DK144265B - PROCEDURE FOR IMPROVING CARTRIDGE AND APPARATUS FOR EXERCISING THE PROCEDURE - Google Patents

Description

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The present invention relates to a method of impregnating corrugated board which is continuously fed from a corrugated cardboard plant in a horizontal, rectilinear path to an impregnation station, and an apparatus for carrying out the method.

The corrugated board consists of a fibrous, corrugated layer and one or two cooperating fibrous outer layers such that the corrugated board will contain a plurality of parallel, corrugated, extending channels having open ends at each of the corrugated board's longitudinal edges.

US Patent No. 3,310,363 discloses a method for treating wet, rigid corrugated board, wherein the corrugated board is passed through a closed space where the corrugated board is affected by gas, preferably dry formaldehyde gas, and dry hydrogen gas which is suitably used. temperature is passed through the enclosed space which, under pressure, surrounds the corrugated board, thereby reducing the water content of the board. The corrugated board is influenced both externally and internally by the gas, thereby providing a completely uniform dry product, which, however, can only be used for packaging purposes. This means that such corrugated board has a rather limited scope.

It is also known to impregnate corrugated board packaging articles by spraying an external impregnating agent for e.g. to make them resistant to humidity and to 25 rainwater. However, this method has the disadvantage that the outer surfaces of the packaging become difficult to apply any labels or direct printing because the impregnating agent can reduce the adhesive capacity of these surfaces.

The object of the present invention is to provide a method for impregnating corrugated board where the outer layer (s) is not affected on their outer surface and which makes the corrugated board useful for a variety of purposes other than just packaging.

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This is achieved with the method according to the invention, characterized in that the corrugated board is applied to the impregnation apparatus with its channels extending transversely of the feed direction and that the open ends of the channels at one side are exposed to suction of air from the channels to form a vacuum. in the interior thereof while impregnating through the open ends at the other side edge an impregnating agent of one or more components in connection with a carrier of one or more components which are optionally introduced under pressure and as a result of the suction effect of said vacuum in the ducts interior, after which excess impregnation material is sucked out of the ducts at the suction side.

In the method according to the invention, where the impregnation takes place from the interior of the ducts, with the impregnating agent being taken up by the fibrous walls of the ducts, the desired properties of corrugated board can be imparted so that it can be used not only for packaging material, but also for many other purposes, e.g. as insulating material, optionally composed of several layers, or depending on the nature of the impregnating agent, the corrugated board can be made water-resistant, fireproof or resistant to chemical stresses.

If soaking of the corrugated board with impregnating agent is not desirable, according to the invention, at least one of the corrugated board's outer surfaces can be covered with at least one of the corrugated board's outer surfaces with a protective layer which prevents air and / or impregnating agent from penetrating this surface.

In a particular embodiment of the invention, water can be applied as a protective layer.

The apparatus for carrying out the method is of the kind in which the corrugated cardboard from a corrugated cardboard system is fed continuously and in a horizontal, rectilinear path to the apparatus, the impregnation being effected by the apparatus introducing impregnating agent into the corrugated board channels during the passage of the corrugated board. This apparatus is peculiar in that it has two means, one along each side of the conveying path of the corrugated cardboard, namely a impregnating insertion means arranged along one side and a suction means for sucking air from the other side. the channels, which engage each longitudinal edge of the conveyed corrugated web 10 and to a certain extent seal the open ends of the corrugated cardboard channels, and that the introducer is divided into zones, and that the suction means has a separate suction chamber for shielding the corrugated cardboard exterior , flat layers for penetrating false air through its pores are provided a screen located between the insertion 15 and the suction means.

Embodiments of the method and associated apparatus according to the invention are described in more detail in the following description in connection with an accompanying drawing, in which: Figure 1 is a schematic side view of a corrugated papermaking apparatus according to the invention; Fig. 3 is a cross-sectional view and in a larger scale; Fig. 4 is another section of the apparatus, in cross-sectional view and in a larger scale. Fig. 4 shows a diagram illustrating the method of using liquid impregnating materials; Fig. 7 a diagram illustrating the method of injecting powder or liquid impregnating materials. Fig. 8 is a perspective view of a means for suctioning impregnating material; Fig. 9 is a cross-section through the means of Fig. 8; Fig. 11 is a perspective view of a member having an intake port; Fig. 12 is a perspective view of a member with incisor spray nozzles; Fig. 13 is a cross-sectional view, fig.14. a screw stopper for closing injection nozzles, Fig. 15 a combined air and material injection nozzle, seen in a cross-section, Fig. 16 nozzle for injecting a liquid impregnating material, in cross-section, and Fig. 17 an injection nozzle for producing impregnating material in atomized form.

