DE1696653B2 - PROCESS AND DEVICE FOR APPLYING A COATING - Google Patents

Description

The invention relates to a method and a device for applying a coating in the form of a film to a running surface, wherein a coating agent directly on an absorption felt sprayed and this is unrolled on the / u covering surface.

It is common to use an agent to protect or decorate certain products overlay. In the case of ferrous metals, for example, it is desirable to treat the material before processing. storage or to cover the dispatch with a thin film of oil to prevent damage to the surface, for example by oxidation, scratching or the like, to be kept to a minimum.

The coating is mostly applied by dripping oil onto the surface and the drops are distributed by means of an absorbent roller rolling on the surface. However as a result, neither a film of uniform thickness nor a uniform surface coverage is produced guaranteed.

In a device for producing a coating (L) SA. Patent 1695 319) are spray heads used. The coating agent is applied to the material to be coated (textiles or paper) applied before the material to be coated passes through pressure rollers. The SprühköplV are not directed against the rollers, but against the material to be coated. For this device however, no control over the thickness of the coating is provided.

It is still customary to cover the surface, in that the coating agent is applied in places, but in certain places there is a thick layer of the coating agent results while on there is no coating agent at all in other places. This creates so-called "tiger stripes", so that the protective effects'. or the decorative. ». effect filiii-like coating is not achieved and the buyer may reject the material.

According to a known coating process (British patent 7721S2) a Vonichuing used which has a transfer roller and a separate honeycomb or blade-like member, which is spaced from the transfer roller at such a distance. that between them a gap is created in which essentially

ίο the coating agent is sprayed from below. By the width of the gap should determine the thickness of the coating to be applied. Independent of The type of material used must be completely saturated or smooth so that the gap

a uniform thickness coating on the transfer roller which is then to be transferred to the material to be coated. The used Nozzles can be replaced by a tube with an axial slot in order to dispense Iber-

= 0 to obtain traction means in a continuous liquid curtain. With this version icdi / ch a collecting container must necessarily be provided because there is always dripping around Coating agent will occur.

In addition to these basic disadvantages in known methods and devices for application a film-like coating, there are further restrictions on the control or regulation, for example the film thickness, the surface coverage or the precise switching on and off. These controls are for each attachment to apply a coating is of great importance, since workpieces are generally different in the same systems Treated and provided with film-like coatings of various thicknesses have to. In addition, the introduction will be brought forward of the coating usually with, for example, an intermittently working manufacturing machine or a conveyor at the same time operated. Since there are no precise controls to apply an oil film in an economical manner, Excessive amounts of oil must be used to avoid loss due to splashing. Compensate for overflow and the like.

The object of the invention is therefore to provide a method and a device for coating to create a surface with a uniform film of the desired thickness, the coating agent Used effectively and hoses, overflows and other wastage are kept to a minimum will.

According to the invention, this object is achieved in the case of a method or a device of the type mentioned at the beginning Art solved in that the spraying on periodically, taking into account the extent the movement of the roller, the area to be coated and the extent of the area to be coated Area and the desired film thickness of the selected switch-on and switch-off times.

In a further development of the method according to the invention, the spraying is cyclically variable Switch-on and switch-off times carried out in order to spray a total amount of coating agent, taking into account the amount of movement of the roller to be coated Area and the extent of the area to be coated, the thickness of the applied to the area filmartiiien überzims determined. In addition, a

Multiple separate spray heads or nozzles be provided, which are arranged along the roller at an axial distance from each other and after Choice can be controlled separately to get the coating material in the desired spray area spray on the roller, and it can be a time setting device can be provided to open and close the spray heads in the desired time sequence close to obtain an effective spray amount less than that for the desired film thickness is the amount obtained by continuous spraying.

The method according to the invention has the advantage that an execution is created by means of which the thickness of the uniform film of a coating agent applied to the surface or the Area triangulation in a certain area exactly lind can be controlled as desired.

I.s is another advantage of the invention. that the Control can be selected to provide a coating of the desired thickness for a wide variety of operating speeds can be obtained using only a single loop controller v.ird.

