Note: Descriptions are shown in the official language in which they were submitted.
THERMAL CONTAINER
The present invention relates to a thermal container which comprises at least
one flat back cushion and a flat front cushion extending in a different plane
above the back cushion, said cushions being connected to one another at
opposite side edges as well as at a further side edge of the thermal container
or being integrally formed or transitioning into one another via a connecting
piece so that a cavity is formed between the back cushion and the front
cushion, the back cushion and the front cushion each being formed from at
least one bag or at least one compartment and from a fibrous material located
in the at least one bag or the at least one compartment, wherein the fibrous
material comprises a stack of a plurality of individual layers made from
creped
fibrous material lying flat one above the other.
Publication EP 3 772 472 Al describes a thermal container of this type. Air
collects between the creped individual layers lying flat one above the other,
which leads to a temperature retention capability of the known thermal
container of up to 72 hours.
The known thermal container has the advantage that due to the fibrous
material that is predominantly used for this purpose it is ecologically
harmless
to recycle.
However, an even longer temperature retention capability of the thermal
container would be desirable for different application purposes or at ambient
temperatures deviating greatly from the temperature of the packaging material.
Publication DE 20 2019 003 407 U1 describes a packaging made from
corrugated cardboard for holding and/or transporting temperature-sensitive
products. The corrugated cardboard is folded to form a cuboid carton, wherein
the side walls of the carton are each formed by two spaced-apart claddings
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Date Recue/Date Received 2022-08-04
between which a thermal insulation material is accommodated. The thermal
insulation material can be, for example, a tubular bag containing paper
shreds.
Such a thermal container serves to maintain the temperature of a packaged
product placed in the carton over a certain period of time. Thanks to the
thermal container, cooling of the packaged goods placed therein, such as food,
drugs, or blood bottles that are to be kept cool, can thus be maintained over
a
certain period of time within a certain temperature window.
However, the known thermal container is relatively difficult to produce. For
example, the size and shape of the tubular bag must be exactly adapted to the
cuboid interior space formed between the claddings of the side walls, and the
tubular bag must subsequently be fastened to the inside with an adhesive. This
is already difficult because the paper shreds in the tubular bag keep
shifting.
Since the paper shreds shift downwards even during use of the thermal
container, the claddings of the side walls must be relatively close together.
Accordingly, only a limited quantity of paper shreds can be accommodated
between the claddings, so that the thermal insulation effect of the cardboard
side walls filled with the paper shreds is only slightly greater than that of
conventional cardboard side walls.
Since the paper shreds cannot be prevented from shifting in this thermal
container, the container does not have stable thermal insulation properties on
all sides, thus making it unsuitable in particular for the transportation and
storage of thermally sensitive products.
It is therefore the object of the present invention to provide a thermal
container
that has a relatively long-term temperature retention function even for
thermally sensitive products.
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Date Recue/Date Received 2022-08-04
This object is achieved by a thermal container which comprises at least one
flat back cushion and a flat front cushion extending in a different plane over
the
back cushion, said cushions being connected to one another at opposite side
edges as well as at a further side edge of the thermal container or being
integrally formed or transitioning into one another via a connecting piece so
that a cavity is formed between the back cushion and the front cushion, the
back cushion and the front cushion each being formed from at least one bag
or at least one compartment and from a fibrous material located in the at
least
one bag or the at least one compartment, wherein the fibrous material
comprises a stack of a plurality of individual layers made from creped fibrous
material lying flat one above the other, wherein the fibrous material further
comprises at least one layer of randomly oriented loose paper shreds and/or
hemp shreds, which layer is not separately enclosed and is arranged in each
case between two of the individual layers formed from unordered fibers and
each having a crepe height 0.3 mm and < 1 mm.
Both cold and warm objects can be stored and transported in the thermal
container according to the invention. The thermal container according to the
invention is particularly suitable as a cooler bag. The at least one object,
the
temperature of which is to be maintained, can advantageously be inserted into
the cavity formed between the back cushion and the front cushion connected
thereto. The cavity can then be closed appropriately.
