DE2339906A1 - Screen washer for screen printing process - has an enclosed housing with an inclined viewing window above an aperture - Google Patents

Abstract

The dirty screen stretched in a frame is passed through the charging opening and mounted on a rotatable holder. A pressurised container, holding cleaning agent is found in the housing and is connected on one side to a compressed air line via a valve and on the other side to a spray gun. Cleaning agent is returned via e.g. a funnel. A further pressurised container for cleaning agent is coupled via a two-way valve with the first container and the spray gun and also to the compressed air line of the first container. The second container is connected via a valve with a refill pipe.

Description

Licentia Pat ent -Vervraltungs- GmbH PT-BK / Tlm / jo

BK 73/1

Screen washing system for cleaning screens using screen printing technology

The present invention relates to a screen washing system for cleaning screens in screen printing technology. Here is that of screen printing in a plastic or metal mesh to remove any remaining ink, as the squeegee used for the production of screen prints left ink in the Tissue cannot avoid. These fabrics are clamped in a frame.

Cleaning systems are already in place to clean these screen printing fabrics commercially available that are completely open, which means that cleaning is carried out completely in the free space so that the cleaning agents used can spray into the free space. Depending on the type the paint mostly uses volatile substances that

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are also highly flammable. Except for the harmful ones There is also a risk of explosion.

Closed screen washing systems have also appeared on the market, but they are without and with a suction device work at an overpressure. They work fully automatically and their cleaning effect is very unsatisfactory and also not controllable from the outside. When this system is opened, the overpressure used causes the resulting Vapors from the cleaning agent also enter the work area.

The task of developing a screen washing system that is completely harmless is derived from these conditions works, no cleaning fumes in the work area and allows controllable cleaning.

This object is achieved by the invention specified in claim 1. The basic idea specified in claim 1 the invention is advantageously further developed by the features specified in claims 2 to 8.

By combining the partly known features, a screen washing system is created that is operationally reliable in terms of their risk of explosion, harmless to the

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Operating personnel is and a monitorable reinisunc; -] 5ruzess allows.

The idea of the invention is illustrated in an exemplary embodiment with the aid of the drawing explained in more detail. The figure of the drawing shows a section in a side view of the sieve washing system according to the invention in a schematic representation.

The entire Siebiraschanlage is housed in the housing 1. It is held at an angle on the front at eye level of the operator and is provided with a viewing window 2. Breakthroughs 3 with work gloves (not shown) protruding into the housing are arranged underneath. There is an airtight, closable loading opening h on at least one side.

On the top of the housing 1 there is one in the housing shining lighting 5 and a membrane valve 6, which prevents on the one hand in excess pressure in the housing 1 Solvent-containing air can get into the working space and, on the other hand, this membrane valve 6 provides for air inlet from the work area when the cleaning of the screen has been blown out using compressed air.

The sieve, which is stretched in its frame and to be cleaned, is introduced into the housing 1 through the loading opening k and inserted into a rotatable holder 7.

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3AD ORIGINAL

In the housing there is a first pressure vessel 8 with a control medium, which on the one hand communicates with the Dru'ckluf line 9 via a pressure reducing valve 10 and on the other hand is connected via a pipe 11 to the spray gun 12 via a two-way valve 13. A Reinigungsrr.i tt elrücklauf \ k, formed as a funnel in this embodiment, is used to collect the dripping from the cleaning object cleaning agent and is also connected via a further valve 15 to the pressure vessel. 8 The first loading of the pressure vessel 8 is carried out via the cleaning agent return lk .

Another pressure vessel l6 is provided and also Connected to the spray gun 12 via the two-wave valve 13. It is planned to reuse the cleaning agent already used in the pressure vessel 8 for pre-cleaning, since it is back to the Druckbuhaltt.-r through the return l4 was fed. After the pre-cleaning, the two-way valve 13 is switched over to the further pressure vessel l6 and

ι flushed the cleaning object with the new cleaning section existing in this pressure vessel. The further pressure vessel 16 is filled with new cleaning agent atif via a special filler neck 17 with a shut-off valve 18.

The pressure vessels 0 and l6 are equipped with overpressure safety valves 19 secured against overpressure.

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BATH ORIGINAL

The housing 1 is spared a suction device 20. This suction device 20 consists of a motor with. Fan and a filter 21 protruding into the interior of the housing.

A compressed air line 22 supplies the compressed air to the washing system and is provided with a shut-off valve 23. Via sin ν : i teres two-way valve 2h , pressure vessels 3 and 16 are kept under compressed air or the compressed air is supplied to Giner blow gun 25 Finally, blow out the object to be cleaned and dry it.

The further pressure vessel l6 is via a further compressed air line 26, a knee switch 27 connected to a spray nozzle 28, the viewing window contaminated during the cleaning process 2 allows to clean. This cleaning effect is supported by a windshield wiper powered by compressed air.

Another shut-off valve is located in the supply line to the blow gun 25 29 and a pneumatic valve 30 is provided in the supply line to the pressure vessel 8, both with the trigger device 20 are connected as switching elements.

The function is described in more detail below. The pressure vessels δ and l6 are via the filler neck

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BATH ORIGINAL

17 with the shut-off valve l8 open and the large charging opening k on the "side and the return l4 with open :: ·. Vü; itil 15 filled.

