DE2134983A1 - Squeegee device - Google Patents

Description

PATENT ADVOCATE Dr. ERNST STURM ./ß ,? _f MUNICH 23 ^IOJi

MUNICH 23 LEOPOLDSTR. 20 / IV

Peter Zimmer in Kufstein, Tiro], Austria.

Squeegee device

The invention relates to a doctor blade device with a rotating doctor roller for applying a liquid or viscous mass on a surface to be treated, especially for stencil printing.

With the help of the previously known doctor blade devices, it is not possible to apply larger amounts of liquid or to apply viscous mass to the material to be treated. This can happen, for example, when printing stencils on textiles in too little penetration of the textile goods with dye. The cause of this deficiency is that the one under a squeegee or squeegee in that there existing wedge gap between squeegee roller and to be treated Surface or stencil undergoing pressure build-up in the mass to be applied is too small to allow a stronger ' Order or to ensure a stronger penetration of the goods. .

The object of the invention is to overcome this deficiency 15611-15618 -1Ο9Ι06 / Ο2 · 8 19Ag 33

ORIGINAL INSPECTED

and a! squeegee device with a rotating ra- ' roller and an area of the squeegee roller that moves in the direction of the surface to be treated guide wall, the concave side of which faces the squeegee roller, to create, through which the mass to be applied in greater Amount than is the case with the previously known doctor blade devices the pail was to be brought to the area to be treated or - especially if the item to be treated is a textile item - greater penetration of the item with the item to be applied Mass, see B. dye is guaranteed, and with which, moreover, in the case of high-speed machines, in particular in the case of printing machines with one printing speed of over 100 m / min, a calming of the flow in the liquid or viscous mass to be applied can be achieved is.

This is achieved according to the invention in that the lower edge of the! baffle in the with the liquid resp. viscous Maeee filled gap under the squeegee roller protrudes, in the "dar Brueaufbau" between the reel roll and the Brttck-B template takes place, and thus forms at least one gap through which the liquid or viscous mass of the to be treated Area in the area under the squeegee roller is fed. '

The measure according to the invention extends the wedge gap between the squeegee roller and the surface to be treated or the stencil, which is used for hydrodynamic pressure build-up, by the gap formed with the aid of the guide wall in the application area, and a higher bruisk can build up in the liquid or viscous mass to be applied ^ soda® a larger mass can be applied to the material to be treated or introduced into it by the doctor blade device according to the invention. Through the extended nip further bsi Rakelvorriehtungen wlr'ä in fast running Haschinen (a.3. Fast running Rotationsschablo-

ORlGINAL INSPECTED

printing machines) create harmful turbulence in the Mass prevented;

The invention is explained below with reference to the drawings explained in more detail by exemplary embodiments, without it to be limited.

Pig. 1 shows in Tertica and Pig. 2 in section H-II of Pig. 1 a printing station of a rotary stencil printing machine. Pig. 3 is an enlarged vertical cross-sectional view of that of Pig. 1 and 2 belonging squeegee device. Pig. 4 shows a plan view and Pig «5, in a section according to VV, the Pig. 4 shows a detailed variant of the front end area of the doctor device. Pig. 6 shows in top view. And Pig. 7 in section VII-TII of Pig. 6 shows another detail variant of the front end region of the doctor blade device. The flg. 8 to 13 show further embodiments erfindungsgeaäßer doctor devices, each in Tertikalsehnitt.

The execution example according to Pig. 1 to 3 show a doctor blade device for a rotary stencil printing machine. In the round stencil 1, which is rotatably mounted with its end pieces 2 in stencil bearings 3 »which are connected to the machine frame 4, there is a squeegee roller 5 , consisting of a number of vertically arranged magnetic cores 7 and these surrounding coils 8, sucked. The web of material 9 to be printed is moved through between the round stencil 1 and the printing substrate 6 with the aid of a rotating printing blanket 10. While the web 9 and the blanket 10 moves in the direction of the arrow 11, the circular stencil 1 rotates in the direction of the arrow 12 and the squeegee roller 5 rolls on the inner wall of the stencil in the direction of the arrow 13 afc _r The parbiufuhr takes place in the usual way by a with