The method and the execution according to the invention also offer the advantage that the (Coating agent is effectively used and spraying. Overflow and other waste; 'uf be kept to a minimum.

The invention is explained below with reference to the drawing, for example.

Fig. 1 is a perspective view of a device according to the invention, the various components thereof being shown in combination with a typical conveyor and roller device for applying a coating to a general flat sheet metal or the like can be used:

F i g. Figure 2 is an end view of the whale device of Figure 1:

F i g. Figure 3 is a partial side elevational view of the sprayer support as seen from the right side of Figure 3 Fig. 2:

Fig. 4 is a sectional view taken along line 4-4 of Fig. 3:

F i g. Fig. 5 is a tvp schematic diagram of the electrical circuit and the circuit of the i'ber / ugsmittcls.

In Fig. 1 shows a warning device which has a frame 10 with a number of conveyor rollers 12 or the like, on which the moving Workpieces 14 are performed. The frame! () Also has spaced apart Guide bearing 16 on. those with sliding bearings 18 for supporting the longitudinal axes 20 of Rollers or rollers 22 are provided. Each roller 22 has a steel frame with a fixed absorbent material such as cotton, linen, gauze. Flannel or the like is coated. The rollers 22 are at a standstill in plane rolling contact with the workpiece 14, which is in a to the longitudinal axis 20 of each roller 22 moved in a transverse direction between the rollers 22. Means not shown, for example a spring, a compressed air cylinder or a counter-rotating device that acts on the bearings 18, press the rollers 22 towards each other and against the one arranged between them Workpiece 14.

In the embodiment described, the WaI-zcnv or direction two opposing rollers 22, both the upper and the lower The surface of the workpiece 14 is provided with a coating. It is to be understood, however, that. if only one of the surfaces of the workpiece 14 is to be provided with a coating, the opposite roller 22 by a simple reaction roller or the like. Can be replaced.

According to the invention, standard absorption rollers are used and an improved method and a device for applying oil or another coating agent to the surface of a workpiece are created. As in Fig. 1 shown, a storage container 24 for coating agent is arranged in the vicinity of the rollers 22, which is marked with ■ ^; nor pump 26 is provided. that from an appropriate energy source, for example one via an air line 28 \ ers;,: »tcn Lulimotor. is driven. The pump 26 pumps the transfer medium from the container 24 through an outlet duct 30 to a carrier 32 which is fastened to the frame 10 in the vicinity of the walls 22. A plurality of spray heads or spray nozzles 34 are arranged on the carrier 32 and are connected to one another by a common flow line 36 and are in direct communication with the pump 26 and the container 24 via the line 30

As in Fig. 2, the spray nozzles 34 direct jets of atomized coating agent in general tangfntialer direction against the roller 22. mi that the coating agent trickles onto the roller 22. before it comes into contact with workpiece 14. the The surface of the roller 22 is made of suction glass Material that absorbs the sprayed or atomized coating agent to a limited extent and it in the form of a uniform film on the surface of the moving relative to the roller 22 Workpiece 14 applies. The spray nozzles 34 are spaced in a direction transverse to the workpiece 14 arranged from each other along the carrier 32 so that the spray sirahlen 38 meet or overlap somewhat in order to ensure uninterrupted loading across the roller 22. The spray jets 38 are deflected by the roller 22 and as a fine mist on the surface of the Workpiece 14 applied. Above roller 22 is a shield 40 is provided through which the spray mist in de; Is held near the roller 22, ;, o that it is from the roller 22 similar to the oil mist being handled in a warehouse, and he is pushed back by the circulating air and straight up the workpiece 14 and the roller 22 are directed backwards. It is well known. to get a good spray, often see; desired, a special coating agent drrch a special spray nozzle through under spray a pressure lying in a limited range. Accordingly is. to be even and to obtain optimal operation, a pressure control valve 42 is arranged in the compressed air line 28. while a pressure valve 44 is arranged in the outlet oil line 30. These valves 42, 44 regulate the pressure and the amount of the coating agent emerging from the pump 26, so that the spray nozzles 34 be fed with means under a desired constant pressure. So with one special coating agent whose viscosity is known. the one exiting from each spray nozzle 34 m;: \ ima! .. · Mence known or can be used as a function ih-

rer viscosity, the outlet pressure and the size of the medium, which is about half as large as the

the nozzle opening can be determined. Due to the amount of coating agent. those from the spray nozzles 34

the roller 22 and the surface of the workpiece 14 would emerge if this were during the entire

