Device for manufacturing shaped forms of packaging

Device for manufacturing cold-formed shaped forms of packaging out of a metal-plastic laminate where the said device contains a die with at least one die opening, in the die opening a stamp which may be driven by the die, and a retaining tool as a clamping facility that holds the laminate securely between the die and the clamping facility. The die and the retaining tool feature a facing edge region and the die, within the edge region, a shoulder region that surrounds the die opening, and the surface of the shoulder region lies 0.01 to 10 mm lower than the surface of the edge region of the die. Parts or in particular the whole of the shoulder region may be covered with a surface layer of low friction characteristics. The metal-plastic laminate is held clamped between the edge of the die and the edge of the retaining tool, and the stamp draws and stretches the part of the laminate in the region of the shoulder over the shoulder into the die opening.

BACKGROUND OF THE INVENTION 
The present invention relates to a deuce for manufacturing cold-formed 
shaped ferns of packaging out of a metal-plastic laminate where the said 
device contains a die with at least one die opening, in the die opening a 
stamp which may be driven by the die, and a retaining tool as a clamping 
facility that holds the laminate securely between the die and the clamping 
facility. Further, the present invention also relates to a process for 
manufacturing cold-formed shaped forms of packaging using the device 
according to the invention. 
It is known to manufacture shaped forms of packaging such as e.g. base 
parts for blister packs, also known as push-through packs, or other 
packaging containers e.g. by deep drawing, stretch-drawing or 
thermoforming. The shaped forms of packaging may be manufactured out of 
thermoplastics or out of composite or laminates such as e.g. aluminum 
foils with plastic films or extruded layers of thermoplastics. 
If the packaging is made of laminates containing metal foils, then this may 
be performed using shaping tools comprising a stamp, a die and a retaining 
tool. During deformation the laminate is clamped securely in place between 
the die and the retaining tool, and the stamp moved towards the laminate. 
As it is lowered, the stamp penetrates deeper into the openings in the die 
thereby deforming the laminate. In the process the laminate is converted 
into a shaped part with one or a plurality of recesses. The recesses are 
surrounded by shoulders and the shoulders correspond to the laminate in 
the original fiat plane. Only that part of the laminate in the region of 
the die opening can flow or be stretched to form a shaped part. In order 
that the laminate, in particular the laminate containing metal foil, can 
be deformed without creating cracks and pores, an adequate lateral 
distance must be maintained between the stamp and the die opening. Cold 
forming a laminate containing a metal foil using this process results in a 
recess sidewall of only small height. This leads to poor drawing ratios, 
i.e. shallow recesses of large diameter, and therefore to packaging forms 
which are too large in relation to the contents. 
One possibility to have more laminate available for deformation may be to 
reduce the retaining force and to employ methods of deep drawing 
technology. This technology may not, however, be employed with laminates 
containing metal foil e.g. for manufacturing blister packs, as folds would 
be produced in the edge or shoulder regions. The edge region and if 
desired the shoulder region of shaped forms of packaging are as a rule 
employed for sealing on the lid. If there are folds present, the edge and 
the shoulders of the part could not be sealed. 
SUMMARY OF THE INVENTION 
The object of the present invention is to describe and realize a device and 
process which enable laminates containing metal foils to be transformed by 
cold forming into shaped forms of packaging or shaped parts that are free 
of folds and larger wall height. 
This objective is achieved by way of the invention, in the form of a device 
characterized that its die and the retaining tool feature a facing edge 
region and within the edge region of the die a shoulder region that 
surrounds the die opening, and the surface of the shoulder region lies 
0.01 to 10 mm lower than the surface of the edge region of the die. 
In a preferred version the surface of the shoulder region of the die lies 
0.1 to 2 mm, preferably 0.15 to 0.3 mm lower than the surface of the edge 
region of the die. 
The device according to the present invention may contain a die with a die 
opening or a plurality of die openings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
The device, and in particular the die, features 1 to 200, preferably 8 to 
40 die openings. The deformation of the metal:plastic laminate is 
performed by a stamp, which may as such push into the die opening. If the 
die exhibits a plurality of openings, the stamp may feature a stamp holder 
or holder plate or the like with a number of stamping tools corresponding 
to the number of die openings. The stamps or stamping tools are 
dimensioned in such a way that they can push into the die opening while 
deforming the metal-plastic laminate. It is advantageous for the diameter 
of the stamp or stamping tool to be 3 to 35%, preferably 1 to 15% and in 
particular 5 to 10% smaller than the diameter of the die opening in 
question. By the diameter in the ease of die openings that are not round, 
such as one with a convex cross-section, e.g. elliptical, oval, polygonal, 
rectangular, trapezium-shaped, rhomboid in shape etc., is to be understood 
the smallest diameter. 
