FI118210B - Method and apparatus for spreading treatment substance from a chamber onto a surface - Google Patents

Description

118210 J

i '

The present invention relates to a method for applying a pigment coating, a surface adhesive, a silicone Kon or similar treatment agent to a moving paper board or fiber web or sheet by means of pressure-spraying nozzles.

10

The invention also relates to an arrangement for carrying out the method and an opening plate for the arrangement. j

In spray coating, moving drops of paperboard or other webs are sprayed with droplets of treatment agent which adhere to the web surface when they hit it. The coating takes place in a closed chamber which opens towards the track and ;; The mist naturally forms droplets of treating agent. Λ This mist must be prevented from entering the environment as well as it. 20 accumulation into larger droplets and condensation of the hand • * · · · • ·. , exposure of nozzle or spray nozzle to 9 · m • · ·, 1 *. Contaminated surface or surface adhesive dirt *** ·.

• * * *. contacting the equipment and liquid or large droplets · · ** · on the web being processed may result in an error in the remaining * · «· ** * 25 products.

• · · • · • · ♦ ··

International Patent Application PCT / FI02 / 00203 discloses a spray coating process in which the above mentioned drawbacks are reduced by placing pressure spray nozzles in the holes of a special nozzle plate. The tips of the nozzles extend into the applicator chamber * facing the web and are arranged at a pressure of · · * behind the nozzle plate. A space under reduced pressure with j, whereby openings of air from the nozzle plates • · ♦ • · 118210 2 flow into the chamber behind the nozzle plate j. The purpose of this flow is, inter alia, to prevent condensed treating agent 5 flowing along the nozzle plate from entering the nozzle jets and thereby into large droplets on the web.

WO 94/11116, for its part, describes a process in which a mist is formed in a separate chamber, from which it is passed through a separate nozzle device to the fin. This device does not use high pressure nozzles for direct spraying of the treating agent onto the web, but the process is done in two steps.

Although the teachings of the publications mentioned above allow the construction of functional coatings or adhesive applicators, their construction is complex and requires quite detailed design to function. Further, a problem with vacuum removal from the nozzle orifice has been the problem that the suction duct may become clogged, leaving no flow to keep the orifice clean. In addition, ·· »! · Especially when vacuum is not used, with large amounts of treatment • · · * ·" material, especially pigment coatings and long-lasting • 1 · • · 2

• · In 1 continuous operation, the tip of the nozzle is shaped as S

• · · · · * 'accumulates which should be removed. As the build-up builds, · · · · · · · · · · · ·: 25 can fly too large droplets at the tip of the nozzle or at the edges of the orifice plate openings.

If there are a large number of droplets, they may lead to product error and to • • 2 lamination from the end user such as a printing company. Even with a smaller number of large droplets * 1; 30 rollers after the coating may become dirty • · · · .3. after damping, since the dryer power is not dimensioned for the larger amount of coating formed by the droplets.

It is an object of the present invention to provide a method for dripping from a nozzle tip and a nozzle plate | edges can be reduced. It is a further object of the invention to provide an arrangement which reduces the droplet problem and which enables the construction of a coating and bonding device which is simpler and / or more reliable than before.

The invention is based on positioning the nozzle or, usually, a plurality of nozzles behind the leading edge of the nozzle plate such that a jet of nozzle provides a flow into the nozzle plate opening to the injection zone.

More specifically, the process i according to the invention is characterized in what is stated in the characterizing part of claim 1. j

The arrangement according to the invention, in turn, is characterized by what is stated in the characterizing part of claim 9.

In turn, the nozzle plate according to the invention has the character * * ·; · *: characterized by what is stated in the character character · ** of claim 17.

* · · • · · * • · * * · »· • * *

The invention provides considerable advantages.

• · • · · * i »• · *. ***. The first advantage of the invention is, of course, the end product. 30 quality certification if the access of oversized droplets can be prevented or reduced • • · * * * '' t,. * Secondly, the device can be used in a nozzle • •:. * · · Pressure, so no suction fans and ducts are needed, so ...

The price of the 4 118210 can be lowered and its structure 4 simplified. Of course, a simpler device is also more reliable. As operational reliability increases and the risk of dripping decreases, continuous operation times of the device may be longer, allowing the user of the device to get better value for money from earlier investments.

The invention will now be explained in more detail with reference to the accompanying drawings.

10; Figure 1 is a schematic cross-sectional view of one embodiment of the invention.

