[0001] The invention relates to a blister-pack with a frame consisting of plane material
with a window-like cut-out,and at least two lateral support sections at an angle to
the outer periphery of the frame, to which a plastic foil is applied in the window
in the form of a trough.
[0002] Blister-packs of the type mentioned above are known from DE-GM 76 37 448. Their production
consists of laying the frame, usually a corrugated cardboard blank, with the window
over a positive mould, then laying a heated foil on the projections of the mould and
the cardboard blank. By means of partial vacuum it is sucked close to the projections
and the surface of the cardboard, and in doing so it forms a skin on the surface of
the cardboard, and finally after mould release the embossed foil is pressed through
the window to form the foil trough.
[0003] Blister-packs serve for the transportation and storage of packaged goods which are
sensitive to impact and easily breakable. The blister-pack carrying the packaged goods
is either enclosed in a despatch carton or two blister-packs surround the packaged
goods and form in themselves the packing for transport when suitably fixed by a band.
In the case of known blister-packs the foil forms a skin over the entire cardboard
blank, including the lateral support sections. This is bound up on the one hand with
the mode of production used, in which the cardboard blank is laid flat on a set of
moulds over the extent of the drawing-bench the other hand, by means of the skin process
only a limited adhesion between foil and cardboard can be achieved, because if one
exceeds a certain temperature in the attempt to improve adhesion, when the partial
vacuum is applied the foil is sucked into the fine channels of the corrugated cardboard
at the inner edges of the window, so that a kind of perforation line develops there
which accordingly possesses diminished strength.
[0004] The known blister-packs thus involve a higher foil consumption than would be required
to take the packaged goods. In addition, as a result of this the mould release is
made so much more difficult that in practice after the foils have formed the skin
the blister-packs are released from the moulds by hand with a knife. Under certain
conditions, it is true, the use of mechanical cutters is possible; yet here too, a
considerable waste of foil cannot be avoided.
[0005] The Invention is based on the problem of producing a blister-pack of the type mentioned
above in which the foil consumption is considerably reduced whilst maintaining an
adequate adhesion and without considerably influencing the tearing strength at the
inner edges of the window.
[0006] Starting from a blister-pack of the type mentioned at the outset, this problem is
solved according to the invention by the fact that the foil is joined to the part
of the frame only as far as the point of junction with the lateral support sections,
by heat-sealing.
[0007] In the blister-pack according to the Invention, the foil covers only the part of
the frame as far as the points of junction or folding lines of the lateral support
sections, or possibly one millimetre beyond. As compared with the known blister-packs
this represents a considerable saving in foil, for example 50 per cent or more. Packaging
using the blister-packs according to the Invention can then be even cheaper than the
cheapest known packages on the basis of rigid foam substances, which suffer from special
problems of space requirements and their destruction after use. Furthermore as a result
of the restricted amount of foil covering no mould release problems occur when producing
the blister-packs according to the invention.
[0008] By means of heat sealing the foil is firmly joined to the plane material, which facilitates
both a good adhesion to the plane material and also the avoidance of an adverse effect
on the tearing strength at the inner edges of the window.
[0009] The production of the blister-packs according to the Invention can for example take
place by pushing the frames on to upright sets of moulds in thermoforming machines,
so that the lateral support sections are located in a vertical arrangement inside
the set of moulds and are not sealed, or else one inserts the frames in line into
individual moulds which are simultaneously sealed to the foil and separated by a hot
sealing plate, so that a deep-drawing process takes place by means of contact heating
and compressed air shaping in one working cycle, similar to what happens in the usual
automatic deep-drawing machines for compound foil shaping in the foodstuffs industry.
A particularly suitable process will be described later on.
[0010] Solid cardboard, corrugated cardboard or even laminated sealable plastic resembling
corrugated cardboard can be used for the plane material for the frame, but corrugated
cardboard is preferred.
[0011] The plastics foil, ie sheets or films used in the present invention are preferably
transparent sheets suitable for deep-drawing especially polyethylene laminated foils,
which are coated on the inner side, ie the one which comes into contact with the plane
material, with an adhesion layer, eg of an ethylene polymer eg, an ethylene/vinyl
acetate co-polymer or an ethylene/acrylic acid/acrylate ester terpolymer. These co-polymers
possess an excellent adhesion both to polyethylene and the plane material.
[0012] However, one can also coat the plane material in thesealing area first of all with
polyethylene or an ethylene/vinyl acetate co-polymer dispersion or an ionomer resin
dispersion, and then apply by means of hot sealing and simultaneous deep-drawing a
normal polyethylene foil, ethylene/vinyl acetate co-polymer foil or ionomeric foil.