The walls of the die opening are as a rule at an angle of 90.degree. to the 
surface of the shoulder region. The edge formed by the wall of the die 
opening and the surface of the shoulder region maybe rounded with a radius 
of e.g. 0.1 to 10 mm, usefully from 0.1 to 1.0 mm. 
In another preferred version the edge regions of the retaining tool and the 
die are each 1 to 100 mm broad, usefully 2 to 30 mm, and preferably 3 to 
20 mm broad. 
The die has an edge region and within this edge region a shoulder region. 
The die openings are arranged in particular symmetrically or also 
asymmetrically within the shoulder region with the shoulder region forming 
struts that surround the die openings. 
The shoulder region of the die features distances of 1 to 50 mm, preferably 
5 to 25 mm, between the edge region of the die and the die openings, and 
between the individual die openings. 
The edge region of the retaining tool or the edge region of the die, or the 
edge regions of the retaining tool and the die, may exhibit a roughness 
pattern over part or the whole of the surface there. Typical roughness 
patterns are corrugations, waffle patterns, embossed patterns, honeycomb 
patterns, knobs, tooth-like patterns, toughened surfaces etc. In the 
working position the edge regions of the retaining tool and the die are 
usefully together over the metal-plastic laminate and, if desired with the 
support of the pattern of roughness, hold the laminate securely in place 
such that it cannot be stretched. The shoulder region of the die usefully 
lies a distance from the parts of the retaining tool facing it, and in 
this region the metal-plastic laminate is not in contact with the 
retaining tool and the metal-plastic laminate can be stretched or flow 
according to the degree to which the stamp is lowered. 
The shoulder regions of the die may be covered wholly or partly With a 
layer that at least on the surface exhibits a lower degree of friction. A 
lower degree of friction in the present case represents values of 0.3 or 
less to 2.2 (dimensionless number), as measured according to British 
Standard BS 2782 method 311 A. The low friction layer may e.g. contain or 
be of plastics such as polytetrafluorethylene, polyoxymethylene 
(polyacetal POM), polyethylene or polyethylene-terephthalate. The low 
friction layer may also exhibit in mixture form two or more of the 
plastics mentioned by way of example and additionally in divided form hard 
substances such as glasses in spherical form. Instead of the plastics 
other materials may be considered for the low friction layer. This means, 
for example, metals such as aluminum or chromium steel, especially also 
with polished surfaces. Other low friction layers such as ceramic layers 
or layers containing graphite, boron nitride or molybdenum disulphide may 
be employed. The thickness of the low fiction layer on the shoulder region 
of the die is not critical as only the surface is of consequence. Under 
industrial conditions the layer is subjected to large demands with regard 
to frictional forces and so a thickness that permits some degree of 
material loss or wear should be preferred. For that reason the thickness 
of layer of the above mentioned plastics may be e.g. from 0.5 to 20 mm. 
The layer of plastic may be inserted in the lowered region of the die as a 
preform, or it may be deposited by spraying, brushing or wiping, or some 
other method of deposition. The plastics may be contained in a matrix of 
some other material such as ceramic or metal. Metal layers may be 
deposited for example on the matrix using chemical or physical methods 
such as electroplating or electrolytic deposition, plating or vapour 
deposition in vacuum, or the die may be at least in part made of the 
metals in question. 
As a rule the stamp exhibits the same number of stamping tools as the 
number of die openings, and these stamping tools penetrate the appointed 
openings in the retaining pad and die openings. Usefully at least the 
surface effecting deformation, i.e. the surface of the stamp or stamping 
tools coming into contact with the laminate, is of e.g. plastics such as 
polytetrafluorethylene, polyoxymethylene (polyacetal POM), polyethylene or 
polyethyleneterephthalate, or two or more of the exemplified plastics 
mentioned above in mixture form, or one or more of the plastics in mixture 
form containing additionally in divided form hard materials such as 
glasses in spherical form. Instead of the above mentioned plastics other 
materials may be considered such as e,g. metals such as aluminum, or 
chromium steel, especially with polished surfaces. Further surface layers 
are ceramic layers or layers containing graphite, boron nitride or 
molybdenum disulphide. The stamps or stamping tools may be covered with 
the materials or the stamps or stamping tools may, at least in the region 
making contact with the laminate, be made partially or wholly of these 
materials. 
