EP3102403A1

EP3102403A1 - Method and device for external lubrication of press rolls of a roller compaction plant and an application of the method

Info

Publication number: EP3102403A1
Application number: EP15703727.6A
Authority: EP
Inventors: Paul Gerteis
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-02-05
Filing date: 2015-01-23
Publication date: 2016-12-14
Also published as: CN106029355A; JP2017506160A; US20170173911A1; WO2015117252A1; CH709229A1; KR20160117486A; CA2938916A1

Abstract

In a method for external lubrication of the press rolls (2 or 2.1<sb />) of a roller compaction plant (1) by means of a continuous coating of said press rolls (2 or 2.1), a thin layer of lubricant and/or non-stick agents are continuously provided to coat the press rolls (2 or 2.1). This coating preferably contains magnesium stearate or a mixture containing magnesium stearate. To carry out the method, at least one coating device (13, 14, 15 or 13.1, 14.1, 15.1) is arranged in a housing in which the press rolls (2 and 2.1) are arranged, by means of which coating device at least one press roll is provided with a thin coating of lubricant and/or non-stick agents, preferably with magnesium stearate or a mixture containing magnesium stearate. The method is used for manufacturing dry granules in the pharmaceutical and food industries.

Description

Method and device for external lubrication of press rolls of a Walzenkompaktieranlage, and application of the method.

The invention relates to a method and a device for external lubrication of the press rolls of a roll compacting system by a continuous coating of the press rolls with a suitable lubricant and the use of the method.

Roller presses of the type are known from EP-A-0525 135. Roller presses are used for pressing powders into slugs or slug fragments, which are then comminuted into granules. This process is also called dry granulation. The dry granulate further serves to produce e.g. Tablets, capsules, sachets, batteries and instant dishes.

From EP 1 764 661 A an apparatus for applying a solid lubricant to a rotating surface in a toner cartridge is known. The lubricant consists of a solid rod made by melt extrusion. The rod contains zinc stearate and lubricating oils. Among a variety of possible stearates agnesstearate is also called. In order to uniformly distribute the lubricant on the rotating surface, first a little lubricant is scraped off a solid rod and then firmly pressed and smeared into a thin film with the aid of a scraper, which must be pressed onto the roller surface with a well-defined force. Essential for the application described is the fact that an extremely thin film adhering well to the surface of lubricant is applied as uniformly as possible and completely on the rotating roller. There must be no lubricant aggregates in this film. The amount of lubricant applied is 0.11 to 1.2 mg / m ² roll surface. An amount greater than 1.2 mg / m ² roll surface is absolutely unsuitable. Apart from the fact that toner cartridges are not the subject of the invention, the non-stick properties of particular agnesiumstearat be adversely affected by an extrusion process.

Another disadvantage is the requirement of an additional scraper, with which the lubricant is pressed onto the roller surface. Another disadvantage is _"that all particles are applied to the process to the role with a

Cleaning device must be completely removed from the roll surface before the next layer of lubricant is applied. As a result, only completely smooth rolls can be used for the process described in EP 1 764 661 A.

From DE 197 31 975 A1 a method for preventing the adhesion of material to be briquet on a roll surface of a briquetting press is known. The final product is a briquette. An emulsion is sprayed onto the surface of press rolls. The emulsion consists of a mixture of graphite, water and gas.

The spraying of an emulsion is in the production of dry granules in the pharmaceutical and food industry at the usually low temperature range (20 to 50 ° C) is not possible because this would require drying of the compacted product, which would largely destroy the benefits of dry granulation.

In the manufacture of tablets by means of suitable presses, a lubricant must generally be added to the powder to be compressed in order to reduce the forces required to eject the tablet (from the die after the powder / granule compaction process). This lubricant added to the powder / granulate is also called internal lubricant. The addition of such a lubricant prevents mechanical damage to the tablet press. By reducing the ejection forces is often also prevents the currently pressed, still in the die tablet is damaged during the ejection process, which is noticeable for example by capping or laminating (capping or laminating) of the tablet. Also, such a lubricant is added to the formulation to prevent or reduce attachment to the tabletting tool (top and / or bottom punch and / or die). The most commonly used lubricant, especially in the pharmaceutical field, is magnesium stearate.

