Note: Descriptions are shown in the official language in which they were submitted.
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The present invention rela-tes to a method o~ making
packages slip-proof.
Especially in connection with the transpor-t and
storage of goods in packages, such as sacks and boxes, the
problem of keeping the packages in a stacked position have
caused substantial difficulties. The reason is to be found in
the desire to stack the packages in high stacks which, however,
presupposes that the stacking takes place with utmost care,
and the fact that a great number of packages consist wholly
or partly of plastic. Especially plastic bags and sacks, but
also boxes of e.g. wellpap, have a smooth surface, which re-
sults in that even one wrongly positioned package can make the
whole stack tip over.
One way of avoiding this inconvenience consists of
making the packages of a non-slip material. It has for example
been suggested to manufacture such packages, especially sacks
of a plastic material, wherein one surface has been made coarse
for instance, by applying to an ordinary plastic foil a thin
layer which forms an irregular net-like structure. This
packaging material, which is suitable per se, is however
primarily intended to be used for certain purposes, especially
for sacks consisting entirely of this material, and the above
mentioned disadvantages still remain when the packaging material
consists e.g. of paper or cardboard.
`The present invention removes these disadvantages by ;
utilizing a plastic product of the above mentioned kind in such
a way that it can be used also for packages made of any
material, especially of cardboard and paper.
According to the present invention there is provided
`` 30 a method of providing non-slippery areas on the normally
;slippery exterior surfaces of bags, sacks or the like flexible
walled containers, comprising forming a non-slip plastic strip
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by extruding a plastic foil in the form of a tube with a eoarse
non-slippery net-like surface at least on one side of the foil,
eutting the tube longitudinally to form a strip of the plastic
foil, winding the strip into a eoil, pulling off a length of
the eoil strip and removing a portion therefrom, and fixing
the portion to the exterior surfaee of the container so that
the coarse net-like surface, or one of the surfaces, of the
portion lies outwardly.
The present invention thus provides a method of
additionally treating the plastic product obtained in tube form
so that it can be applied to any package in such areas whereby
it, when stacked, transported or under similar conditions will
eome into contaet with those surfaees with whieh sliding
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might take place. These areas are primarily the upper and the
lower surfaces of the package, which come into contact with the
adjoining packages, and according to the invention it is thus
possible to provide these surfaces with one or more strips of
the non-slip material. It is also suitable to use these adhesive
strips for closing the packages, the closing strips simultaneously
forming a non-slip surface to which another package grips even
when this has a smooth surface.
~lthough the invention also includes a method according
to which the tubular plastic foil is cut so that only one or two
flat plastic webs are obtained, which can be wound onto a corres-
- ponding number of rolls, the method primarily comprises cutting
the foil into a plurality of strips, which are wound onto easily
managable separate rolls. According to one and the same method
strips of varying width can be manufactured and it is also
possible to wind strips of varying length onto the different
I rolls.
¦ According to the invention the plastic foil can be made
sticky either by applying thereto an adhesive, or by thermally
softening (thermal sealing) those surfaces intended to come into
engagement with the packages. The thermal softening can be
effected by means of conventional devices which, if desired, can
soften the whole area of the plastic foil or only those parts
which are to stick to the packages, for instance, in form of
bands, dots or lines.
The adhesive can be applied to the plastic foil after
cutting up the same when this lies in one or in two planes one
above the other, which foil webs thereafter or not until cut up ;~
into their final widths are fed over suitable adhesive rolls which
apply adhesive to one of their surfaces. Naturally it is also
¦ possible to apply the adhesive by spraying or in any other known
way and it is also possible after applying the adhesive -to dry
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the adhesive e.g. by feeding the foil over suitable heating rolls.
Thus, according to the above described method rolls are
obtained wherein the coiled foil strip has its adhesive surface
always engaging directly the norl-slip surface of the underlying
layer. When desired the foil strips can also be provided with a
conventional protective layer, which covers the adhesive surface
and which is ripped off beEore using the strip. These protective
coverings can be applied as a continuous layer onto the entire
! web width after providing the same with an adhesive layer, or
alternatively after cutting the strips into their final width.
In the last mentioned case it is then possible to make the pro-
tective layer somewhat wider than the foil strip which facilitates
¦ its removal.
It is also possible to provide the adhesive foil with
reinforcing threads or a reinforcing net which is applied in
connection with the application of the adhesive or in connection
with the extrusion of the plastic foil.
As the manufacturex of the adhesive products in question
are completely free to choose the width of the strips in any
desired manner, it is understood that the expression "strip" also
comprises fairly wide strips which are of importance when e.g.
cardboard boxes of predetermined dimensions are to be provided
with such strips. The width of the strip can then be chosen
exactly as desired, for example so that the whole bottom and/or
top of the cardboard box is covered with a non-slip foil strip of
corresponding size. It is, however, to be understood that also
fairly narrow strips corresponding to the commonly used tape-
strips, e.g. for closing packages, can provide a big enough non-
slip surface which prevents the packages from sliding when in
contact with slippery surfaces.
The adhesive strips may be wound up onto rolls in con-
tinuous lengths, which are not cut into suitable lengths by means
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of conventional cutting devices until the strips are to be used.
It is however, also possible to provide the strips with trans-
verse perforations so that adhesive s-trips of a predetermined
length can be torn off. This perforation is made in a conventional
manner and at any desired manufacturing stage. In case the
adhesive surface is protected with a protective layer of paper
or plastic, the perforations can include also this layer. It
is also possible to stamp out from a wide foil provided with a
' protective layer variously shaped bodies such as triangular,
circular, annular bodies and the like, which may be only per-
forated in order to be separated completely only at time of use.