In impregnating corrugated board which is made in a generally known manner in a corrugated board manufacturing facility, a corrugated web 2 passes through an impregnation station 1 having at one of its longitudinal edges an impregnating insertion means 3 and at the other of its longitudinal edges a suction means. 4. The insertion means 3 is an elongated, divided housing with guide rails 5 for guiding the corrugated web 2 through said impregnation station. Furthermore, sealing lips 6 of a resilient material for sealing against the corrugated web are provided on the guide rails 5 as it is passed through the insertion means 3, as shown in Fig. 2 and Fig. 3. Further, sealing means 7 are provided in connection with the ends of the insertion member 3 which abut the edges of the corrugated web 2 as it is passed through the impregnation station. A vacuum chamber 8 is arranged in conjunction with the sealing means 7 at the inlet side of the insertion member 3, as shown in Figs. 2, 6 and 7. The insertion member 3 further includes an inlet chamber 9 with inlet 14, as shown in Fig. 3, for introducing impregnating material. to the impregnation station. The flow 35 of the impregnating material through the inlet 14 can be controlled by a throttle member 15 which can be displaced and adjusted by means of an adjusting screw 16. A compressed air chamber 10 is arranged in the inlet guide 3 next to the inlet chamber 9. From pressure -air chamber 10 is supplied with hot compressed air, and from another compressed air chamber 11 cold air is supplied. Adjustable inlets 17 supply hot and cold compressed air, respectively, to chambers 10 and 11. An electric heating means 18 is arranged near the inlet 14 in the inlet means 3. A liquid impregnating material is stored in a storage container 29 and is passed therefrom through a pipeline. 19 to the insertion member 3. When the vacuum does not affect the insertion member 3, possible impregnating material may flow to a collection container 13. The insertion member 3 is placed on a rack placed in the impregnation station by means of a fastening means 21. The insertion member 3 is thus arranged to fit. close to the 15 edge of the corrugated web 2.

The suction means 4 is in the form of an elongated divided housing with guide rails 22 and 23. These guide rails extend into the housing through a longitudinal opening 24 through which the longitudinal edges of the second corrugated web 2 are passed. The longitudinal edges of the guide rails 22 and 23 extend beyond the opening 24 and have flanges 22 'and 23', respectively, connected to the member 4. The flange 23 'is fixedly mounted on one side wall of the member 4. The flange 22' is adjustably disposed on the adjacent side wall of the member 4 by means of an adjustment slot 25 and a screw bolt 26 with nut 27. The adjustment of the flange 22 'allows changes of the distance d between the guide rails 22 and 23 as needed. To the flanges 22 'and 23' and projecting beyond their longitudinal edges, there are attached elastic sealing flanges 28 which abut the upper and lower sides of the corrugated web 2, respectively, and protrude beyond the outer longitudinal edges of the guide rails 22 and 23. The inner end of the guide rail has an elastic sealing strip. In the vicinity of the outer longitudinal edges of the guide rails 22 and 23, holes 29 for outflow of air are formed in these.

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The suction means 4, having separate chambers, is provided with suction nozzles 30, shown in Fig. 5. These suction nozzles 30 are, for each chamber, connected to a corresponding chamber 32 in the suction box by means of tubular tubes 31, as shown in Fig. 2. Pipelines 33 connect the chambers 32 to a vacuum pump 34 driven by an electric motor 35. Additional suction devices may be used to produce the required vacuum if needed. The chambers in the suction box 32 serve as vacuum containers and as a temporary separator. The impregnation material is passed through the exhaust pipe 36 of the vacuum pump 34 to an impregnator material separator 37. Then, the recovered impregnation material is passed from the separator 37 through a partially shown pipeline 38 to a container 39. The regenerated impregnation material 39 is passed through the container 39 pipeline for impregnating material container 20.

The impregnation is carried out as follows. The corrugated board web 2, which is finished in a corrugated cardboard plant, is passed through the impregnation station at a speed of 20 60-120 m per minute. However, it is possible that the corrugated web may be advanced at a greater speed. One of the longitudinal edges of the corrugated web is guided through the insertion means 3, while the other of the longitudinal edges of the corrugated web is guided through the suction member 4 under close connection. The suction means 4 causes a suction of air from the corrugated cardboard ducts. The corrugated web is heated by a heating apparatus (not shown) as it passes through the suction means 4, thereby keeping the impregnating material flowing and preventing clogging of the corrugated cardboard channels. Due to the location of the suction nozzles 30 at equal intervals along the suction means 4, this is supplied with a uniform vacuum produced by the vacuum pump 34. The suction box 32 acts as a liquid separator, thereby preventing the liquid impregnating material from entering the the vacuum pump 34. The separated liquid impregnating material is fed from the suction box 32 to the storage container 20 by means of a heated pump system not shown in the drawing. The suction box 32 is also heated. Return of the recovered impregnation material from the separator 37 and the suction box 32 to the storage container 20 takes place in a closed circuit for the impregnated material used. The air which is purified in the separator 37 is fed to the compressed air means 10 and 11 of the introducer 3. The impregnating material is sucked into the channels of the corrugated web 2 in the area of the inlet chamber or zone 9 shown in Fig. 6 due to the working pressure of suction means 4 and the working pressure of the insertion member 3. The impregnating material is heated to a very high temperature by the heating means 18 of the insertion member 3, and as a result the material penetrates into the channels of the corrugated cardboard 21 s. A diagonal current movement 9 'is formed from the insertion means 3 to the suction means 4 due to the high velocity of the corrugated web 2 through the impregnation station and the flow rate of the impregnating material as it flows into the corrugated canals under the influence of the suction of the suction means 4. compressed air zone 10 and cold compressed air zone 11, the air acts to push the impregnating material through the corrugations of the corrugated cardboard immediately after the material has been introduced into zone 9. The compressed air zones 10 and 11 act to dry the corrugated corrugated duct caused by impregnation mats -25 rial.

The efficiency of the stated process of impregnating corrugated cardboard with a liquid is highly dependent on the vacuum obtained in the impregnation station. It is extremely important that the vacuum has a continuous and regular effect so that a large amount of air can be controlled by it. The greater the vacuum, the greater the acceleration and velocity of the liquid impregnating material into the corrugated cardboard channels.