The ionomers in question are pseudo-crosslinked, thermoplastic, transparent plastics,
chiefly co-polymer of ethylene with monomers containing carboxyl groups. (See Römpps
Chemielexikon, 7th Edn, Frank'sche Verlagsbuchhandlung, Stuttgart 1973, pp 1622, 1623.)
A particularly suitable ionomer is commercially obtainable under the trade name "Surlyn
A" (Manufacturers: Du Pont).
[0013] Moreover, the plane material can be coated in the sealing area first of all with
a coating containing polyvinylchloride, which makes possible the use of PVC foils.
[0014] To achieve greater stability laminated foils of three or more layers are used, in
which the outer layer consists of a polyamide or polyester and the inner layer consists
of plastic which can be sealed with the plane material, for example the abovementioned
ethylene/vinyl acetate co-polymers.ethylene/acrylic acid/acrylate ester terpolym or
ionomer resins. These foils also possess the advantage that during the heat sealing
process they do not stick to the contact heating devices even at high temperatures.
[0015] Packaging with the blister-packs according to the Invention is done either by inverting
a blister-pack over the goods to be packaged, which are prepared in a despatch box
on anti-crush pad, or else by using two blister-packs which may be surrounded by a
packing carton, in which case preferably care should be taken to see that both blister-packs
are given a certain amount of pre-tensioning.
[0016] The blister-packs of the Invention possess at least two lateral supporting sections.
The strength of the blister-pack when assembled is thus, it is true, not optimum,
but is adequate for some purposes, especially if the blister-packs are used in conjunction
with packing cartons. Possibly parts of the packing carton, especially flaps, could
take over support functions as well. Without the use of a packing carton a considerably
greater strength can be attained by means of lateral support sections on all four
sides of the frame.
[0017] Naturally one must take care to see that the height of the supporting sections is
at least as great as the depth of the foil troughs.
[0018] The dimensions and shape of the frame and also the shape . of the window are not
subject in principle to any special restrictions. On the grounds of economising on
material one selects the frame to be only as wide as is absolutely necessary, but
one should not go below a certain minimum width for reasons of breaking strength and
foil adhesion. The shapes of the window and the trough are chosen to suit the dimensions
of the goods to be packaged and the type of pack (one or two blister-packs, with or
without packing carton).
[0019] In an advantageous design the blister-pack according to the Invention has a window-like
cut-out which is larger than the packed goods to be accommodated or larger than the
part of the packed goods to be accommodated.
[0020] In the packs formed from two blister-packs known from DE-GM 76 37 448, the blister-packs
have windows of the size of the part of the packed goods lying in them. Whilst the
packed goods are not meant to come in contact with the outer walls of the packing
carton, the edges of the packed goods are to be partially retained by the window cut-outs
in the plane material and to this end it is further provided that bent-over parts
of the cardboard blanks located on the lateral support sections rest against the packed
goods.
[0021] When corrugated cardboard is used, however, it has been found that the upright ridges
in the corrugated cardboard area chafe through the foil, which affects the strength
of the packaging, but also the packed goods are so badly damaged by the rubbing movements,
even if the foil is not chafed right through, that for example in the case of veneered
loudspeaker units the goods are no longer saleable.
[0022] Furthermore,in the case of corrugated cardboard which is in contact with the packed
product, the deceleration figures for the drop test leave something to be desired,
since in free fall there is a very strong braking action exerted on the packed product
because of the high compression value.
[0023] The above problems are avoided if the window-type cut-out is larger than the packed
product to be enclosed or is larger than the part of the packed product to be enclosed.
[0024] In a further advantageous design the lateral parts of the foil trough in the blister
pack containing the packed product do not run parallel to the external surfaces of
the packed product lying there, but run outwards from the edges of the packed product
surfaces located on the bottom of the foil trough. In respect to the blister-pack
this means that the side walls of the foil trough from the inner edge of the window
outwards do not run downwards vertically to the plane of the frame, but deviate inwards
from the perpendicular by an angle amounting to at least about 10°. The top limit
is determined by economic considerations, which would render angles of more than 70°
of no interest. Generally speaking the angle is from 20 to 60
0, preferably 30 to 50°, an angle of about 45
0 giving particularly good results in many cases. In most cases only a small depth
of the foil trough is necessary , since it has only to be large enough to ensure that
the packed product is fixed, e.g..between two blister-packs.