However, this substance also has several undesirable properties. The addition of magnesium stearate usually leads to a reduction in tablet strength. The hydrophobic properties of this lubricant (magnesium stearate) can also lead to problems with the release of the active substance, which can lead to a deterioration of the biopharmaceutical availability. Both the problems of release and of the compressibility of the powder, e.g. The reduction in tablet strength can also be significantly enhanced by more or less intensive mixing. As a result, the magnesium stearate is distributed in such a way that it is no longer possible to produce sufficiently strong tablets or the release is reduced in such a way that the intended effect in the body is no longer achieved or is not achieved to a sufficient extent.

Also in the processing of powder mixtures using Walzenkompaktieranlagen very often lubricants are used. Such lubricants are used, inter alia. to reduce the friction during the powder transport through the screws. Propagation in this transport area can be prevented as far as possible or at least reduced so much that sufficient powder is transported in order to carry out the process under the selected manufacturing conditions can.

Further, a lubricant is added to the mixture to be roll-compacted to prevent the formation of powder / slug remnants on the press rolls. However, this can lead to analogous problems, as in the tableting: on the one hand, a reduction in the slug strength, resulting in the same process conditions granules with more fines. This in turn leads to poorer flow properties of the granules, which can result in larger weight fluctuations when tableting. There is also the danger that the grinding of the slugs in the presence of magnesium stearate leads to problems in the release, because the hydrophobic magnesium stearate is better distributed on the surface of the granular particles, which can lead to a poorer wettability. This better distribution over the surface of the granule particles can also lead to a reduction in tablet strength during subsequent compression into tablets.

When the magnesium stearate concentration in the composition to be roll compacted is e.g. Reduced to less than 0.3% (m / m), or even omitted entirely from the addition of magnesium stearate, problems such as reducing the compressibility and reducing the release of magnesium stearate can be remedied or reduced to an acceptable level. As a result, however, the addition of scraps remains usually increases to the surface of the roll presses. Even though these residues may be mechanically removed from the press rolls by so-called scraper wipers, which by the way do not touch the roll surface, before this press roll section is used again to press slugs, it is generally not possible to prevent the press roll surfaces with caking , which can be different thickness, are provided. Such caking leads to greater gap fluctuations, so that slugs arise with (significantly) higher fluctuations in the apparent density than would be the case without such caking. Since fluctuations in the pupal density lead to fluctuations in the slug strength, this can lead to problems in the flowability of the granules and the compressibility into tablets, which manifests itself in weight fluctuations of the tablets or in the tablet strength.

Another problem associated with caking is the determination of the apparent density of the slug during the manufacture of these slugs.

This density, which is determined while the slug is still between the press rolls (= the so-called "at gap" density (gap = gap = smallest effective distance between the press rolls)), is calculated from the amount of slugs produced per unit time (= Amount of granules under steady state conditions) and the volume produced between the press rolls. To calculate this volume, the average gap over the chosen period must be determined, which can only be achieved with sufficient accuracy (of 1, 5% or better, but in any case better than 3%) if there are no or few caking on the press roll surfaces available. This "at gap" density is a direct measure of the apparent density of the slugs, which in turn essentially determines the properties of the slug and the resulting granules, so that monitoring or even control of this "at gap" density for the quality of the slug Granules is extremely relevant. Too low a density leads to too low strength and therefore to an increased fines content in the granules, which has flowability problems in tableting. Too high a density tends to cause problems in achieving the required tablet strength (Tensile Strength) in tabletting Since the relationship between at gap density and slug strength may vary from batch to batch, direct determination of slug strength is preferable but even then a reliable determination of the "at gap" density is and remains important, since the production of slugs with a high apparent density can result in granules with tablet hardness compressibility problems.

A reliable determination of the "at-gap" density is therefore of great economic interest since it avoids defective productions which are associated with considerable costs, for which purpose the described caking on the press-roller surfaces must be avoided or reduced to such a low level. that the required accuracy for determining the "at gap" density is ensured.

As previously described in the literature (Dawes et al) such caking can be avoided by spraying a solvent-containing suspension of magnesium stearate onto the press roll surface. An organic solvent is used for this purpose, so that this has largely evaporated before the spray jet occurs on the press roll surface.