The outer layers of the corrugated web 2 are very porous. Therefore, a considerable amount of air will penetrate through these porous layers into the corrugated canals, causing a significant loss of vacuum and its effect to draw the liquid impregnating material into the corrugated canals.

It has been found that applying a fine film of water to the outer layers prior to the impregnation process provides an effective sealing of the pores thereby increasing the vacuum during the impregnation step.

Sealing of the pores can also be achieved by appropriate mechanical measures, e.g. an arrangement of shielded 10 vacuum zones above and below the corrugated web 2, respectively, as it passes through the impregnation station, eliminating air above and below the corrugated web surface 2. Another measure consists of applying sealing foil to conveyor belts 15 disposed above. above and below the corrugated web 2. Such sealing foils will effectively seal the pores in the outer layers and ward off air penetration.

There are various ways of passing the impregnating material into the channels 20 of the horizontally moving corrugated web 2 through the insertion member 3. In the first way, the impregnating material in the form of a liquid curtain passes past the open mouths of the corrugated cardboard channels. The vacuum formed in the ducts due to the suction effect of the suction means 4 sucks the liquid impregnating material 25 from the curtain into the corrugated cardboard ducts as the material descends in front of said orifices. Another way is to use an additional suction device located at the insertion side of the device to act on the mouths of the ducts.

The use of such an additional vacuum at the mouths of the ducts 30 draws the liquid impregnating material into the suction means 4, after which the material is sucked through the ducts. A third way is to bring the flat surface of the liquid impregnating material up to the corrugated web 2. When the surface reaches the mouths of the corrugated cardboard channels, the liquid impregnating material is sucked into the channels by means of the vacuum. A fourth way is to use a specially shaped insertion means which is well sealed and pressed firmly against the edge of the corrugated web 2. The impregnating material is fed into the corrugated cardboard channels by means of the specially designed insertion means 5 and is sucked through the channels as soon as it has been affected by the vacuum caused by the suction means 4. It is possible in this case to have an adjustable metering pump which can feed the impregnating material into the corrugated cardboard channels at various pressures or inject the material into the channels through spray nozzles.

The length of the feed section varies for the different ways. However, it is always necessary to have short sealing zones 8 in the impregnation station to allow the vacuum to be built up and fully provided in the ducts before proceeding to the insertion zone of the station 9. The sealing zone 8 may be either active or passive relative to the pressure within. the channels of the corrugated board 2, see Figs. 6 and 7.

Small liquid spray columns of impregnating material adhere to the interior of the channels as the corrugated web 2 passes through the introductory zone of the station 9. These small columns of liquid impregnating material taken together form a sealing strip 9 'extending diagonally across the entire width of the waveguide. two vacuum zones. There is a pulling effect at the suction side of the vacuum and braking action at the insertion side due to an increasing degree of vacuum. The braking effect is undesirable and can only occur if the entire feed side is hermetically sealed. This braking effect is eliminated by allowing a metered air flow immediately after the introduction zone 9. The metered air flow is at normal atmospheric pressure. The combination of the air flow at atmospheric pressure and the pull of the vacuum on the other side of the diagonal liquid strip 9 'causes an acceleration of the velocity of the impregnating material flow through the corrugated cardboard channels.

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However, the capacity of the acceleration caused by the measured flow at atmospheric pressure is not sufficient for the use at high production rates. Therefore, the air from the inlet side in zones 10 and 11 after the inlet zone 9 must be compressed. This air is blown directly into the corrugated cardboard ducts immediately behind the liquid impregnating material. The compressed air zones 10 and 11 comprise spray nozzles specially designed to introduce air under high pressure and at high velocity into the corrugated cardboard ducts. Because the high air velocity into the ducts would cause a sudden cooling and delay of the impregnation process, the compressed air in zone 10 must be preheated to at least 120 ° C. The hot compressed air in zone 10 fulfills several functions, firstly it increases the speed of the liquid impregnating material, secondly it prevents an overly concentrated deposition of impregnating material, because its heat prevents rapid cooling of the material, which results in economical consumption. of the liquid impregnating material, and thirdly, it cleans the corrugated cardboard ducts and blows out any remaining liquid impregnating material from the ducts due to the high velocity and volume of the air flow.

The actual cooling of the impregnated ducts is carried out in zone 11 directly after the hot compressed air zone 10.

Cold, compressed air is forced through the corrugated cardboard channels as the corrugated web 2 passes through zone 11. The cold compressed air cools the impregnated ducts as it flows out through the open channels on both sides of the corrugated cardboard web 2.

If the outer layers of the corrugated web 2 have been wetted by a film of water, the corrugated web 2 must be ventilated from the outside by a stream of hot or cold air. This flow of air causes a rapid evaporation of said water film, thereby producing complete cooling of the corrugated board. To ensure the necessary impregnation temperature in the impregnating material at the insertion side of the apparatus, both the insertion side and the suction side are heated. Heating the suction side causes the excess amount of impregnating material to remain in liquid form as it passes to separators 22 and 37 and returns therefrom to the insertion side of the impregnation station. Maintaining a high temperature throughout the impregnation station is particularly important where the impregnating material has a high melting point and very hot injection is used in the impregnation zone. A special fan located in front of the zone where the corrugated board enters the impregnation station continuously extracts most of the air from the corrugated canals. This enables the vacuum pump 34 to have its full power during the operation of the impregnator.