Metal-plastic laminates that may be employed may e.g. be laminates 
containing an 8 to 150 .mu.m, preferably 20 to 80 .mu.m thick metal foil. 
The foil may e.g. be of steel, iron, copper and preferably aluminum. 
Included thereby are also metal foils out of alloys containing for the 
main part one of the above mentioned metals. Preferred foils of aluminum 
may e.g. be of aluminum having a purity of 98.3%, usefully 98.5% and in 
particular 99.8%, the rest making up the 100% being the usual impurities. 
Further, for aluminum foils for example of the AlFeSi type may be 
employed. 
Plastics that may be employed may be e.g. layers, films or film-laminates, 
whereby the films and film-laminates may be uni-axially or biaxially 
stretched, and of thermoplastics classified as polyolefins, polyamides, 
polyesters, polyvinyl chlorides and others. 
Typical examples of thermoplastics from the polyolefin range are 
polyethylenes such as MDPE, HDPE, uni and biaxially stretched 
polyethylenes, polypropylenes such as east polypropylene and uni or 
biaxially stretched polypropylenes or, from the polyester range, 
polyethylene-terephthalate. 
The thickness of the thermoplastic in the form of layer, film or 
film-laminate in the metal-plastic may be e.g. 12 to 100 .mu.m, preferably 
20 to 60 .mu.m. 
The metal foils and thermoplastics may be made into laminates e.g. by 
adhesive bonding, calandering or extrusion bonding. To join the layers one 
may employ adhesives and bonding agents as necessary, and the surfaces to 
be joined may be modified by plasma, corona or flame pre-treatment. 
Examples of metal-plastic laminates are those having a first layer e.g. a 
film or a film-laminate of the above mentioned thermoplastics, a second 
layer in the form of a metal foil and, on the free side of the metal foil, 
a third layer viz., a sealing layer of a polyolefin such as polyethylene 
or polypropylene or PVC. 
Further useable metal-plastic laminates may exhibit a first layer e.g. a 
film or film-laminate of the above mentioned thermoplastics, a second 
layer in the form of a metal foil, and a third layer, for example a film 
or film-laminate or an extruded layer out of one of the above mentioned 
thermoplastics. Further layers such as sealing layers may be provided. 
The metal-plastic laminates may feature a sealing layer in the form of a 
sealable film or a sealable mating at least on one of the outer lying 
sides, or on both outer sides. The sealing layer is of necessity the 
outermost layer in the laminate. In particular the sealing layer may be on 
one outer side of the laminate, and should be directed towards the 
contents or shoulder side of the shaped packaging, this in order to enable 
the lidding foil or the like to be sealed into place. 
Typical examples of metal-plastic laminates used in practice are: 
oPA 25/Al 45 /PVC 60 
oPA 25/Al 45 /oPA 25 
Al 120/PP 50 
oPA 25/Al 60/PE 50 and 
oPA 25/Al 60/PP 60 
where oPa stands for oriented polyamide, PVC for polyvinylchloride, PE for 
polyethylene, PP for polypropylene and Al for aluminum and the numbers the 
thickness of the layer or foil in .mu.m. 
Seen in FIG. 1 is a device comprising a die 1, a retaining tool 5 and a 
stamp 6. In the present case the stamp features a support (nor shown) and 
mounted thereon a number of stamping tools 6. The number of stamping tools 
corresponds to the number of openings in the die 1. The stamp or the 
stamping tools 6 penetrate the opening 7 in the retaining tool 5. A 
metal-plastic laminate (not shown) is placed between the die 1 and the 
retaining tool 5. By applying force, the retaining tool 5 is pressed 
against the die 1, as a result of which the metal-plastic laminate is held 
securely at all places of contact between the die 1 and the retaining tool 
5 and essentially unable to be stretched. The stamping tools 6 are lowered 
under the application of force and enter the opening 7 in the retaining 
tool, press against the metal-plastic laminate (not shown) and, while 
deforming the metal-plastic laminate, pass through the die openings 8 in 
the die, until the desired degree of deformation of the metal-plastic 
laminate has been achieved. 
