DE102008040307A1 - Belt for a machine for producing web materials such as paper or cardboard, comprises a support structure with fibers on a web material contact side of the support structure with fiber materials to be connected - Google Patents

Abstract

The belt (10) comprises a support structure (12) with fibers (14, 16) passing in the belt longitudinal and transverse directions on a web material contact side (18) of the support structure with fiber material (22, 24) to be connected, in which the fiber material comprises elastomeric polymer material (26) that forms a fluid permeable composite structure together with the fiber of fiber materials. The elastomeric polymer material is equipped with a mass of 80-240 g/m 2>. The fiber material is formed with a mass of 600 g/m 2>and is bound with the support structure by needling. The belt (10) comprises a support structure (12) with fibers (14, 16) passing in the belt longitudinal and transverse directions on a web material contact side (18) of the support structure with fiber material (22, 24) to be connected, in which the fiber material comprises elastomeric polymer material (26) that forms a fluid permeable composite structure together with the fiber of fiber materials. The elastomeric polymer material is equipped with a mass of 80-240 g/m 2>. The fiber material is formed with a mass of 600 g/m 2>and is bound with the support structure by needling. The fiber material is formed as felt or fleece products. The fibers are made from a material having tear resistance of 100 cN/tex. The support structure is made from a fiber of polyethylene material having ultrahigh molecular weight, aramide material, liquid crystalline material and/or high performance polyamide material. The support structure comprises nylon fibers. The carrier structure is formed as non-woven fabrics or woven fabrics. The elastomeric polymer material is provided in particle form in the fiber material and forms the liquid permeable composite structure with the fibers of the fiber materials by pressure and/or temperature exertion. The belt exhibits a fluid permeability of 1-200 cfm and a thickness of less than 2.5 mm. Independent claims are included for: (1) a method for producing a belt for a machine for production of web material such as paper or cardboard; and (2) a machine for producing web material such as paper or cardboard.

Description

The The present invention relates to a belt for a machine for the production of web material, in particular paper or cardboard, and a method for producing such a tape and a machine for producing sheet material with such Tape.

In Dry or press sections of paper machines are called so-called. Press felts used bands, which to be produced Contact web material and together with this by Pressnip be moved through. Due to the pressure load generated in the press nips Liquid is pressed out of the web material to be produced. This liquid should in the press felt, so that too finished sheet material contacting tape and over this will be dissipated. So it is in such a Tape not only the requirement to apply liquid to a web material contact surface to be able to record and deliver it to the back, but the tape must also be in a press nip or possibly several successive press nips occurring physical loads over take up as long as possible an operating life can. At the same time the tape should be over as possible its entire width, ie in the macroscopic area, as well as in the microscopic area as even as possible Surface or drainage characteristics exhibit.

From the WO 2004/085727 A2 For example, a press felt for a papermaking machine is known which comprises a layer of fibrous material which is, for example, needled onto a support structure formed as a fabric. In this layer of fibrous material elastomeric polymer material is introduced in particle form by applying a dispersion. Upon heating, the polymeric material melts and combines with the fibers of the fibrous material to form a composite structure. In this composite structure, the individual fibers of the fiber material are bonded together by the molten and resolidified polymeric material. At the same time, however, the polymer material does not completely fill the voids formed in the fibrous material, so that the composite structure formed of elastomeric polymer material and fibers of the fibrous material is generally porous, that is permeable to the fluid to be withdrawn from the web to be manufactured, generally water.

It is the object of the present invention, such a band for a machine for producing web material, in particular Paper or board, and a method for producing such Bandes provide which is very durable at low thickness and a very uniform Fluidabführcharakteristik about has the entire band surface away.

According to a first aspect of the present invention, this object is achieved by a belt for a machine for producing sheet material, in particular paper or cardboard, comprising a support structure with threads running substantially in a band longitudinal direction and a belt transverse direction on a web material contact side of the support structure with the fiber material connected thereto in which fibrous material is elastomeric polymeric material which together with the fibers of the fibrous material forms a fluid-permeable composite structure, the polymeric material having a mass in the range of 50-500 g / m ² , preferably 80-240 g / m ² .