The impregnating apparatus of the present invention is very versatile. It can be adapted to any existing corrugated cardboard making machine as a compact high performance apparatus for placement between a clean cutting station 41 and a reel or storage station 42. Alternatively, the apparatus may be incorporated into a new plant as a fixed component. The equipment of the present invention can also be incorporated into the drying station of the wave making plant above the final heating station. This arrangement is particularly important in the case where an aqueous plastic emulsion is used in the impregnation process.

Multilayer corrugated board is often made with different wave sizes and thus varying heights along the corrugated layers. This physical nature of such corrugated board requires a special adjustment and control of the impregnation material supply to suit the various corrugated sheets. Ie The rough wave flow conditions (A group) are quite different from those required for a finer wave (B group). The coarse corrugation of the A group requires a shorter insertion step relative to the web movement because it has a greater capacity to absorb impregnation material. Under these conditions, a much higher flow rate is achieved through the corrugated cardboard channels due to the better flow conditions than at the B group's finer waves. It is therefore necessary to provide the corrugated sheets separately with impregnating material from a separate insertion means, taking into account the different wave types. In order to avoid this peculiar complication, it is possible to make the corrugated board of a material by which the most favorable flow penetration of the impregnating material can be obtained. Ie that the intermediate layers of corrugated board must consist of a particularly thin, absorbent material in order to provide a light and rapid penetration of the liquid impregnating material.

Another type of corrugated cardboard construction comprises the use of at least two corrugated cardboard layers having the same corrugated size. This type of corrugated board construction is possible due to the stabilizing effect of the impregnation material used in this process. In this case, the corrugated corrugations corresponding to each other 20 are arranged facing each other so that one back supports the other back, and the thus corrugated layers are passed through the impregnation apparatus in this way. This structure and mode of application of the corrugated board causes all channels to be supplied to the permeable liquid 25 under the same conditions. The repeated use of the same wave sizes is of particular importance in the process of injecting the impregnating material as foam into the corrugated cardboard channels. In this case, the cured plastic foam will provide a completely new condition of stability. 1 2 3 4 5 6

The penetration depth of the impregnating material depends on 2 different factors. It is a function of the variation of 3 the velocity at which the impregnating material flows 4 across the corrugated web. It is also a function of the temperature 5 of the impregnation material used in the process.

6 Changing the temperature of the air, the measurement and variation of the air pressure needed for various purposes of the process also affect the penetration depth of the liquid impregnating material. The rate of flow through the corrugated cardboard channels is dependent on the 5 degree of vacuum used in the system. This flow through the channels, in turn, may be influenced by external means, such as a film of water applied to the corrugated board or by increased evaporation from the corrugated board channels. A rapid evaporation of the film of water from the outside of the corrugated board will act to reduce the depth of penetration of the impregnating material, the rapid evaporation of the film of water causing cooling of the corrugated board. The depth of penetration of the impregnating material also depends on the speed at which the corrugated board is made. Finally, different types of impregnating material will provide different results in terms of the penetration depth as well as the viscosity of the impregnating material used.

In view of these many varied factors of penetration depth in the corrugated board channels, it is clear that any desired impregnation is possible in most of the various types of corrugated board produced. For example, it is possible to make a completely impregnated corrugated cardboard which may be externally dark-colored on both sides of the cardboard depending on the material used. It is also possible to make a partially impregnated corrugated board, the outer layer of which has a light color on both sides of the cardboard. It is also possible to make corrugated board, one side of which is completely impregnated, while its other side is partially impregnated, whereby the exterior appears dark on one side and light on its other side. By a suitable wetting on the outside of the corrugated board, these can be kept free for writing, printing or adhesive. In this case, the corrugated board may also have a dark color on one side and a partially dark and partially light color on its other side. A partial impregnation can also be carried out such that the corrugated board on both its outer surfaces has partial dark surfaces and partial light surfaces. The latter product may be made by the outer surfaces of the cardboard being partially applied to a film of water, thereby forming fields upon which may be applied, printed or glued. With 5 corrugated board made up of several layers of waves, it is possible to impregnate only one of the layers with a complete impregnation. Ie only the outer layer of the cardboard, which in particular requires a complete impregnation, is treated, while its inner layer can be fully or partially impregnated. Of course, these separate coating methods depend on the desired use of the corrugated board.

Intrusion of air from the outside into the voids of the ducts, where there is a vacuum, occurs under great pressure and degrades the efficiency of the vacuum. For this reason, it is desirable to take appropriate precautions to reduce this penetration of air. This can be achieved as above by applying a film of water to the outer layer of the corrugated board during the entire process.

This wetting of the corrugated cardboard outer layer also prevents these layers from being affected by the impregnating material. Wetting the corrugated board prior to 20 during and after the impregnation step is a necessary measure to preserve the protective film of water when using a hot impregnating material. Ie the heat from the impregnating material causes the water to evaporate. The vacuum present in the corrugated channels trucks a portion of the film of water into the pores of the paper, whereby this water evaporates upon contact with the hot iron impregnating material. The slow velocity of the water through the pores of the cardboard forms a shield against further penetration of air. On the other hand, by wetting the corrugated cardboard outer layer, the impregnating material is hindered by a complete penetration of the outer layer. In this way, the use of a film 30 of water over the outer layer of the corrugated board during the impregnation serves a dual purpose. When greater speeds of corrugated board feed through the impregnation station are used, much shorter wetting periods are available. In this case, it is necessary to soften the water during use by adding a plasticizer to increase the penetration of the water into the corrugated board. Increasing the temperature of the water also works to increase the penetration ability. For obtaining a reliable seal of the outer layer of the corrugated board, there is also another method which also provides a particularly deep penetration of the impregnating material. This method consists in using a film of impregnation material instead of water on the outer layer of the corrugated board, while in the interior of the corrugated board only vacuum is provided. Or, if aqueous plastic emulsion is used instead of a film of water, then the water content of the emulsion will evaporate by the heat of the impregnating material having a high melting point. Thereby, a tough outer layer of plastic 10 with high tensile strength is produced over the outer surface of the corrugated board.