[0025] Production of the foil trough as shown can be achieved in an advantageous manner
by using a mould which is obtained by means of forming a suitably dimensioned piece
of foil over the packed product in the state suitable for deep-drawing, by means of
a draw frame, the window of the draw frame being adapted to the desired window of
the subsequent blister-pack, that is to say, the window of the draw frame preferably
possesses approximately the same dimensions as the window of the subsequent blister-pack.
A suitable mould is obtained from the foil cast, e.g. by plaster-casting. In special
cases the window of the draw-frame is chosen somewhat smaller for the production of
the mould. This is described below.
[0026] The design of the blister-pack in such a manner that on the blister-pack containing
the packed product the inner edges of the frame window do not come into contact at
any point with the packed product can be achieved in yet another advantageous model,
however, by letting the blister-pack have a foil border running round the inner edges
of the window which projects over the frame. As a result of the foil border one achieves
a better strength distribution and thus a spring effect if the pack falls. This foil
border is obtained by designing the mould used in such a way that the upper edge of
the mould has a greater width than the frame of the blister-pack. But one can also
produce the foil border in such a manner that one keeps a correspondingly dimensioned
strip free from heat contact inside the window during the heat-sealing process, e.g.
by means of a groove in the heating plate used for sealing.
[0027] An especially good distribution of strength is achieved by using blister-packs which
possess both a foil border projecting inwards and trough side walls deviating inwards
from the perpendicular.
For producing these blister-packs preferably a mould is used obtained as a result
of excess pressure of a foil sheet in a condition suitable for deep-drawing, by means
of a tensioning frame over the packed product and casting of the foil mould so obtained
with a moulding compound, the dimensions of the tensioning frame window, however,
being somewhat smaller as compared with the window of the subsequent blister-pack,
namely are reduced by the width of the foil border.
[0028] In a further advantageous design of the new blister-pack having a subdivided window
with several separate troughs, these latter are separated not by ridges made of the
frame material but formed of the foil. This has the advantage that one can produce
blister-packs with a differing number of troughs from the same blank. In addition,
with partitions consisting of foil no safety gap is required as is the case with partitions
of corrugated cardboard.
[0029] In a further advantageous design the blister-pack according to the invention possesses
four lateral supporting sections, two adjoining sections being joined to each other
in each case, and a crease running diagonally over the frame which in each case continues
in the narrow support sections in such a way that the creases between frame and narrow
support sections form the angle bisectors for the angles enclosed by the creases.
For it has been found that assembling blister-packs provided only with four lateral
support sections or assembling blanks which are merely pre-creased requires such a
high time outlay at the packing factory that the costs incurred by this are higher
than the costs for the blank.
[0030] The blank used for the production of the blister-pack according to the Invention
is stored in the collapsed condition (diagonally folded) and erected by positive action
by the application of slight lateral pressure before the foil is applied. The finished
blister-packs are then collapsed diagonally again, stored flat and despatched, and
when used are again erected by positive action by a slight lateral pressure.
[0031] In a further advantageous design the blister-pack of the Invention possesses four
lateral support sections joined to one another, creases running centrally along the
narrow lateral support sections and parallel to the connecting edges of the support
sections, which creases continue in the frame, and creases or slots running from the
outer edges of the window diagonally to the inner edges of the window. Preferably
flaps are located at least on the narrow support sections, in which the creases of
the narrow support sections continue. The advantage of these designs consists in the
fact that by means of a light pressure on the centre of the narrow lateral support
sections the blister-pack can be collapsed, which results in the erection of the frame
and possibly of the flaps, the narrow lateral support sections are folded inwards
over the creases and the broad lateral support sections come to lie on top of each
other.
[0032] In a further advantageous design the abovementioned blister-pack possesses four flaps
hinged to the lateral support sections which together form a base. In this way one
packaging unit can be formed from two blister-packs which, once the bases have been
closed in a known manner and a strap has been applied, does not necessarily require
an additional box for despatch. The blister-pack frames can rest against each other,
so that the packed product is surrounded by foil on all sides. However, in many cases
it is not necessary for the packed product to be enveloped completely in foil, but
rather, once the packed product has been laid in position, a greater or lesser gap
can exist between the flat surfaces of the frames, the packed product being held in
a fixed position from two sides between the blister-packs. Advantageously the blister-packs
are placed under a slight pre-tension, which can be done by dimensioning the despatch
carton accordingly or using a strap. If the despatch carton is one involving a pull-over
sheath or is a slide-on or banded box, this type of packing is particularly economic
on material.