By the use of polymer material in the range of amounts indicated above ensured that with sufficient fluid absorption capacity in the porous and thus fluid-permeable composite structure the Total thickness of the band can be kept comparatively thin, but at the same time the loads occurring in Pressnips when pressing the tape between two press rolls or the like can be included.

In order to make the band as thin or compact as possible, it is further proposed that the fiber material is formed with a mass of at most 600 g / m ² . The fiber material may be connected to the support structure by needling and may be formed, for example felt or fleece-like.

• – Polyurethanmaterial, oder/und
• – Polyharnstoffmaterial
• – Styrolbutadien-Blockcopolymermaterial, oder/und
• – Polypropylenmaterial, oder/und
• – aliphatisches Polyamidmaterial.

In order to be able to provide the fluid-permeable composite structure with the required elasticity in connection with the fibers of the fiber material, it is further proposed that the elastomeric polymer material comprises:

• - Polyurethane material, or / and
• - Polyurea material
• Styrene-butadiene block copolymer material, or / and
• - polypropylene material, or / and
• - aliphatic polyamide material.

Also It should be noted here that the polymer material consists of a single material, but of course may also include mixtures thereof.

The threads of the support structure may preferably be constructed of a material having a tensile strength of at least 80 cN / tex, preferably at least 100 cN / tex. As in the band according to the invention for the support structure threads of ultra-high-strength material having a modulus of elasticity on given area can be provided, so threads that have grown the tensile and compressive loads improved, can be achieved in a very thin design of such a support structure a very high strength both in the tape longitudinal direction and in the tape transverse direction. At the same time, in this way, without making the entire band thicker, the volume for the fiber material can be increased, which improves the Fluidabführvermögen. Through the use of ultra-high-strength threads, which are therefore also made thinner, at the same time a more level support structure is per se obtainable, which has an advantageous effect on the surface quality of the entire band.

• – Polyethylenmaterial mit ultrahohem Molekulargewicht, oder/und
• – Aramidmaterial, oder/und
• – Flüssigkristallmaterial, oder/und
• – Hochleistungspolyamidmaterial.

A particularly advantageous embodiment may provide that the support structure is constructed with threads of:

• - Ultra high molecular weight polyethylene material, or / and
• Aramid material, or / and
• - Liquid crystal material, or / and
• - High performance polyamide material.

It is self-evident that in one and the same support structure Threads of different materials can be provided wherein, for example, the substantially in the tape longitudinal direction itself extending filaments and in the band transverse direction itself extending threads each constructed of the same material could be.

Further The support structure can contain nylon threads and can be used as Tissue or scrim be formed.

To the Structure of the tape according to the invention can be provided be that the elastomeric polymer material in particle form in the Fiber material is introduced and with the fibers of the fiber material the fluid-permeable composite structure by pressure and / or temperature exerting generated.

The Band may preferably have a fluid permeability in the range from 1-200 cfm (cubic feet per square meter and minute) as well as a thickness of less than 3.5 mm, preferably less than 2.5 mm.

• a) Bereitstellen einer Tragestruktur mit im Wesentlichen in einer Bandlängsrichtung und einer Bandquerrichtung verlaufenden Fäden,
• b) Verbinden von Fasermaterial mit der Tragestruktur an einer Bahnmaterialkontaktseite,
• c) Einbringen von elastomerem Polymermaterial in das Fasermaterial zum Bilden einer fluidpermeablen Verbundstruktur zusammen mit den Fasern des Fasermaterials, wobei das elastomere Polymermaterial mit einer Masse im Bereich von 50–500 g/m², vorzugsweise 80–240 g/m², vorgesehen wird.