Reduced permeation of air through the corrugated cardboard surfaces can also be achieved by sealing means disposed above and below the corrugated impregnation zones, respectively, as the cardboard passes through the impregnating apparatus. The sealants are vacuum zones disposed immediately above and below the corrugated board, respectively. These vacuum zones can be designed in a variety of ways. The vacuum may be formed in sealing cavities after air has been removed through the pores of the paper 20 into the corrugated cardboard ducts, where vacuum is safely formed by the suction means 4. When the air is removed through the pores of the paper, the protective vacuum zones or sealing cavities are formed.

The air may also be removed from the sealing cavities using direct precautions. A vacuum connection for removing air from above and below the corrugated board, respectively, can be carried out with a fan or a vacuum pump. A direct suction produced from the inside to the outside causes a strong outer vacuum, while the vacuum can be produced within the corrugated cardboard channels by the suction means 4. This extra outer vacuum causes the impregnating material to flow through the corrugated cardboard channels with a much larger velocity. That is, the impregnating material is, in effect, in the form of atomized, small droplets will be drawn from the inner portions of the corrugated cardboard channels to the outer layer of the cardboard, whereby a very rapid penetration into the pores of the cardboard takes place. Additional vacuum zones 8 located at the beginning and 5 at the end of the impregnation operation act to seal the inlet points of inflowing air to the corrugated cardboard ducts at these particular locations. Although the corrugated board can be evacuated exclusively through the outer layer, it can be seen from the above that the permeability of the impregnating material can also be controlled by controlling the vacuum conditions both inside and outside the corrugated board.

It is also possible to make use of direct pressure zones at the outside of the corrugated board, in contrast to the above mentioned measures. In this way, reaction gases are pressed into the pores of the paper to produce a strong reaction with a reactive impregnating material coming through from the inside of the channels to the outside of the corrugated board. This provides additional means for controlling the impregnation process and an opportunity to improve the quality of the impregnation of the corrugated board material.

Hot plates placed above and below the corrugated board as it passes through the impregnation apparatus, respectively, may also affect the amount of permeated air penetrating the pores of the outer layer of cardboard during the impregnation process. The heated air above the paper reduces the pressure above the corrugated board. In addition, the hot air keeps the liquid impregnating material's temperature high for a prolonged period of time, and the entire heated state of paper, air and impregnating material enables the impregnation to be carried out much more easily. When powdered impregnating material such as powdered paraffin is used, the warm air will penetrate the pores of the paper and cause the individual particles to melt, thereby supporting the impregnation process.

You can also use a magnetic field device instead of heated plates. This apparatus is used to attract the impregnating material which has been dielectric polarized in the opposite direction. In this way, the impregnating material is deposited on the cardboard layer when affected by the magnetic field. The use of magnetic apparatus for carrying out the process is particularly useful when a volatile impregnating material in the form of nebulizers, powders, etc. is used. The same result can be obtained magnetically if metal additives are added to the impregnating material. If the corrugated board itself already contains a static charge, the dielectric polarization of the impregnating material can be accomplished without the use of a magnetic apparatus. The static charge on the corrugated board acts to strengthen the board and form the opposite pole to the impregnating material which has been similarly polarized dielectric before being introduced into the channels.

20 In order to obtain a direct seal along the insertion means and the suction means as the corrugated board passes through the impregnating apparatus, sealing flanges 6 and 28 are provided at the ends of the guide members 5, 22 and 23. The sealing flanges 6 and 28 are formed of a flexible material and 25 extends within the width between said controls 5, 22 and 23 to move towards the corrugated board as it passes through the apparatus. Since the controls 5, 22 and 23 can be adjusted to suit the thickness of the corrugated board, the sealing flanges will always exert a sealing effect on the corrugated board.

Sealing ribs 5 ', see Fig. 5, can be used in place of the flanges 6 and 28. These sealing ribs 5' extend in the direction of the corrugated conveyor movement and are lightly pressed against its outer layer of cardboard to form fine grooves in the corrugated cardboard as it passes the impregnator .

Sealing between the corrugated board and the impregnating apparatus can be achieved by using tightly sealing means along the lateral inlet points of the corrugated web »A particularly good seal is obtained by an insertion means and a suction means which continuously adjusts to horizontal changes of the corrugated path when the corrugated path adjusts.

The latter seal must be designed to have a single unit supplying the impregnating material to the corrugated web 2. This requires an adjustable slot 10 to be applied only at the input and output of the corrugated cardboard through impregnating apparatus. This construction has insertion and suction means connected to each other by means of a closed space.