[0033] In a further advantageous design the blister-pack according to the Invention possesses
four lateral support sections joined to each other and of trapezoidal cut broadening
towards the frame side, creases running centrally in the narrow lateral support sections
and more or leas parallel to the connecting edges of the lateral support sections,
which creases continue in the frame, triangular peaks located and the four corners
of the frame and projecting upwards, and creases or slots running diagonally along
the frame.
[0034] In this case advantageously there are located at least on the narrow support sections
flaps in which the creases of the narrow lateral support sections continue. This design
preferably finds application as a stackable fruit or vegetable crate.
[0035] In the case of a further advantageous pack two blister-packs having two lateral support
sections, in each case on two sides only. preferably the long sides, are combined
with a despatch carton with in each case four base and cover flaps, two base and two
cover flaps being turned inwards and thus forming the two missing lateral support
sections for the blister-packs. In this connection it is preferable for the flaps
of the despatch carton which are to be turned inwards on the side edges to be reduced
by the thickness of the material, so that a snug fit of the blister-packs is ensured.
In a further advantageous design the reduction in material thickness does not extend
over the entire flap , but towards the outer edge a lip-type projection is obtained.
There are then located on the side edges of the blister-pack support sections corresponding
recesses into which the lips of the box flaps fit. The two remaining base and cover
flaps of the despatch carton in each case have only to ensure the closure of the pack.
Forces exerted during transportation, e.g. by falling, are taken up by the cover and
base flaps turned inwards, without there being any risk of the pack coming open.
[0036] In a further advantageous pack the blister-pack after the packed product has been
accommodated is top-sealed by a foil. This packing is suitable for goods sensitive
to moisture and gas, e.g. to the effects of oxygen, and also for display packs, and
in the case of packed products sensitive to impact or liable to break if dropped a
padding, e.g. a compression pad, can be arranged between the packed product and the
covering foil which does not appreciably affect the view. With this type of packaging
vacuum packs with inspection windows can be produced by evacuating the air from the
blister-pack accommodating the packed product before sealing with the cover foil.
[0037] In a further advantageous design along these lines a moisture-proof pack consists
of two blister-packs with the trough apertures sealed to each other, a closure being
welded in at a suitable point, this being facilitated preferably by the appropriate
design of the blister-packs.
[0038] When creases or slots are referred to above, this refers exclusively to the blanks
used for producing the blister-packs. The foil itself requires no creases for folding
the blister-packs after their production, as by its very nature it responds to all
folds without difficulty. In a similar manner this also applies to slots, where there
is the additional feature that the slots required in the frame for the production
of the blank for the blister-packs only undergo an adhesive effect from the sealing
on of the foil, so that when the blister-pack is produced after assembling the blank
no special adhesion of these slots is absolutely necessary. With square blister-packs,
of course, long and short sides can be interchanged.
[0039] The invention also relates to a process for the production of a blister-pack, which
is characterised by the fact that in one working cycle a plastic foil is sealed on
to the frame of a blank made of plane material, applying pressure and heat by means
of contact heating, the temperature of which is above the sealing temperature of the
foil, it is rendered deformable and brought into a mould corresponding to the subsequent
foil trough for the blister-pack.
[0040] This process may be performed by inverting the blank over a trough mould with dimensions
adapted to the internal measurements of the assembled blank, in such a way that the
frame lies with the punched-out window uppermost. A sheet of foil is then laid on
the blank which is adapted to the outside measurements of the frame. If one uses a
folding box-type blank, in which the window frame is formed by folding over flaps
which correspond to the cover flaps but are shortened to form the window, then the
fourflaps folded inwards at rightangles lie uppermost. These flaps forming the frame
are subsequently covered over by the foil.
[0041] The mould with the blank thus assembled together with the section of foil applied
is then subjected to the contact heating, which can for example be a hot sealing plate
provided on the contact side with apertures. The dimensions of the contact heating
device are equivalent at least to the outside dimensions of the frame. The temperature
of the contact heating device is above that of the sealing and deformation of the
foil. This contact heating device is applied with a high pressure on the upper side
of the mould accommodating the blank and the foil and during the sealing of the foil
to the blank at the same time effects a hermetic seal. Preferably the heating plate
is equipped with an anti-stick layer, for example made of polytetrafluorethylene or
silicon rubber which prevents the foil from adhering.
[0042] When the foil, under the action of the contact heating device, has reached adequate
thermoformability, shaping takes place; the foil is cooled by the mould and thus becomes
stable in shape. As the foil reaches only to the edge of the frame (or possibly very
slightly beyond it, e.g. 1 mm), the mould release of the finished blister-pack presents
no difficulties.