The metal-plastic laminate is held both in the edge region and in the 
shoulder region 13 between the retaining tool 5 and the die 1, essentially 
unable to be stretched, and the deformation of the laminate effected 
solely within the material covering the die opening 8. 
The device according to the invention is shown in FIGS. 2 and 3 again with 
the die 1, the retaining tool 5 and the stamp (stamping tools) 6. The 
retaining tool 5 features an edge region 12. A roughness pattern 9 is 
provided in the edge region 11 of the die. The whole shoulder region 13 
i.e. the region of the die 1 that is located within the die region 11 and 
forms the shoulders that surround the die openings, is lower than the edge 
region 11. Lowering the shoulder region 13 of the die 1 may be achieved by 
a chip-forming process such as milling or by spark erosion etc. The die 1 
may also be in two parts such that the edge region 11 and the shoulder 
region 13 can be moved and adjusted with respect to each other and, on 
reaching the desired difference in height, may be secured in place with 
respect to each other. The die 1 may also be a casting that already 
exhibits the lower height in the shoulder region 13. Likewise, it is also 
conceivable for the retaining tool not to exhibit a flat surface facing 
the die 1, but an edge region 12 and a shoulder region that is lower than 
the edge region 12. The metal-plastic laminate is secured, in a 
non-stretchable manner clamped between the retaining tool 5 and the die 1, 
especially in the edge region 11 of the die that is covered by the edge 
region 12 of the retaining tool. In the shoulder region 13, both along the 
edge region and the shoulders between the die openings, the metal-plastic 
laminate may flow and be deformed by stretching to a degree determined by 
the extent that the stamp 6 is lowered into the die openings 8. 
Shown in FIG. 3 is the additional advantage of a low friction layer 3 e.g. 
polytetrafluorethylene, polyoxymethylene; polyolefins or 
polyethylene-terephthalate etc. The layer usefully extends over the whole 
of the shoulder region 13 of the die 1. In specific cases it is possible 
to employ a layer that extends over only part of the shoulder region 13. 
FIG. 4, a plan view of a die 1, shows the edge region 11 shaded dark and 
the shoulder region 13 lightly shaded. The edge region 11 may feature a 
roughness pattern 9. The shoulder region 13 lies 0.01 to 10 mm lower than 
the edge region 11. In an advantageous version the lightly shaded region 
i.e. the shoulder region 13, is partly and especially fully covered with 
the described low friction deposit or layer 3. The die openings 8 are 
shown by way of example in a regular array in the shoulder region 13. As a 
rule this concerns holes i.e. openings or recesses that are round in 
cross-section or openings that are oval in cross-section. Also openings 
that are polygonal in cross-section e.g. rectangular, square or six sided 
may be created without any difficulty. 
A retaining tool 5 is shown in plan view in FIG. 5. The surface 14 of the 
retaining tool 5 which faces the die and comes to rest on the laminate 
during manufacture may be flat. In the production stage the laminate is 
securely clamped across the areas of contact with the edge region 12 of 
the retaining tool 5 and the edge region 11 of the die 1, and viz., such 
that the laminate can not stretch or flow there. Instead of a flat surface 
the retaining tool 5 may also feature an edge region 12 and lower region 
within the edge region, or the retaining tool 5 may essentially comprise 
only of the edge region i.e. a ring. 
A roughness pattern may be provided over part or the whole of the surface 
in the edge region 12 of the retaining tool 5. The edge region of the 
retaining tool 5 is usefully positioned and essentially of the same 
dimension as the edge region 11 of the die 1. 
The retaining tool 5 exhibits a plurality of openings 7 or recesses, in the 
present case openings. The openings 7 are penetrated by the stamp or 
stamping tools and, accordingly, the holes are arranged in the same manner 
and at least approximately the same size as the openings 8 in the die 1. 
In the present illustrated example a relatively small die is shown. It is 
also possible to design dies according to the present invention the 
shoulder region of which is subdivided by transverse and/or longitudinal 
struts. The metal-plastic laminate is held, clamped securely in place, in 
the region of these struts. This enables a plurality of shaped packaging 
to be produced e.g. with one die and one stroke of the stamp. After the 
shaping process, the shaped packs that are produced simultaneously may be 
separated e.g. at dividing lines along the struts. 
