WO2008040635A1

WO2008040635A1 - Wallpaper substrate and method for the production thereof

Info

Publication number: WO2008040635A1
Application number: PCT/EP2007/059838
Authority: WO
Inventors: Frank Fetkenheuer; Marco Menz; Michael Nogowski; Thomas Ullrich; Horst Leupold
Original assignee: Dresden Papier Gmbh
Priority date: 2006-09-29
Filing date: 2007-09-18
Publication date: 2008-04-10
Also published as: PL2066842T3; DE102006058929B4; EP2066842A1; DE102006058929A1; ES2366928T3; EP2066842B1; RU2428537C2; RU2009113685A; ATE510963T1; UA93738C2

Abstract

The invention relates to a wallpaper substrate for a wallpaper that can be peeled in a dry manner, has a minimal wet expansion and consists of a multilayer strip with an upper and lower side, between which are arranged a fibrous lower layer of a fibre mixture on cellulose basis and synthetic fibers and a fibrous upper layer of a fibre mixture on cellulose basis and free of synthetic fibres. The invention also relates to a method for producing such a wallpaper substrate. The aim of the invention is to allow a nearly faultless printing of the upper side with high quality, particularly by direct printing, and at low cost. A printability is to be achieved by virtue of the fact that the number of imperfections in the print is reduced to a minimum. The solution provided according to the invention is that the lower and upper layer are felted with one another by couching, the upper side is satinated and configured for direct printing, especially for gravure printing.

Description

Wallpaper substrate and process for its preparation

The invention relates to a wallpaper substrate for a dry peelable wallpaper with minimal wet stretch. This consists of a multilayer web with an underside facing the wall when using the wallpaper and a top facing the room when the wallpaper is used. In between, in the bottom-to-top direction, there are disposed a fibrous cellulosic fibrous base layer and synthetic fibers and a fibrous top layer of a cellulosic non-fiber synthetic pulp mixture.

The invention also relates to a method for producing a wallpaper substrate for a dry peelable wallpaper with minimal wet stretch, in which a multilayer web is formed with an underside facing the wall when the wallpaper is used and an upper side facing the room when the wallpaper is used. In this case, a fibrous lower layer composed of a pulp mixture of cellulose and synthetic fibers and a fibrous upper layer of a synthetic fiber-free cellulose fiber mixture are connected to one another.

From DE 27 14 206 Al a wallpaper substrate and a process for its preparation is known which consists of a lower layer, in addition to cellulose fibers and thermoplastic Synthetic fibers contains and an upper layer containing only cellulose fibers known. Both layers are glued together by lamination using glue. In addition, the process is conducted in such a way that the synthesis fibers fuse together. This solution is aimed primarily at a good connection of the layers and a good removability of the wallpaper in the case of renovation. Direct printing of this wallpaper substrate is not provided.

A method and a wallpaper substrate of the aforementioned type is also known from EP 0118 221 Bl. Here, a lower phase containing both cellulose and synthetic fibers and an upper cellulosic fiber-containing upper phase are bonded together. Direct printing of the substrate is not provided here. Rather, a vinyl layer is applied to the top, which is to serve the subsequent printing. The composition of the upper phase serves here for better adhesion of this vinyl layer.

The object of the invention is now to provide a wallpaper substrate and a method for its production, with a direct, almost error-free printing of the top in good quality in particular by means of direct printing and in this case in particular by intaglio is possible and which is inexpensive to produce. In particular, a printability should be achieved by minimizing the number of imperfections, so-called missing dots, in the printout.

The problem is solved on the arrangement side, that the lower layer and the upper layer are matted together by Gautschen, and the upper surface satin and is formed by direct printing, especially for gravure, with a maximum of 1 missing dot per cm ² printable.

A multi-layered wallpaper substrate, which from a bottom, the bottom facing the wall, consisting of a cellulose and synthetic fiber blend, and an upper facing in the space top, consisting of a cellulose fiber layer, with an applied on the top pigment coating, which was satin finished, and in this way and Way an advantageous surface structure is created, ensures a very good printability in gravure printing with a small number of defects.

In one embodiment of the invention, it is provided that a lower functional layer is applied to the underside. By means of this functional layer, for example, a curling of the wallpaper can be prevented.

A further embodiment according to the invention provides that the fibers based on cellulose consist of 50 to 100% of chemically produced fibers and may contain 0 to 50% of mechanically treated fibers and / or 0 to 50% of recovered paper fibers in each case in a supplementary proportion. The possibility of adding mechanically processed fibers and / or recovered paper fibers on the one hand improves the range of variation in the structure and, on the other hand, enables cost-effective production.