109886/0288

OfHGfNALlNSPECTEO

Color tube 14 provided with outlet openings, from which the in front of the doctor roller 5 lying paint sump 15 is fed. The squeegee roller 5 presses on the inner wall of the stencil when it is rolled over the paint from the paint sump 15 through the sieve openings of the round stencil · 1 onto the Web 9 »

According to the invention is in front of the doctor roller 5, i.e. in front of the area moving in the direction of the circular scraper 1 the doctor roller 5 a guide wall 16 is arranged, which parallel to the axis of the doctor roller 5 over the entire working width the doctor blade device extends. The baffle 16 is attached to the paint tube 14 with the aid of arms 17. The The guide wall 16 has a drop profile, the concave side of which faces the doctor roller 5 and whose tip The edge lies in the gap between the squeegee roller 5 and the Runise template 1. Between the guide wall 16 and the doctor roller 5 is a downwardly narrowing gap 18 is formed by which the printing ink flows to the area 19 under the squeegee roller 5. Another gap 20 through which the paint mass Area 19 flows in between the baffle 16 and the Round template 1 formed.

While in known doctor devices, the pressure build-up in the ink, which for the amount of amount conveyed through the sieve openings of the round template * 'the color mass is decisive, approximately in area 19, is in a doctor blade device according to Fig. 1 to 3 primarily through the gap 18, the zone of the effective The build-up of pressure in the paint mass is extended by the length of the gap. Since the pressure that is decisive for color penetration is in the color mass is roughly proportional to the length of the gap, lengthways the pressure build-up takes place, a pressure can be built up with a doctor blade device according to FIGS. 1 to 3 ir the ink mass which is about four times as great as the pressure which builds up only in area 19 without baffle wall 16

103886/0288 originally inspected

would. A pressure build-up also takes place in the further gap 20 in the parb mass, but in that of the contact zone Areas of the circular template 1 that are further away between the circular template 1 and the web 9 are not closed should be strong so that the paint does not prematurely penetrate through the sieve openings of the round stencil i.

The guide wall 16 is formed by noses formed on it 21 held at a distance from the doctor roller 1. The position of the guide wall 16 and thus the course of the column 18 and 20 can by adjusting the Par tube 14, with the the guide wall 16 is connected via the arms 17. the required Pressure and penetration ratios can be adjusted accordingly.

In the simple version according to Pig. 2 is the one between Squeegee roller 5 and guide wall 16 formed gap 18 open at the two longitudinal ends, so that there is a certain pressure drop could be done. This can be done with the help of a squeegee roller, the front end regions of which according to Pig. 4 trnd or according to FIGS. 6 and 7 »are effectively prevented will. According to fig. 4 and 5 is on an end face Pin 22 of the doctor roller 5 an elastic, porous ring 23 is arranged, z.U. glued. The ring 23 is on the End face 24 of the guide wall 16 and thus seals the gap 18 from the front. In the contact zone between the ring and round template 1 becomes the ring 23, like from Pig. 5 can be seen, compressed. The ring 23 also seals against the Round template 1 eb. Same puncture as ring 23 have the. Sealing lip rings 25 according to Pig. 6 and 7, which are arranged on the end pin 22 of the doctor roller 5 are. Through the sealing lip rings 25, one of which is on the end face of the guide wall 16 rests, wi »4 the gap · 18 sealed at the front. To make the sharp edge 26 between squeegee roller 5 and pin 22 harmless, the Sealing lip rings 25 preceded by a ring 27 which consists of

109886/0288

consists of an elastomeric material of relatively high Shore hardness. '■ -

Further embodiments according to the invention doctor devices, Figures 8 to 10, wherein it is here (as in Pig. 1 to 3) to squeegee devices in border template 1 of Rotationsschablonendruckma- -. Aindi arranged machines