In that case, however, there is a contamination both in installations where crushing of the slugs in a separate process housing adjacent to the slug production housing, and in particular in plants where chopping takes place in the housing in which the slugs are also produced of the granules with solvent unavoidable. This is because the solvent vapors are absorbed by the surfaces of the granule particles, so that a Contamination of the tablets, which are made from this granulate, not, or will be difficult to avoid. The removal of these solvent residues from the granules and / or the tablets is likely to be rather difficult and cost intensive, so that spraying a solvent-containing magnesium stearate suspension is not an economically viable solution for preventing caking on press roll surfaces and / or reducing the internal magnesium stearate concentration is.

The disposal of such solvent-containing vapors leads to an increase in manufacturing costs, and further arise in the quality control additional analytical costs.

Since such spray systems are often operated with spray air, the associated amounts of air must also be able to escape from the process housing, which causes additional costs, because these particle-containing air quantities must be passed over Fiher, since the escape of fine powder particles from the process housing is at least undesirable and many cases even with a risk to the operating personnel is connected.

The object of the invention is on the one hand to prevent caking and the problems associated with it completely or almost completely, and on the other hand to reduce the internal amount of lubricants and / or non-stick agents, especially magnesium stearate, so much that neither problems caused by lubricants and / or non-stick agents, in particular magnesium stearate, during pressing into tablets, nor is the release of the active ingredient in the dissolution of the tablets adversely affected. This task should now be realized because of the associated with solvent use economic and process engineering disadvantages without the use of solvents.

This object is achieved according to the invention by coating the press rolls solvent-free and continuously with a thin layer of lubricant and / or non-sticking agent.

The coating without solvent has the advantage that the product does not have to be aftertreated. The solvent would have to be removed with great effort from the product, if that's even possible. Another advantage This solvent-free coating is that caking on the press roll surfaces avoided or largely avoided. This can produce Schölpen with smaller variations in the apparent density. This results in a better granule quality.

The coating with a lubricious and / or non-sticking agent, in particular magnesium stearate, has the advantage that magnesium stearate is used most frequently as a lubricant and / or antiblocking agent in the pharmaceutical sector and is approved by the authorities.

Furthermore, the coating with a magnesium stearate-containing powder mixture has proven itself. A mixture of magnesium stearate with an adjuvant or Hiffsstoffgemisch, consisting of substances that are already included in the formulation has also proved to be suitable.

Also, the coating with one or more compacts containing a suitable lubricating and / or non-sticking agent, preferably magnesium stearate, has proved to be suitable. These compacts are e.g. produced by compressing magnesium stearate-containing powders by means of (tablet) presses. Thus, e.g. by admixing well tablettable substances, for example microcrystalline celluloses, which are very often present in the formulation, sufficiently solid magnesium stearate-containing compacts are produced, which then lead to a direct contact pressure of the press roll surface with a small contact force on the press roll surface.

The advantage of such compacts is that they can be easily refilled in a containment area. In addition, compacts take up less volume than a powder with the same magnesium stearate concentration.

A further advantage of these coatings is that the concentration of lubricating and / or non-sticking agent, in particular magnesium stearate, in the product produced by the roll compacting system is reduced by less than 0.01% to 0.2% (m / m). , usually by less than 0.04 to 0, 1% (m / m) increases. Nevertheless, caking on the press roll surfaces were completely prevented or reduced to a non-relevant level. In order to prevent caking by the addition of internal lubricating and / or non-sticking agent, in particular magnesium stearate, significantly higher concentrations are generally required, namely from 0.5% to 1.5%. The external lubrication caused by contrast in the product just an increase in lubricating and / or anti-blocking agent _"especially the magnesium concentration of usually 0.04% to 0.1%.

A reduction of the lubricating and / or anti-adhesive, in particular the magnesium stearate concentration in turn has an extremely beneficial effect on the solution of lubricating and / or non-sticking agents, in particular magnesium stearate-induced problems in the tableting of the granules to sufficiently solid tablets. The reduction in the solution of lubricating and / or non-sticking agents, in particular magnesium stearate-induced problems in the release of the active ingredient from tablets or capsules, is likewise advantageous.