Figure 2 shows one opening j 15 of the nozzle plate according to the invention. '^

The invention is intended to be applied in spray application devices in which a spray chamber is positioned against a moving web, bounded on one side by said web and on the other sides by chamber walls. Opposite to the web, there is a nozzle plate on the side of the spray chamber with a · · ·] * / nozzle array behind which spraying agent, such as surface glue or pigment coating, is sprayed onto the web. The nozzle plate has an opening for each nozzle and a

• * · -S

The jet formed by the 25 nozzle flies directly from the nozzle feed pressure to the web surface. The jet formed by the nozzle generates mist, which must be prevented from entering the environment and the nozzle chamber behind the nozzle plate. Similarly, care must be taken to ensure that • • I 30 mist, which condenses on the surfaces of the spray chamber, does not come into contact with, for example, spray jets.

Such a spray application device is described, for example, in International Patent Application PCT / FI02 / 00203. In these • · ·; the devices use pressure-diffuser nozzles, ie • ··· · · V · '118210 f: -' ·: I? 5. tions in which the spray jet is formed solely by the action of a pressure difference across the nozzle orifice. , 7

Figure 1 illustrates one embodiment of the invention. Figure-5 only shows the nozzle plate 4, 5 and the nozzle and the position of the nozzle relative to the plate. Otherwise, the device may be as described above. It is essential that the device has a spray chamber 9 opening towards the path to be treated and a nozzle chamber 1 separated from it by a nozzle plate 4, 5, consisting of two spaced apart spacers. only from the wall of which the inner wall 4 is on the side of the nozzle chamber 1; and external wall 5 on 9 sides of spray caramel. Between the walls 4, 5 - there is a space 6, which can be filled with cooling or heating medium. At the nozzle plate 4, 5 there is formed a nozzle hole 8 at the nozzle 1 15 defined by an opening edge of the inner wall 4, an opening edge of the outer wall 5 and a support ring 10 therebetween, and a collar 11 mounted around the nozzle opening 8 1 has a bevel 7 which opens into the nozzle chamber 1 and extends into the region of the inner and outer walls 4, 5 and the support ring 10.

• ·. . The collar 11, in turn, has a bevel 12 at the opening, which • 1 · • · 1 .1 opens in the direction of the spray chamber 9.

• · «• 1 • · ittt1 ,. The outer surface on the side of the spray chamber of the collar 11 forms the outer surface of the nozzle orifice. The invention provides the positioning of the tip 3 of the nozzle 2 with respect to this outer surface.

,, The minimum requirement is that the tip 3 of the nozzle 2 is spaced • · mtt away from this surface in the direction of the nozzle chamber, i.e. the nozzle is * · '·; 2 seen from the direction of the spray chamber, collar 11 2 * 1 ·; 1 30 behind the outside. In the following, the invention will be explained by the design of one embodiment of ·· »: ... ·. This example is applicable to nozzles for forming a fan-like jet.

. ·. A: In the example, the nozzle spacing is 60 mm and the fans expand t

* 1 · J

• m · '· »118210.

such that a path extending from the nozzles; a uniform blanket is created. The purpose of this dimensioning example is merely to illustrate one embodiment of the invention in order to make the invention more comprehensible. It is obvious that, for example, at a different distance between the nozzles and the shape of the spray jet they form, the structure of the nozzle plate and the position of the nozzle must be changed accordingly. However, the limitations which the structure must strictly meet are set forth in the claims.

10 ί

The idea of the invention is that the nozzle 2, and in particular its tip, remains substantially cleaner when isolated from the spray mist in the spray chamber 9. Isolation j is possible at a nozzle opening 8, properly dimensioned with nozzle 2 located sufficiently far from the spray chamber 15, which prevents conceptual, 20 lye mists from entering nozzle opening 8 to dirt • · 1 · · · ·,: v

. . nozzle and nozzle chamber. The nozzle shower forms a s

• · · t ·, 1 .1 nozzle chamber 1 out of clean air spray chamber; • · · --y '\ o has 9 directional flows. Because nozzle chamber 1 does not / cannot get fog, there is no need for a lower pressure relative to ambient pressure to remove mist, but nozzle chamber 1 ··· 1 1 may be at ambient pressure. to collect | • · • 2 mists from the chamber and to help prevent fog from escaping into the surrounding • · * ··· 1. The chamber vacuum can be generated by:: 1: 30 below the nozzles 2.