The creped individual fibrous layers of the back cushion and the front cushion
in themselves bring about a particularly advantageous thermal insulation of
the
at least one object placed in the thermal container from the surroundings.
This
is achieved in particular by the air inclusions or air gaps formed between the
individual layers made from creped fibrous material lying flat one above the
other. Due to creping of the individual layers, each of the individual layers
has
a plurality of peaks and troughs with air accumulating in the troughs. Since
the
creping is never identical from one individual layer to the next, and the
individual layers are not stacked on top of one another or pressed into one
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Date Recue/Date Received 2022-08-04
another in a form-fitting manner, the troughs of the respective overlying
individual layerl do not or do not completely fit into the troughs of the
respective
underlying individual layer, so that an air gap is maintained in all cases.
Moreover, in the present invention a layer of paper shreds and/or hemp shreds,
i.e., a layer of randomly oriented paper shreds and/or hemp shreds, is
arranged at least between two of the creped individual layers. Although the
paper shreds are individual paper elements not connected to one another to
form a closed layer, and the hemp shreds are individual hemp elements not
connected to one another to form a closed layer, which shift, for example, in
the side walls of the thermal container described in publication DE 20 2019
003 407 U1 and which are not held together separately by a bag or the like in
the present invention, the paper shreds and/or the hemp shreds surprisingly
remain largely in their respective positions between the individual layers in
the
present invention. This is due to the special creping of the individual layers
lying on both sides of the shredded paper layer and/or shredded hemp layer.
The peaks and troughs, which are formed as a result of the creping of these
individual layers and are spaced apart from one another in terms of their
height
by no more than 1 mm, particularly preferably by less than 0.4 mm, act like
teeth that hold the paper shreds and/or the hemp shreds so that they cannot
shift between the individual layers.
In the present invention, at least these two creped individual layers arranged
on both sides of the shredded paper layer and/or shredded hemp layer, but
preferably all of the creped individual layers, have a crepe height of 0.3 mm,
so that a large amount of air can collect between the individual layers or at
least between the shredded paper layer and/or shredded hemp layer and the
individual layers lying on both sides of the shredded paper layer and/or
shredded hemp layer, which air serves for thermal insulation.
Moreover, a large number of air gaps are formed between the paper shreds
and/or hemp shreds, which in addition to the air inclusions already present
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Date Recue/Date Received 2022-08-04
between the individual layers result in excellent thermal insulation
properties
of the thermal container.
The paper shreds and/or hemp shreds are unordered, i.e., they have a wide
variety of orientations within the layer. They can thus lie one above the
other
and/or form tangles and/or project in the direction of the respectively
abutting
creped individual layer.
In order to form suitably large air inclusions between the individual layers
and
to hold the paper shreds and/or hemp shreds well, each of the individual
layers
preferably has a crepe height of 0.3 mm, preferably of 0.4 mm, particularly
preferably of 0.6 mm, or of 0.65 mm in one exemplary embodiment. This is
therefore so-called high creping.
For example, in the present invention, either 4 or 8 of the creped individual
layers are stacked one above the other without intermediate paper shreds
and/or hemp shreds, i.e., 4-layer or 8-layer stacks are formed, wherein one
layer of the shredded paper and/or shredded hemp is arranged between each
two of the 4-layer or 8-layer stacks. For example, the thermal container 16
has
creped individual layers with one or three shredded paper layers and/or
shredded hemp layers.
The bag or compartment also has a protective function for the fibrous material
located therein.
The fibrous material used in the present invention both for the creped
individual
layers and for the paper shreds, which can be a primary fibrous material such
as a pulp, a mechanical wood pulp or a semichemical paper pulp, and/or a
secondary fibrous material such as a fibrous material obtained from recycled
paper, and the hemp used for the hemp shreds have the advantage that they
are both natural materials that are harmless to the environment and easy to
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Date Recue/Date Received 2022-08-04
recycle and as such exhibit low heat conduction and thus good thermal
insulation properties.