[0043] In a preferred form of embodiment of the process of the Invention the deformability
of the foil is brought about by pressing it by means of compressed air to the contact
heating device. To this end compressed air is blown into the mould from below and
by means of this the foil is pressed to the contact heating device for just as long
as it takes to reach the temperature of deformation.
[0044] In a further preferred mode of embodiment the foil-shaping is produced by pressing
the foil to the mould by means of compressed air. For tMs purpose, for example, one
proceeds, after removing the air from the mould, to press the foil into the mould
by means of compressed air, which is blown in through the heating plate, and in the
mould the foil cools and thus becomes stable in shape. With this version of the process
one gets a draping action through blowing.
[0045] Instead of compressed air, the process of the Invention can also make use of subratmospheric
pressure, or the two processes can be combined. With this vacuum process, instead
of blowing the compressed air, a vacuum is applied at the opposite point. Thus one
gets a draping action through suction.
[0046] According to the Invention working with compressed air is preferred as in this way
one has a greater amount of play in regard to the pressure used.. Thus for example
when producing blister-packs using triply corrugated cardboard, with the blowing process
one can always build up an adequate pressure, whilst with the vacuum process too great
a loss of suction occurs through the cardboard. On the other hand by using a combination
of the blowing and vacuum processes it is possible to place all the connections either
on the mould or on the contact heating device, which is an advantage in certain cases.
[0047] Thus for example by arranging the vacuum and compressed air connections on the contact
heating device, the foil can first be sucked on to the contact heating device and
then blown into the mould. In the case of fully automated production of the blister-packs
this is an advantage. Then only de-aerated moulds need pass through a shaping device
of this type, and connections which work through the mould are not required.
[0048] In a further preferred form of embodiment the process of the Invention is executed
in such a way that when shaping the foil one leaves a foil border which runs round
the inside edges of the window projecting over the frame. This foil border runs approximately
flush with the frame and is preferably continuous. As a result of the foil border
one achieves a better strength distribution and hence spring effect if the pack is
dropped.
[0049] This foil border can be obtained by the design of the mould, by dimensioning the
upper edge of the mould wider than the frame of the blank or subsequent blister-pack.
But one can also produce the foil border in such a way that one leaves an appropriately
dimensioned strip on the inside edges of the window free from heat impact from the
contact heating device, e.g. by means of a suitable groove in the hot-plate of the
contact heating device.
[0050] In a further preferred form of embodiment it is provided that when shaping the foil
one leaves ridge-shaped foil sections. By this means one obtains blister-packs with
several separate troughs which are separated not by ridges made of the frame material
but made from the foil. In this way one produces blister-packs with a differing number
of troughs from one and the same blank. The ridges can be produced, like the foil
border, either by an appropriate design of the mould, or by keeping the ridge area
free from heat impact from the contact heating device, e.g. by means of a suitable
groove in the said device.
[0051] The mould used for the process of the Invention is preferably produced so that one
presses a sheet of foil in a condition suitable for deep-drawing by means of a tensioning
or draw-frame over the goods intended for packaging, the window of the draw-frame
being adapted to fit the desired window of the subsequent blister-pack, that is to
say the window of the draw-frame possesses approximately the same or somewhat smaller
dimensions - namely reduced by the width of the foil border - than those of the subsequent
blister-pack. After cooling a suitable mould is produced from the form-stable foil
casting, for example by plaster-casting.
[0052] In the process of the Invention one is dealing in the case of all variants with a
negative process, that is to say that the mould supplies the end product direct. A
further advantage as compared with known positive processes consists in the fact that
one achieves a more favourable distribution of the foil thickness. For one thing the
differences between the thickest and thinnest points are less, and for another the
foil at the junction with the frame is thicker than on the floor of the trough and
not the other way round.
[0053] The invention also relates to a process for the production of a pack which is characterised
by the fact that one inverts a blister-pack according to the Invention over the packed
product located in the lower part of a carton on a base, e.g. on a compression pad,
with the frame downwards, and one then causes the arrangement to pass through a radiation
heating device. When this is done the foil is heated accordingly and shrinks to the
packed product, so that a good fixing of the packed product is achieved.
[0054] With this type of pack the blister-packs employed are preferably produced using a
normal heat-shrinking foil. However, this is not absolutely necessary, since when
producing the blister-packs by developing the foil trough according to the vacuum
or blowing shaping process a stretching takes place anyway, which imparts shrinkage
properties to the foil.
[0055] The advantage of this process lies in the fact that even with differently shaped
packed products, using a blister-pack of unchanged dimensions a contoured packaging
unit can still be obtained; the only pre-requisite is that the trough of the blister-pack,
even in the vertical direction, should be somewhat larger than the packed product.