According to FIG. 8, the doctor roller 5 is in a doctor box arranged, one wall 28 of which into a guide wall 16 at the bottom passes, between which and the squeegee roller 5 there is a gap 18 through which the paint from the above Squeegee roller 5 located ink supply 15 'from the ink tube 14 is fed, the area 19 flows under the doctor roller, with a pressure build-up in the gap 18 in the? Arl> Äasse takes place, the guide wall 16 is sealed against the round template 1 by a flexible sealing strip 29, which is attached to the guide wall 16 with the aid of a strip 30 iet. As a result - in general, in contrast to FIGS. 1 to 3 - there is only one Gap 18 is present. The wall 31 of the squeegee box carries a slidable covering 32 at the bottom, on which the squeegee roller 5 sealingly supported. The squeegee box, which apart from the walls 28 and 31 parallel to the axis of the squeegee roller 5, still Has end walls is suspended from the arm tube 14 via holder 33. If the squeegee box is in the direction of the Arrow 34 is raised, the gap 18 is narrowed and the pressure build-up in this gap is changed. The pressure build-up in the Gap 18 is strongest when gap 18 is not too narrow and not too wide, that is, a medium gap width. at further lifting of the squeegee box finally comes the Guide wall 16 to rest on the doctor roller 5 and the gap is locked. .

Also in the embodiment according to FIG. 9 the squeegee roller 5 is in a squeegee box. The pressure build-up gap 18 forming baffle 16 extends in

! 03886/0288

this jail practically over half the circumference of the squeegee roller 5. The overhead construction gap 18 is therefore longer than it is hot the previous embodiments

. In the embodiment according to FIG. 10, a squeegee roller 5 is again arranged in a squeegee box and a pressure build-up gap 18 is formed between the squeegee roller 5 and the guide wall. In addition, a roller 35 with a fan-like covering is rotatably arranged in the doctor blade box. In the squeegee box, the ink supply 15 ^r 'has the NiYeau 37 · Bin cavity 39 formed by two fan blades 38 is now filled with ink below the level 37. If the doctor roller 5 moves in the direction of the arrow 13 and the roller 35 in the arrow direction 40, this ink mass is transported to the beginning of the gap 41. The cavity 39 is squeezed out by the nose 42 at the upper end of the guide wall 16 and the pressure build-up gap 18 is filled with paint in this way. Within this gap 18 there is a further increase in pressure due to the rotation of the squeegee roller 5 and the associated entrainment of the ink in the narrowing gap 18. In this embodiment, on the one hand, a very high pressure is generated and, on the other hand, the pressure build-up takes place over time .

In the exemplary embodiment according to FIG. 11, the gap is whose lower edge protrudes into the application area, extended by the arrangement of 'two rollers, whereby a further increase in pressure is achieved in the order. The squeegee device is located inside the round scraper! One 1. In a doctor blade box 43 are arranged two rollers, an upper roller 44 which rotates in the direction of arrow 60, and one lower roller as a doctor roller 5, the direction of rotation is denoted by 13, above the roller 44 is a with liquid Color-filled trough-shaped cavity 15 »of one Paint tube 14 (Fig. 12). From this cavity, the paint flows into the gap 18 between the two downward moving side of the roller 44 and the squeegee box 43 »

109886/0288

As a result of the movement of the surface of the roller 44, the paint in the gap 18 experiences an increase in pressure. In the area the paint emerges from the gap 18 and flows into the gap 46 between the side moving downwards the doctor roller 5 and the doctor box 43 is formed. In this gap 46 there is a further pressure increase in the color, which is finally in cen under the squeegee roller 5 located area 59 arrives and in the zone 19 through the screen openings of the round stencil 1 is pressed and penetrates into the web 9. The noses 21, which are considered normal lying to the axes of the roller 44 and the doctor roller 5 Rib walls are formed, are used for exact centering and guidance of the roller 44 and the squeegee roller 5 in the squeegee box 43. A small cavity 47, which extends above the Squeegee roller 5 extends parallel to the squeegee axis, serves to ensure pressure compensation of the squeegee roller 5. This is because the pressure increase in the gap 46 in the lower region of the doctor roller 5 results in higher specific values Pressures act on this than in the upper area. That I the total force acting on the doctor roller 5 from the specific pressure and from the surface exposed to pressure results, the exposed to the liquid pressure surface of the doctor roller 5 is in its upper circumference through the cavity 47 enlarged. The sealing of the dye under pressure in the area 59 is carried out in the circumferential direction of the round stencil 1 on the one hand by the squeegee roller touching the round stencil 5 and on the other hand by a sealing lip 53 lying parallel to the axis of the doctor roller 5, e.g. made of polytetrafluoroethylene, causes. Several sealing lips can also be present.

