particular PVC plastisols

b) Field of application of the invention

The invention relates to a method for applying organic Baschichtungsstoffen on metal strips * The application can be made on all coating systems for strips and sheets, \ especially on broadband coating systems,

c) Characteristic of the known technical solutions

For the application of organic coating materials, a variety of methods are known. In one method, the coating materials are applied with the 3-roll coater. Here, all 3 rollers move in a direction opposite to the tape run. The coating material is fed continuously to the coating material trough (coater trough), picked up by the dipping roller at relatively high speed and pressed into the nip between dipping roller and dosing roller. The dosing roller runs more slowly than the remaining rollers and thus smoothes the wet film on the dipping and dipping roller Beschichterwalze. While an oscillating doctor blade continuously removes the surface of the metering roller from the coating material, the immersion roller, with its relative movement between the immersion roller and the coating roller, transfers the coating material to the rubber casing at a slower rate

rotating basset roller. The smooth coating material thus metered onto the coating roller is now applied by the contact pressure and the relative movement between the application fluid and the belt surface to be coated. The relative movement of the three rollers with one another results from the different peripheral speeds with the same direction of rotation. The circumferential speed of the application roller must always be greater in the opposite direction of rotation be as the belt speed to avoid tearing of the wet film as well as destruction of the rubber coat of the Beschik hetungswalze.

In this procedure, the following conditions must be met:

^ ^{a (1} » ² - ¹ » ^{5) V} Band

Dipping roller «(2 - 3) Band

^V metering roller ^{a (} 1/10 ^{) V} belt

    · Ii

A further method is described in OS 1940 665, in which case the order is carried out by means of 2 rolls _v .

All of these processes require a degree of purity of the coating substance which is below the TuL and can hardly be achieved technically. The counteracting principle of action means that larger solid particles are retained in the nip (dosing roll) (dosing roll) and cause ridge-like surfaces. These grooves go intermittently down to the substrate in depth and have a length of 30 - 50 m.

Surface application is adversely affected by this method of application, if the degree of purity of the coating materials is not so poor. »The high-quality steel rollers used as dipping and dosing rollers are susceptible to scratches and other mechanical influences. Especially the dosing roller is subject to a foreign body component and always oscillating scraper movement high wear,

d) Object of the invention

The present invention should be achieved when using coating materials with insufficient purity, in particular PVC plastisols, coating qualities that meet the requirements set »

e) Presentation of the essence of the invention

The object of the invention is to develop a process for the continuous application of coating materials, in particular PVC plastisols having an insufficient degree of purity.

According to the invention the object is achieved in that the particles located in the nip are conveyed out of the roll gap by the synchronization of dipping and dosing roller and thus the Längsriefenbildung is avoided. A further improvement of the surface quality is recorded by the use of rubber rollers as metering and dipping rollers. By changing the sense of rotation of the 'rollers' (immersion and metering rollers) and the use of rubber rollers over the entire coating trough a favorable flow behavior of the coating materials is achieved, which causes a uniform layer thickness over the entire bandwidth. This procedure must meet the following conditions:

(1.2 - 1.5 | · ^V

Band ^V TW " ^Kd - ^Oi ' ^v Band

v _DW = o - Vic T _Baud

Where:

^V BW speed coating roller

^V TW- n dipping roller ⁷ DW n metering • tr ^v band tape

f) embodiment

The invention will be explained below with reference to an exemplary embodiment.

The pig. 1 shows a schematic illustration of the coating process on a coating system for metal strips. On a coating installation, sheet metal strips are coated with PVC plastisol.

On a coating system, not shown here, the sheet metal collar 2 is guided over deflection rollers (rollers) 1 to the coater roller 3 »Coater container 6 is the coating material 7, plastisol, in which the rubberized dipping roller 5 protrudes. The coating medium 7 is taken up by the fountain roller 5 and transported upwards in a clockwise direction.

By means of the rubberized metering roller 4, which has a retrograde direction of rotation, synchronization with the dipping roller 5, the layer thickness is determined according to the nip size. The optimum speed of the metering roller 4 0 to 1/10 V _{B d} must be set depending on the degree of purity. By the rubberized dipping and metering rollers 5; 4, optimal distribution of plastisolesr 7 across the entire bandwidth is achieved.

The fountain roller 5 transfers the coating material 7 to the rubberized coater roller 3 and from there to the belt 2.

Claims (2)

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• · " Claims ι 1, application method for metal strips with organic coating materials, in particular PYC plastisols, characterized in that the Dosiervialze (4) is moved backwards and the speed V _DW = 0.- 1/10 V _Baad , V _TW = (2 to 5) • ^V band ^{UQd V} BW = ^ ¹ » ^{2 to 1} » ³⁾ ' ^V band is set. 2. The method according to claim 1, characterized in that the Dosiervtalze (4) and the Tauchvialze (5) are coated with a G-ummimantel. For this 1 page drawings