In the example mentioned above, where the packed product is located on a bed in the
lower part of a box, a padded lid can then if necessary be laid on top of it.
[0056] Below the invention is described in the drawings on the basis of advantageous designs.
[0057]
Fig. 1 shows a plan view of a blister-pack according to the Invention,
Fig. 2 shows a longitudinal section through the blister-pack of Fig. 1 along the line
A-B,
Fig. 3 shows a longitudinal section through a further form of embodiment of a blister-pack
according to the Invention,
Fig. 4 shows a blank for a further form of embodiment of a blister-pack according
to the Invention,
Fig. 5 shows a blank for a further form of embodiment of a blister-pack according
to the Invention,
Fig. 6 shows a plan view of the finished blister-pack produced from the blank of Fig.
5
Fig. 7 shows a blank for a further form of embodiment of a blister-pack according
to the invention,
Fig. 8 shows a plan view of the finished blister-pack produced from the blank of Fig.
7,
Fig. 9 shows a plan view of a further form of embodiment of a blister-pack according
to the invention when laid flat, and
Fig. 10 shows a blank of a despatch carton for the blister-pack of Fig. 9.
[0058] The blister-pack shown in Figures 1 and 2 consists of the surrounding frame 2 with
two lateral support sections 3, the corrugated cardboard blank, and the foil 4, which
is joined to the frame as far as the point of junction of the lateral support sections
3 by means of hot-sealing. The foil is a polyethylene/ ethylene vinyl acetate co-polymerisate
transparent laminar foil, which is sealed with the ethylene vinyl acetate co-polymer-
side to the frame.. The window 5 of the blister-pack is larger than the packed product
accommodated, the lower part of a loudspeaker unit 6. A second blister-pack (not shown)
is inverted over the top end of the loudspeaker unit 6, with its lateral support sections
facing upwards. The entire arrangement is held together with slight pre-tensioning
by a despatch carton (not shown). In tis way the inside edges 7 of the window of the
frame do not come into contact at any point with the packed product 6. The lateral
parts 8 of the foil trough do not run parallel to the outer surfaces 9 of the packed
product accommodated therein, but run from the edges 10 of the surface of the packed
product lying on the floor of the foil trough outwards, so that the lateral parts
8 have an angle of inclination of 45° to the perpendicular in relation to the plane
of the frame.
[0059] In the form of embodiment of Fig. 3 the blister-pack has a foil border 11 running
round the inside edges 7 of the window and projecting over the frame 2, which border,
regardless of the material thickness of the frame 2, runs flush with the frame. The
packed product 6 is the loudspeaker unit of Fig. 1, and here the side surfaces 9 of
the unit can lie against the side surfaces 8 of the foil trough, as the foil border
11 takes care of the safety margin between it and the inside edges 7 of the window
of the blister-pack. Furthermore by means of the foil border 11 one achieves a better
strength distribution and hence sprung action if the pack is dropped. Just as in the
case of the form of embodiment shown in Fig. 1, at the top end of the unit 6 a second
blister-pack (not shown) is located, the lateral support sections of which face upwards.
The entire arrangement is held under pre-tension by a despatch carton (not shown).
[0060] Fig. 4 shows a further form of embodiment of a blister-pack according to the invention
in blank form. This blank possesses four lateral support sections 21a, 21b, 22a, 22b,
the narrow supporting sections 21a, 21b having side flaps 23a and 25a, 26b 23b. The
blank possesses a crease
"running diagonally over the frame 24 which in each case continues in the narrow support
sections 21a, 21b in such a way that the creases 27a, 27b between the frame and the
narrow support sections 21a, 21b form the bisectors of the angles enclosed by the
creases 25a, 26a and 25b, 26b. These creases make it possible to collapse the blank,
after assembling and connecting the lateral support sections 21a, 22a and 21b, 22b
through the side flaps 23a. and 23b by means of wire stitching. This blank
is erected by positive action by a slight lateral pressure before the foil is applied.
After the foil has been applied the finished blister-pack is collapsed by diagonal
folding, stored in the flat state and despatched and again erected by positive action
before use.
[0061] Fig. 5 shows a further form of embodiment of a blister-pack according to the invention,
in the form of a blank, and Fig. 6 shows a plan view of the finished blister-pack.
