DE102004056318A1 - Roller cladding/press mantle, at a web production/finishing machine, has an elastic matrix with embedded filling material with external heat to give reversible dimension changes - Google Patents

Abstract

The roller cladding or press mantle (2) around the core (3) of the roller (1), in a machine for the production or finishing of a fiber web, has an elastic matrix (6) with an embedded filling material (7',7") at least in sections. The cladding matrix dimensions can be varied by exposure to external heat or an electrical current to give a reversible and targeted size change, with a higher temperature (T2) at the roller ends (8) than the temperature (T1) at the roller center (9). The elastic matrix is of a polymer material, and the filling material is of particles and/or fibers or fluid-filled spheres. The cladding has a top layer (4) and one or more lower layers (5).

Description

These The invention relates to a roll cover or a press cover after The preamble of claim 1. Furthermore, the Invention a calender and a press for selectively influencing the cross profile of a Material web, in particular a fibrous web. In addition, concerns the invention is a spreader roll.

Roll covers are For example, in presses, Glättwerken or spreader rollers used. Press jackets, for example, use in a shoe press.

Out The prior art discloses various techniques, one Fibrous web in their production and processing with respect. Properties such as basis weight, Smoothness, Thickness to affect moisture.

So For example, press rollers are cambered to the deflection of a pair of rollers to balance in the press nip and thus in the press nip on the Width as possible to produce the same line force. Such a bombage is static and can not compensate for fluctuations in line power.

Out The prior art further includes variable-compression presses known. In shoe presses, for example, the press shoe by a in Machine transverse direction extending punch row formed, each Stamp independent can be approached by the other stamps. This construction is very expensive.

It the object of the present invention is a roll cover or to propose a press cover whose thickness over the width specifically reversible is adjustable. It is about it In addition, the object of the present invention is a calender, a Spreading roller and to propose a press with which the Transverse profile of a material web is selectively influenced and the about that Be simply constructed.

The The object is solved by the features of claims 1, 16, 17 and 18.

Of the Roll cover or press cover according to the genus has an elastic matrix material, which at least one Section of the roll cover or the press jacket forms.

In addition, according to the invention provided that in the elastic matrix material at least in sections at least one filler embedded whose dimension is reversibly targeted by external influence variable is.

By the provision of a filler which is embedded in the elastic matrix material and its Dimension due to external influence reversibly selectively changeable is it possible to create a simply constructed roll cover whose thickness over the Width is locally targeted and reversibly adjustable.

Preferably For example, the elastic matrix material comprises a polymeric material.

Of the filler can be both particulate as well as fibrous be educated. Of course is also a combination of particulate filler and fibrous filler conceivable.

To a particularly preferred embodiment The invention provides that the dimension of the filler changeable by temperature change is. Thus, the thickness of the roll cover or the press jacket is specifically by temperature change reversibly adjustable. Thus, it is, for example, possible by local cooling or Heat To change the thickness of the roll cover locally and thus, for example, the press nip targeted.

Around one possible huge Variation range for the adjustment of the thickness of the roll cover or press jacket to It is useful if the dimension of the filler is obtained between smallest and largest extent by a factor greater than 1 to 200, preferably by a factor greater than 1 to 20 changeable is.

hereby is it possible To adapt the roll cover to almost any requirement.

A Concrete embodiment of the invention provides that the particulate filler as filled with fluid elastic hollow body is trained. Such a hollow body is particularly simple constructed and can be incorporated easily into the matrix material be to the roll cover according to the invention or press cover to form.

A Another specific embodiment of the invention provides that the hollow body is spherical. A spherical one hollow body is due to its symmetrical shape position independent in the matrix material einarbeitbar and thus contributes to the simple and inexpensive Structure of the roll cover according to the invention or Pressmantels at.

According to a further advantageous embodiment of the invention it is provided that the fluid is a gas. As is known, the volume of gases increases when heated and decreases reversibly on cooling. Thus, a gas is ideal as Füllme Dium suitable for the elastic hollow body, since by using a gas, the volume of the hollow body can be changed reversibly with temperature change.

The Gas and the material surrounding the gas are particularly so coordinated that the gas is not or only slightly from the surrounding Material volatile is.

Preferably includes the forming the hollow body Material an elastic polymeric material.

To another embodiment The invention provides that the dimension by electrical Voltage changeable is.

When Concrete embodiment of this embodiment can be provided be that the filler one Includes piezoelectric material.

Of course it is according to the invention conceivable fillers mix with different expansion behavior with each other for example, locally different thicknesses and / or hardnesses of the roll cover or to adjust the press jacket.

Depending on the specific requirement of the respective roll cover or Pressmantel, it is conceivable that the filler composition and / or Filler concentration over the Width changes.

Also dependent from the specific requirement of the respective roll cover or press cover It is conceivable that the filler composition and / or filler concentration over the Thickness changes.

For some Applications, it may be useful if the filler concentration and / or filler composition zonal changes. For other applications However, it may be useful if the filler concentration and / or filler continuously changes.

By the use of a roll cover according to the invention in one calender or a press, it is possible a calender or to create a press, with the or the cross profile of the to be processed web, in particular fibrous web targeted and can be variably influenced, and which) structurally particular simple, without, for example, elaborate Hydraulic components, executed can be.

