FI67670B - ANORDNING FOER ATT UTBREDA ETT TUNT SKIKT AV ETT OEVERDRAGNINGSMATERIAL PAO EN LOEPANDE MATERIALBANA - Google Patents

Description

~ 2 ~ 67670 The present invention relates to a device for obtaining a thin layer of flux on a backing roller moving on a web of material by means of a slit nozzle device in which the inlet lip of the nozzle gap, in particular the wide nozzle gap, is fixed and the discharge lip is developed as a movable scraper rod.

U.S. Pat. No. 3,919,974 discloses a slit nozzle apparatus in which the nozzle lips of a nozzle gap are fixed and in which the nozzle lips can be moved relative to each other to position the nozzle gap. Such a slit nozzle assembly requires a length corresponding exactly to the coating width and the width of the web of material from the back pressure roller. Self-cleaning of the nozzle lips to provide the scratch-free coating surface possible does not exist.

U.S. Pat. No. 2,946,307 discloses a coating apparatus in which a coating material is applied to a web of material either by a pattern roll through which the web of material to be coated is passed and then scraped off excess by scraper or in a basin between a web of material passing over the guide roll. The advantages of slit nozzle equipment cannot be achieved with such equipment.

An apparatus such as that initially described has become known via DE-OS 1 964 908. One of the scraper bearing parts is formed by a cleaning spatula printed on the scraper rod with a variable compression pressure 11a.

All of these known 1lystyslaitteissa head must roll back pressure accurately correspond to the length of the material web width, so that the counter pressure roller soiling outside the coating width, as well as the downstream nozzle lip rubbing against vastapainete-box without any intervening material web would estetyk i-p.

It is an object of the invention to provide the device mentioned at the beginning, which makes it unnecessary to place and replace different counterweights for different material webs, and tl 67670 also ensures that the free ends of the counter-roller remain free of flux during longer production times.

This object is achieved according to the invention in that the doctor-rod is removed from the outside of the width of the web-shaped portion and the rod segments are moved oscillating the entire running time so that the segment of course come into contact with the intermediate doctor bearing parts of the slot, thus shaped the downstream nozzle lip a doctor bar to ensure that even if the bearing, the doctor rod is sufficiently lubricated with the coating material, however, that the main coating material is not present outside the intended end coating area, nor on the surface of the back pressure roll outside the material web width,

The scraper rod is easy to manufacture and replace for any desired coating and material web width.

The scraper iron is preferably attached to the rod, which in turn is attached to the drive of the scraper rod, from which it can be easily removed. It is further expedient to place the sealing strips in the mold gap outside the track width.

If it is necessary to coat two or more tracks continuously next to each other with the end coating equipment, it is advantageous to make several segmental grooves in the scraper iron in places where the counter roll is not covered by the paper web to be coated. The scraper rod may be made of steel and the back pressure roller coated with a flexible material such as hard rubber, rubber, etc. Alternatively, the scraper rod may be hard rubber and the back pressure roller a chromed steel roller. To the outlet side nozzle lip should be easily and accurately be put in place, the two doctor bearing parts attached to each other by means of screws appropriate and in the right place to focus kartiomaisi1la pinnapuikoi11a.

In order to be able to apply the coating material evenly evenly, the scraper rod can also be shaped as a spiral scraper.

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For convenience, the downstream nozzle lip must scrape the flexible rods adjustable nozzle lips material web and the pressure roll at the contact point along the length of the entire track of bets by means of aid of pressure screws. Thus, uniformity of the coating thickness can be easily achieved.

The distribution of the coating can be further influenced by placing a flow stop in the slot nozzle body in the slit nozzle body, which can be adjusted with tension and pressure screws. It is expedient to place the slit nozzle assembly on the side next to the back pressure roller and to install it movable relative to the roller. In this case, it is advantageous to seal the inlet nozzle lip of the slit nozzle formed by the molds into a wide-slit nozzle.

By developing the application and coating apparatus according to the invention, it is achieved that the back pressure 1a can always remain unchanged in the apparatus, while the special shape of the scraper rod and the use of this This is particularly important in the case of thin layers, on the order of 1-40 g / m 2.

In the following, the invention will be described in more detail by means of a structural example and the accompanying drawings. The drawings show:

Figure 1 is a schematic front view of a coating device according to the invention.

Figure 2 is a side view of the coating apparatus of Figure 1 as seen from left in Figure 1; and

Figure 3 is an enlarged side view of the coating nozzle of the device of Figure 1;

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The device according to the invention for applying a thin layer of coating material comprises a back pressure roller 1 which is coated with rubber or hard rubber. The back pressure of the roll 1 is passed over the direction of the arrow A, coated with the direction of the material web the web width is a. The head 1lystysleveys b is smaller than the track width, while the counter-pressure roller 1 is longer than the track width a. The back pressure of the roll 1 on the other side of the rakosuutinlaitteisto 3 provided with a nozzle slot fixed flow and the downstream nozzles-type. The width of the slit nozzle is marked with d. There are end plates 4 at both ends of the slit nozzle assembly.

