DE9303814U1 - Application device - Google Patents

Description

Johannes Zimmer, Ebentaler Str. 133, 9020 Klagenfurt/Austria

Application device

The invention relates to an application device for coating, painting or the like of flat material (substrate), comprising a bearing surface for the flat material, a transfer roller forming an application roller, which is located between its casing and the bearing surface in a force-fitting connection with the flat material for the purpose of applying the substance, and a metering roller, by means of which a substance taken from a substance chamber is applied to the transfer roller in a metered quantity, whereby the transfer roller and the metering roller are mounted without an axle bearing only on the circumference in such a way that they can be moved evasively across the material bearing surface and can be subjected to a contact pressure.

Known devices of the type mentioned (AT-PS 37 8 335) comprise an application roller and a metering roller, which are arranged in a trough (substance space) below a contact roller for the substrate. The two rollers are pressed against the contact roller or the substrate by means of magnetic force or fluid pressure against the weight force bending them. Such a pressing leads to disturbances in the application result, not only in the case of rollers whose lengths are two meters or more. The substance must be carried along by the rollers on their circumference from bottom to top, whereby the application roller dips more or less into the substance at a part of its circumference depending on the working speed, the substance viscosity and/or the surface quality of the roller. This leads to an undesirable dependence of the application result on the

Substance viscosity, roller surface quality and/or working speed. It is not possible to achieve precise and reproducible dosing of quantities that meets the highest standards and different requirements.

In contrast, the invention is based on the task of applying a viscous substance layer by means of a dosing roller and an application roller that are each mounted in an evasive manner, free from deflection forces of the rollers that impair the application result, and with optimal adaptation to different substance viscosities, roller surfaces, application quantities and/or different working speeds with a precisely pre-settable and thus reproducible quantity on non-

absorbent or substance-penetrating material surface ¹ .

The problem is solved in conjunction with the features of the device mentioned at the beginning in that the substance space outside the peripheral area of the transfer roller is separated from the latter between a peripheral section of the metering roller that is spaced apart from the transfer roller and a metering blade and/or sliding surface that is adjacent to the latter and forms the complete substance space separation from the transfer roller, and in that the metering roller is arranged above the transfer roller and rests on the transfer roller with its own weight. According to the invention, a quantity-dosed surface substance film applied to the metering roller or roller is moved from top to bottom by means of the metering roller or roller and applied flatly to the outer surface of the transfer roller. The metering roller rests on the transfer roller with at least its own weight, rolling freely. This arrangement, in combination with the rollers, which are mounted without axle bearings, i.e. can be moved in the plane of the pressing direction without forced bearings, allows a

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disruptive influence on the substance film transfer or application due to roller deflections is avoided. Also, as a result of the complete separation of the substance space that supplies the metering roller with substance from the transfer roller, an otherwise disadvantageous influence of the substance space on the roller pressure force and/or the substance film applied to the transfer roller is eliminated. The device according to the invention allows the diameters and/or surface properties of the rollers to be freely selected to a large extent, thereby achieving optimal application results. In particular, this means that substances with a wide range of viscosities can be applied to the substrate in precise and reproducible quantities at different working speeds and/or application performance or dosage amounts, whereby the nature of the substrate can also vary considerably. It has been found that the device according to the invention produces a uniform coating at all points, i.e. with a constant layer thickness, on a highly or deeply structured substrate with relief depths/heights of, for example, 0.5 mm and more, despite these structural differences. It has been shown that the device according to the invention can be used to apply coatings with excellent uniformity, even in very thin layers, to hard, soft, smooth and/or highly structured substrates with a relief-like structure. This is of particular importance, since the composition and viscosity of paints must be adjusted very precisely to the specific quality in question, meaning that particularly precise operating conditions must be observed when processing paints. In particular, when applying paints, the application result can be significantly impaired or rendered unusable even by minor disturbances in the substance film caused by irregularities in the pressure force between the rollers, irregularities in the dosing quantity and/or influences on the substance in the substance space assigned to the dosing roller.

It was considered necessary to use devices with only limited application areas for varnishing material webs, in particular plastic webs such as floor coverings or similar, with axially or positively mounted anilox rollers for gravure or relief printing.