According to a further aspect, the object mentioned at the outset is achieved by a method for producing a strip for a machine for producing web material, in particular paper or board, comprising the measures:

• a) provision of a carrying structure with threads extending substantially in a band longitudinal direction and a transverse band direction,
• b) bonding fiber material to the support structure at a web material contact side,
• c) introducing an elastomeric polymeric material in the fiber material for forming a fluid permeable composite structure together with the fibers of the fibrous material, wherein the elastomeric polymer material having a weight ranging from 50-500 g / m ^2, preferably 80-240 g / m ^2, is provided ,

there Preferably, the procedure is that the elastomeric polymer material is introduced as a dispersion in the fiber material and after removal of water, the material is melted or heated to a compound of the polymer material with fibers of the surface to achieve.

The The present invention further relates to a machine for manufacturing of sheet material, in particular paper or cardboard, comprising a Press section with a maximum of two press nips and one in endless configuration can be passed through the press section according to the invention Tape.

at A particularly preferred embodiment variant can be provided be that two bands of substantially the same construction are provided on both sides of the web material to be produced.

The The present invention will be described below with reference to the attached figures explained. It shows:

1 a principle sectional view of a belt for a machine for producing web material, such. Paper, in an intermediate phase of the production of this tape;

2 a plan view of a web material contact surface of the finished tape.

The 1 shows, for example, in longitudinal section, so cut in a band longitudinal direction, a generally with 10 designated band, which can be used as so-called. Press felt in a drying or pressing section of a paper machine or the like. It shows the 1 the ribbon 10 in an intermediate state that occurs during its production.

The ribbon 10 includes a support structure 12 , which are in the band longitudinal direction MD extending threads 14 and in a ribbon transverse direction extending threads 16 is constructed. The carrying structure 12 can do it with the threads 14 . 16 be designed as a tissue or as a clutch. These threads 14 . 16 are made of ultra-high-strength material, preferably polymer material, with a tensile strength of at least 80 cN / tex, preferably at least 100 cN / tex, constructed in this way even with comparatively small thread cross-sections and correspondingly thin support structure 12 both in the tape longitudinal direction MD as well as across a high To achieve strength. As building material for the threads 14 respectively. 16 For example, an ultrahigh molecular weight polyethylene material may be used, such as, for example, B. the material available under the trade name or the brand Tensylon. Aramid material, such as. B. Kevlar (trade name or trade mark), or liquid crystal material, such as. B. Vectran (trade name or brand), may be for the threads 14 respectively. 16 used as well as high performance polyamide material. With the use of such materials can be a very thin support structure 12 be built from a single layer with a high degree of opening, since due to the use of ultra-high-strength building material for the threads 14 . 16 These can be constructed not only with a comparatively small diameter, but also the per area or length to be provided threads in the tape longitudinal direction MD and the tape transverse direction only in limited number must be present. To further improve the dynamic properties and also reduce the manufacturing costs, the threads 14 or 16 can also be combined with nylon threads.

It should be noted that, of course, in the threads 14 as well as the threads 16 different fiber materials in one and the same support structure 12 Of course, depending on the requirements occurring in a specific application area, it can of course be used.

At a web material contact side 18 the carrying structure 12 is a common with 20 designated fiber material, such as fleece or felt-like material, provided. In the example shown, this is constructed in two layers with two layers 22 . 24 where, for example, the two layers 22 . 24 each other may be the same or different, in particular may have different degrees of opening. It goes without saying that more than the illustrated two layers 22 . 24 may be provided by fiber material, as well as only a single layer.

The fiber material 20 is preferably constructed with nylon fibers and is compatible with the support structure 14 connected by needling. In order to achieve an efficient connection with the support structure here, needles with a special design, for example a teardrop-like barb design, can be used, which also causes damage to the thin threads 14 . 16 the carrying structure 12 can be avoided. The fiber material 20 is preferably provided with a mass not exceeding 600 g / m ² .