Another advantage of the invention is that caking on the press roll surfaces is prevented so that the volume of the slugs produced per unit of time between the pressurized press rolls is better than 3%, preferably better than 2% and more particularly better than 1, 5% can be determined. This is the basis for a correspondingly precise determination of the apparent density of the slugs (= "at gap" density) between the pressurized press rolls, since these consist of the mass of slugs or granules produced per unit time and the unit time between the slices This accuracy is only possible if the press rolls are free from caking or the caking is reduced to a non-relevant extent.

The external lubrication may possibly even completely dispense with the addition of lubricating and / or non-sticking agent, in particular magnesium stearate, to the powder to be compacted so that any problems with respect to the re-compressibility of the original powder mixture (= compressibility of the granules obtained) are sufficient fixed tablets and / or the release of the active ingredient from tablets or capsules. A further advantage is that, in particular when applying a powder layer according to the invention, the aggregates containing antiadhesive agent are not pressed onto the press roll surface and distributed as uniformly as possible on the press roll surface. This avoids that the lowest possible coefficient of friction between the product to be compacted roll and the press roll surface is formed, so that the collection of powder between the press roll rollers is not unnecessarily difficult. Such a feeder is essential for the roll compacting process.

The invention will be described in more detail with reference to drawings. Show it.

Figure 1 shows the method in which the invention is applied

2 shows the device according to the invention

Figure 3 shows a variant of the inventive device

In FIG. 1, the reference numeral 1 shows a process housing. Within the process housing 1, the press rolls 2 and 2.1 are arranged. The associated measuring device 2.2 is used to measure the rotational speed of the press rollers 2 and 2.1. In the lower part of the process housing 1, a granulating roller 3 is arranged with a screen basket 3.1. The roll pressing force is measured by means of a measuring device 4 and the nip (= smallest effective distance between the press rolls) with a measuring device 5. Below the process housing 1 is a collecting container 6 for the dry granules, which is on a weighing device 7. This weighing device 7 is connected via a collecting line 9 to a computer 8. More than one signal line may be needed, depending on how many load cells are needed.

In Fig. 2 and Fig. 3, like parts of Fig. 1 are given the same reference numerals. In Fig. 2 are located within the process housing 1, the two press rollers 2 and 2.1. The product is supplied by means of a screw conveyor 12 and forms after the pressing operation between the counter-rotating, pressurized press rollers 2 and 2.1 a scarf or Schülpenbruchstücke 10th

Depending on a lubricant supply is arranged on a storage container 15 and 15.1 in the lateral region of the press rolls 2 and 2. Under each container 15 and 15.1 are depending on a transfer roller 13 and 13.1 and a conveyor roller 14 and 14.1 arranged. The lubricating and / or anti-adhesive agent feed 15 and 15.1 are placed on the process housing 1 of the roll compacting system in such a way that the transfer rolls 13 and 13.1 touch the press rolls in the region 16 and 16.1 respectively after the scraper scraps 11 and 11.1 and before the product feed 12. In fact, in this area it is to be expected that there will no longer be any scabs or rag particles on the press roll surfaces during roll compaction. It should be emphasized that these scraper wipers do not touch the press roll surface, so that abrasion between the surface of the press rolls and the scraper wiper is basically avoided.

The application of a thin lubricant and / or non-stick layer with a delivery and transfer roll can also be accomplished with a device consisting of more than two rolls, e.g. two conveyor rollers and a transfer roller done. Also, each press roll may be provided with a plurality of such application devices to apply a thin layer of powder to the press roll surface. The diameter of the conveying and transfer rollers can be the same but also different. It is irrelevant whether the diameter of the conveying roller is larger or smaller than that of the transfer roller.

In operation, the storage container 15 or 15.1 (FIG. 2) contains a suitable lubricant and / or antiblocking agent, preferably magnesium stearate or a magnesium stearate-containing powder mixture, which is transferred to the transfer roller 13 or 13.1 by the conveyor roller 14 or 14.1. The transfer roller 13 or 13.1 then applies the lubricating and / or anti-adhesive agent to the surface of the press roller 2 or 2.1.