The blister-pack possesses four lateral support sections 31a, 32a, 31b, 32b, which
are joined together by the flap 34 by glueing, the flaps 35a, 36a, 35b, 36b forming
the frame. The narrow support sections 31a, 31b possess creases 33a, 33b running centrally
and parallel to the connecting edges 38a, 38b, 38c, 38d of the supporting sections
and which continue in the frame flaps 35a, 35b and the stiffening flaps 37a, 37b which
are folded inwards when the blank is assembled. After the blank has been assembled
it is not absolutely necessary to glue the slots 39a, 39b, 39c, 39d, as a good cohesion
of the frame is achieved by the sealing on of the foil. After the foil has been sealed
on, the finished blister-pack can be collapsed by a light pressure on the centre of
the narrow lateral support sections 31a, 31b, when the frame flaps 35a, 36a, 35b,
36b open out and also the stiffener flaps 37a, 37b, the narrow support sections 31a,
31b are folded inwards over the creases 33a, 33b and the broad support sections 32a,
32b come to lie on top of each other.
[0062] Fig. 7 shows a further form of embodiment of a blister-pack according to the invention,
in the form of a blank, and Fig. 8 shows a plan view of the blister-pack produced
from the blank of Fig. 7. The blister-pack contains four lateral support sections
41a, 42a, 41b, 42b, which are all joined to each other by the side flap 45 by glueing,
flaps 43a, 44a, 43b, 44b forming the frame. These flaps are separated by diagonal
slots 49a, 49b, 49c, 49d in such a way that when the blank is assembled triangular
peaks 50a, 50b, 50c, 50d are left on the frame side. The narrow support sections 41a,
41b possess creases 48a, 48b running centrally and more or less parallel to the connecting
edges 47a, 47b, 47c, 47d which creases continue in the narrow frame flaps 43a, 43b.
After the blank has been assembled it is not absolutely necessary to glue the slits
49a, 49b, 49c, 49d, as a good cohesion of the frame is guaranteed by the sealing on
of the foil. The lateral support sections 41a, 42a, 41b, 42b possess a trapezoidal
blank, and broaden towards the frame side. This broadening is preferably selected
so that the deviation from the rightangled blank amounts to a material thickness x.
Because of the deviation of the lateral support sections from the rightangled crosss-section
the creases 48a, 48b do not run strictly parallel to the connecting edges 47a, 47b,
47c, 47d, but are somewhat displaced. The lateral support sections of the blister-pack
with the triangular peaks located on them are inclined slightly outwards on all sides
because of the trapezoidal shape, so that the blister-pack is capable of being stacked.
Accordingly this form of embodiment of Figs. 7 and 8 finds application as stackable
fruit or vegetable crates.
[0063] The collapsing and assembling of the blanks and blister-packs takes place exactly
as in the case of the forms of embodiment of Figures 5 and 6.
[0064] Fig. 9 shows a further form of embodiment of a blister-pack according to the invention
when laid flat. Two of these blister-packs are combined with a despatch carton, which
is shown in Fig. 10 as the blank, to form a single packing unit. The blister-pack
possesses two support sections 51a, 51b located on the long sides and having recesses
52a, 52b in which the projecting lips 62a, 62b located on the narrow flaps 61a, 61b
of a despatch carton rest. For packaging purposes an assembled blister-pack with support
sections 51a, 51b projecting outside is pushed into the despatch carton far enough
so that the narrow cover flaps 61a
1, 61b
1 can be folded inwards, so that they lie against the lateral parts 63a, 63b, the lips
62a
1, 62b
1 resting in the recesses 52a, 52b of the blister-pack and the edges 64a
1, and 64b
1 rest against the frame 53 of the blister-pack. When the goods to be packaged have
been inserted, a second assembled blister-pack is pushed in from the other end of
the despatch carton, with support sections 51a, 51b sticking out, over which the cover
flaps 61a
2, 61b
2 of the despatch carton can be tucked in. The entire packing unit is finally closed
by the cover flaps 65a, 65b.
[0065] In the embodiment shown in Figure 7 flaps 46a, 46b corresponding to the flaps 37a
and 37b of Figure 5 may be provided on the narrow support sections 41a and 41b, the
grooves or creases (48a and 48b) of the narrow support section continuing in the flaps
in the same way as the grooves in 33a and 33b Figure 5.
I 1. Blister-pack with a frame of plane material with a window-like cut-out and at
least two lateral support sections at an angle to the outer periphery of the frame,
on which a plastic foil is applied as a trough in the window space, characterised
by the fact that the plastic foil is joined by heat-sealing only with the section
of the frame (2) as far as the point of junction of the lateral supporting sections
(3).
2. Blister-pack in accordance with Claim 1, characterised by the fact that the window-like
cut-out (5) is larger than the packaged goods which it must take (6) or larger than
the section of the packaged goods which is to be taken.