To improve the printability, it is provided in one embodiment of the invention that a pigment coating forming the upper side is applied to the upper layer.

It is advantageous that the pigment coating contains inorganic, in particular mineral constituents, since these constituents bring about further smoothing with uniform roughness and good ink coverage.

Preferred mineral materials for the pigment coating are mixed or individually represented by caolins, titanium dioxide, carbonates, talc and special pigments. In a further preferred embodiment of the invention it is provided that the functional layer has a grammage of 0 to 5 g / m ² , the upper layer has a grammage of 5 to 40 g / m ² , the pigment coating a grammage of 5 to 35 g / m ² and the lower layer has a grammage corresponding to the total grammage of the substrate to be adjusted minus the grammages of the functional layer, the upper layer and the pigment stroke.

Preferably, the wallpaper substrate has a total grammage of 60 to 180 g / m ² .

The process-side solution of the problem provides that the lower and upper layers, preferably by means of wires, each made of a cellulosic suspension or a cellulosic suspension with admixing synthetic fibers for the lower layer, are formed and then joined together by Gautschen and the top by means of satin with a high print quality suitable for a direct printing, in particular a gravure printing is created and that all processes are carried out at a temperature below the melting temperature of the synthetic fibers. On the one hand, the adjustment of the temperature prevents crosslinking of the synthetic fibers, so that the wallpaper substrate retains its flexible basic structure. On the other hand, the satin finish, for which the pure cellulose structure of the top is very well suited, achieves a very even surface, which helps avoid the creation of missing dots in direct printing.

In a variant of the method, it is provided to apply a functional layer to the side of the lower layer facing towards the lower side. By means of this functional layer, the adhesion and processing properties of the wallpaper can be influenced. In particular, it can be used to prevent curling.

In a further embodiment of the method, provision is made for hen that on the upper side of the upper layer facing the top layer forming a pigment coat is applied in situ, which serves on the one hand pre-inking of the wallpaper and on the other hand further improves the surface structure. This pigment coating can expediently be applied directly during the production, since an additional treatment step which would require additional handling of the wallpaper substrate rolls is thus avoided.

In a variant, on the other hand, it is provided that a pigment coating forming the upper side is applied separately to the side of the upper layer facing the surface. Thus, in providing the wallpaper substrate, the manufacturer may be better able to serve the customer's interest.

If the pigment coating from the liquid phase is applied to the pre-dried composite of the layers, the composite is able to withdraw liquid from the pigment coating very quickly, as a result of which it more quickly reaches a dry state.

In a manner similar to the application of the pigment coating, the satinization may be carried out in situ or separately and in both cases by means of a calender.

The invention will be described below with reference to an embodiment in more detail.

The accompanying drawing shows a cross section through a substrate according to the invention.

The wallpaper substrate 1 according to the invention has a underside 2 facing the wall when the wallpaper is used and an upper side 3 pointing into the room when the wallpaper is used.

In between, a lower functional layer 4, a fibrous lower layer 5 of a pulp mixture of cellulose and synthetic fibers and a fibrous upper layer 6 of a synthetic fiber-free cellulose fiber mixture are arranged. The lower The layer 5 and the upper layer 6 are matted together by Gautschen. On the upper layer 6 a top 3 forming pigment coating 7 is applied. The upper side 3 is satined and designed for printing by virtually direct printing, in particular for gravure printing, almost error-free.

The wallpaper substrate according to the invention is produced on a duplex slow motion machine. It is quite common to produce both layers 5 and 6 from the same pulp mixture of cellulose and synthetic fibers. In contrast, according to the invention, the synthetic fibers are not dosed in the upper layer 6. The upper layer 6 is the position which shows after wallpapering the finished wallpaper to the inside of the room.

This creates a much smoother and less porous surface. For further refinement of the surface 3, a pigment coating 7 is applied, which is then satined. The surface 3 produced in this way has a structure which is required for the almost perfect printability in gravure printing, in particular for the small number of imperfections, so-called missing dots.

In the wallpaper substrate 1, a functional layer 4 can be applied to the underside of the lower layer to maintain certain properties, such as, for example, anti-curling, fiber adhesion and the like.

Thus, a wallpaper substrate 1 is specified, which satisfies the highest demands made by the gravure printing. This wallpaper substrate 1 thus has properties as it has provided for a gravure conventional wallpaper paper.

The wallpaper substrate 1 according to the invention was in a Gram maturity range of 130 g / m ² produced.

The upper layer was made of 100% cellulose fibers and had a grammage of 35 g / m ^2.

The lower web consisted of a nonwoven wallpaper (cellulose and synthetic fiber mixture) corresponding to the state of the art with a surface weight of 73 g / m ² .