The object according to the invention can likewise be achieved with the aid of compacts which contain suitable lubricants and / or antiblocking agents, preferably magnesium stearate. These compacts are prepared, for example, by compressing magnesium stearate-containing powders by means of suitable (tablet) presses. During production, it must be ensured that the lubricating and / or non-sticking effect of the substances used is retained to a sufficient extent. For this reason extrusion or fusion processes are used Production of such magnesium stearate containing moldings, because thereby the lubricating and / or non-stick properties of the magnesium stearate are significantly reduced.

The lubricants and / or antiadhesive containing compacts are shown schematically by the reference numeral 19 or 19.1 (Figure 3). These sufficiently solid compacts are pressed with an adjustable, preferably constant force, shown schematically by the spring assembly 18 and 18.1 in Fig. 3, directly on the surface of the press rollers 2 and 2.1. The device with which these compacts are pressed onto the press roll surfaces, and the compacts themselves are located in a housing 17 and 17.1. The housing with the compacts is also basically mounted in the area of the press rolls, in which it is expected that no more slugs or rump parts or only small for the process irrelevant amounts of slugs or rag parts on the surface of the respective press rolls (= roll surfaces ) are located. Accordingly, the respective compact pressing device with the compacts located therein is mounted in the region between the respective scraper stripper (11 or 11.1) and the product feed device (12), which is shown schematically in Fig. 3 with the hatched areas 16 and 16.1.

Both with the devices shown schematically in FIG. 2 and with those shown schematically in FIG. 3, thin layers of lubricant and / or non-stick agent, preferably magnesium stearate, are reproducibly applied to the press roll surface. For this purpose, it is sufficient for each press roll to use only one of these devices, but of course it can also combinations of these coating devices are used.

The exact amount of lubricating and / or anti-sticking agent, preferably magnesium stearate or a magnesium stearate-containing mixture applied with these coating devices and ultimately received by the roll compacting powder from the press roll surface will depend on the process conditions chosen, such as Texture of the surface of the conveying and transfer rollers (Nos. 13 and 13.1 in Fig. 2), the contact pressure and the mechanical strength of the compacts (Nos. 19 and 19.1 in FIG. 3), the nature of the surface of the press rolls (Nos. 2 and 2.1 in Fig. 3, respectively) (eg, smooth, roughened, rimmed, corded or trough-shaped press roll surfaces) and the properties of the powder to be compacted. This results in variations in the amount of lubricating and / or anti-sticking agent, especially magnesium stearate, ultimately absorbed by the powder from the press roll surface, from 0.015 mg to 0.2 mg, especially between 0.03 mg and 0.05 mg magnesium stearate each Square centimeter press roll surface. This then leads, depending on which roller press force and gap is compacted, to an increase in the magnesium stearate concentration in the slug or in the granules, which is between 0.01% and 0.2% (m / m), in particular between 0 , 04% and 0.1% (m / m). The amount of magnesium stearate introduced into the product by this solvent-free coating is thus significantly lower than the amount necessary for internal lubrication to completely or almost completely prevent caking on the press roll surfaces. In order to avoid caking on the press rollers with the aid of internal lubrication, internal concentrations of between 0.5% and 1.5% (m / m) are generally required, depending on the product properties and condition of the press roll surface.

With such magnesium stearate application devices, several substances without pad formation on the press rolls could be perfectly roll compacted and crushed. As a rule, no significant restrictions of the possible process parameters, such as roll pressing force, nip and / or press roll speed, also known as production parameters, required for dry granulation with the aid of roll compaction had to be accepted.

Thus, for example, when smooth pressing surfaces were used, the caking substance citric acid could be processed without the addition of the (internal) lubricant magnesium stearate over the same preparation parameter range as magnesium stearate coated press rolls. By coating with magnesium stearate, however, caking was completely avoided or reduced to an insignificant extent. This manufacturing area amounts to a gap of 24 mm per meter of press roll diameter over the complete roller press force range of 80 kN per cm press roller width and per meter

Pressing roller diameter.

By addition of 1% agnesiumstearat to this powder (so-called internal magnesium stearate), although the caking could also be largely prevented, but the production range was significantly limited. Thus, when using press rolls with a smooth surface, regardless of the selected gap, only pressing forces of a maximum of 48 kN per cm of press roll width and per meter of press roll diameter could be realized. And with a gap of 18 mm per meter of press roll diameter, only a force of no more than 20 kN per cm of press roll width and per meter of press roll diameter could be applied.