3. Blister-pack in accordance with at least one of Claims 1 and 2, characterised by
the fact that in the blister-pack containing the packaged goods the inside edges of
the window (7) of the frame at no point come into contact with the packaged goods
(6).
4. Blister-pack in accordance with at least one of Claims 1 to 3, characterised by
the fact that in the blister-pack containing the packaged goods the lateral part (8)
of the foil trough does not run parallel to the outer surfaces (9) of the packaged
goods (6) lying there, but runs outwards from the edges (10) of the surface of the
packaged goods to be found on the bottom of the foil trough.
5. Blister-pack in accordance with at least one of Claims 1 to 4, characterised by
a foil border (11) surrounding the inside edges of the window (7) and projecting over
the frame (2).
6. Blister-pack in accordance with at least one of Claims 1 to 5, characterised by
the fact that in the case of a sub-divided window with several separate troughs these
are separated not by ridges formed of the frame material, but formed of the foil.
7. Blister-pack in accordance with at least one of Claims 1 to 6, characterised by
four lateral support sections (21a, 22a, 21b, 22b), of which in each case two adjoining
support sections (21a, 22a and 21b, 22b) are connected with each other, and a crease
(25a, 25b), running diagonally over the frame (24) which in each case continues in
the narrow supporting sections (21a, 21b) in such a manner that the creases (27a,
27b) between frame and narrow support sections (21a, 21b) form the bisecting lines
with the angle enclosed by the creases (25a, 26a and 25b, 26b).
8. Blister-pack in accordance with at least one of Claims 1 to 6, characterised by
four lateral support sections (31a, 32a, 31b, 32b) connected with each other, creases
(33a, 33b) running centrally in the narrow lateral support sections (31a, 31b) and
parallel to the connecting edges (38a, 38b, 38c, 38d) of the support sections, which
continue in the frame, and creases or slots (39a, 39b, 39c, 39d) running diagonally
from the outside edges of the window to the inside edges of the window.
9. Blister-pack in accordance with at least one of Claims 1 to 6, characterised by
four lateral support sections (41a, 42a, 41b, 42b) of trapezoidal section tapering
towards the frame side, creases (48a, 48b) running centrally in the narrow lateral
support sections (41a, 41b) and almost parallel to the connecting edges (47a, 47b,
47c, 47d) of the lateral support sections, which continue in the frame, triangular
peaks (50a, 50b, 50c, 50d) located at the four corners of the frame and projecting
upwards, and slots or creases (49a, 49b, 49c, 49d) running diagonally in the frame.
10. Blister-pack in accordance with Claim 8 or 9, characterised by flaps (37a, 37b
or 46a, 46b) located at least on the narrow support sections (31a, 31b or 41a, 41b),.
in which the grooves (33a, 33b or 48a, 48b) of the narrow support section continue.
11. Blister-pack in accordance with Claim 8, characterised by four flaps located on
the lateral support sections, which together form a tray.
12. Blister-pack in accordance with at least one of Claims 1 to 11, characterised
by the fact that the frame consists of corrugated cardboard and the plastic parts
are a transparent foil which is suitable for deep-drawing.
13. Process for the production of a blister-pack in accordance with at least one of
Claims 1 to 12, characterised by the fact that in one working cycle one seals a plastic
foil to the frame of a blank made of plane material using pressure and heat application
by means of contact heating, the temperature of which is above the sealing temperature
of the foil, one renders it deformable and brings it into a mould corresponding to
the subsequent foil trough of the blister-pack.
14. Process in accordance with Claim 13, characterised by the fact that one brings
about the deformability of the foil by pressure by means of compressed air on the
contact heating device.
15. Process in accordance with Claims 13 or 14, characterised by the fact that one
produces the deformation of the foil by applying it by compressed air to the mould.
16. Process in accordance with at least one of Claims 13 to 15, characterised by the
fact that when deforming the foil one leaves a foil rim running round the inside edges
of the window and projecting over the frame.
17. Process in accordance with at least one of Claims 13 to 16, characterised by the
fact that when deforming the foil one leaves ridge-shaped foil sections.
18. Process in accordance with at least one of Claims 13 to 17, characterised by the
fact that one uses a mould which has been produced by excess pressure on the foil
sheet when in a suitable condition for deep-drawing by means of a stretcher frame
over the goods to be packaged, the window of the stretcher frame possessing the same
or somewhat smaller dimensions, namely reduced by the width of the foil border, than
the dimensions of the window of the subsequent blister-pack, and by casting the foil
mould with a moulding compound.