The sprayed amount of coating agent is inside a film circuit corresponding to 100 "ο would be open

uniform thickness on the surface of the workpiece 5 ratio between switch-on time and switch-off time

14 received. Without further control, the over- can be changed and, for example, to 25 "η

Zugsmittcl of the spray nozzles 34 can be adjusted evenly across to 75 "ο, with the out of the

Distributed or applied over the roller 22, and spray nozzles 34 emerging amount 25 °, o the maximum

although the maximum possible amount is in continuous operation. Thus, the cyclical

Amount applied. io clichéd control 52 the thickness of the recorded

Each spray nozzle 34 is controlled with a valve 45 of the conventional film. Since the controls the film thickness

cher design, which is provided by a spring-energizing device 52 from which the surface covering

is closed and an electromagnet is opened, the controlling device 48 operates independently

and which can be switched on and off to tet, the setting is actually cyclical too

to allow or shut off a flow. These 15 actuating nozzles 34 are not affected,

precise individual control of the spray nozzles 34 is thus eleven in If, for example, on a carrier 32

Connection with other suitable controls, evenly spaced spray nozzles

used to measure both the width of the sen 34 and the surface covering

Spray jets on the roller 22 covered area kung controlling device 48 is set such that

as well as the thickness of the surface of the workpiece ao that all spray nozzles 34 except two nozzles on each

kes 14 applied film can be operated to the end as desired, the third to ninth work

to the. Nozzle, counted according to FIG. 1, from left to right.

The control for the area coverage is with This determines the area covered. The 48 denotes, and it has separate switches, for example the device 52 controlling the film thickness, which has a 50 a, 50 b and 50 c (FIG. 5), each of which opens and closes the third to nine cyclically in series with 5 the electrical feed line 49 and the elec- tron nozzle 34, the first and second solenoid valves 46 or the solenoid valves such as the tenth and eleventh nozzles 34 being always closed. By controlling the various remaining, determined from the cyclically actuated nozzle switch in the correct combinations, it is possible to open some or all of the spray nozzles 34 sen 34 emerging amount of coating agent as a percentage. The control rate of the maximum amount with continuous spraying of the spray nozzles 34 is practically done by hen. As a result, both the width of the sprayer is in the middle of the roller 22 outwards, since narrow ches or the surface coverage and the workpieces are generally arranged in the middle of the conveying quantity of the applied coating agent or the direction. However, the thickness of the film can be precisely controlled. It has been found that valves 46 with switches 50 of controller 48 in FIG. 35 can, with this method, be grouped in any desired manner, and they of film thickness or area coverage, one can actually be individually arranged to maximize uniform film of coating agent Variations of the spray area can be applied to the desired area,
borrowed. The pump 26 used is of the type 22 and thus the surface coverage on the work 40 in which, despite the changing flow condition part 14, the control 48 appropriately sets a substantially constant outlet pressure. is available. Thus, if one or more spray