In the fiber material 20 is generally one with 26 designated elastomeric polymer material provided. This is used in the production of the band 10 after the fiber material 20 at the web material contact side 18 the carrying structure 12 has been provided and possibly also on a machine contact page 28 fiber material 30 has been provided, for. B. from the web material contact page 18 forth in the fiber material 20 brought in. For this purpose, a preferably aqueous dispersion with elastomeric polymer material particles 32 for a web material contact surface 34 of the fiber material 20 be applied, for example by spraying, rolling, blade coating, foam application, coagulation or padding or other suitable technique. The dispersion moves with the particles 26 in the volume range of the fiber material 20 , and the particles 26 of the elastomeric polymer material, which are preferably made of thermoplastic material, become entangled in the net-like structure of the fibrous material 20 , where a larger part of the particles 26 in the web material contact surface 34 close volume range of the fiber material 20 will remain. However, particles can also penetrate into deeper areas, possibly even into the area of the support structure 12 inside move.

As particularly suitable materials for these particles 26 have polyurethane material, Polyureamaterial, styrene-butadiene block copolymer material, polyether amide block copolymer material, polypropylene, aliphatic polyamides such. As PA 11 or PA 12 proved. The size of the particles 26 is preferably adjusted so that when applied in dispersion at least 50% of the particles have a size in the range of 50 nm-150 microns. When applied in a powdery, ie substantially dry, form, at least half of the particles should have a size in the range of 20 μm-200 μm.

After the particles 26 into the fiber material 20 have been introduced and when introduced in the form of a dispersion and the liquid used for this purpose has been deducted as far as possible, the particles are possibly also heated under pressure to melt them. The particles wet the surfaces of the fibers of the fiber material 20 or to move around these fibers, so that in particular in fiber crossover points a firm anchoring of the fibers takes place with each other. In this case, for example, in a calendering by the case on the tape 10 pressure exerted a distribution of the molten particulate material take place, so that in particular a direct contact between the molten particles and the subsequent cooling creates a firm connection between them.

In this way, a band can 10 be generated in its fiber material 20 the polymer material 26 is present such that the previously existing particles now also with each other and with the fibers of the fiber material 20 form a composite structure that has a variety of cavities 36 having. Through these cavities 36 may pass from one to the web material contact surface 34 provided to be produced web material fluid and through the entire band 10 be conveyed through.

It thus follows with the use of the above-described construction materials for the support structure 12 on the one hand and the elastomeric polymer material 26 in the fiber material 20 on the other hand a band 10 which, even with a comparatively small thickness of less than 3.5 mm, preferably less than 2.5 mm, has excellent strength with nevertheless obtained liquid permeability in the range of 1-200 cfm and thus in particular for high-speed applications, for example in machines for the production of graphic paper having a speed of more than 1600 m / min, preferably more than 1800 m / min, most preferably more than 2000 m / min is particularly suitable.

For other applications, the speed range should be above 1400 m / min, preferably above 1600 m / min, and most preferably above 1800 m / min. In these applications or to obtain the permeability specified above, it is provided that the elastomeric polymer material in the fiber material 20 or in the entire volume 10 with a mass in the range of 50-500 g / m ² , preferably 80-240 g / m ² .

The previously described tape has a reduced weight at low weight Water absorption property with improved drainage behavior in a press nip on. It has been shown that in abrasion tests a lower fiber loss is recognizable, as well as a lesser one Loss of permeability and thickness over the lifetime time. The entire volume is due in particular to the structure of the Carrying structure high strength and has a high uniformity in press sections and less waviness. With the polymer material used, not just to form the desired porosity is present in association with the fibers of the fiber material, but also forms a structural element, both in the macroscopic as well as on a microscopic scale a very uniform Pressure distribution or pressure load ensured in the press nip.