Unlike paper or the corrugated cardboard used in publication DE 20 2019 003
407 U1, at least the two individual layers, which are located on both sides of
the respective layer of paper shreds and/or hemp shreds, are formed from
unordered fibers. These individual layers, which are in addition also creped,
thus have a higher surface roughness than paper or corrugated cardboard and
thus hold the paper shreds and/or hemp shreds particularly well.
In addition, the form of the fibrous material used leads to an advantageous
softness and bulkiness, which ensures that the packaged good can be safely
stored and transported in the thermal container.
The thermal container, according to the invention, is easy to stack but can
also
be used as a shopping bag.
In a preferred embodiment of the present invention, a coefficient of static
friction between one of the individual layers and a layer of the paper from
which
the paper shreds are formed, is greater by at least a factor of 1.1,
preferably
by at least a factor of 1.25, particularly preferably by at least a factor of
1.34,
than the coefficient of static friction between two layers of the paper from
which
the paper shreds are formed.
As a result, the paper shreds adhere particularly well to the creped
individual
layers and thus hardly shift. In particular, the paper shreds adhere better to
the
creped individual layers than they would adhere, for example, to cardboard
packaging as used, for example, in publication DE 20 2019 003 407 U1 to form
the side walls of the packaging. Even more so, in this embodiment of the
invention the paper shreds adhere better to the creped individual layers than
they would adhere to the tubular bag consisting of a polyethylene film in
which
they are accommodated in publication DE 20 2019 003 407 U1. Thus, the
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Date Recue/Date Received 2022-08-04
coefficient of static friction between a layer of the paper from which the
paper
shreds are formed and one of the creped individual layers used in the present
invention is greater by at least a factor of 1.9 than the coefficient of
static friction
between a layer of the paper from which the paper shreds are formed and the
polyethylene film used in publication DE 20 2019 003 407 U1.
Assuming that the coefficient of static friction between two layers of the
paper
from which the paper shreds used in the present invention are formed is on
average 0.4, in the present invention the coefficient of static friction
between a
layer of the paper from which the paper shreds are formed and one of the
individual creped layers will be at least 0.5, preferably 0.55 and
particularly
preferably above 0.6, under the same measurement conditions.
The individual layers of the creped fibrous material preferably have a creping
factor of at least 40%, in a special embodiment 44%. The latter creping factor
corresponds to an elongation of 80%.
If the at least one bag in the present invention is formed from a fleece made
of
thermoplastic material, it offers good moisture protection for the fibrous
material therein, which has good absorbency. This is particularly the case if
the
fleece is a polypropylene spunbond.
It is particularly advantageous if the at least one bag encompasses the
fibrous
material like a tube. In this case, lateral edges of the at least one bag can
also
be sewn up.
In another, likewise advantageous embodiment of the present invention, the at
least one bag or the at least one compartment of the back cushion as well as
the at least one bag or the at least one compartment of the front cushion are
made from paper. As a result, the entire thermal container consists of
ecologically recyclable material, namely paper and fibrous material.
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Date Recue/Date Received 2022-08-04
In an advantageous embodiment of the invention, this can be achieved in that
the at least one bag or the at least one compartment of the back cushion as
well as the at least one bag or the at least one compartment of the front
cushion
are formed by an inner paper bag inserted into an outer paper bag, wherein
the fibrous material is located each time between an outer side of the inner
paper bag and an inner side of the outer paper bag. The inner paper bag is
thus inserted into the outer paper bag, and the fibrous material is inserted
between the material of the inner paper bag and the material of the outer
paper
bag at least on the front side and the back side of this embodiment of the
thermal container according to the invention. The respectively packaged item,
which is typically to be kept cool, can then be placed into the inner paper
bag.
In an expedient configuration of this embodiment of the invention, the inner
paper bag and the outer paper bag while containing fibrous material are
connected to one another. As a result, the fibrous material inside cannot
slide
out of the space between the outer paper bag and the inner paper bag. This
also means that there is no risk of the packaged item sliding into the space
between the outer paper bag and the inner paper bag.