Similarly, if a cyclically operating nozzles 34 are open, the pump 26 delivers an adjustable switch-on and switch-off control 52 (FIG. 1 coating agent quantity, which corresponds to the switch-off and FIG emerges from the nozzles 34 is required. The device 49 in series-connected contacts 53 has selected spray nozzles 34 spray a uniform and the opening and closing of the spray nozzle selected or determined by the area at a certain spray pressure and control 48 with a certain viscosity of the coating agent 34 can cause. Such a cyclical work- Thereby the roller 22 is fully covered, whereby the control 52 can be a commercially available 50 in turn a full coverage of the surface of the control, for example controls HP 5 and advancing workpiece 14 with a film HP 501 Cyclflex Control Timers the eagle signal of uniform thickness is obtained. As the Company of Moline, Illinois. Such timing controls spraying without the aid of air and only through the can be set in such a way that it takes place with a given pressure of the coating agent, any switch-on time (contacts 53 closed) and with fog formation and a back-spraying or a given switch-off time (contacts 53 open) spray reduced to a minimum,
can work. The duration of each cycle is unlimited. Workpieces with a width of up to can be set independently of the other. However, if handled at an altitude of 2.54 m. If the center distance of the cycles is consecutive, that is between the spray nozzles 34 by the control sprayed when the two cycles are combined. 60 coating agent, the spray pressure and the used a certain ratio of switch-on time to off nozzle size is determined, the maximum width switching time is oiden in front. If accordingly the cyclic spray area is enlarged by the fact that only clichéd control 52 is arranged or switched on ^{during half along the length of the carrier 32, further spray nozzles or 50 0 O of the overall circuit.} A switching and during the other half or just simple execution serving this purpose is a switching off if 50% of the total circuit is shown in FIG. 2, 3 and 4, and it has one effect, the spray nozzles 34 produce a quantity under the channel-shaped portion 54 which can extend over the length of the generally constant pressure coating with the roller 22. The spray nozzles 34

. ".. ^ -», "" vt ernaiien. In aer rraxis nanu wc iwcaic vjwvi ........ _?

the carrier 32 extends adjustable speed of the workpiece 14 under the roller 22 in

The canal-shaped Te I 54 · £ ™ J ^te £ ™ Χ _ε1 . _the range lower than about 9 m / sec ta

Change bearings 60 parallel to the roller ^ J ^ ' _d _ _{higher a} , _{s about 600 m / min} . _The roller 22

Each bearing 60 has two triangular _{shapes that they correspond to the moving part}

T 7ΐί! ^ Distance from one another located workpiece can follow freely, so that they are on this, η

sponding ends to spaced ™™ ^nana _not rolls _g i r _eitende full surface contact,

"They end up at mutually aligned ends or they can be joined together for the same purpose.

protruding ends at ™ «' ^π ™ Js. _dd - _{{ t} device are driven synchronously.

Journals or Lagersüfte «« ^ fesüg s nd. D »g _{mastered (s} S _{act? Applicatio rule} _ _s of

on the canal-shaped part 53 ^ njerndnet sukl α _dry coating to a heavy wet

of the sea pins 66 8e ^ ni ^ ri «^ the s« _ ^ b ^ _{fume thickness controlling zy} .

^^^^ «.". N'SAShHtiinae clichéd device 52 to be used

^ working device 52 use

tr ΒΑ 76 at which a change of 10 see looks

.ugi are. By changing the as and '/ 3 see switch-on time up to Vs see switch-off time 76 in the direction against and 10 see switch-on time is possible.

"7ÄSrsÄieSS 3. sJd = _s ; s ^^ r _ht ^^

on the rollers 22, as will be understood that various modifications are possible

Facilities required is | · _dy . _k j _{d For} example, a rod, a cylinder

2 Ä 35 3> w _e , L ", die mi, den, Oberen *.! sprayed, will.

1 sheet of drawings

Claims (3)

Patent claims: » 1. Method of applying a coating in the form of a film to a continuous surface, whereby a coating agent is sprayed directly onto an absorption roller and this onto the roller to be coated Surface is unrolled, thereby marked! that the spraying on periodically, taking into account the extent the movement of the roller, the area to be coated and the extent of the area to be coated Area as well as the desired film thickness of the selected kin and switch-off times. 2. Device for performing a method according to claim 1, characterized by a SU'uereinricluu · "·.! (48), one of the spray heads (34) has associated equipment (46), which optionally opens or closes the spray head (34) to control the spray area. 3. Device according to claim 2. thereby marked / calibrated. that a '/. < icinstelhorrichtung (52) is provided. to open and close the spray heads (34) in the desired time sequence.