DE102007006821A1 - Roll cover with friction-reducing filler - Google Patents

Abstract

The roller (1) has a roll cover (4) covering a generated surface of a cylindrical roller base (3), and comprising a top layer (7). The top layer lies outside, and is made from a material mixture (8) with a polymer material. A filler material (9) is sectionally embedded into the polymer material and formed from fluorine containing material e.g. polytetrafluoroethylene, polyvinylidene fluoride and fluorinated ethylene propylene. The filler material has a higher abrasion resistance and a smaller detention and sliding friction coefficient than the material mixing.

Description

The The invention relates to a roller according to the preamble of the claim 1.

roll are used in many places on a web-processing machine. about Such rolls either the material web is guided directly or it is the web guided on a belt, which the material web supports. Further, the surface becomes the wear layer of the roll cover of the roller often by means of a fixed or oscillating scraper cleaned with this is in tribological contact.

About that In addition, scrapers are used, for example, when painting paper. Here is a scraper acting as a doctor either on the entire roll length with the roll cover in contact (z. B. film press) or the metering contacted the roll cover only in the edge zones of the roll cover (eg in the case of a counter-coating roll).

By the conditions of use mentioned are roll covers one exposed to heavy wear, which is either uniformly over the entire surface of the roll cover or only in certain Zones of the surface of the roll cover manifested.

From the US 6,328,681 the use of UHMW-PE particles is known, which are embedded as a particulate filler in the polymeric matrix material of the wear layer. The UHMW-PE particles have an increased abrasion resistance compared to the polymeric matrix material in which they are embedded. This is intended to improve the service life of the rolls.

Especially in applications with high wear or in high Wear subject zones of the roll cover proves the use of such UHMW-PE particles is not sufficient.

It the object of the present invention is a roller with a Roll cover with a wear layer to propose, despite the opposite the state of the art improved life cost is to produce.

The Invention is solved by a roller for a Machine for processing a material web, in particular paper, Carton or tissue machine, with a cylindrical roll core and with a the outer surface of the roller core overlapping Roll cover. The roll shell of the invention Roller further comprises an outer wear layer a material mixture with polymer material, d. H. from a mixture of materials, the Polymer material comprises. In the material mixture is at least in sections embedded a filler, which has a higher abrasion resistance as the material mixture has. According to the invention the filler also has a lower adhesive and Sliding friction coefficient as the material mixture.

hereby is a cost-effectively manufactured roller with a Roll cover created with a wear layer consisting of a material mixture with Polymer material is constructed, in which a filler embedded, which has a higher abrasion resistance and a lower coefficient of static friction and sliding friction than the material mixture has.

By the inventive construction of the roll cover Wears this means less than that from the state The prior art known roll covers, since the wear layer on the one hand has a higher abrasion resistance and secondly because of the lower friction values a lower friction between the wear layer and one with the wear layer in tribological Contact located component arises. Due to the lower friction Furthermore, the heating of the tribologically stressed Roller cover reduced, whereby the material fatigue of the Roller cover is slowed down significantly.

The Use of the filler according to the invention the both a higher abrasion resistance than also a lower coefficient of static friction and sliding friction than the Material mix in which he has embedded has opposite a roll cover in which a first filler with higher abrasion resistance and a second filler with a lower adhesive and Sliding friction coefficient is embedded in the material mixture the advantage that in the roll cover according to the invention the friction reducing filler due to its increased Abrasion resistance is not removed, whereas in the roll cover with two fillers, the first filler due to its higher frictional resistance and the second Filler due to its lower abrasion resistance stronger than the filler of the invention is removed.

Under Abrasion resistance in the sense of the present invention should be understood the abrasion resistance, as this according to DIN standard 53516 is determined.

advantageous Embodiments of the invention are in the subclaims specified.

A particularly advantageous embodiment of the invention provides that the filler is particulate. Particles typically have isotropic properties, which is why particles are needed to provide a special property simply and inexpensively Mixed material can be mixed without having to pay attention to their orientation in the mixture.