By the use of a roll cover according to the invention for a spreader roll is it possible, to provide a simply constructed spreader roll, in which For example, to set the spreader effect no sectioned roll core is required. Furthermore, it is when using the roll cover according to the invention in a spreader roll also no longer required, the roll core to bend to achieve a spreader effect, resulting in a complex and susceptible roller bearing necessary.

Consequently a spreader roller is created in which the spreading effect can be influenced selectively and variably, and which constructive particularly easy and resistant to wear is constructed.

The The invention will be explained in more detail with reference to the following schematic drawings. It demonstrate:

1 a roll cover according to the invention on a calender roll in longitudinal section,

2 a further embodiment of a roll cover according to the invention on a calender roll in longitudinal section,

The 1 shows a section of a calender roll 1 with a roll cover 2 which is on a roll core 3 is applied.

The roll cover has an upper reference position 4 , so-called "top layer" and one or more below the upper reference position 4 arranged (n) reference position (s) on, or with the reference numeral 5 are designated.

The upper reference position 4 comprises an elastic matrix material 6 , which is formed in the illustrated embodiment by an epoxy resin. In the matrix material 6 is a particulate filler 7 embedded. The filler particles 7 In the present embodiment, as a spherical hollow body filled with a gas, an elastic polymeric material is formed.

The concentration of filler particles 7 is about the width of the calender roll 1 constant. The filler particles of the present embodiment are those whose dimension between the smallest and largest possible extent by the factor greater than 1 to 200, preferably by the factor greater than 1 and 20 is variable.

In the in the 1 illustrated state of the calender roll 1 the thickness of the roll cover changes 2 locally across the width. This will be done achieved by the two edge areas 8th of the roll cover 2 be brought to a temperature T2, which is higher than the temperature T1 of the central region 9 of the roll cover 2 is. Consequently, the filler particles have 7 ' at the edge 8th a larger volume than the filler particles 7 '' in the middle area 9 , It follows that the thickness of the roll cover 2 at the edge 8th greater than the thickness of the roll cover 2 in the middle area 9 ,

The different temperatures on the roll cover 2 can be adjusted, for example, by sectional hot and cold air bubbles.

In operation of the calender roll 1 in a calender thus reduces the nip in the edge region 2 , whereby the calender pressure is increased in the edge region. The thickness of the paper web thus decreases as it passes through the nip at the edge regions, whereby the gloss is increased.

The 2 shows a further embodiment of a roll cover 2 ,

All characteristics, which to those of the 1 are identical, are denoted by the same reference numerals and will not be discussed further.

In the embodiment of the 2 are formed as a fluid filled hollow body filler particles 7 by fibrous piezo elements 10 replaced and in the matrix material 6 embedded.

The presentation of the 2 shows the roll cover 2 in a state in which the piezo elements 10 ' at the edge 8th a tension has been applied so that they have expanded, increasing the thickness of the roll cover 2 at the edge 8th higher than the thickness of the center region 9 of the roll cover 2 is, on its piezo elements 10 '' no voltage is applied.

Of course it is with the roll cover according to the invention Any kind of profiling in roll width possible, so that almost every any thickness profile is adjustable.

Claims (18)

Roll cover or press cover for use in a machine for producing a material web, in particular a fibrous web, wherein the roll cover or the press cover has an elastic matrix material, characterized in that in the elastic matrix material at least in sections at least one filler is embedded whose dimension by external influence reversibly targeted is changeable. Roll cover or press cover according to claim 1, characterized characterized in that the elastic matrix material is a polymeric Material includes. Roll cover or press cover according to claim 1 or 2, characterized in that the filler particulate and / or fibrous is. Roll cover or press cover according to one of claims 1 to 3, characterized in that the dimension of the filler between smallest and largest extent between the factor greater than 1 and 200, preferably variable between the factor greater than 1 and 20 is. Roll cover or press cover according to one of claims 1 to 4, characterized in that the dimension by temperature change variable is. Roll cover or press cover according to one of claims 1 to 5, characterized in that the particulate filler as filled with fluid elastic hollow body is trained. Roll cover or press cover according to claim 6, characterized characterized in that the hollow body spherical is. Roll cover or press cover according to claim 6 or 7, characterized in that the fluid is a gas, and in particular not volatile from the surrounding material. Roll cover or press cover according to one of claims 6 to 8 characterized in that the hollow body is an elastic polymeric Material includes. Roll cover or press cover according to one of claims 1 to 4, characterized in that the dimension by electrical Voltage changeable is. Roll cover or press cover according to claim 10, characterized characterized in that the filler Includes a piezoelectric material. Roll cover or press cover according to one of claims 1 to 12, characterized in that fillers with different Expansion behavior are mixed together. Roll cover or press cover according to one of claims 1 to 12, characterized in that the filler composition and / or filler concentration over the Width changes. Roll cover or press cover after one of claims 1 to 13, characterized in that the filler composition and / or filler concentration changes across the thickness. Roll cover or press cover according to claim 13 or 14, characterized in that the change is zonal or continuous he follows. calender with a nip formed by two rolls, characterized that as a roll cover at least one of the rolls a roll cover according to one of the claims 1 to 15 is used. Press with a nip formed by two rolls, characterized in that as a roll cover at least one of Rolls a roll cover according to one of claims 1 to 15 is used. Spreader roll with a roll cover after one the claims 1 to 15.