The thermal container according to the invention is particularly ecologically
valuable if the creped fibrous material is made from cellulose wadding, which
is made from at least 90% recycled waste paper with waste paper qualities in
accordance with DIN EN 643.
It has been found to be particularly advantageous if the paper shreds are made
from shredded or chopped paper or if the hemp shreds are made from
shredded or chopped hemp. For example, paper shredded for reasons of data
privacy can be used in an ecologically worthwhile manner. Moreover, the
dimensions of paper shredded by conventional shredding devices are ideal for
achieving good temperature retention capability in the thermal container
according to the invention.
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Date Recue/Date Received 2022-08-04
Preferably, the paper shreds and/or hemp shreds have a width in a range of
0.5 cm to 1 cm. The length of the paper shreds and/or hemp shreds can be
the same or different. For example, the paper shreds and/or hemp shreds can
be up to 4 cm long or longer. The longer the paper shreds and/or hemp shreds,
the better the thermal properties of the thermal container according to the
invention.
Preferred embodiments of the present invention are explained in more detail
below with reference to figures, wherein
Figure 1 schematically shows in a top view a possible embodiment of a thermal
container according to the invention;
Figure 2 schematically shows in a top view an embodiment of the thermal
container according to the invention with a packaged item inserted;
Figure 3 schematically shows in a sectional side view a possible embodiment
of a back or front cushion of an embodiment of the thermal container according
to the invention; and
Figure 4 schematically shows in a perspective side view another embodiment
of the thermal container according to the invention.
The represented embodiments are not shown to scale in any of the figures.
Rather, for the sake of clarity, certain features are shown particularly large
in
the figures in comparison to other features of the invention. Most of the
hidden
features are shown with dashed lines.
Figure 1 schematically shows in a top view a possible embodiment of a thermal
container 1 according to the invention. In the exemplary embodiment shown,
the thermal container 1 is a cooler bag for transportation purposes. Such a
cooler bag can have, for example, an outer width from 300 to 600 mm and an
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Date Recue/Date Received 2022-08-04
outer length from 300 to 600 mm. The closure flap of the cooler bag can have
a length from 50 to 120 mm. Other dimensions are also possible, of course.
The thermal container 1 can, however, also be used to keep objects warm
In Figure 2, the thermal container 1 from Figure 1 is shown in a top view. It
is
open and a packaged item 15 has been inserted therein.
The thermal container 1 has a flat back cushion 2 and a flat front cushion 3.
The back cushion 2 is connected to the front cushion 3 on the opposite side
edges 4, 5 of the thermal container 1. In the exemplary embodiment shown,
this connection is realized by seams 16, 17 running along the side edges 4, 5.
In other embodiments of the invention, which are not shown, this connection
can be made alone or in combination with the seams 16, 17 by gluing and/or
crimping the material.
In the exemplary embodiment shown in Figs. 1 and 2, the back cushion 2 and
the front cushion 3 are formed from the same material web in the form of a bag
web. For this reason, the back cushion 2 is formed integrally with the front
cushion 3 on a further side edge 6 of the thermal container 1. The material of
the back cushion 2 thus merges directly into the material of the front cushion
3 at the side edge 6 which can form, for example, a lower edge of a pocket.
In other embodiments of the present invention that are not shown, the back
cushion 2 and the front cushion 3 can also be formed separately and
connected to one another at the side edge 6. Furthermore, it is possible that,
in other embodiments of the present invention, at least one piece of material
is provided between the back cushion 2 and the front cushion 3 and connected
to the side edges 4, 5 and/or 6. The piece of material can, for example, be
strip-like or web-like.
Date Recue/Date Received 2022-08-04
A cavity 7 is formed between the back cushion 2 and the front cushion 3, into
which the packaged good 15 is inserted, as can be seen in Figure 2.