The use of injection of the liquid impregnating material provides a very economical way to impregnate the corrugated cardboard channels. Use of compressed air passing out of a spray nozzle placed behind a curtain of impregnating material forms an atomization inside the insertion member 3. These spray nozzles are located at short distances 20 directly behind said liquid curtain and beyond the center of the corrugated board. channels. The spraying arrangement is arranged at the beginning of the insertion zone 9 in the vicinity of the evacuated zone 8, as shown in Fig. 7. A special high-pressure apparatus which produces a finely divided spray of impregnating material ensures that the impregnating material is injected into the corrugated cardboard channels without the use of air. Use of such a special apparatus results in a particularly well-concentrated wetting of the corrugated board. Optionally, the impregnating material can be mixed with 30 air effectively. An example of this may be the use of the spray gun principle whereby impregnation material and lpft are mixed and then injected directly into the corrugated cardboard channels.

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The use of an impregnating fluid syringe completely changes the state conditions within the corrugated cardboard channels during the impregnation process. Eg. there is no liquid column of impregnating material flowing through the channels of the corrugated board. Therefore, as previously described, the sealing function is not necessary at all. Because the liquid columns are no longer present in the channels, the braking effect ceases due to the direct contact between the impregnating fluid and the inner surface of the corrugated cardboard channels. Thus, the friction of the liquid columns is completely eliminated by using a nebulizer which moves under the influence of compressed air. While columns of fluid move at a rate of only about 2 m per second, compressed air can move a nebulizer through the ducts at a rate of at least 80 m per second. second. By eliminating the braking effect, the high velocity produced by the nozzles and the high pressure needed to atomize the impregnating fluid can be achieved in the corrugated cardboard channels. The movement through the corrugated cardboard channels is completely impeded by spray-impregnation with liquid. The atomizing fluid is accelerated into the channels where it immediately reaches the vacuum atmosphere created by suction by the suction means 4. This combination of spray and suction function helps prevent any loss of velocity of the impregnating fluid as it passes through the corrugated cardboard channels. Very fine droplets of spray liquid moisten the inner surfaces of the corrugated cardboard channels as the material moves in zone 9 from the insertion member 3 to the suction member 4 as shown in Fig. 7. A deposition from the impregnating spray is very limited. Therefore, in order to prevent a large loss of impregnation material due to unused amounts of the spraying, the spray material can be fed with a special nozzle in a rotating, helical web. This way of injecting the droplet impregnating material into the channels of the corrugated cardboard 35 causes the material to be deposited on the inner walls of the channels due to the centrifugal force resulting from the revolving helical movement.

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It is very obvious that a very fine adjustment of the degree of impregnation can be achieved when the spraying method is used. The better the control, the better the efficiency and yield of using the special impregnation process.

5 When the impregnating material is injected, as shown in Fig. 7, a large gap is created at the suction side of the impregnator. It is of utmost importance to fill the large gap formed at this point with a suitable impregnation material. The special function necessary for moving the columns of impregnating material through the corrugated cardboard channels is no longer necessary. Therefore, instead of having a varied function, as suggested above in the other embodiments of the invention, it is desirable to have a series of staggered functions acting in parallel or reciprocally.

The injection zone 9 shown in Figure 7 is immediately followed by a blocking zone 40. There is neither compressed air nor suction in the blocking zone 40. The offset parallel function shown in Figure 7 results in 20 being the entire inner surface of the corrugated cardboard channels is completely coated with impregnation material as it is introduced through the syringe insertion zone and movement through and out of the corrugated cardboard channels is blocked by the blocking zone 40. Although the offset parallel function, see Fig. 7, 25 includes a suction zone 4 ', it also has a compressed air entry zone 11 which follows the blocking zone 40.

The compressed air feeding zone 11 removes excess impregnation material introduced in the direction of the suction zone 4 'which lies on the opposite side. 1 Once the corrugated cardboard channels have been filled with injected impregnation material, it is important to stop the flow from the spray into the channels. This is accomplished, as shown in Fig. 7, by using the lock zone 40 which is hermetically sealed at the insertion side immediately after the syringe insertion zone 9. Furthermore, a sealing zone 40 which is also hermetically sealed is located close to the suction zone 4 'which is located opposite the feed zone 9. Compressed air feed zone 5 11 adjacent to the lock zone 40 at the feed side serves to cool and dry the impregnated ducts. At the two blocking zones 40 which are diagonally opposite to each other, as shown in Fig. 7, the impregnating material has time to penetrate the cardboard layers of the corrugated web 2 as it is passed through the impregnating apparatus. The blocking zone 40, located immediately after the insertion zone 9, prevents too rapid drainage of impregnation material which is introduced into the corrugated cardboard channels. If, in the embodiment, a cold impregnation material has been injected, the zone 11 is adapted to introduce hot compressed air after the blocking zone 40 which causes a rapid drying of the material which has been injected into the corrugated cardboard ducts. However, if a hot impregnating material has been used, a cold compressed air zone must be used in the same manner after the blocking zone 40 to cool and cause the impregnating material to solidify.

Any application of printed text to the corrugated board should be done immediately before the corrugated board is introduced into the impregnation station. The ink used stops the penetration of the impregnating material in a manner similar to the application of water film to the outer layer of the corrugated board. In fact, it is possible to use a water color as a printing ink. It is possible to build a single machine unit from the combination of a printing apparatus, a coating installation and an impregnating apparatus. 1 2 3 4 5 6

Another important design of the impregnation process inside 2 involves the use of evaporation of the impregnating material 3 and its subsequent injection into the corrugated cardboard ducts 4 as steam. The vacuum created using the suction means 4 causes a reduction in the degree of evaporation of the 6 impregnating material. To carry out this process, the impregnating material is brought into a specially designed vacuum container to evaporate. Thereafter, the steam formed in the vacuum container is sucked into the corrugated cardboard channels in a substantially compressed state. The impregnating material may also be injected as steam at a temperature causing it to evaporate from a state of the finest smoke in the vacuum prevailing inside the corrugated cardboard ducts.

