Technical field
[0001] The present invention refers to a method and a device for embossing and printing
a web of flexible material, such as paper and nonwoven material. Especially it refers
to production of tissue products such as toilet and kitchen paper, paper towels, handkerchiefs,
wiping material and the like. The invention further refers to an embossed and printed
web of flexible material, such as paper and nonwoven.
Background of the invention
[0002] It is common to emboss and print tissue products. Embossing is a way of increasing
the bulk of the paper and it also gives a three-dimensional structure to the paper,
which improves the absorption properties and also the aesthetic appearance of the
tissue product. Embossing may further be a way of laminating two or more tissue paper
plies together, at which a mechanical joining of the plies occur in the embossing
sites. Embossing is often combined with gluing for laminating tissue paper plies.
This is for example disclosed in US 3,414,459, in which laminating of tissue plies
by a combined embossing and gluing procedure is shown. The embossing is of so called
foot-to-foot type according to which the raised protuberances of the embossed tissue
plies are joined together. In US 3,867,225 there is also disclosed a combined embossing
and gluing process, but where the embossing is of so called nested type according
to which the raised projections of one tissue ply will rest in and be joined to the
depressions of the opposite ply.
[0003] Printing of tissue paper is often made for aesthetical reasons. The printing pattern
could be any pattern including more or less continuous lines, line segments, dots,
trademarks, logotypes, symbols, fantasy characters etc. One conventional way of embossing
and printing a tissue paper is to perform the embossing first and subsequently the
printing. This method will result in that the printing colorant will be located substantially
only on the raised projections of the embossing pattern. An example of such method
is found in US 5,339,730.
[0004] According to an alternative method the printing of one tissue ply is made first and
subsequently this tissue ply is embossed and laminated with another tissue ply. A
drawback with such a method is that the colorant is not always completely dry before
the embossing, which means a risk that the printing will be blurred.
[0005] In both these methods there is a risk that the embossing deteriorate the quality
of the printing.
Object and most important features of the invention
[0006] The object of the present invention is to provide a method for producing a printed
and embossed web of flexible material, such as paper and nonwoven material of an improved
quality especially printing quality. According to one embodiment the invention refers
to printed and embossed tissue paper, which may be a one-ply or multi-ply tissue product.
[0007] This object has according to one embodiment of the invention been provided by embossing
the web by bringing it into a first nip between a pattern roll and an impression roll,
said pattern roll having a three dimensional pattern of alternating raised and recessed
portions, said three dimensional pattern being interrupted by substantially smooth
areas, so that the web will be embossed in selected areas while leaving other areas
substantially unembossed;
subsequently bringing the web into a second nip between said impression roll and a
printing roll carrying a colorant in a selected pattern, said pattern roll and printing
roll are synchronized so that said colorant is transferred at least mainly to unembossed
areas of the web in said selected pattern.
[0008] According to an alternative embodiment of the invention the method comprises: printing
the web in a selected pattern by bringing it into a first nip between an impression
roll and a printing roll carrying a colorant in the selected pattern; subsequently
embossing the web by bringing it into a second nip between a pattern roll and an impression
roll, said pattern roll having a three dimensional pattern of alternating raised and
recessed portions, said three dimensional pattern being interrupted by substantially
smooth areas, so that the web will be embossed in selected areas while leaving other
areas substantially unembossed;
said pattern roll and printing roll are synchronized so that embossing occurs at least
mainly in the areas of the web that are not printed in said selected pattern.
[0009] The web that undergoes the embossing and printing steps can be a one-ply or a multi-ply
material. The multi-ply web can be a laminated web in which the plies have been joined
by for example by gluing and/or embossing. The multi-ply web can alternatively comprise
two or more plies which have not been joined, and which will be joined together by
the embossing step and an optional subsequent gluing step or the like.
[0010] According to a preferred embodiment the pattern roll is of a harder material than
the impression roll, which is of a non-rigid material, so that the three dimensional
pattern on the pattern roll will cause temporary or permanent impressions in the surface
of the impression roll.
[0011] The non-embossed areas of the web entering the second press nip will present raised
areas with respect to the printing roll adapted to receive the colorant in said selected
printing pattern, while said impression roll serves as a counter roll during the printing.