The sieve to be cleaned is supplied through the feed se ffn'ang 'ί in the interior of the system is brought and g-brack there the pivot point in the fixed 7 and the BeschickungsoTfinmg k _a e scchlossen.

After the valves are closed 15 and l8 can. \ ^ S main stop valve for compressed air 23 to be opened. The two-way valve 2k initially directs the air to the pressure vessels 8 and 16 and blocks the direction to the blow-out valve 25 · The pressure reducing valve 10 reduces the pressure to 3> 5 - ^ι ί Atü by setting it. When the pressure builds up above the solvent in the pressure vessels £ and Io, the compressed air line to the blow gun 25 is additionally blocked via an electropneumatic valve 30 and the electrical line to the suction device is forcibly interrupted. The overpressure safety valves 19 protect the pressure vessels 8 and 16 from bursting. The two-way valve 13 is now set so that the solvent can rise from the pressure container S via the line to the spray gun 12. The line to the pressure vessel l6 is blocked by the two-way valve.

Now you can turn your hands into two through the two openings 3

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SAD ORIQiNAL

Slide on gloves that are attached to cuffs on the inside of the system. You then take hold of the spray; -. -: o-Ie 12 and, by pulling the trigger, sprays detergent, which is pushed up by the pressure, onto the sieve to be cleaned. You can possibly use the other .Icr.d to run a brush over the sieve for pre-cleaning. 1 it.i. ^r . . Does the sieve work with a mechanical device? ~ c -.- η. In order to be able to clean the sieve on the back as well, the sieve is held in a pivot point.

Should the window on the Inside of dirty solvent splattered see '. In, you can press the knee switch 27 with your knee and click on it Spray the clean solvent, which is also under pressure, from the pressure vessel 16 onto the window 2. If necessary, a windshield wiper can support the cleaning efiect.

When the pre-cleaning process is finished, change over of the two-way valve 13, the solvent supply from the pressure vessel 8 is blocked and opened to the pressure vessel l6. so the sieve can be briefly washed with fresh solvent in the same way as when pre-cleaning.

The two-way valve 2k is now switched over so that the compressed air to the pressure vessels 8 and 16 is blocked and directed in the direction of the blow gun 25. After opening valve 15

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BAb öftKMNAL

If the compressed air still present in the pressure vessels 8 and 1 escapes through the cleaning agent collected in the return line i4, the used cleaning agent runs back into the pressure vessel 8 here or immediately thereafter. Valve 15 is then closed again. Only when there is axial pressure in the pressure vessels 16 and 8 does the pn3-imatic valve 30 open the shut-off valve 29 and release the compressed air line to the blow gun 25. At the same time, the contact to the suction device is closed so that it starts up. Now you can again push both hands through the openings 3 into the gloves, take the pistol 25 and direct the compressed air onto the sieve by pulling the trigger and thus blow the remaining cleaning agent out of the fabric and off the frame. The diaphragm valve 5 prevents air containing detergent from entering the working area when there is excess pressure and, on the other hand, this diaphragm valve 6 ensures a supply of air from the working area when the blowing out is ended. The suction device 20 can now be switched off and the dry, cleaned sieve can be removed from the system via the feed opening k. The filter 21 made of ceramic tubes prevents cleaning agent from being sprayed into the suction device.

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BATH

Claims (8)

Claims 1. / Screen washing system for cleaning sieves of the screen printing technique, characterized by the combination of the following partly known features that the washing insert is arranged in a closed housing C1) with an inclined viewing window (2) and underneath: -. Eit ;: Breakthroughs (3) is arranged with work gloves protruding into the housing and has an airtight, closable loading opening (kl) on at least one side, so that the object to be cleaned is rotatably supported (7) in the housing (1) is that in the Gehhu. = «(l) at least one pressure vessel (8) with cleaning agent is arranged, which is connected on the one hand to a compressed air line (9) via at least one valve (10) and on the other hand connected to a spray gun (12) and that a cleaning agent return (IA) to the pressure vessel C8) is arranged. 2 »Screen washing system according to claim 1, characterized in that that a further pressure vessel (l6) with cleaning agent is arranged, which via a two-way valve (13) is in communication with the first pressure vessel (8) and the spray gun C 12) and is connected to the compressed air line (9) of the first pressure vessel Co) is connected. 3 screen washing system according to claim 2, characterized in that BK 73/1 509808/0541 - 10 - BAD ORjQiNAL that the further pressure vessel (l6) is connected to a refill nozzle (l7) via a valve (18). 4. screen washing system according to claim 1 or 2, characterized ge3: indicates, that a blow gun (25) is arranged, which is connected to the compressed air line (9). 5 · Screen washing system according to claim 1, characterized in that that the housing (l) has a filter (2l) with a suction device (20) is connected. 6. screen washing system according to claim 6, characterized in that the suction device (20) with a valve (29) in the compressed air line to the blow gun and with a
pneumatic valve (30) in the compressed air line to the
first pressure vessel (8) is connected. Screen washing system according to claim 2, characterized in that a window cleaning nozzle (28) is arranged, the supply line (26) of which is connected to the further pressure vessel (16) via a knee switch (2?). 8. Screen washing system according to claim 1, characterized in that that a diaphragm valve (6) is arranged on the housing (i). BK 7 "\ / 1 509808/0541