A Variety of fluorine-containing polymeric materials combine in itself the properties of a high abrasion resistance paired with low coefficient of adhesion and sliding friction. As a particularly advantageous it turns out, therefore, if the filler of a fluorine-containing polymeric material is formed. Exemplary is the polymeric fluorine-containing Material PTFE, PVDF or FEP.

exemplary PTFE has a sliding friction coefficient against steel when dry of about 0.2 or less, whereas PE or rubber based material mixes against steel in a dry state. Sliding friction coefficients from 0.3-0.6 (for PE) and 0.3-1.0 (for Rubber).

For a variety of applications may still be useful if the material mixture itself one or more fillers includes. The or the fillers can in this case be particulate or fibrous. Also mixtures of particulate and fibrous fillers are conceivable.

Preferably the polymeric fluorochemical filler is in an amount from 1 to 100 phr, preferably 2 to 50 phr (parts per hundred Parts rubber = parts by weight based on 100 parts of rubber) in the Wear layer before. Exemplary are good results with roller covers with a wear layer of a material mixture with polymer material achieved in which PTFE particles in an amount of 1 to 100 phr are embedded.

Preferably the polymeric fluorine-containing filler particles have a Size in the range of 1 micron to 2 mm, preferably in the range of 1 .mu.m to 500 .mu.m, particularly preferred in the range 5 μm to 100 μm. In the specified Size range will be the best results. achieved the life of the rolls according to the invention.

When suitable combination of materials to the above-mentioned filler proves to be when the polymer material of the material mixture Elastomer, a thermoplastic or a duromer or a mixture thereof is. As an elastomer here comes, for example, NBR (acrylonitrile-butadiene rubber), CSM (Chlorinated Sulfonated Polyethylene), NR (Natural Rubber), PU (Polyurethane), HNBR (Hydrogenated Nitrile), SBR (styrene-butadiene rubber), CR (Chloro-butadiene rubber) or a mixture thereof. In particular, PA (polyamide), PES (polyethersulfone) proves to be a thermoplastic or PEEK (polyetheretherketone) or a mixture thereof. As the thermoset one or more epoxy resin (s) is preferably used.

It may depend on the specific area of application of the roller be useful if the filler (in radial Direction of the roll mantle) over the entire Thickness of the wear layer is embedded in the material mixture or if the filler is only in a section of the thickness of Wear layer is embedded in the material mixture. Furthermore, can it in a use of the roller in a uniform Loss over the roll length occurs be useful if the filler over the entire Length of the wear layer is embedded in the material mixture. Is the roller according to the invention in operation only partially exposed to increased wear, so it may be completely sufficient if the filler only in one or more areas of the length of the wear layer embedded in the material mixture. This embodiment provides about it In addition, a particularly inexpensive invention Roller ready.

Of course The filler can be used in areas where this is in the material mixture is embedded, evenly or be distributed unevenly. Under the term is evenly distributed in this context to understand that in the area where the filler embedded, locally everywhere the same filler concentration prevails. Distributed evenly under the term It should be understood in this context that in the area in the filler embedded a locally varying Filler concentration is.

To a very specific embodiment of the invention is provided that the wear layer considered in their length two the Wear layer limiting in their length border areas and has a center region arranged between the edge regions and the filler only in the two marginal sections in the material mixture is embedded. Also in this case it is of course conceivable that the filler either over the entire thickness of the wear layer or over only a thickness portion of the wear layer embedded in the material mixture is.

constructive The dimensioning of these edge regions can be carried out in this way be considered that in the longitudinal extent of the roller the both edge zones when used as intended the roller respectively under the material web, d. H. that the material web each overlaps with each of the two border zones or that exactly complete the two edge zones with the material web, d. H. that in each case no overlap between the margins and given the material web. Furthermore, it is possible that considered in the longitudinal extent of the roller under normal conditions Use of the roller between the web and the edge zones each one Distance remains.

The Forming a roll cover with only in the edge areas in the Material mixture with polymer material embedded filler is then useful, for example, if a scraper only in the two edge zones the roll cover is used or contact only in the edge zones Has.