[0012] The invention further refers to a device for embossing and printing a web of flexible
material, such as paper and nonwoven material, said device comprising an embossing
roll having a three dimensional pattern of alternating raised and recessed portions,
said three dimensional pattern being interrupted by relatively smooth areas;
a printing roll adapted to carry a colorant in a selected pattern, said embossing
roll and said printing roll being synchronized, an impression roll cooperating with
the embossing roll and the printing roll.
[0013] In addition the invention refers to a printed and embossed web of flexible material,
such a paper and nonwoven, wherein the web is embossed in selected areas and that
other areas are relatively smooth and non-embossed and that the web is printed in
a selected pattern at least mainly in said smooth and non-embossed areas.
[0014] According to one embodiment at least 50% of the printed area of said selected printing
pattern is located on the non-embossed areas of the web. According to further embodiments
at least 75% and preferably at least 90% of the printed area of said selected printing
pattern is located on the smooth non-embossed portions of the web. According to an
additional embodiment substantially all printed area of said selected printing pattern
is located on the smooth non-embossed portions of the web.
[0015] In a preferred embodiment said selected embossed areas are arranged as groups of
embossment sites having said substantially smooth and unembossed areas between said
groups of embossment sites, and that at least some of said smooth and unembossed areas
have an uninterrupted surface area of at least 1 cm
2, preferably at least 1.5 cm
2 and more preferably at least 2 cm
2 having no embossment sites thereon.
[0016] The paper web may in one embodiment besides said selected printing pattern be provided
with other printing patterns optionally configured on the paper web.
[0017] The web of material is according to one embodiment tissue paper, which may be a one-ply
or multi-ply tissue product.
[0018] Further features of the invention are disclosed in the following description and
in the claims.
Description of drawings
[0019] The invention will in the following be closer described with reference to some embodiments
shown in the accompanying drawings.
Fig. 1 shows a schematic side view of a device for performing the method according
to one embodiment of the invention.
Fig. 2 is a side view corresponding to Fig. 2 but according to another embodiment.
Fig. 3 shows a schematic view of a detail of an alternative embodiment of a device
according to the present invention.
Fig. 4 is a schematic view of a web material according to the invention.
Description of an embodiment
[0020] Fig. 1 shows a device for producing a web material, e g paper, especially tissue
paper.
[0021] The web can be a one-ply or a multi-ply material. The multi-ply web can be a laminated
web in which the plies have been joined by for example by gluing and/or embossing.
The multi-ply web can alternatively comprise two or more plies which have not yet
been joined.
[0022] The web 1 is brought into a first nip between the impression roll 3 and a printing
roll 14 carrying a colorant in a selected pattern. The printing roll 14 is according
to one embodiment a so called block-printing roll. Non-limiting examples of such block-printing
rolls are laser-engraved solid or sleeve rubber rolls. Colorant is transferred to
the printing roll 14 via an anilox roll 15, which picks up colorant from an enclosed
doctor chamber 16 for ink.
[0023] The printing pattern 10 is optional and can be geometrical patterns, figurative patterns,
symbols, text, trade names, logotypes etc.
[0024] The web 1 is subsequently fed into a second nip between a pattern roll 2 and an impression
roll 3. The pattern roll 2 has a three dimensional pattern of alternating raised 4
and recessed portions 5, said three dimensional pattern being interrupted by relatively
smooth areas 6. The pattern roll 2 is of a harder material than the impression roll
3, which is of a non-rigid material. The impression roll 3 can be of a resilient rubber
material or of a yielding but non-resilient material, for example a cellulosic material,
in which permanent impressions will be formed by the impression roll 3. The pattern
roll 2 can be of steel or of a rubber material that is harder than the material in
the impression roll. so that the three dimensional pattern on the pattern roll will
cause temporary or permanent impressions in the surface of the pattern roll.
[0025] According to an alternative embodiment, illustrated in Fig. 3, the impression roll
3 roll is of a rigid material, for example steel, and has a three-dimensional pattern
of alternating raised 11 and recessed portions 12, said three dimensional pattern
being interrupted by relatively smooth areas 13 the three-dimensional pattern on the
impression roll 3 matching to that of the pattern roll 2. The pattern roll 2 and impression
rolls 3 are driven so that the alternating raised and recessed portions patterns thereon
will match into each other and the relatively smooth areas will be facing each other.