As a functional layer, starch was applied in a basis weight range of 0.3 g / m ² for anticurling treatment.

The inorganic pigment sting was applied in a basis weight range of 22 g / m ² .

The wallpaper substrate 1 according to the invention has a surface roughness measured according to Parker Print Surf (DIN ISO 8791-4) of <2.0 μm, in particular <1.7 μm.

Currently, coated wallpaper nonwovens that are available on the market have a Parker Print Surf value of> 2.5 μm. Uncoated wallpapers have a Parker Print Surf value of> 5 μm.

Papers which are currently used in rotogravure for the particular application in question usually have a Parker Print Surf value of <1.7 μm.

The test print in the gravure printing process carried out under industrial conditions showed a closed print image without defects (missing dots).

Wallpaper substrate and process for its preparation

LIST OF REFERENCE NUMBERS

1 wallpaper substrate

2 bottom

3 top

4 functional layer

5 lower layer

6 upper position

7 pigment stroke

Claims

Wallpaper substrate and process for its preparationpatent claims

A wallpaper substrate for a dry peelable wallpaper with minimal wet stretch, consisting of a multi-layered web with an underside facing the wall when using the wallpaper and a top facing the room when the wallpaper is used, between which a fibrous one in the direction from bottom to top lower layer of a fiber mixture on Zelluloseba ^¬ sis and synthetic fibers and a fibrous upper layer of a synthetic fiber-free fiber material mixture disposed cellulosic dadurchgekenn ^¬ characterized in that the lower layer and the upper layer by couching are entangled with each other, and satin top and is printable by direct printing designed for, in particular ^¬ sondere for gravure printing, with more than 1 missing dot per cm ^2.

2. wallpaper substrate according to claim 1, characterized ge - characterizing ze i seframe that on the underside of a unte ^¬ re function layer is applied.

3. Tapesubstrate according to claim 1 or 2, characterized ge kenn ze i chnet that the fibers on cellulose basis of 50 to 100% chemically produced fibers and in each case supplemental share 0 to 50% mechanically processed fibers and / or 0 to 50% Waste fibers may contain recovered paper.

4. wallpaper substrate according to claim 1 or 3, characterized in that on the upper layer a top coat forming pigment is applied

5. wallpaper substrate according to claim 4, characterized in that the pigment coating anor- ganic holds, in particular mineral components ^¬ ent.

6. wallpaper substrate according to claim 5, characterized in that the pigment coating contains ge ^¬ mixed or individually Caoline, titanium dioxide, carbonates, talc and special pigments.

7. wallpaper substrate according to any one of claims 3 to 6, since - by in that the radio ^¬ tion layer has a grammage of 0 to 5 g / m ^2, the upper layer has a grammage of 5 to 40 g / m ^2, the pigment brushed a Grammage of 5 to 35 g / m ² and the lower layer has a grammage corresponding to the set total grammage of the substrate minus the grammages of the functional layer, the upper layer and the pigment ^¬ striches.

8. Wallpaper substrate according to claim 7, dadurchge ^¬ indicates that the wallpaper substrate has a total grammage of 60 to 180 g / m ² .

9. A process for the production of a wallpaper substrate for a dry peelable wallpaper with minimum wet stretch, in which a multilayer web is generated with a bottom facing the wall when using the wallpaper and a top facing the wall when using the wallpaper, wherein a fibrous lower La ^¬ ge synthesis fibers from a fiber mixture of cellulose and syn and a fibrous upper layer of a syn thesis ^¬ fiber-free cellulose fiber mixture are connected to one another, characterized in that the lower and the upper layer, preferential , be joined by means of long wires, each from a cellulose suspension or a cellulose suspension with admixture of synthetic fibers for the lower layer formed on ^¬ and closing by couching together and the top by means of a satin finishing with a for

Direct printing, in particular a gravure printing suitable high print quality is created and that all operations are carried out at a temperature below the melting temperature of the synthetic fibers.

10. The method according to claim 9, characterized ge kennze i chnet that on the underside facing side of the lower layer, a functional layer is introduced ^¬ .

11. The method according to claim 9 or 10, characterized in that on the side facing the upper side of the upper layer a top bil ^¬ dender pigment coating is applied in situ.

12. Method according to claim 11, characterized in that a pigment coating forming the upper side is applied separately to the side of the upper layer facing the surface.

13. The method according to claim 11, characterized in that the pigment coating is applied from the liquid phase to the predried composite of the layers.

14. A method according to any one of claims 11 to 13, wherein a satinization is carried out in situ by means of a calender.

15. The method according to claim 11 to 13, characterized in that the satinizing sepa ^¬ rat is performed by means of a calender.