* · · · • · 1 • · • · • · 1. ···. In this example, the nozzles which form a · · · · fan-shaped jet and are set so that the jet 9 m: -1 -1 · · · 2 · · 118210 '177 are inclined with respect to the horizontal. In this case, the parallelogram formed by the nozzle orifice is 45x62 mm, the horizontal width of the orifice is 45 mm and the perpendicular width of the orifice, i.e., the vertical width of the orifice, is 20 mm. The apertures of the collars 5 11 in this embodiment are parallel and when the nozzle plate 4, 5 is in an upright position, the apertures of the collars 11 are arranged obliquely so that when a horizontal straight line is drawn through the lower corners of the apertures in relation to. In this arrangement, the nozzle tip is j •. .2 about 10 mm behind the surface 1 of the outer spray chamber 8 on the nozzle plate, i.e. the outer surface of the collar 11. In this case, the edges of the spray fan are at a distance of 10 mm from the edges of the nozzle hole and the fan does not draw any liquid at the edges of the hole. On the other hand, however, the shower and; the distance between the nozzle hole is so small that the jet 1

energy causes the air to flow in this gap. At the outlet of the nozzle hole there is a bevel 12 entering 1.5 mm to control the outflow of air from the nozzle hole 8.

. 20 nozzle fan so it does not interfere with the spray fan {·· «* · • ♦.-7. . passage to the track being processed. Also, the nozzle bore 8 may have a bevel 7 on the nozzle bore 8 to provide an accelerating flow in the nozzle bore 8. The opening angle of this bevel 7 can be 35 degrees.

• · ♦ · · • ♦ · _ _ ·. ···? ·· * · 25 ···

• · .V

* ··· * When the nozzle is insulated in a non-fogging area and where flows are calmer t * J J r • ·: a hornless nozzle can be used. The hornless nozzle collects less ··· • »* ··· * deposits and drips less than the horned nozzle.

: 30 j • · ♦ *: ***: An essential feature of one embodiment of the invention is the collar 11 around the nozzle orifice. is to control the liquid flow from the mist flowing along the front wall of the nozzle plate so that it circulates the nozzle orifice 8 and the jet of spray at a sufficient distance and thus the liquid; get on the fly. Collar 11 is shown in front in Figure 2. Collar 11 prevents excessive drainage from accumulating at the edges of mouth 5 tin hole 8 due to both the gravity of the ground and the airflow of the spray chamber. In order for the collar to pass through the nozzle hole of the fluid flowing along the face plate, the flow must be directed so that it does not run perpendicular to the collar. The collar must thus be rotated in an oblique position with respect to the flow 10, whereby the collar edge will direct the flow 1 past the nozzle opening to the intact portion of the nozzle plate. *

In one preferred embodiment of the invention, the nozzle has a fan angle of at least 30 degrees to the horizontal.

15 In this case, the top and bottom edges of the opening must be at an angle of 35 degrees to the horizontal. Horizontally, it is understood here to be transverse to the direction of travel of the web, since the applicator can be positioned in any position in principle. The side walls 15, 16 may be straight inside the collar 20 11. The nozzle orifice angle depends * * on * the type of nozzle fan shape and angle you want to use.

*: ··: The mist formed inside the spray chamber 9 should remain liquid, even when condensed on the walls of the chamber; * * · · Should cure to the chamber walls. If hardening occurs, there is a risk, in addition to contamination, of • loosening the cakes from the walls and moving onto the track, which * * * * j * '*. I created can track serious quality errors. The pigment coatings * "*. *, 30 and the adhesives have different requirements in this respect. The use of pigment coatings to over-induce drying and curing of the mixture, so they have to be removed. It is advantageous to cool the walls of the spray chamber for appliqué application. * The wall structure of Figure 1 was able to keep the maximum nozzle opening temperature in the calculation model below 10 ° C with 10 ° C water as the coolant and 35 ° C. The temperature of the chamber is increased by the heat of the web to be treated and the heat of the coating, if a hot coating composition is used, whereas the adhesive compositions used in paper and board production are usually starch based and thus solidify when cooled. the walls must be heated with starch precipitate- For example, hot water is used in the nozzle plate.

The following features are essential for various embodiments of the invention. These features may be realized individually or in combination in the same embodiment. The nozzles must be located behind the outer surface of the nozzle plate openings. It is possible that the distance between the outer surface and the tip of the nozzle may be even small, but preferably the distance should be at least. 20 tails 5 mm, most preferably 10 mm, so that already · ·,. reasonably strong flow. The nozzle jet should also be • far enough away from the edges of the nozzle orifice. The distance »· ·: \ should preferably be 10 mm. When increasing the distance between the nozzle tip 3 and the outermost surface facing the track • ♦ ♦. '4 •• j · 25 The ejector effect of the jet increases. At a distance of • · * ·· ** 3-50 mm, at least the effect of the invention is considered to be obtained.