[0026] The term relatively smooth in this respect means that these areas of the pattern
roll either lack a three-dimensional pattern of alternating raised and recessed portions
that will cause a visible embossing pattern in the web, or that these areas have only
a slight three-dimensional pattern that is much less pronounced than said three-dimensional
pattern of alternating raised and recessed portions.
[0027] As stated above the three dimensional pattern on the pattern roll 2 is interrupted
by relatively smooth areas 6, which means that the web will be embossed in selected
areas 7 while leaving other areas 8 substantially non-embossed. The embossing pattern
is optional and is characterized by a number of embossing sites 9 arranged in groups
which are spaced from each other so as to leave smooth non-embossed areas 8 therebetween.
A smooth non-embossed area 8 is defined as an uninterrupted area of at least 1 cm
2, preferably at least 1.5 cm
2 and more preferably at least 2 cm
2 having no embossment sites thereon. According to another embodiment the embossing
pattern comprises individual embossing sites located spaced from each other, wherein
the spaces between the individual embossing sites form said non-embossed areas.
[0028] The pattern roll 14 and the printing roll 2 are synchronized so that said colorant
is transferred at least mainly to the non-embossed areas 8 of the web in the selected
printing pattern. The term Aat least mainly@ in this respect means that at least 50%
of the printed area of said printing pattern 10 will be located on the non-embossed
areas 8 of the web 1. According to preferred embodiments at least 75% and more preferably
at least 90% of the printed area of the printing pattern 10 is located on the smooth
non-embossed portions 8 of the web. According to one embodiment substantially all
printed area of the printing pattern 10 is located on the relatively smooth non-embossed
portions 8 of the web.
[0029] According to an alternative embodiment shown in Fig. 2 the embossing and printing
steps are reversed, so that the pattern or embossing roll 2 is located before the
printing roll 14. Also in this case the pattern roll 2 and printing roll 14 are synchronized
so that the colorant is transferred at least mainly to the non-embossed areas 8 of
the web in the selected pattern.
[0030] The embossing and printing method and device according to the invention provides
an improved printing quality since at least the main part of the printing pattern
will be located on non-embossed areas of the web.
[0031] It is also encompassed by the present invention that the paper web 1 entering the
embossing and printing stations at the pattern roll, the printing roll 14 and the
impression roll 13 has been given a first printing basic pattern, for example over
its entire surface and that the pattern provided by the printing roll 14 is an additional
pattern.
[0032] The web 1 can after the embossing and printing undergo optional process steps such
as lamination with additional plies, before converting into the final product.
1. Method for embossing and printing a web (1) of flexible material, such as paper and
nonwoven material,
characterized in
printing the web (1) in a selected pattern by bringing it into a first nip between
an impression roll (3) and a printing roll (14) carrying a colorant in a selected
pattern; subsequently embossing the web by bringing it into a second nip between a
pattern roll (2) and said impression roll (3), said pattern roll having a three dimensional
pattern of alternating raised (4) and recessed portions (5), said three dimensional
pattern being interrupted by relatively smooth areas (6), so that the web will be
embossed in selected areas (7) while leaving other areas (8) substantially unembossed;
said pattern roll (2) and printing roll (14) being synchronized so that embossing
occurs at least mainly in the areas of the web that are not printed in said selected
pattern.
2. Method for embossing and printing a web (1) of flexible material, such as paper and
nonwoven material,
characterized in
embossing the web (1) by bringing it into a first nip between a pattern roll (2) and
an impression roll (3), said pattern roll having a three dimensional pattern of alternating
raised (4) and recessed portions (5), said three dimensional pattern being interrupted
by relatively smooth areas (6), so that the web will be embossed in selected areas
(7) while leaving other areas (8) substantially non-embossed;
subsequently bringing the web into a second nip between said impression roll (3) and
a printing roll (14) carrying a colorant in a selected pattern, said pattern roll
(2) and printing roll (14) are synchronized so that said colorant is transferred at
least mainly to unembossed areas (8) of the web in said selected pattern (10).
3. Method as claimed in claim 1 or 2, characterized in
that the pattern roll (2) is of a harder material than the impression roll (3), which
is of a non-rigid material, so that the three dimensional pattern (4,5) on the pattern
roll will cause temporary or permanent impressions in the surface of the impression
roll.