By changing the number of revolutions of the roller 44 »the Circular template 1 is not touched, the pressure build-up in the Color can be influenced and adapted to the special conditions. For an intense coloring, strong Penetration of the web to be printed (e.g. in the case of pile fabrics) is a higher speed of the roller 44 that of the

109896/0218

Squeegee roller 5 required. It is also used as a Variant of the illustrated embodiment - gap 18 narrower than the gap 46. The doctor roller 5, which touches the circular template 1 is either simply taken along by the circular template or is driven, but then so that the circumferential speed of the doctor roller 5 is constantly equal to the circumferential speed of the circular stencil 1, so that practically no wear and tear occur between squeegee roller 5 and round stencil 1. The wear of the circular template 1 by the Sealing lip 53 is small, especially when the sealing lip 53 is made of a material with a low coefficient of friction with respect to the stencil material (preferably nickel) is used. This applies to polytetrafluoroethylene in particularly to.

An example of the drive of the doctor roller 5 and the roller 44 is shown in fig. 12 can be seen. The doctor roller 5 has at its front end a pin 22 protruding from this, which carries the gear 48. This gear 48 meshes with the repeat wheel 49, which also serves to drive the gear wheel 50 attached to the end of the circular template 1. The pitch circle diameter of the gear 48 agrees with that The diameter of the squeegee roller 5, and the pitch circle ·? diameter of the gear 50 with the diameter of the round template 1. As a result, the round stencil 1 and the doctor roller 5 have the same peripheral speed. the Roller 44 is over the drive shaft firmly connected to its end 51 set in rotation by a drive device 52. The drive device 52 can be a stepless one Be gear, which receives its drive movement from the reporting gear box, from which also the movement for the gear 49 is served. This drive unit °; 52 can also be a variable-speed motor be that by an electrical circuit in the adjustable Gear ratio to the main drive of the machine and thus also stands for the speed of the round template 1.

109886/0288

The electromagnet «8 in the printing table 6 have the task of to press the squeegee roller 5 against the stencil wall and a shift of the doctor box 43 upwards * and thus »- among other things a lifting of the sealing lip 53 from the template " to prevent inner wall. For this purpose there is the Squeegee roller 5 at least partially. magnetizable (ferromagnetic) material. ·,

In the embodiment of Fig. 13 the roller is stationary. 4-4 'is not in direct contact with the round stencil 1, rather a lower color space 61 is provided. This measure ensures that wear, especially on the ltundach template I ₁ Öie, is only a few tenths of a millimeter in today's production by galvanoplasty, even if the roller 44 * is at a higher circumferential speed than the round template 1 for the purpose of more intensive paint application is driven. Over the printing table 6, the pressure device 10 moves with the web 9 in the direction of the arrow 11. The circular stencil 1 rotates in the direction of the arrow 12. Inside the circular stencil 1 is the squeegee box 43, whose trough-shaped cavity 15 is filled with paint the paint tube 14 is fed. . · ■: =. -; . ^; _ ■■ -.- ...

According to Fi & vi3, however, in the squeegee box 43, of the squeegee device, there is only one orphan 44 _f who rotates in the direction of arrow 13. The roller 44 can be driven by a drive device arranged outside the round set template 1 in such a way that the speed can be adjusted. Depending on the speed of rotation of the orphan 44, a corresponding pressure build-up occurs in the paint flowing through the gap 18. The liquid pressure in the paint in the area 61 located under the roller 44 'is decisive for the passage of paint through the sieve openings of the rounds eh abl on es 1 in the area of the * zone 19 between the sealing lips 53' 54, which consist, for example, of polytetrafluoroethylene.

109886/0280

It 'does not matter whether the roller 44', relative to the Round template 1 rotates in the same direction or in the opposite direction (as shown). A feature of the invention is that the Walee 44 'does not touch the round stencil 1, which was achieved by appropriate storage of the orphan 44 * in the squeegee box 45 will. The sealing of the squeegee box 43 with respect to the round stencil 1 is done by the gasket soups 53, 54, which be pressed against the stencil wall in that strips 62 made of magnetizable material are arranged at the lower end of the doctor blade, which under the action of the Magnetic field of the electromagnet β are attracted, whereby the squeegee box 43 and the sealing lips 53 »54 are pulled in the direction of the round template 1.