The nozzle opening should have a * 30 collar at the edges as described above. The collar thickness of the front wall of the nozzle plate may not need to be very large, but as the amount of fluid flowing along the front plate increases, the collar thickness also • · «•. y,, ·, · must be incremented. The collar must be annular and the • • * 10 118210 j tin openings must be spaced apart so that fluid flowing along the front wall 5 can flow down between the collars and does not accumulate at the top of the collars, allowing it to easily flow over the collars. a nozzle opening. Collar

5 and the shape of the orifice hole need not be the parallelogram described above. Obviously, when using nozzle jets of different shapes, the shape of the hole and collar also needs to be changed. Examples include ovals and circles for similarly shaped showers. J

10 \

In addition to the above, the present invention has other embodiments.

The shape of the spray jet need not necessarily be J

15 straight fan-shaped, but it can be another oval. In this case, of course, the nozzle opening geometry is different should be provided accordingly. The nozzle opening does not necessarily have to be beveled in the direction of the nozzle chamber, but the walls of the nozzle opening may be straight. Although only one nozzle and nozzle hole have been described above, it is clear that the production * · '' · scale device has a number of nozzles sufficiently • ♦ ·? .-- 4! .1 ·· processing to form the width. ! • · · · · · · · · · 2 · · / · r * "1: Instead of a collar, there is another way to prevent the treatment agent from entering the nozzle openings. - -i; 3; pa could be to provide an air blast at least on the flow side of the orifice * ··, i.e. practically at the top, so that:: 1; it directs the direction of flow through the nozzle plate away from the orifice. • or · outward from the edge of the orifice Blowing orifices • · · 9 · · may be slit or row of blowing holes.

* · • · · · '• 1 · -r • · · 2 • · 1 3 ···· ...

118210 H i

The collar and nozzle plate may be integral. Alternatively, the collar is machined into a portion protruding from the nozzle plate as in the example above, or the collar may be formed by machined channels around the nozzle hole.

5, the coating or other treatment medium is directed to flow past the nozzle orifice. The duct may be projecting, or it may be a milled groove or otherwise machined or modified inlet groove. The penetrating collar or groove may only surround the nozzle opening toward the opening in the direction of the fluid flowing on the surface of the nozzle plate 10, or it may be around the entire opening. A further alternative for forming the collar is to coat the nozzle orifice at least partially with a hydrophobic material that directs the treatment medium to flow past the orifice. Of course, the collar can also be formed as a combination of these, in particular by combining the plating Ϊ with another formed collar, or by using a parallel groove and ridge.

The invention can be applied not only to the treatment of continuous material paths 20, but also to the processing of sheet-like material bodies. Ar - *: 2: Kits can be cut sheets of paper or cardboard or sheets of material such as plywood, gypsum board or similar. The invention as such is not limited to the treatment of any particular * 1 ····· material, but for example in the treatment of moving strips, the invention makes it possible to implement tef 2 · .3. hefty production device. When handling sheet - like pieces, 4 sheets may be moved relative to the applicator or:. the device itself can move over the surface of the sheet.

··· .. · • · «· • 1 1 • · • · * ·· '• · * · · · · ···! m · · • · ♦ 2 * · · 3 • ·

Claims (18)