Further It is conceivable that the roll cover formed only from the wear layer or that the roll cover by the wear layer and a or more intermediate layers formed between the roll core and the wear layer is or are and usually a have greater hardness than the wear layer. The one or more intermediate layer (s) can here by a hard rubber material or a mixture thereof.

For a variety of uses of the invention Roller may also make sense if the two Edge areas a different hardness, especially a larger one Hardness, as the middle area have. Typical hardness values for the wear layer are in the range between 10 and 300 P & J, preferably 10 to 100 P & J. It is particularly advantageous if the edge regions 10 to 60 harder P & J as the center region of the wear layer. A higher one Hardness causes higher breaking strength of the roll cover. Often, however, it is due to limitations in papermaking or further processing difficult with a hard roll cover too work. For example, the painting of paper works only with a soft roll cover. By providing a roll cover with harder edge zones than the middle area is, for example, a Roll cover with increased breaking strength available which is suitable for painting paper.

at intended use of the roller is the Surface of the wear layer with the material web and / or can be brought into contact with a band and / or with a scraper. These Use is, for example, in almost every machine for refining a Fiber web or machine for producing a fibrous web given.

So should, for example, by the invention, a machine for finishing a fibrous web or a machine for producing a fibrous web, with a roll with a roll cover protected with a wear layer when using a squeegee or scraper with the surface the wear layer in a contact area in tribological contact is brought, wherein the wear layer of the roll cover of a Material mixture is formed with polymer material and in the material mixture at least in the area of the squeegee or scraper in tribological Contact is a filler embedded, which is a higher Abrasion resistance and a lower coefficient of adhesion and sliding friction has as the material mixture.

The Invention will be further with reference to the following schematic drawings explained. Show it:

1 a sectional view of a roller according to the invention in cross section,

2 the roller of the invention 1 in perspective view.

The 1 shows a roller according to the invention 1 for a paper, board or tissue machine in cross-section in the region of a peripheral zone 2 (please refer 2 ). The roller 1 has a cylindrical roller core 3 and a lateral surface of the roll core 3 covering roll cover 4 , The roll cover 4 is with an adhesive layer 5 with the roll core 3 connected. The roll cover has an intermediate layer formed of hard rubber 6 and an outer wear layer 7 , which in the intended use of the roller 1 with a scraper in tribologisachem contact can be brought. The wear layer 7 includes a material mixture 8th with an elastomeric polymer material such as NBR, in which in the two edge regions (see 2 ) a particulate fluorine-containing filler 9 embedded, which has a higher abrasion resistance and a lower coefficient of adhesion and sliding friction than the material mixture 8th Has.

Presently, the polymeric fluorine-containing filler 9 made of the material PTFE and lies in the wear layer 7 in an amount of 1 to 100 phr, preferably 2 to 50 phr (parts per hundred parts rubber). The PTFE particles 9 furthermore have a size in the range from 1 μm to 2 mm, preferably in the range from 1 μm to 500 μm, particularly preferably in the range from 5 μm to 100 μm. The filler 9 is here over the entire thickness of the wear layer 7 distributed in the material mixture 8th embedded. Furthermore, the filler is 9 in the border areas 2 , ie in the areas in which present filler 9 in the material mixture 8th is embedded, in the material mixture 8th equally distributed.

• 1) 100 phr Elastomer
• 2) 5–50 phr Ruß
• 3) 5–50 phr Kieselsäure
• 4) 1–100 phr, bevorzugt 2–50 phr PTFE-Partikel
• 5) 1–40 phr Vulkanisationsmittel (z. B. Peroxid, bevorzugt 1–10 phr)
• 6) 0,1–10 phr Zusatzchemikalien, wie z. B. Aktivatoren (z. B. ZnO oder MgO,), Stearinsäure, Beschleuniger, Alterungsschutzmittel oder Prozessadditive allein oder in Kombination;

wobei die Materialmischung 8 durch die bestandteile 1) bis 3), 5) und 6) gebildet ist.Exemplary is the wear layer 7 in the border areas 2 constructed as follows:

• 1) 100 phr elastomer
• 2) 5-50 phr of soot
• 3) 5-50 phr of silica
• 4) 1-100 phr, preferably 2-50 phr of PTFE particles
• 5) 1-40 phr vulcanizing agent (eg peroxide, preferably 1-10 phr)
• 6) 0.1-10 phr of additional chemicals such. Activators (eg ZnO or MgO), stearic acid, accelerators, anti-aging agents or process additives alone or in combination;

the material mixture 8th by the components 1) to 3), 5) and 6) is formed.