Dye, therefore, the sealing lip passes 54, is stripped from the doctor blades 55 and 56 · kn the doctor blade which handles the stencil cleaning inside, a guide surface 57 is connected, through which the scraped ink is supplied to the trough-shaped cavity supplied 15 of the doctor blade box 43rd The paint stripped from the outside of the stencil by the squeegee 56 is discharged via a channel 58.

Squeegee devices according to the invention in general and the illustrated exemplary embodiments in particular are Not restricted to use in rotary stencils on rotary stencil printing machines. For example, are ter-like squeegee devices even with flat stencils or even when applying a liquid moisture-sensitive liquid Dimensions can be used without templates.

109888/0288

Claims (1)

Claims Squeegee device with a squeegee roller for applying a liquid or viscous mass to a surface to be treated, in particular for stencil printing, with a guide wall arranged in front of the area of the squeegee roller moving in the direction of the surface to be treated, the concave side of which is the squeegee roller · '· .; is facing, characterized in that the lower edge of the guide wall (16) protrudes into the gap filled with the liquid or viscous mass under the squeegee roller (5), in which the ψ hydrodynamic pressure build-up between the squeegee roller (5) and ■ ■ ■ · Printing stencil (1) takes place, and so at least a pin gap (18,20) forms, "through which the liquid or viscous Mass of the area to be treated in the area under the squeegee roller (5) is fed ^ 2. Squeegee device according to claim 1, characterized in that the guide wall (16) follows the curvature of the squeegee Has drop profile with downward pointing tip, which protrudes into the gap under the squeegee roller. 3. Squeegee device according to claim 1, characterized in that the guide wall (16) as part of the boundary wall of a Squeegee box formed lit, in which the Räkelrolle (5) is rotatably arranged. 4. Door direction according to claim 1 and 3 »characterized in that daf two rollers (5, 44) one above the other in a doctor blade (43) are arranged, the obese orphan (44) a variable drive, and the lower orphan as a doctor blade ε β (5) on the surface to be treated or stencil (1) rolls off with as little slip as possible. ' 5 »Door direction according to claim 1 and 3, characterized in that 108886/0288 that a lower color space (61) is provided below the driven roller (44 *). 6. Apparatus according to claim 4, characterized in that the upper roller (9). and the squeegee roller (11) rotate in opposite directions. 7. Device according to one of claims 1 to 6, characterized in that that on the in the direction of the surface to be treated or template (1). moving side of the reels "(5.44.44») a narrow gap (18.18 », 46); for the passage the application mass, e.g. with the help of the wall of a doctor blade box (43), is formed. 8. Device according to one of claims 4, 6 and 7 »characterized in that that the roller (44) provided with a variable drive is surrounded by a narrower gap than the one below arranged. 9. Squeegee device according to one of claims 1 to 3, characterized in that the guide wall (16) relative to the doctor roller (5), preferably arranged to be adjustable until it is in contact with the same. 10. Squeegee device according to one of claims 1 to 9, characterized ' characterized in that the squeegee roller (5) has a ring (23) made of porous, elastic at its front ends Material that carries on the end face (24) of the baffle (16) is applied. 11. Squeegee device according to one of claims 1 to 9 _t characterized in that the doctor roller carries at least one sealing lip ring (25) (5) .eeitigen etirn-at its ends which bears against the end face (24) of the baffle (16). 1?. Device according to one of Claims 1 to 11, characterized 109886/0288 BATH ORIGINAL characterized in that one on the inner and or outer wall Round stencil (1) attacking squeegees (55,56) are provided for cleaning the round stencil (1) from application compound. 13. Gate direction according to claim 12, characterized in that attacking the ah-the inner wall of the round template (1) Squeegee (55) a guide surface (57) for the return of the wiped off application dimensions to the application device, for example to the trough-shaped cavity (15) of the squeegee box (43) · is connected. 14. The device according to claim 12, characterized in that on the outer wall of the circular template (1) acting ". Squeegee (56) has a channel (58) for removing the wiped off Order brake 'is connected. BATH ORIGINAL 108886/0288