The band constructed according to the invention 10 can preferably be used in press sections with a single press nip or tandem press nip, especially in conjunction with a grooved roll surface. In such a press section, two such bands may be provided, which then receive the web material to be produced and thus remove water from both sides. Alternatively, such a band may be combined with a band of material permeable or impermeable to the liquid to be discharged, for example a conveyor belt coated with polyuretane material.

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

• - WO 2004/085727 A2 [0003]

Claims (16)

Belt for a machine for the production of web material, in particular paper or cardboard, comprising a support structure ( 12 ) with threads running essentially in one band longitudinal direction and one transverse band direction ( 14 . 16 ) on a web material contact side ( 18 ) of the support structure ( 12 ) with this bonded fiber material ( 22 . 24 ), in the fiber material ( 22 . 24 ) elastomeric polymer material ( 26 ), which together with the fibers of the fiber material ( 22 . 24 ) forms a fluid-permeable composite structure, wherein the elastomeric polymer material ( 26 ) having a mass in the range of 50-500 g / m ² , preferably 80-240 g / m ² , is provided. Tape according to claim 1, characterized in that the fibrous material ( 22 . 24 ) is formed with a mass of at most 600 g / m ² . Tape according to one of claims 1 or 2, characterized in that the fiber material ( 22 . 24 ) with the support structure ( 12 ) is connected by needlepunching. Tape according to one of claims 1 to 3, characterized in that the fiber material ( 22 . 24 ) is formed felt or fleece-like. Tape according to one of claims 1 to 4, characterized in that the elastomeric polymer material ( 26 ) comprises: - polyurethane material, and / or - polyurea material, or / and - styrene butadiene block copolymer material, and / or - polypropylene material, or / and - aliphatic polyamide material. Tape according to one of claims 1 to 5, characterized characterized in that the threads of a material with a Tensile force of at least 80 cN / tex, in particular of at least 100 cN / tex, are constructed. Tape according to one of claims 1 to 6, characterized in that the support structure ( 12 ) is constructed with threads of: - ultra high molecular weight polyethylene material and / or - aramid material, and / or - liquid crystal material, or / and - high performance polyamide material Tape according to one of claims 1 to 7, characterized in that the support structure ( 12 ) Contains nylon threads. Tape according to one of claims 1 to 8, characterized in that the support structure ( 12 ) is designed as a fabric or scrim. Tape according to one of claims 1 to 9, characterized in that the elastomeric polymer material ( 26 ) in particle form into the fiber material ( 22 . 24 ) and with the fibers of the fiber material ( 22 . 24 ) generates the fluid-permeable composite structure by pressure and / or temperature. Tape according to one of claims 1 to 10, characterized in that the tape ( 10 ) has a fluid permeability in the range of 1-200 cfm. Tape according to one of claims 1 to 11, characterized in that the tape ( 10 ) has a thickness of less than 3.5 mm, preferably less than 2.5 mm. Method for producing a strip for a machine for producing web material, in particular paper or cardboard, in particular according to one of the preceding claims, comprising the measures: a) providing a carrying structure ( 12 ) with threads running essentially in one band longitudinal direction and one transverse band direction ( 14 . 16 ), b) bonding fiber material ( 22 . 24 ) with the support structure ( 12 ) on a web material contact side ( 18 ), c) introducing elastomeric polymer material ( 26 ) in the fiber material ( 22 . 24 ) for forming a fluid-permeable composite structure together with the fibers of the fiber material ( 22 . 24 ), wherein the elastomeric polymer material ( 26 ) with a mass in the range of 50-500 g / m ² , preferably 80-240 g / m ² , is provided. Process according to claim 13, characterized in that the elastomeric polymer material ( 26 ) in particle form into the fiber material ( 22 . 24 ) is introduced. Machine for producing web material, in particular paper or cardboard, comprising a press section with at most two press nips, such as a belt which can be passed through the press section in endless configuration ( 10 ) according to one of claims 1 to 12. Machine according to claim 15, characterized in that two bands ( 10 ) are provided with substantially the same structure on both sides of the web material to be produced.