The same smooth press roll surface was also used in the compaction of citric acid without internal magnesium stearate but with magnesium stearate coated press rolls. In the external magnesium stearate coating, however, the slugs contained significantly less than 1% magnesium stearate, namely between 0.01% and at most 0.1% (m / m) magnesium stearate, depending on the press rolls of the powder coating apparatus used or the pressing force of the compacts (the in the latter case were prepared from a magnesium stearate-containing powder mixture) and their mechanical strength.

Also in the compaction of mannitol, there were no significant restrictions on roll compacting parameters relevant to dry granulation by means of roll compaction as compared to non-lubricated powder using smooth press roll surfaces and coating magnesium stearate press rolls.

In the case of mannitol, the external coating of the press roll surfaces also reduced the concentration of magnesium stearate in the roll-compacted product by at least a factor of 10 to 0.1% (m / m). As a rule, concentrations of 0.02% to 0.05% (m / m) have been realized, which is up to a factor of 50 less than with internal lubrication.

Although there are generally no significant tolerances of roll compaction parameters relevant to dry granulation by roll compaction due to coating of the press roll surface with magnesium stearate compared to non-lubricated powder, this is not true for each roller-compacting powders. Restrictions in the compaction between the roll presses can be caused, for example, by the fact that a thin layer of magnesium stearate leads to so-called feed problems. Especially when Einsäte smooth press roll surfaces this phenomenon is so pronounced in certain materials, such as corn starch that the roll compaction is possible only at low forces and / or gap widths.

Using smooth press roll surfaces, even with an internal amount of magnesium stearate of 0.1% (m / m), the production parameter range in roll compaction of corn starch was severely restricted. For example, an internal magnesium stearate amount of only 0.1% using smooth press rolls resulted in a maximum force of 28kN / cm press roll width and per meter press roll diameter for a gap of 4 mm per meter of press roll diameter. From a gap of 8 mm per meter of press roll diameter, only a force of 12 kN per cm of press roll width and per meter of press roll diameter could be exerted. From 12 mm gap per meter press roll diameter no significant force could be exercised.

However, when the surface of a smooth roll was roughened so that the press rolls thereafter had a surface roughness of 0.5 μm to 1.5 μm, especially 0.8 μm to 1.2 μm, an internal magnesium stearate concentration of 0 resulted While 1% in the product corn starch still reduces the potential roll compaction parameters compared to the non-lubricated product, this reduction was and is generally of little practical importance for dry granulation using roll compaction. Even with the addition of 1% of internal magnesium stearate, the manufacturing parameter range was still sufficiently high using the above-mentioned roughened smooth press roll surfaces (although slightly less than an internal magnesium stearate concentration of 0.1% (m / m)) but external lubrication Not only did the nip roll surface area result in a slightly larger fabrication parameter range than an internal 1% magnesium stearate, but also to a much lower concentration of magnesium stearate in the roll compacted product. It was lower by a factor of 10 to 50, namely 0.1% to 0.02% depending on the nature of the transfer rollers using the roller-based feeder (see Fig. 2). And the press roll surfaces remained free from caking.

These results clearly show that the use of roughened press roll surfaces, characterized in that the press roll surfaces have a surface roughness of from 0.5 μm to 1.5 μm, preferably from 0.8 μm to 1.2 μm, in combination with a device for Application of a thin layer of lubricants and / or non-stick agents, in particular magnesium stearate, are outstandingly suitable for compacting powders with the aid of a roll compacting system, not only ensuring a sufficiently large production parameter range, but also the concentration of magnesium stearate in the granules by only 0.01 % to 0.2% (m / m), in particular only 0.04% to 0,% 8 (m / m). In this case, the press roll surfaces remain free of caking or the extent of caking is so low that this has no or an insignificant effect on the granule quality. Furthermore, this also ensures that the "at gap" density can be determined with an accuracy of 1.5% or better, but in any case better than 3%.