The webs of material 2 to be coated can be, for example, paper webs, plastic films, thin metal webs, fabric webs and combinations thereof. Thus, the web 2 can be made of aluminum film, up to 0.006 mm, 0.012 mm, 0.02 mm and 0.12 mm thick. Suitable paper webs are glossy, coated or creped papers 40-120 g / m 2, plastic films are polyethylene films 40-120 ny /, in thickness limits, axially drawn so-called oriented polypropylene films, thickness 30-120 nyx. and polyester films of the same thickness. Furthermore, two hard PVC films and softened monomeric and polymeric PVC films can be used as the webs to be coated, and, for example, carpet fastening tapes and bandages can be used as fabric webs.

Paraffins and microcrystalline waxes having an operating temperature of 75 ° C to 100 ° C in amounts of 4 to 40 g / m 2 are used as the finishing agents. Further suitable dopants are ethyl vinyl acetate copolymers mixed with paraffin and resins, operating temperature 140 ° C to 190 ° C when processing the surface of the packaging material. The operating temperatures of the melting cloths used are between 140 ° C and 190 ° C, with the amounts of coating agent 2 being 12-40 g / m 2, while the temperatures of the thermoset adhesive are from 70 ° C to 80 ° C and the amounts of coating agent from 40 g / m 2. Polyurethane adhesives, which consist of two components, are mixed shortly before coating.

Aqueous emulsions '6' 67670 and dispersions as PVDC coating at room temperature are also used as coating agents, acrylate adhesive as aqueous dispersions also for coating at room temperature, various starch adhesives used at 70 ° C-90 ° C, adhesives and topcoats, which are dissolved in organic solvents and used at room temperature and finally polyvinyl-based cold-adhesive PVC.

The inlet nozzle lip 5 of the slit nozzle apparatus 3 is made fixed.

The exit lip of the slit nozzle is formed as a movable scraper rod 6. The scraper seam 6 has segment-shaped grooves 7 extending beyond the web width a over the roll width c, whereby the scraper rod 6 resembles a key cross-section. Thus, the entire scraper rod bearing remains filled with a full rod and the coating material has no chance of accumulating in spaces from which the end 1 flux11a could enter places where it is not desired to enter. Also in the construction of the scraper 1aa, the necessary gaps between the two scraper bearing parts 9 and 10 are continuously closed by the scraper rod 6.

The slit nozzle apparatus 3 enters the end 1 through the lapping and coating material channel 11. The main coating channel 11 is at the junction of the upper nozzle half 12 and the lower nozzle half 13. The nozzle halves 12 and 13 are provided with heating and cooling bores 11a 14.

The outlet side nozzle lip forming the metering rod 6 is used oski1 gently through hammasvaihdemoottori1la 15 attached to the connecting rod 16 and a fixed doctor bar 6 bar 17 so that the doctor rod 6 on the one hand continuously seals the gap 8, both the doctor bearing parts between 9 and 10, but on the other hand, due to the shape of a segment of the grooves 7 of the material web 2 Outside it is may come into contact with the back pressure roller 1. Thus, the scraper rod 6 cannot damage the back pressure roll 1, and at the same time it is ensured that no coating material enters the surface of the back pressure roller 1.

67670

The connecting rod 16 can be easily detached from the rod 17, after which the scraper rod 6 can be easily pulled out of the scraper bearing and replaced by a scraper rod corresponding to the changed track width α. Geared motor 15 rotational speed of 9-11 rpm, with a corresponding oscillating movement of the metering rod 6, thereby achieving the downstream nozzle huulelle good scraping efficiency and thus scratch-resistant coating, forming tread will surely be prevented. The slit nozzle apparatus 3 can be moved by a moving device not shown in the drawings in such a way that the fixed inlet nozzle flush 5 rests lightly on the material web, thus creating a sealing effect so that the coating material does not leak downwards. The fixed inlet nozzle lip 5 is screwed to the lower nozzle half 1 and has a control damper 1B. The structure of the nozzle lip is best seen in Figure 3.

The scraper rod 6 is mounted on a two-part scraper bearing. The scraper bearing part 9 is fastened to the scraper bearing part 10 by means of clamping screws 20. The scraper bearing part 9 is first lightly tightened with clamping screws 20. Then lightly set with a plastic hammer 12 mm, the tightness h_ can be absorbed through the entire drilling length. b

The tightening screws 20 are now permanently tightened.

Between the clamping screws 20 of the bearing part 9 of the scraper formed as a terminal strip, which screws are spaced about 100 mm apart, there are pre-drilled holes in the scraper bearing 9. After the final positioning of the position 1 has taken place, these pre-drilled holes are further drilled so that they penetrate the scraper bearing part 10. The conical landscape 11a scraper drill 1a is drilled so that the conical surfaces 21 with the tension thread 22 guide the scraper bearing arranged in place. 9 and 10 even after disassembly in exactly the right place 67670. In the scraper bearing θ ', after tightening the conical surfaces 21 and after removing the tightening screws 20, it can be disassembled for cleaning as often as desired.