A further embodiment of the process comprises a foam covering of the corrugated board with a self-curing foam. The foam material 10 is composed of at least two components and is mixed to a very concentrated state before being brought to the corrugated cardboard channels. This mixture enables the foam material to reach the channels in a very uniform liquid state. By covering the channels with foam, it is possible to use corrugated cardboard which has extraordinarily large channels without losing quality in the coverage. Impregnated corrugated board, which has been covered with plastic foam, has an extraordinarily high insulating capacity. It is particularly suitable for transporting products that are sensitive to temperatures. Moreover, such treated corrugated board is fully usable for building structures.

Units for an impregnation apparatus shown in Figs. 8-14 include an insertion means and a suction means which consist of interchangeable and heatable standard elements 25 made of metal, preferably light metal. The suction means and the insertion means are each composed of at least two active and one passive components. An inlet head 43 is equivalent to the component 8 shown in Fig. 7. This inlet head 43 is disposed at the beginning of both the introducer and suction means. The inlet heads 43 provide a frictionless insertion at the longitudinal side edges of the corrugated web 2. The protruding outer layers 2 'at the edge of the corrugated web 2 are bent plow-shaped in the inlet head 43, as shown in Fig. 10. This is made possible by inserting the edges of the corrugated web 2 into 35 for these formed cavities 44 and 44 'without causing the longitudinal edges to be blocked. The sides of the corrugated web 2 will abut the abutment surfaces 44 ". This enables the openings of the corrugated cardboard channels to slide directly past the suction openings 49 shown in FIG. 9 and the spray nozzles 46, 5 shown in FIG. 10. The abutment surfaces 44 "shown in conjunction with the inlet head shown in FIG. 8 simultaneously constitute sealing of the corrugated cardboard ducts which are later evacuated.

There are at least two interchangeable standard elements in the suction means. Each of them has a closed, independent suction chamber 47 and a suction nozzle 48. The standard element shown in Fig. 11 has a suction opening 49. The standard element can be easily and quickly replaced at either the suction side or the feed side if alternate replacement is planned. .

When the connecting and controlling means 50 are released, the block 51 can be easily removed from the bypass steam lines 52. This method is also possible with the block 51 'of the insertion means including the spray nozzles 53 having the same diameter as the width of the suction opening 49.

The connecting and control means 50 are adjustably arranged on the front faces of the insertion and suction means. Therefore, the connecting and controlling means 50 can be adapted to any type of corrugated board. These members 50 form a fixed portion with a sealing cam 54 and the spacer and connector members 55 which may be interchangeable. These solid members are only replaced if the sealing cam 54 is to be adjusted.

The block 51 'shown in Figs. 10 and 12 constitutes an independent, independent member of the insertion member. The block 51 'has a single pressure chamber 47 and supply tube 48 for introducing 30 impregnating fluid and compressed air. The insertion means constitutes a stable unit when the control means 50, the connecting means 55 and the guide means 56 are screwed together in a coherent manner with the steam pipes 52. The entire unit of the insertion means is arranged on rails not shown. This unit is flattened 35 by tensioned compression springs which provide a responsive and tight fit to the ends of the corrugated cardboard ducts in the corrugated web 2. This way of mounting the insertion member 3 and suction member 4 readily enables them to adjust itself after any movement of the passing corrugated web 2. This constructive relationship clearly ensures a high efficiency of the impregnator during any phase of the corrugated web 2 passing through said apparatus.

The units of the insertion means 3 and of the suction means 4 can be used either to produce a suction or a positive pressure. Where it is desirable to have a vacuum produced in the process, some of the standard elements of the suction means 4 will be connected to a vacuum pump. However, if it is desirable to have a positive pressure acting through the unit in question, the standard elements must be connected to a fan. These units are very multifaceted and therefore they can be easily adapted to any desirable operating condition by the process of the present invention. The same versatility of the unit applies to the insertion means 3, where it is desirable to introduce an impregnating liquid, hot compressed air or cold compressed air. The adjustment of the air flow rate and the velocity of the air is easily controlled by replacing the spray nozzles 53 with other nozzles having a greater or a smaller capacity.

When replacing individual nozzles 53, it is necessary to loosen the front guide members 50 and the connecting means 55 so that the connecting members 55 can be moved upwards or downwards into the adjustment slots not shown on the block 51 '.

Ie the opening between the connecting members 55 is made large enough to remove the spray nozzles 53 disposed in the block 51 '. The spray nozzles 53 are provided with screw-threaded threads and a notched or nut-shaped head which provides a means for quickly removing said spray nozzles from the block 51 '.

Regulation of the impregnating material through the impregnating apparatus of the present invention may be effected by measuring pumps of known type. In all cases where compressed air is used as in the injection of impregnating material by means of hot or cold compressed air means, the varying pressures can be quickly controlled by means of said measuring pump.

Wetting rollers or sealing strips may be mounted 5 at each end of the insertion means and the suction means. The shafts of the rollers or strips are fixed at one end in mounting means, while the other end of the shafts is mounted so that they can slide freely. In this way, the sealing or wetting function can be adapted to the movements of the impregnator.