A particularly useful and advantageous embodiment of the invention is that a pressure roller is arranged above the metering roller, which is mounted without an axle bearing, i.e. only on two opposite circumferential sides in the area of the roller ends and can therefore be moved in the plane of the pressing or pressing direction without forced bearing, with the pressure roller resting on the metering roller with its own weight. The metering roller and the pressure roller rest on the transfer roller with their weight forces, with the contact pressure being advantageously adjustable by the dimensioning of the weight-loading pressure roller, so that the diameter of the metering roller/roller can be freely selected with regard to a desired working speed and/or the viscosity of a paste or varnish. It is particularly advantageous according to the invention to provide the weight-loading pressure roller as a doctor roller forming the metering doctor blade. A rolling dosing film application to the dosing roller is achieved, whereby this rolling dosing is particularly wear-resistant in contrast to a dosing application to the dosing roller using a profile strip or an elastic doctor blade (scraper doctor). The dosing and discharging weight-loaded pressure roller also removes any dirt that may occur when a doctor blade is in contact with the dosing roller with scraping friction.

According to a particularly preferred design of the application device according to the invention, the transfer roller rests with its own weight on the material surface (substrate) or the material bearing surface. In this way, the weight forces

all rollers, i.e. the transfer roller, the metering roller and if necessary the pressure roller, together contribute to pressing the transfer roller against the substrate. There is a frictional connection between the rollers along the contact lines of the rotating peripheral surfaces. It is important that the frictional connection is generated unhindered by bearing forces and/or free from contact pressure directed against the roller weight forces. The total weight force acting through the roller weight can be very advantageously increased by additional force application means acting in the direction of the weight force in the form of a magnetic and/or mechanical auxiliary device. Due to the roller weight effect, however, the additional force application means are not required for a large number of applications. It is clear that the possibly

additionally applied to the mechanical and/or magnetic auxiliary force applied to the rollers, which are only mounted stationary perpendicular to the direction of pressure, is only provided to support the force in the direction of the additive roller weight forces. A significant advantage of the invention is generally that the diameters of all working rollers can be easily adapted to the respective application requirements. It has been found that with the device according to the invention, the application results can be influenced surprisingly favorably not only by the free choice of roller diameters but also by the properties of the roller surfaces. For very small amounts of substance to be transferred, the jacket surface of the transfer roller is preferably smooth or roughened, while for larger transfer quantities it is expediently provided with a particularly pronounced roughening or a structure formed by a groove, a fabric, a braid, a wire winding or the like. It is particularly advantageous that the cover layer of the transfer roller can be made of a soft material such as soft rubber or similar. This makes it possible to coat relatively hard substrates particularly well, particularly for thin-layer applications of

A particularly soft coating layer is provided for the application of varnishes or similar substances to structured and/or relief-like material webs such as plastic flooring with structure heights or depths of 0.5 mm and more.
5

It is very advantageous that a heating element for influencing the substance viscosity and/or for heating melting substances such as hot melt adhesive or the like can be provided in the substance space provided according to the invention on the metering roller in spatial separation from the transfer roller. This achieves a particularly process-related advantage, whereby, for example, the application quantity can be reduced in a targeted and very finely effective manner by heating the substance and the associated influence on the substance viscosity.

If necessary, it is expedient to provide an additional axial and/or circumferential drive for the transfer roller. Such a drive can cause the transfer roller to advance or lag behind the flat material (substrate) in order to carry out a change in the application quantity as required during operation. However, it should be noted that such a drive, with which the other rollers can also be equipped to influence the application quantity, only forms a rotary drive for the respective roller, without affecting its free unrolling or mobility transversely to the material bearing surface due to the bearing according to the invention.

Still other embodiments of the invention are specified in subclaims, and further advantages and embodiments or possibilities of the invention emerge from the following description of the embodiments shown in the schematic drawing. They show:

·

Fig. 1 in frontal roller view a

application device according to the invention with a metering blade in the form of a weight-loading roller and

Fig. 2 in frontal roller view a

Application device according to the invention with a metering blade formed by a doctor blade.

The devices according to the invention shown in the embodiments according to Fig. 1 and 2 comprise a material bearing surface 40 in the form of a rotating, stationary roller 4. This forms a stationary,

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i.e. a counter-support roller which is mounted immovably in the direction during operation and over whose upper vertex a substrate in the form of a material web 6 is guided, the web 6 being conveyed in the direction R when the roller 4 rotates by means of a rotary drive (not shown).

A substance transfer roller 1 rests on the roller 4 with its own weight. A metering roller 2 rests on this with its own weight, and according to Fig. 1, a doctor and weight-loading roller rests on the metering roller 2 with its own weight. The rollers 1 to 4 are arranged in a vertical plane S common to their axes. In this arrangement, the dead weight bearing of the rollers 1 to 3 is achieved by the fact that the axle stubs of the rollers 1 to 3 rest freely on the circumference against lateral bearing surfaces 15, 25 and 35 parallel to the plane S. In this way, the transfer roller 1 is pressed against the bearing surface 40 or the material web 6 under its own weight and under the weights of the rollers 2 and 3. The rollers 1, 2 and 3 are thus held freely movable in the plane S.