In the embodiment shown in Figs. 1 and 2, the back cushion 2 has a back
cushion section 21 protruding from the front cushion 3 on one side. In other
embodiments of the present invention, a closure flap can also be connected to
one side to the back cushion 2. The protruding back cushion section 21 or the
closure flap, as indicated schematically by the arrow A in Fig. 2, is folded
onto
a surface of the front cushion 3 to close the cavity 7 and is connected
directly
or indirectly to it. The protruding back cushion section 21 or the closure
flap
can, for example, be glued to the front cushion 3 by means of adhesive lines.
Adhesive tufts may be used for this as well.
The back cushion 2 and the front cushion 3 each comprise a bag 8. The bag
8 encloses a fibrous material 9 in a tube-like manner. As can be seen in
Figure
4, at least one compartment 18 may be provided instead of the bag 8 in which
the fibrous material 9 is located. Compared to the bag 8, the compartment 18
is not completely formed around the fibrous material 9 but can be closed in
advantageous variants of the invention.
In the thermal container 1 shown in Figures 1 and 2, the fibrous material 9 is
used, which is shown schematically in Figure 3 in a sectional side view that
is
not to scale.
The fibrous material 9 consists of a stack of a plurality of individual layers
91
made from creped fibrous material lying flat one above the other. What is
special about the creped fibrous material used here is that it is so-called
high
crepe. The creped fibrous material used therefore has a particularly high
crepe
height d of 0.3 mm, for example of 0.35 mm, per individual layer 91. In
some embodiments of the present invention, the crepe height d is even greater,
for example 0.5 mm or even 0.65 mm. In the material used, which is
cellulose wadding in the exemplary embodiment shown, the crepe height d of
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Date Recue/Date Received 2022-08-04
0.65 mm leads to an elongation of 80% which in turn corresponds to a crepe
factor of 44%.
High crepe is a very thin material which can also have holes,
In the exemplary embodiment shown, the grammage of the creped fibrous
material used is 23 grams per square meter, but can also be different in other
embodiments of the invention.
In the embodiment shown, the coefficient of static friction between one of the
individual layers 91 and a layer of the paper, from which the paper shreds 92
are formed, is greater by at least a factor of 1.34 than the coefficient of
static
friction between two layers of the paper from which the paper shreds 92 are
formed. This was tested as follows:
A flat mat was used for each of the test measurements; this was checked by
means of a water level. In test measurements (a) the mat was covered in each
case with one layer of the paper, from which the paper shreds 92 are formed;
in test measurements (b) it was covered in each case with a polypropylene
film; in test measurements (c) it was covered in each case with a layer of
cardboard; and in test measurements (d) it was covered in each case with one
of the creped individual layers 91, here with high crepe. Furthermore, a
planar
surface of a measuring body was covered with a layer of the paper from which
the paper shreds 92 are formed. The dimensions of the measuring body
consisting of beech wood are 10 cm x 10 cm x 1.8 cm.
The covered measuring body was placed on the covered mat. The mat was
then raised on one side until the measuring body moved. The height by which
the mat was raised until the measuring body moved was measured and
recorded. The following measured values resulted:
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Date Recue/Date Received 2022-08-04
Friction pairing Measured Measured Measured
values test 1 values test 2 values test 3
(a) Paper/paper 27.2 28.0
27.2
(b) Paper/polypropylene 17,1 19.3
18.0
film
(c) Paper / cardboard 27.7 32.0
27.0
joifqper / high crepe 37.8 38.1 36.5
Table 1: Measured values from static friction test
In the exemplary embodiment shown, the creped fibrous material was
produced in the following way:
The base material that was used is recycled cellulose wadding from selected
waste paper qualities in accordance with DIN EN 643.
After a wet pulping process and removal of non-paper components, but without
additional bleaching, the recycled cellulose wadding was creped out on a
Yankee cylinder by means of a ceramic-coated steel scraper.
In order to achieve the high crepe height d and thus a high volume of the
stack
formed from the individual layers 91, the adhesion of the cellulose fibers to
the
cylinder surface, the geometry of the scraper as well as the angle of attack
of
the scraper and the draft angle of the creped cellulose wadding web are
specifically adjusted. The elongation or the crepe factor is produced
accordingly by the difference in speed between the Yankee cylinder and the
reel-up.