A method of spreading treating agent onto a sheet or movable paper, cardboard or fiber web by means of pressure-spreading spray nozzles (2), characterized in that the treating substance is measured through nozzle heels (8) in a nozzle disk (4, 5) in such manner. that the tip (3) of the nozzle is located at a distance from the outermost surface (11) of the nozzle plate (4, 5) wetting the treatment (11) so that the energy of the jet from each nozzle (2) forms an air stream 10 through the respective nozzle heels and the flow is directed to the spray zone. Method according to Claim 1, characterized in that a flow of the liquid into the nozzle heel (8) along the nozzle plate (4, 5) is prevented by directing the treatment material floating around the nozzle plate in the direction from the nozzle heel. • i * · ' 3. A method according to claim 1 or 2, characterized in that a flow of the liquid into the nozzle heels (8) * ': along the nozzle plate (4, 5) is prevented by surrounding the nozzle heels; 20 form a protruding collar (11) without a horizontal edge. Method according to claim 1, characterized in that a flow of the liquid into the nozzle heels (8) along the nozzle plate (4, 5) is prevented by forming around the nozzle heels an at least partially opening opening. blow beam on Yf • m: <25 side of incoming flow. ; • · · • '' Υ. '/ Ί' ·· * · ::; ι * · · * * *. *. 5. A method according to claim 1, characterized by * · · ···. by flowing the liquid into the nozzle heels (8); ,., 118210: 1 17> ': ψ' ',' The nozzle disk (4, 5) is prevented by forming a nozzle | the surface of the disc around the nozzle heel protruding collar, which is a | hot with the record. * Method according to claim 1, characterized in that a flow of the liquid into the nozzle heel (8) along the nozzle plate (4, 5) is prevented by forming around the nozzle heel an at least partially nozzle hole surrounding the surface of the nozzle plate's inner surface. . ' Method according to claim 1, characterized in that a flow of the liquid into the nozzle heels (8) along the nozzle plate (4, 5) is prevented by coating the surface of the nozzle plate at least partially around the opening by means of a hydrophobic substance. Method according to any of the claims 1-7, characterized in that the distance between the jet and the edges of the nozzle (8) is adjusted to at least 10 mm. • * · ** '> * * F • · · · is • · -S Apparatus for spreading treatment material onto a sheet * *: · *: or a movable paper, cardboard or fiber web, wherein the device comprises a spray chamber (9) which opens onto the surface for treatment, a nozzle chamber in (1) having at least one pressure-spreading spray nozzle (2) and a | Nozzle disc (4, 5) separating the nozzle chamber (1) from the spray chamber (9) and having for each nozzle (2) nozzle heels (8), characterized in that the tip (3) of each nozzle 2 is located at a distance from the outermost one, towards that of the bed. act the surface wetting the surface (11) of the nozzle plate (4, • ♦. $ • · •. 5). * · *.? • *; I • '. .1 · '·' * 118210 Device according to claim 9, characterized in that the distance between the tip (3) of the nozzle and the outermost one; the surface (11) is at least 5 mm, preferably 10 mm. Device according to Claim 9 or 10, 4 characterized in that nozzles (2) are used which form a solar spring beam, the solar springs being arranged at an angle of at least 30 degrees in relation 1 to a direction transverse. towards the direction of movement of the track. Device according to any of claims 9 - 11, characterized by collars "A (11) formed around the nozzle heel (8), which project from the wall (5) of the nozzle disk (4) on the side of the spray chamber (9) and which, in relation to the direction of movement of the web, do not exhibit any edges; £, ': A parallel to the direction of the transversal: 4' .f Device according to any one of claims 9 -: 1 · 11, characterized by collars' 2: ***: (11) formed around the nozzle heel (8), which project from the nozzle disk (4). , 5) wall (5) v. | The "1" side (5) of the spray chamber (9) and which do not have any adjacent edges parallel to the direction transverse to the direction of movement of the web 1 and which are uniformly formed with the nozzle disk. * 1 ·· '. ·' • ψ · Device according to any of claims 9 -: 11, characterized by collars formed around the nozzle heel (8), * · .2 ·. Which are formed by an inwardly facing channel being machined into the nozzle disk. j ··· • 1. 1 • 1 * * · · • 1 Device according to any one of claims 9 to 2, characterized by collars formed around the nozzle heels (8), which are formed by coating the etherstone a part of the surroundings of the nozzle by means of a hydrophobic substance. Device according to any one of claims 12 to 15, characterized in that angles between the edges (13, 14) of the collar, which are not parallel to the direction of movement of the web, are relative to a direction transverse to the direction of movement of the web. at least 35 °. Nozzle disk (4, 5) for use in a device for spreading a treatment blank onto a sheet or a movable paper, cardboard or fiber web by means of pressure-spreading spray nozzles (2), said nozzle disk (4). 5) includes | nozzle heels (8) for spray nozzles (2), characterized by -. . that each nozzle heel (8) is surrounded on one side (4,5) of the disc t *: · *: by a collar (11), and I - the collars (11), which surround each other *: · *: lying nozzle heel (8), located at a distance from each other. t · * * * • · * if • · • * m '.j ,, 18. Nozzle disk according to claim 11, characterized in that the openings of the collars (11) are made of parallel: ***: the gram and where the nozzle disk (4, 5) is arranged in vertical position **: the openings of the collars (11) are arranged obliquely in such a way that when a straight line is drawn through their lowest corner, each side of the parallelograms is in an eating minimum 30 · • · · * * *. *, degree of angle in relation to this straight line. * · · • · *