The wear layer 7 in the middle area 10 is identical to the use layer in the edge zones except for the PTFE particles 2 built up, the wear layer 7 has in the middle area 10 no PTFE particles.

The 2 shows the roller 1 of the 1 in perspective view. As can be seen, the wear layer has 7 the roller 1 in length, two consider the wear layer 7 bordering in their length border areas 2 and one between the border areas 2 arranged center area 10 where the filler 9 only in the two margins 2 in the material mixture 8th is embedded.

Furthermore, the wear layer has 7 in the two border areas 2 a greater hardness than in the middle area 10 , The wear layer 7 has in the middle area 10 a hardness between 10 and 100 P & J, with the two edge areas 2 have a hardness larger by 10 to 60 P & J.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 6328681 [0005]

Claims (15)

Roller ( 1 ) for a machine for processing a material web, in particular a paper, board or tissue machine, with a cylindrical roll core ( 3 ) and with a the outer surface of the roll core ( 3 ) covering roll cover ( 4 ), which has an outer wear layer ( 7 ) of a material mixture ( 8th ) comprising polymer material into which at least in sections a filler ( 9 ), which has a higher abrasion resistance than the material mixture ( 8th ), characterized in that the filler ( 9 ) also a lower coefficient of static friction and sliding friction than the material mixture ( 8th ) Has. Roller according to claim 1, characterized in that the filler ( 9 ) is particulate. Roller according to claim 1 or 2, characterized in that the filler ( 9 ) is formed of a fluorine-containing polymeric material. Roller according to claim 3, characterized in that the polymeric fluorochemical material is PTFE, PVDF or FEP. Roller according to one of claims 1 to 4, characterized in that the material mixture one or more Includes filler (s). Roll according to one of claims 3 to 5, characterized in that the polymeric fluorine-containing filler ( 9 ) in an amount of 1 to 100 phr, preferably 2 to 50 phr (parts per hundred parts rubber) in the wear layer ( 7 ) is present. Roll according to one of claims 3 to 6, characterized in that the polymeric fluorine-containing filler particles ( 9 ) have a size in the range from 1 μm to 2 mm, preferably in the range from 1 μm to 500 μm, particularly preferably in the range from 5 μm to 100 μm. Roller according to one of claims 1 to 7, characterized in that the polymer material is an elastomer, a thermoplastic or a duromer or a mixture thereof. Roller according to one of claims 1 to 8, characterized in that the filler ( 9 ) over the entire thickness of the wear layer ( 7 ) distributed in the material mixture ( 8th ) is embedded. Roller according to one of claims 1 to 8, characterized in that the filler ( 9 ) only in a portion of the thickness of the wear layer ( 7 ) into the material mixture ( 8th ) is embedded. Roller according to one of claims 1 to 10, characterized in that the filler ( 9 ) over the entire length of the wear layer ( 7 ) into the material mixture ( 8th ) is embedded. Roller according to one of claims 1 to 10, characterized in that the filler ( 9 ) only partially over the length of the wear layer ( 7 ) into the material mixture ( 8th ) is embedded. Roller according to claim 12, characterized in that the wear layer ( 7 ) in its length two considers the wear layer ( 7 ) limiting in their length edge regions ( 2 ) and one between the border areas ( 2 ) center region ( 10 ) and the filler ( 9 ) only in the two marginal sections ( 2 ) into the material mixture ( 8th ) is embedded. Roller according to claim 13, characterized in that the two edge regions ( 2 ) have a different hardness, in particular a greater hardness, than the middle region ( 10 ). Roller according to one of Claims 1 to 14, characterized in that, when the roller is used as intended ( 1 ) the surface of the wear layer ( 7 ) can be brought into contact with a material web and / or with a belt and / or with a scraper.