The scraper rod 6 and its scraper bearing 9, 10 can be moved by tightening by means of tension and pressure screws 23, which screws tighten the sealing strips 24 in the supply gap 25 outside the coating width. The end profile can be actuated by tension and pressure screws 26.

The bearing parts 9 and 10 of the scraper n hold the scraper rod 6 more than 3/4 of its circumference so that its position and shape during the oscillating movement remain suitable for a bore with a fitting tightness Hy. The tightness of the scraper rod itself is hc. The borehole and the scraper rod 6 thus have a limited clearance, so that a scraper may enter the doctor of the scraper, which acts as a lubricant, but which can move in the gap mol between the two bearing parts 9 and 10 and accumulate in the slit nozzle end plates. The segment grooves 7 at the points described above guarantee the integrity of the back pressure roll 1 outside the material path 2 and the tightness of the gap Θ along the entire length of the scraper rod.

The discharge nozzle lip in the form of a scraper rod 6 with its associated scraper bearings is shaped as a flexible nozzle lip. By means of the tension and pressure screws 26, the contact surface of the back pressure roller 1, the material web 2 and the oscillating scraper rod 6 can be influenced over the entire track width. Thus, changes can be made to the distribution of the coating.

A factor which can also influence the distribution of the coating is the flow retaining strip 27 in the inlet channel 11 leading to the slit nozzle. This retaining strip 22 can be adjusted by means of tension and pressure screws 2B so that the distribution of the coating material over the entire track width can be influenced. The retaining strip 27 has use mainly with high viscosity masses.

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Coating agents with a viscosity range from water to 25,000 Poise can be used in the slit nozzle apparatus of the invention. Surface weights are between 1-400 g / m. The scraper rod 6 is normally made of steel, while the back pressure roller 1 is coated with rubber; the back pressure roller 1 can also be chromed steel. Alternatively, the scraper rod 6 may be hard rubber and the back pressure roller 1 chromed steel, which has been ground with the highest precision. The roundness accuracy should be 0.001-0.003 mm. These accuracies are necessary in order to achieve the best possible distribution of the coating. At a dry weight of 25 g / m2, the oscillations of 1 g / m must not exceed - 1,5 g / m; 1 g / m 2 of coating agent corresponds to a coating thickness of 0.001 mm when the specific gravity is 0.9. For coatings, the distribution of which should be very good despite the oscillations of the material web 2, a screw scraper is used instead of the scraper rod 6. The main loading weight is then determined by the wire thickness of the screwdriver. The stainless steel printing wires can be wound around the scraper rod 6 in one or more turns. The coating material is then pressed onto the web of material through the gaps formed between the yarns. However, the line shows weak lines, which are not always undesirable. When a threaded scraper is used as a scraper rod 6, the threads in the scraper bearing must be sealed so that the end flux 1 cannot rotate around the scraper rod 6 and settle above the scraper rod 6 on the material path 2.

In preparing the outlet side nozzle lip-shaped scraper rod 6 must make sure that the two doctor bearing parts 9 and 10 form, for example, the drill hole, which is 12 mm in diameter has an arrangement stringency H ,. The fit must be valid for the entire length of the slit nozzle up to 2,600 mm and beyond. Only then can the scraper rod 6 be easily pushed in and out.

The semicircular bore in the scraper bearing 10 is first made by milling and then ground with a shape grinding wheel. In the same way, a corresponding semicircular surface is made in the scraper bearing part 9. The · · · 67670 part 9 is then made. Accordingly, the positioning of the scraper bearing part 9 in the height direction is adjusted so that the drilling surfaces together form part of the same circle. The borehole is checked by felting on cylindrical ground surfaces. The final adjustment follows after the surface hardness of the nozzle lip and the scraper bearing part 9 is 1000-1200 Vickers.

Claims (6)

67670 i 1 L. Apparatus for providing a thin layer of topcoat to a web (2) moving over a counter-pressure roller (I) by means of a slit nozzle device (3) with a fixed nozzle nozzle in the nozzle slot and a nozzle nozzle formed in a two-part scraper bearing ), characterized in that the scraper rod (6) is provided with segment-shaped grooves (7) outside the track width (a) and thus used by oscillators so that the segment-shaped grooves (7) cannot come into contact with the slots (8) in both bearing parts of the scraper 1. (9, 10). Device according to Claim 1, characterized in that the scraper rod (6) is fixedly connected to the bar (17), which in turn can be easily detached from the drive devices (15, 16) of the scraper rod (6). Device according to Claim 1 or 2, characterized in that sealing strips (24) resting on the scraper rod (6) are arranged in the nozzle gap outside the track width (a) and the coating 1 width (b). Device according to Claim 1, 2 or 3, characterized in that a plurality of segment-shaped grooves (7) are arranged along the length of the scraper rod (6). Device according to one of the preceding claims, characterized in that the scraper rod (6) is a threaded scraper. Device according to Claim 1, characterized in that the inlet nozzle lip (5) of the slit nozzle is designed as a sealing lip 1.