Due to the contact forces between the roller contact lines Al, A2 and A3, the adjacent rollers roll under friction

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force effect on each other when the counter-contact roller 4 is set in rotation by means of its drive. The rotation directions of the rollers are indicated by arrows.

In the embodiment according to Fig. 1, a trough-shaped substance chamber 52 is formed on the metering roller 2, with which substance 91 rests against the metering roller 2 in a circumferential angle range of approximately up to 180° measured in the direction of rotation of the metering roller 2 and against the plane S. At the bottom and on the long side opposite the rollers 2 and 3, the wall of the substance chamber 52 is formed by a doctor blade holding strip 51, the latter carrying an elastic doctor blade 5 or the like that rests tangentially and in a substance-tight manner against the metering roller 2. The doctor blade 5 is designed to be elastic in such a way that a substance-tight contact is established with the metering roller 2 in every operating state. The substance chamber is closed at the front with walls 55. The substance is fed into the substance chamber 52 from a feed pipe 9 that is expediently designed as a distribution pipe.

The upper weight-loading roller 3 is also arranged and designed as a roller dosing blade. The substance 91 is thus applied from the substance chamber 52 to the roller 2 by means of the roller 3 through a rolling dosing. The latter transports the applied substance liquid film over a circumferential angle of 180° from the contact line Al between the rollers 2 and 3 to the contact line A2 between the rollers 2 and 3 from top to bottom. At the contact line A2, the substance film is deposited on the transfer roller 1 and transferred by this from top to bottom - also over a circumferential angle of 180° - to the contact line A3 between the rollers 1 and 4, where it is applied to the material web 6.

In combination with the rollers resting on each other by gravity, it is essential to the invention that/3 the substance space

52 outside the peripheral area of the transfer roller 1, separated from it by the elastic doctor blade 5, only between the latter and the metering doctor blade 3 which is adjacent to the metering roller 2 and forms the complete substance space separation from the transfer roller 1. It is particularly advantageous that the metering roller 2 can be made relatively small when using a weight-bearing and doctor roller 3 which is relatively large compared to it. The transfer roller 1 can also be provided with a relatively small diameter due to the rollers or rolls being stacked on top of one another under the force of weight.

Due to the roller stack arrangement according to the invention and the separation of the substance space from the transfer roller 1, the application result can be influenced very precisely by freely selecting the roller diameters for the rollers 1 and 2 and by practically any design of the roller surfaces with a smooth, rough or structured shell. It is also particularly advantageous that the shell 12 of the transfer roller 1 can be designed with the desired surface properties, so that shells made of a particularly hard material up to a particularly soft, flexible material can be used in the device according to the invention, whereby there are no particular restrictions with regard to the choice of material. This means that shell materials can be used that are not attacked by the chemical properties of the substance film.

In the embodiment according to Fig. 1 as well as according to Fig.

2, the transfer roller 1 consists partly of magnetizable material. It comprises a relatively thick-walled magnetizable tube 11 arranged between the roller core and the roller shell 12. The transfer roller 1 is thus magnetized by means of the magnetic force of a magnetic device arranged stationary under the material bearing surface 40 in the form of e.g.

a magnetic bar against the bearing surface 40 or the sub-

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stratbahn 6. It should be noted that, if necessary, with this magnetic pressure of the transfer roller 1, only the pressure force caused by the roller's own weight is increased. The rollers 2 and/or 3, preferably the roller 3, can also be suitably assigned an auxiliary force device (not shown), which applies magnetic force and/or mechanical force to the respective possibly partially magnetizable roller in addition to the pressure of the roller's own weight. The arrangement of such auxiliary force devices also remains essential to the invention, since the rollers 1 and 2 and - in the exemplary embodiment - the roller in their joint arrangement above the substrate or the material web 6 are loosely mounted in their location, i.e. each in a stationary bearing plane common to the axes of two adjacent rollers, freely movable in the direction perpendicular to the roller axis. At least the metering roller 2 and - in the preferred embodiment of the device with the roller 3 - also the roller 3 already rest under their own weight.

It is particularly advantageous to arrange a heating element 8, shown in dashed lines in Fig. 1 and Fig. 2, in the substance space 52 for influencing the substance viscosity and/or for heating melting substances such as hot melt adhesive or the like.