The spray nozzles 53 in Figs. 13-17 are made of ordinary screw-in screws, Fig. 14, each provided with a piercing and a head with a recess. The combined spray nozzle 53 shown in Fig. 15 operates on the spray gun principle. A supply tube 58 is located centrally in the bore 57 of the spray nozzles 53, thereby forming spaces 59.

Through the tube 58, the liquid impregnating material is introduced. The space 59 forms a passage for air from the pressure chamber 47, which is shown by dashed arrows 60.

The streams of compressed air through the gap 59 disperse the liquid impregnating material flowing into the spray nozzles 53 to form a very fine shower of impregnating material.

Using the present invention, it is possible to impregnate any kind of corrugated cardboard material. The impregnation process can be performed before the cardboard has been cleaned. This can be advantageous because all wave-. the channels of the paperboard will remain open and undamaged and therefore do not interfere with the application of the impregnating material 30 through the channels. Immediately after impregnation, the corrugated board is treated with longitudinal cleaning and straightening tools in case the corrugated channels have been partially pushed out of the proper shape. At the beginning of the clean cutting and straightening operation, the corrugated cardboard still has an elevated temperature of approx. 70 to 90 ° C

And contains a certain amount of moisture. These latter properties are very important for the impregnation of the corrugated board material.

The impregnating material used in the impregnation process is selected to exhibit the desired properties ultimately desired in the impregnated corrugated board.

As already stated above, the impregnating material can. le used for the corrugated board occur in many different states, e.g. liquid, steam, powder, foam, 10 gas and dust. Although the impregnating material may be selected as a species of high temperature melting, it can also be a low temperature soluble impregnating material having a volatile consistency. The choice of the various impregnating materials can also be made from an emulsion or a foam-forming plastic material.

The spraying method when applying impregnating material is particularly useful for exclusively the corrugated board interior treatment. The spraying method works at the highest degree of humidity, and is therefore very useful in carrying out the impregnation, so that the corrugated cardboard outermost layer of cladding board becomes free of impregnating material.

Therefore, coating or stamping can be carried out on this outer layer of garment paper. Instead of impregnation by the spraying method, impregnation of the corrugated board can be effected by means of a liquid, which permeates all the corrugated cardboard layers of liquid impregnating material.

A liquid impregnating material can be subjected to a foaming process and then sucked through the corrugated cardboard channels in the form of foam. This way of introducing foamy impregnating materials is different from the use of hardening foamy materials. Here, the impregnating liquid constitutes a fine and regular wetting of the corrugated board as the impregnating material foam is passed through the corrugated board channels. After the impregnated cardboard layers are dried, the channels are free of residual foam.

144265 27

The components of a foam-forming plastic material are completely mixed before being fed into the corrugated cardboard channels. Once the plastic foam has been sucked through the corrugated cardboard channels, any residue adhering to the 5 channel cardboard layer will be completely foamed in the channels. This plastic foam hardens in the ducts and creates an inseparable connection between all the cardboard layers.

The impregnation material may be sucked into the corrugated cardboard ducts in the form of a shower or mist mixed with air or injected directly into the corrugated cardboard without air. In addition, spraying can be converted into a fine vapor mist in a spray condensation chamber where the material is heated if necessary and then sucked through the corrugated cardboard ducts. Hot and cold impregnation materials can also be injected into a vacuum chamber where it is atomized. The atomized impregnation material can then be sucked from the vacuum chamber through the corrugated cardboard channels. The impregnating material can also be converted to gas using a carburetor. Pulling of the gas 20 through the corrugated cardboard channels provides a sealing effect on the material and also ties the cardboard fibers together.

Impregnating materials in the form of powder or dust can be introduced into the corrugated cardboard channels in a very fine atomized state. They are uniformly adhered to the cardboard layers 25 using a special moisture content in the corrugated cardboard, a dielectric polarization or by external mechanical means. The powdered impregnating material can either bond with the cardboard components or be subjected to melting using a special heating 30 by means of the corrugated board's specific heat. It is also possible to mix a water-soluble powdery impregnation material with the moisture of yet fresh corrugated board to impregnate said corrugated board.

Claims (4)

144265 A method of impregnating corrugated board, which is continuously fed from a corrugated cardboard plant and rectilinearly in a horizontal path to an impregnation station, characterized in that the corrugated board is advanced with its channels extending across the corrugated board web with both ends of the open corrugated board. and at its one side edge is subjected to a suction of air from the ducts to create a vacuum in their interior and at the other of the side edges 10 of the cardboard an impregnating material of one or more components is supplied in connection with a carrier of one or more components which of the suction effect of said vacuum, possibly in connection with a pressure function, is introduced into the interior of the channels, whereupon any excess of impregnating material obtained is sucked out of the channels at the suction side. A method according to claim 1, wherein soaking of the corrugated board with impregnating agent is not desired, characterized in that, either before or while the impregnating material is sucked into the ducts, at least 20 cover one of the corrugated board's outer surfaces with a protective layer which prevents air and / or impregnating agents to penetrate this surface. Method according to claim 2, characterized in that water is applied as a protective layer. 1 2 3 4 5 6 Apparatus for carrying out the method according to claim 1 2 and of the type of impregnating corrugated board which is continuously fed from a 3 corrugated cardboard plant and the rectilinear 4 in a horizontal path to the apparatus, the impregnation being carried out by passing during corrugated board through the apparatus, impregnating agent introduces into the corrugated cardboard channels, characterized in that it has two means, arranged one along each side of the corrugated path, namely a impregnating insertion means arranged along one side and one opposite it and along the other.