4. Method as claimed in claim 1 or 2, characterized in
that the impression roll (3) roll is of a rigid material and has a three-dimensional pattern
of alternating raised (11) and recessed portions (12), said three dimensional pattern
being interrupted by relatively smooth areas (13), the three-dimensional pattern on
the impression roll (3) matching to that of the pattern roll (2), and that the pattern
roll and impression rolls are driven so that the alternating raised (4,11) and recessed
portions (5,12) patterns thereon will match into each other and the relatively smooth
areas (6,13) will be facing each other.
5. Method as claimed in claim 2, characterized in
that the nonembossed areas (8) of the web (1) entering the second press nip will present
raised areas with respect to the printing roll (14) adapted to receive the colorant
in said selected printing pattern.
6. Method as claimed in any of claims 1-5, characterized in
synchronizing the pattern roll (2) and the printing roll (14) so that at least 50%
of the printed area of said selected printing pattern (10) will be located on the
non-embossed areas of the web.
7. Method as claimed in claim 6,
characterized in
synchronizing the pattern roll (2) and the printing roll (14) so that at least 75%
and preferably at least 90% of the printed area of said selected printing pattern
will be located on the smooth, non-embossed portions of the web.
8. Method as claimed in claim 7,
characterized in
synchronizing the pattern roll (2) and the printing roll (14) so that substantially
all printed area of said selected printing pattern will be located on the smooth non-embossed
portions of the web.
9. Method as claimed in any of claims 1-8,
characterized in
synchronizing the pattern roll (2) and the printing roll (14) so as to arrange said
selected embossed areas (7) as groups of embossment sites spaced apart and leave substantially
smooth and unembossed areas (8) between said groups of embossment sites, wherein at
least some of said smooth and unembossed areas (8) have an uninterrupted surface area
of at least 1 cm2 having no embossment sites thereon.
10. Method as claimed in claim 9,
characterized in
synchronizing the pattern roll (2) and the printing roll (14) so that at least some
of said smooth and unembossed areas (8) will have an uninterrupted surface area of
at least 1.5 cm2 and preferably at least 2 cm2 with no embossment sites thereon.
11. A device for embossing and printing a web (1) of flexible material, such as paper
and nonwoven material,
characterized in
a printing roll (14) adapted to carry a colorant in a selected pattern,
a pattern roll (2) having a three dimensional pattern of alternating raised (4) and
recessed portions (5), said three dimensional pattern being interrupted by relatively
smooth areas (6);
said pattern roll and said printing roll (14) being synchronized; an impression roll
(3) cooperating with the pattern roll and the printing roll.
12. Device as claimed in claim 11, characterized in
that the pattern roll (2) is of a harder material than the impression roll (3).
13. Device as claimed in claim 11, characterized in
that the impression roll (3) roll is of a rigid material and has a three-dimensional pattern
of alternating raised (11) and recessed portions (12), said three dimensional pattern
being interrupted by relatively smooth areas (13), the three-dimensional pattern on
the impression roll (3) matching to that of the pattern roll.
14. A printed and embossed web (1) of flexible material, such a paper and nonwoven, characterized in
that the web (1) is embossed in selected areas (7) and that other areas (8) are relatively
smooth and non-embossed and that the web is printed in a selected pattern (10) in
said smooth and non-embossed areas (8).
15. A printed and embossed web as claimed in claim 14,
characterized in
that at least 50% of the printed area of said selected printing pattern (10) is located
on the non-embossed areas of the web.
16. A printed and embossed web as claimed in claim 15,
characterized in
that at least 75% and preferably at least 90% of the printed area of said selected printing
pattern is located on the smooth, non-embossed portions of the web.
17. A printed and embossed web as claimed in claim 16,
characterized in
that substantially all printed area of said selected printing pattern is located on the
smooth non-embossed portions of the web.
18. A printed and embossed web as claimed in any of claims 14-17,
characterized in
that said selected embossed areas (7) are arranged as groups of embossment sites spaced
apart so as to leave substantially smooth and unembossed areas (8) between said groups
of embossment sites, and that at least some of said smooth and unembossed areas (8)
have an uninterrupted surface area of at least 1 cm2 having no embossment sites thereon.
19. A printed and embossed web as claimed in claim 18,
characterized in
that at least some of said smooth and unembossed areas (8) have an uninterrupted surface
area of at least at least 1.5 cm2 and preferably at least 2 cm2 with no embossment sites thereon.
20. A printed and embossed web as claimed in any of claims 14-19,
characterized in
that the web is a one-ply or multi-ply tissue paper.