In some cases (e.g., for the product Neosorb), it has been surprisingly found that external lubrication, even a slight expansion (of little practical importance for dry granulation), resulted in the potential roll compaction parameters. In this example, roughened smooth press rolls were used. By external application of a thin layer of magnesium stearate to the press rolls with the apparatus shown schematically in Fig. 3 with the magnesium stearate containing compacts pressed onto the surface, the production range at a gap of 16 mm per meter press roll diameter of 72 kN to 80 kN each cm of press roll width and per meter of press roll diameter. Also in this case, only small concentrations of magnesium stearate were measured in the roll-compacted product, namely 0.04% to a maximum of 0.12% (m / m).

Claims

claims

1. A method for external lubrication of the press rolls (2, 2.1) of a Walzenkompaktieranlage by a continuous coating of the rotating press rolls (2 and 2.1), characterized in that for coating the press rolls (2 and 2.1) solvent-free and continuously with a thin layer of lubricant - Be provided and / or non-stick agent.

2. The method according to claim 1, characterized in that this coating is carried out with a powder of magnesium stearate

3. The method according to claim 1, characterized in that the coating is carried out with a powder of a mixture containing magnesium stearate.

4. The method according to claim 1, characterized in that the coating is carried out with one or more compacts, which consists of a mixture containing magnesium stearate or exist.

A process according to claims 1 to 4, characterized in that the amount of magnesium stearate taken up by the product to be roll compacted from the press roll surface is from 0.015 mg to 0.2 mg, preferably from 0.03 mg to 0.05 mg per square centimeter of press roll surface.

6. The method according to claims 1 to 5, characterized in that the concentration of lubricating and / or non-sticking agent, in particular magnesium stearate in the product produced by the Walzenkompaktieranlage by less than 0.01% to 0.2% (m / m) , preferably by less than 0.04% to 0, 1% (m / m) increases.

7. Process according to claims 1 to 6, characterized in that the apparent density of the between acted upon with force Press rolls located slugs can be determined with an accuracy of better than 3%, preferably better than 2% and in particular better than 1.5%,

8. Method according to claims 1 to 7, characterized in _"that particular press roll surfaces which have a surface roughness of 0.5 pm to 1.5 pm, preferably 0.8 pm to 1.2 pm, have, to the compacting of powders with a Walzenkompaktieranlage suitable.

9. The method according to claims 1 to 7, characterized in that in particular when using press roll surfaces having a surface roughness of 0.5 pm to 1, 5 pm, preferably 0.8 pm to 1.2 pm, the press rolls free from caking or the caking is reduced to such a low level that the accuracy with which the "at gap" density of the slugs can be determined is better than 3%, in particular better than 2% or very particularly better than 1, 5% ,

10. The method according to claims 1 to 7, characterized in that in particular when using press roll surfaces with a surface roughness of 0.5 pm to 1, 5 pm, preferably 0.8 pm to 1.2 pm, the concentration of magnesium stearate in the granules to less than 0.01% to 0.2% (m / m), in particular less than 0.04% to 0.1% (m / m) increases.

11. A device for carrying out the method according to claims 1 to 10, characterized in that in the housing in which the press rollers (2 and 2.1) are arranged at least one roll rollers based on coating means (13, 14, 15 or 13.1, 14.1, 15.1 ) or on compacts based coating device (17, 18 and 19 or 17.1, 18.1 and 19.1) is provided with the at least one press roller (2 or 2.1) with a thin layer of lubricating and / or non-sticking agent, preferably with magnesium stearate or with a Magnesium stearate-containing mixture is provided.

12. A device for carrying out the method according to claims 1 to 10, characterized in that in the housing in which the press rollers (2 and 2.1) are arranged at least one roll rollers based on coating means (13, 14, 15 or 13.1, 14.1, 15.1 ) or on compacts based coating device (17, 18 and 19 or 17.1, 18.1 and 19.1) is provided with the press roller Qn (2 and / or 2.1) with a thin layer of lubricating and / or non-stick, preferably with magnesium stearate or with a mixture containing agnesstearate is or will be provided.

13. A device for carrying out the method according to claims 1 to 10, characterized in that the transfer roller (13 or 13.1) between the scraper wiper (11 or 11.1) and the product feed (12) is arranged.

14. A device for carrying out the method according to claims 1 to 10, characterized in that the compacts (19 or 19.1) between the scraper wiper (11 or 11.1) and the product feed (12) are pressed onto the press roller surface (s).

15 Application of the method according to claims 1 to 11 for the production of dry granules in the pharmaceutical and food industries.