After creping, the individual layers 91 are doubled, for example to form a
plurality of stacks with 4 individual layers 91 each. This is preferably done
on
a laying machine. The individual layers 91 typically lie one above another in
the same layer generation direction. However, since the creping never lies
exactly one above the other, the stacking of the individual layers 91 results
in
a correspondingly high stack height and at the same time a high stack volume.
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Date Recue/Date Received 2022-08-04
In principle, however, it is also conceivable to place the individual layers
one
above the other with an alternating alignment so that the creping crosses from
individual layer 91 to individual layer 91 or so that the respective creping
of the
individual layers 91 crosses.
Paper shreds 92 are then scattered onto one of the stacks of the individual
layers 91 and a further stack of the individual layers 91 is placed on this
layer
of paper shreds. This process can be repeated several times so that, as a
result, a stack of the creped individual layers 91 is formed with at least one
layer of the paper shreds 92, each arranged between two of the individual
layers 91'.
The creped individual layers 91' on either side of the layer of paper shreds
92,
each of which creped individual layers can have the same creping but also a
different creping from the other individual layers 91, have a crepe height d <
1
mm, preferably <0.6 mm, in certain cases of < 0.4 mm.
The stack produced in this way is/can then be cut into the desired width
depending on the size of the back cushion 2 and the front cushion 3.
Subsequently, the stack is enclosed within the bag 8.
In the exemplary embodiment shown in Figures 1, 2 and 3, the bag 8 consists
of a polypropylene spunbond with which the stack of the individual layers 91
and the paper shreds 92 is enclosed in a tube-like manner. The polypropylene
spunbond ensures cohesion of the individual layers 91, 911 and of the paper
shreds 92.
The proportion of the bag 8 in relation to the total weight of the thermal
container 1 is not more than 4 wt.%. Thus, according to Art. 16(3) of the
German Packaging Act (VerpackG), the thermal container 1 can be fully
credited against the quota of paper. This results in disposal cost savings.
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Date Recue/Date Received 2022-08-04
As shown schematically in Figure 1, the bag 8 can be fastened to the creped
fibrous material 9, which is located outside in the stack, by means of lines
13
of hotmelt adhesive placed at a distance from one another. These lines are,
for example, approximately 20 mm apart and extend along the material web
from which in each case the back cushion 2 and the front cushion 3 are formed.
It is advantageous if this material web has areas filled with the fibrous
material
9 and adjoining pure fleece areas. Then, a fleece area, which adjoins a back
cushion section of the material band, can be used as a closing flap for
closing
the thermal container 1. A fleece protrusion over the areas filled with the
fibrous
material 9 can, for example, be approximately 50 mm.
In order to form the back cushion 2 and the front cushion 3 from the material
web, the latter is cut transversely to its web running direction.
Subsequently, a section of the area of the separated material web piece filled
with the fibrous material 9, which later forms the front cushion 3, is folded
over
the rest of this material web piece that forms the back cushion. The side
edges
4, 5 are then sewn and/or glued and/or crimped together. The crimping is
preferably carried out by means of gears. The gluing can be dispensed with.
Figure 4 schematically shows another embodiment of a thermal container 1'
according to the invention in a perspective side view.
The thermal container 1' comprises an outer paper bag 11 and an inner paper
bag 12 located in the outer paper bag 11. Fibrous material 9, which is
constructed as described above, is inserted between the inner paper bag 12
and the outer paper bag 11 on at least two opposite sides of the thermal
container 1'.
Date Recue/Date Received 2022-08-04
The inner paper bag 12 and the outer paper bag 11 are connected to one
another while including the fibrous material 9.
Carrying handles 14 are provided on an upper side of the thermal container 1'.
Suitable closure means may also be provided on the thermal container 1'.
As shown, the thermal container 1' may have a block bottom 19 but may also
be designed without the block bottom 19.
In the described embodiments, hemp shreds can be used instead of the paper
shreds 92 or in addition to the paper shreds 92.
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Date Recue/Date Received 2022-08-04
