[0001] The invention relates to poster paper, which is presented by the preamble portion
of the claim l.
[0002] Today poster papers are known, which are intended for posters containing advertisements,
announcements or the like and which are fixed to appropriate sites by means of an
adhesive substance. Different fixing sites are e.g. various wall surfaces, both outdoors
and indoors, advertising columns and hoardings intended particularly for posters.
The construction of the poster papers nowadays in use is such, that difficulties arise,
when old poster sheets are replaced with new ones. Because the poster paper is fixed
on the surface with an adhesive, there will be difficulties in removing it and in
this case fixing of a new poster sheet directly onto the old one is the only satisfactory
solution. The surface of the older poster paper may in this case cause difficulties
in fixing. Moreover, if the old poster paper has a figure having various intensive
colours and the new poster paper is thin and has poor opacity, the figure on the old
poster paper will be visible through the new paper in a striking way. This all results
in a mottled appearance of a surface containing advertisements and different posters
and the desired effect of the original design is not achieved with the external appearance
of the advertisements.
[0003] The poster paper according to the invention eliminates the aforementioned drawbacks
completely. For gaining this purpose the poster paper according to the invention is
mainly characterized in what is presented by the characterizing portion of the claim
l. As the fibrous layer between the front side figure surface and the back side glue
surface in a poster paper comprises two layers, which are detachable from each other,
a new poster sheet can be fixed easily and shiftly by detaching the layers in the
old sheet from each other and by gluing the new paper onto the lowest layer of the
old sheet, which remains fixed on the surface. The old figure will in this case not
be disturbing the external appearance of the new poster sheet. The adhesion ability
of the new poster sheet will also be improved.
[0004] According to a preferred embodiment, the bottom layer lower in the fibrous layer
is made mainly of mechanical pulp and the top layer upper in the construction is mainly
constituted of chemical pulp as raw material. This optimizes the costs in manufacture.
[0005] The invention is described in the following in more detail with reference to the
accompanying drawing, wherein
Fig. l is a schematic side view of a poster paper of the invention fixed on the surface,
Fig. 2 shows the separation of the layers from each other in the poster paper of Fig.
l on fixing the new paper and
Fig. 3 shows a new poster paper of the invention fixed in the place of the old one.
[0006] Fig. l shows the poster paper l of the invention, fixed on a appropriate surface
and seen in a direction perpendicular of the plane thereof. The front side of the
paper comprises a surface 3 for the figure. This surface can be constituted of a coating
suitable for printing. The back side of the paper comprises a surface 4 for gluing,
onto which an adhesive layer 4ʹ is formed when the paper is fixed. Between the said
surfaces there is a fibrous layer 2 giving strenght to the poster paper. The fibrous
layer comprises a top layer 2a on the side of the figure surface 3 as well as a bottom
layer 2b on the side of the surface 4 for gluing. The back surface of the bottom layer
2b forms the aforementioned surface 4 for adhesive substance. The layers are attached
to each other along a boundary surface 7 between the layers.
[0007] When an old poster or the like is replaced with a new one, the procedure is as shown
in Fig. 2. The poster paper containing the old advertisement or the like is peeled
in the direction of its plane along the boundary surface 7 between the layers 2a and
2b e.g. manually. Only the adhesive layer 4ʹ and the bottom layer 2b of the old poster
remain stuck on the surface whereas the top layer 2a containing the old figure is
removed. Onto this bottom layer, the new poster paper containing a new advertisement
or the like can be attached likewise by gluing. The new poster paper can also have
the structure of the poster paper of the invention, as shown by Fig. 3. When this
new advertisement is removed later, similar procedure as described hereinabove can
be applied.
[0008] The top layer 2a and the bottom layer 2b can each contain mainly one or several types
of fibres, such as mechanical ground wood pulp, refined mechanical pulp, chemical
pulp or synthetic fibres as well as raw materials generally used in pulp, such as
fillers, sizing agents and additives. Both layers can have a totally similar composition
or their compositions can differ e.g. so, that the top layer 2a is mainly constituted
of chemical pulp, i.e. of wood pulp manufactured in chemical process, and the bottom
layer 2b is mainly constituted of ground wood pulp or of other mechanically manufactured
pulp. The last mentioned alternative has the advantage, that raw material of higher
quality can be used in forming the surface layer important for the external appearance
of the poster, while a cheaper material can be used in the bottom layer, which lies
between the surface layer and the adhesive surface and whose purpose is to make the
peeling of the fibrous layer of the paper possible and to act as an new surface for
fixing a new poster paper.
[0009] The separate layers 2a and 2b of the fibrous layer 2 can in practice be manufactured
so, that in the manufacturing process two paper webs are brought together in a wet
state, but in a state, where they have a sufficiently high dry substance content.
In this case the layers become bonded together strongly enough and the construction
of the poster paper becomes firm enough for the use in practice. The bond so formed
at the boundary surface 7 between the two layers is, however, weak enough so that
the poster paper can later be peeled along this boundary surface. When the poster
paper is manufactured in above mentioned way, no particular separating layer between
the layers 2a and 2b is needed.
[0010] The optimum range within which the dry substance content of the joined paper webs
must lie in the joining stage is dependent of many factors, such as the type of the
layers and the raw materials therein as well as of the drying rate of the paper. These
all factors can mastered by a man skilled in the art for obtaining the optimal result.
It can be mentioned as a general rule, that the dry substance content should be higher
than l0% by weight in order to prevent the layers from becoming too adherent to each
other.
[0011] The surface 3 for the figures can be formed onto the top layer 2a by a usual operation
in a paper machine or in a separate operational stage. It can be composed of a coating
containing e.g. some surface sizing agents, pigment coating, lacquer, plastic or the
like, all known to man skilled in the art. The purpose of this coating is to enhance
the forming of the figure containing the necessary information onto the poster paper
surface. This can be done manually or by printing.
[0012] The grammages of the top layer 2a and the bottom layer 2b can each lie within a range
of 20-200 g/m² and the grammage of the surface coating, dependent on its type, can
be within a range of l-l50 g/m². The top layer and the bottom layer do not necessarily
have to be of equal thickness, but the bottom layer can for example be thinner, because
its main purpose is to act as a layer which separates the top layer 2a and the figure
surface 3 from the surface 4 intended for gluing.
[0013] The invention is by no means restricted to only those embodiments disclosed in the
description, but it can be altered within the scope of the invention presented by
the claims. The essential feature of the invention is, that the fibrous layer of the
poster paper comprises two layers and the poster paper is peelable along the boundary
surface between these layers on replacing the poster paper with a new one. The amount
of different layers is by no means restricted, e.g. the surface coating on the top
layer 2a is not always necessary, depending on the specific use. The fibrous layers
2 can also be constituted of more than two layers so, that it contains at least one
boundary surface 7, along which the fibrous layers can be separated from each other.
1. Poster paper (l) intended to be fixed by means of adhesive substance onto a surface
for advertisements, announcements or the like information and comprising a fibrous
layer (2), on the front side thereof a surface (3) for figure and on the back side
thereof a surface (4) for adhesive substance, characterized in that the fibrous layer comprises a top layer (2a) and a bottom layer (2b), which
are releasably attached to each other so, that the paper can be peeled in the direction
of its plane along the boundary surface (7) situated between the top layer and the
bottom layer.
2. Paper in accordance with claim l, characterized in that the top layer (2a) is mainly constituted of chemical pulp and the bottom
layer (2b) is mainly constituted of ground wood pulp or of other mechanically manufactured
pulp.