In the embodiment according to Fig. 2, the profile strip 51 delimiting the substance space 52 is also part of a metering doctor device that applies a substance film to the metering roller 2. In contrast to the embodiment according to Fig. 1, it is therefore arranged on the other long side of the metering roller 2. An elastic doctor blade 56 or the like is inserted into the profile strip 51, which lies tangentially with its free end on the metering roller 2 to seal off the substance and to strip off the substance. This metering doctor system is located at a circumferential angle distance of approx. 45° in front of the metering roller 2 in the direction of the metering roller 2.

downstream system α2 of the two rollers 1 and 2. Instead of the doctor blade 56, the profile strip 51 can be extended with a section 53 shown in dashed lines and with this can rest directly elastically on the metering roller 2 to form the metering doctor blade. In any case, a metering film transported from top to bottom is applied to the metering roller 2 using the doctor blade 56 or the doctor edge 53, which then reaches the transfer roller 1 along the unwinding/attachment line A2 between the rollers 1 and 2, with which it is transferred from top to bottom to the substrate or the material web 6.

In the embodiment according to Fig. 2, a roller 30 is only shown in dashed lines. It is expediently provided as a weight-loading roller resting with its own weight on the metering roller 2.

Claims (13)

- 12 - Protection claims: 1. Application device for coating, painting or similar. of flat material (6), comprising a bearing surface (40) for the flat material, a transfer roller (1) forming an application roller, which is located between its casing and the bearing surface (40) in a force-locking connection with the flat material (6) for the substance application, and a metering roller (2), by means of which substance (91) taken from a substance chamber (52) is applied to the transfer roller (1) in a metered amount, wherein the transfer roller (1) and the metering roller (2) are mounted without an axle bearing only on the circumference in such a way that they can be moved evasively across the material bearing surface (40) and can be subjected to a contact force, characterized in that the substance chamber (52) outside the circumferential area of the transfer roller (1) is separated from the latter between a circumferential section of the Dosing roller (2) and a dosing blade (3, 53, 54) adjacent to this, forming the complete substance space separation from the transfer roller (1). 56) and/or sliding surface (5) and the metering roller (2) is arranged above the transfer roller (1) and rests with its own weight on the transfer roller (1). 2. Application device according to claim 1, characterized in that the metering doctor blade (3, 53, 56) is arranged at a circumferential distance of at least 40° in front of the metering roller/transfer roller system (A2) following in the direction of rotation of the metering roller (2). &igr; * 3. Application device according to claim 1 or 2, characterized in that a pressure roller (3, 30) is arranged above the metering roller (2), which is mounted circumferentially without an axle bearing in such a way that it rests on the metering roller (2) with its own weight. 4. Application device according to claim 3, characterized in that the pressure roller is designed as a metering doctor roller (3) producing the metering film on the metering roller (2). 5. Application device according to one of claims 1 to 4, characterized in that the transfer roller (1) rests with its own weight on the material surface (6) or the material bearing surface (40). 6. Application device according to claim 5, characterized in that the transfer roller (I) at least partially made of magnetizable material, preferably in the form of a relatively thick-walled tube (II) with which it can be magnetically pressed against the material storage surface (40) by the magnetic force of a magnetic device (7) arranged below the material storage surface (40), such as a magnetic bar. 7. Application device according to one of claims 1 to 6, characterized in that the material bearing surface (40) is formed in the form of a rotating counter-contact roller (4). 8. Application device according to one of claims 1 to 8, characterized in that the circumferentially mounted, adjacent rollers (1, 2, 3) in an at least almost vertical bearing plane (S) are arranged one above the other, whereby the transfer roller (1) is pressed against the flat material (6) under the effect of the roller's own weight. 9. Application device according to one of claims 1 to 8, characterized in that the jacket surface of the transfer roller (1) consists of a soft material, preferably in the form of a soft rubber, textile covering (12) or the like. 10 10. Application device according to one of claims 1 to 9, characterized in that the surface of the dosing roller (2) is rough and/or structured, preferably with a groove, a fabric, a braid, a wire winding or the like. 11. Application device according to one of claims 1 to 10, characterized in that the application device comprises at least one auxiliary force device by means of which rollers (1, 2, 3) lying against one another or on top of one another under their own weight can be subjected to a contact force in addition to the contact force caused by their own weight. 12. Application device according to one of claims 1 to 11, characterized in that a heating element (8) for influencing the substance viscosity and/or for heating melting substances such as hot melt adhesives or the like is arranged in the substance chamber (52). 13. Application device according to one of claims 1 to 12, characterized in that the transfer roller (1) is connected to an axial and/or peripheral drive, preferably in the form of a friction drive.