Note: Descriptions are shown in the official language in which they were submitted.
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Pack for Tablet-form Products and a Process for its Production
This invention relates to a pack for tablet-form products, more
particularly hygroscopic detergent tablets, of a closed substantially
rectangular film bag in which at least one tablet is accommodated and to a
process for the production of this pack.
Hygroscopic detergent tablets have to be packed in moisture-proof
packs, for example tubular film bags. The packs in question are normally
so-called flow packs. Normally, such tablets are individually packed, i.e. a
corresponding number of tablets are introduced into the washing process
from individual packs, according to portioning and depending on the water
hardness and the degree of soiling. To this end, the film bags have to be
individually opened and the disposed of.
With certain detergent tablets, the basic dose is two or more tablets.
Accordingly, taking packaging costs and user friendliness in account, a bag
capable of accommodating two or more tablets is useful for such
applications. A bag such as this is normally made from a section of film
web, for example of polypropylene film, the film web section being coated
with an adhesive, for example a cold adhesive, along its longitudinal edges
and at both transverse ends of the section of film web to be subsequently
cut to length and that part of the film web section which will be in contact
with the tablets being left uncoated. The tablets are then applied and the
film section is folded or wrapped about its longitudinal axis so that the two
longitudinal edges coated with adhesive and the transverse ends likewise
coated with adhesive come to lie on top of one another and form a closed
film bag with longitudinal and transverse fins which is separated from the
other film bags similarly formed from the film web by cutting along the
transverse ends.
Due to this method of production and packaging, the tablets are
loosely accommodated in the film bag which could be avoided by not
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overdimensioning the section of film web. However, this would make
production very difficult or even impossible and might even lead to tablet
damage. Since, therefore, the film bag is inevitably larger to a certain
extent than the volume of the tablet, it has been found in practice that it is
difficult, particularly with tablets having a preferably granular surface
structure, for example laundry detergent tablets or dishwasher tablets, to
portion the tablets exactly by machine at the high tablet-wrapping rates of
modern flow pack machines. This means that, for example where two
tablets are accommodated in one and the same bag, the tablets can easily
slide in the longitudinal and transverse directions on the smooth film. This
results in unevenness on the upper side of the bag which leads to machine
malfunctions during the subsequent grouping of the filled bags (flow packs)
and their introduction into a cardboard box by suction lifters. This is
because the suction lifters are unable to operate properly. In addition, the
fact that the tablets are able to move in the pack during transportation and
even in storage poses the risk of abrasion and, in extreme cases, even
edge breakage or tablet fracture.
The problem addressed by the invention was to find a way of
enabling the tablets to be exactly and safely positioned in the pack without
significantly adding to the production and packaging costs.
In a pack of the type mentioned at the beginning, the solution to this
problem as provided by the invention is characterized in that, in its zone of
contact with the at least one tablet, the film bag is coated at least locally
with a friction-increasing nonslip coating.
By applying such a coating to the film web section during the
production of the pack, which is easy to do, it is possible for example
selectively to increase the coefficient of static friction of the film (for
example from 0.467 N for a normal polypropylene film to 0.544 a with a
suitable coating) so that a clear improvement in productivity is achieved
without a significant increase in production and packaging costs. The
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tablets are no longer able to move, i.e. remain exactly in position.
In a pack in which the film bag is formed from a folded film web
section coated with adhesive along its longitudinal edges and at both
transverse ends, the friction-increasing nonslip coating is formed with
particular advantage by a coating of adhesive. The adhesive used for this
coating may preferably be the same adhesive used to coat the longitudinal
and transverse edges of the film web section so that the coatings may be
applied in a single operation, enabling the process as a whole to be carried
out virtually unchanged at substantially the same cost.
In order not to complicate removal of the tablets from the film bag by
the user of the product, the coating is only applied locally, preferably in
the
form of spots and/or lines.
To produce a film bag from a section of film web, the invention also
provides a process in which a rectangular film web section is coated with
adhesive along its longitudinal edges and at both transverse ends, the at
least one tablet is placed in the zone between the longitudinal edges and
the transverse ends and the film web section is then folded about its longi-
tudinal axis so that the adhesive-coated longitudinal edges and transverse
ends lie on top of one another and the closed film bag thus formed is cut
along the two transverse ends to form transverse edges, the process being
characterized in that that part of the film web section which accommodates
the at least one tablet is also coated at least locally with adhesive.
The invention is described in more detail in the following with
reference to the accompanying drawings, wherein:
Figure 1 is a perspective view of an adhesive-coated film web for the
production of a film bag in accordance with the prior art.
Figure 2 is a partial side elevation of a pack according to the
invention.
Figures 3 to 5 are perspective views of a film web with differently
designed friction-increasing nonslip coatings for the production of a pack
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according to the invention.
A pack for tablet-form products, more particularly hygroscopic
detergent tablets 1, comprises a closed substantially rectangular film bag 2.
At both transverse edges 3, of which only one is shown in Fig. 2, the film
bag 2 is closed by a coating of adhesive to form a so-called transverse fin.
Longitudinally, the film bag 2 formed from a film web is closed by a so-
called longitudinal fin 4, as explained in more detail hereinafter. The film
bag 2 preferably accommodates two tablets 1. According to the invention,
the rear zone of contact (not visible in the drawing) of the tablets 1 with
the
inside of the film bag 2 is provided with a friction-increasing nonslip
coating,
as will be explained in more detail hereinafter.
According to the prior art, a film bag 2 without the friction-increasing
nonslip coating according to the invention is normally made from a film
web, for example of polypropylene film, as shown in Fig. 1. One such film
web is denoted by the reference numeral 5 in Fig. 1. It is provided with a
coating of adhesive along its longitudinal edges 6 and transverse ends 7
which form the transverse edges 3 of the film bag 2 after subsequent
separation along the chain lines 8. A substantially rectangular region -
denoted by the reference numeral 9 - of such a film web section 10 remains
uncoated in the prior art, two tablets 1, for example, being applied to that
region.
However, at the high tablet-wrapping rates of modern flow pack
machines, the problem exists that the tablets 1 cannot be exactly
positioned. In addition, they can easily shift longitudinally (double arrow
11 ) and transversely (double arrow 12) in the region 9 so that, as the
packaging process continues, unevenness develops on the upper surface
of the bag and leads to machine malfunctions during the subsequent
grouping of the already packed film bags 2 and their introduction into a
cardboard box by suction lifters. This is because the suction lifters are
unable to work properly. In addition, because the tablets 1 are able to shift
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in the film bag 2, tablet abrasion and edge breakage can occur.
The film bag 2 shown in Fig. 2 is made from a film web 5 according
to Figs. 1 and 3 to 5 by applying the adhesive coating along the longitudinal
edges 6 and the transverse edges 7, placing the tablets 1 in the zone 9 and
5 then folding the particular film web section 10 about its longitudinal axis
(double arrow 11) so that the two adhesive-coated longitudinal edges 6 lie
on top of one another to form a two-layer longitudinal fin 4. At the same
time, the transverse ends 7 are also folded adhesively together and then
separated along the lines 8, after which the packed film bag 2 is finished.
To produce a pack according to the invention (cf. Fig. 3), a friction-
increasing nonslip coating is applied to the contact zone 9 which is denoted
by the reference numeral 13 in Fig. 3. The coating in question is preferably
another adhesive coating which is applied at the same time as the
adhesive coatings on the longitudinal edges 6 and transverse ends 7. The
adhesive is preferably a cold adhesive. When the tablets 1 are subse-
quently placed on the region 9 thus partly coated, they automatically
adhere to the region 13 of the film so that they are exactly and safely pos-
itioned. However, the subsequent removal of the tablets 1 from a packed
film bag 2 is not difficult because the coating 13 is only locally applied.
The coating 13 can assume different forms, as shown for example in
Figs. 4 and 5. Thus, the coating 13 may be locally applied in the form of
spots andlor lines; other coating patterns are of course also possible.
Basically, the simplest solution is to form the friction-increasing
nonslip coating by an adhesive coating which is used together with the
adhesive coating to make the particular film web section 10 into a closed
film bag 2. However, any other locally friction-increasing nonslip coating
may also be applied to the region 9 in accordance with the invention.