The present invention also relates to a process for manufacturing 
cold-formed packaging forms out era metal-plastic laminate by deformation 
of the same and in particular by drawing the laminate with the aid of a 
die and a retaining tool that hold the laminate securely and a stamp that 
deforms the laminate, where the die and the retaining tool feature facing 
edge regions and the laminate is held, clamped and non-stretchable, 
between the edge of the die and the edge of the retaining tool, and the 
stamp draws the laminate over the shoulders of the die into the die 
openings which are situated within a shoulder region in the die, the 
surface of the shoulder region lying 0.01 to 10 mm lower than the edge 
region of the die, and the laminate is drawn and/or stretched in a sliding 
manner over the surface of the shoulder region. 
Cold-forming in the present case includes deformation at temperatures e.g. 
of 10.degree. to 35.degree. C. and preferably 20.degree. to 30.degree. C. 
The device according to the invention may be employed for manufacturing 
cold formed shaped packaging forms such as blister packs for 
pharmaceuticals, foodstuffs and luxury consumables, technical articles, 
for base and lid parts of semi-rigid and rigid packaging, for wraps etc. 
out of metal-plastic laminates. A drawing ratio, i.e. a ratio of diameter 
to the height of the recess formed, of e.g. 2 to 3 may be achieved. The 
diameter of the recess, if not round in cross-section, is to be understood 
as the smallest diameter i.e. in the case of non-circular cross-sections, 
such as a convex cross-section e.g. elliptical, oval, polygonal, 
rectangular, trapezium shaped, rhomboid etc. 
The largest diameter of individual recesses may be e.g. 1 to 500 mm; the 
height of a recess from 1 to 100 mm 
The laminates that are processed into shaped forms of packaging such as 
blister packs and in particular base parts of blister packs remain 
pore-free even at high drawing ratios, and the reject rate related to 
deformation i.e. shaping is substantially reduced. 
EXAMPLE 
1. A metal-plastic laminate comprising a 25 .mu.m thick oriented film of 
polyethylene, a 45 .mu.m thick aluminum foil and a 60 .mu.m thick PVC 
layer was subjected to deformation trials in a device according to the 
invention featuring a die, a retaining tool and a stamp. In the finished 
product the PVC layer represents the inside of the packaging. The die 
produces a packaging form exhibiting 10 blisters i.e. a blister base with 
10 recesses, the diameter of each recess being 13.5 mm. Accordingly, the 
die exhibits 10 openings, while the retaining tool likewise exhibits 10 
openings at the same sites. The stamp features 10 stamping tools which are 
able to penetrate the openings in the retaining tool and effect the 
deformation of the laminate as dictated by the openings in the die. The 
diameter of each stamping tool is 12.8 mm The die features a 20 mm broad 
edge region with the shoulder region lying within the edge region. The 
edge region of the die is provided with a roughness pattern in the form of 
grooving. The surface of the shoulder region is 0.3 mm lower than the edge 
region. This was achieved by milling the die i.e. subjecting it to a 
chip-forming process. The laminate is introduced between the die and the 
retaining tool and the retaining tool lowered against the die, as a result 
of which the laminate is held securely such that the laminate material 
pressed between the retaining tool and the die is not able to flow. The 
stamp is then lowered, deforming the laminate until its originally flat 
surface in the region of the die opening is 3.7 mm lower. The process is 
carried out cold i.e. without any heat being applied. The stamp is lowered 
and then raised, the pressure on the retaining tool removed; a base part 
for a blister pack may then be removed from the device. The measured 
pore-free permanent depth of deformation mounted to 3.1 mm. 
2. The trial described under example 1 was repeated. In this case, however, 
the shoulder region of the die employed is 0.15 mm lower than the surface 
of the edge region. The whole of the shoulder region was milled to a depth 
or 8.15 mm below the edge region and an 8 mm thick layer of 
polytetrafluorethylene (Teflon) inserted in the whole shoulder region. The 
shoulder region is therefore 0.15 mm lower than the edge region of the 
die. The diameter of the die opening was again 13.5 mm, the diameter of 
the stamp 12.8 mm. A laminate--same as in the first example--is introduced 
into the device and again processed into a base part for a blister pack. 
The stamp is lowered 3.8 mm and again withdrawn. The measured pore-free, 
permanent depth of deformation amounted to 3.2 mm. 
3. A comparative trial was carried out with a die exhibiting no edge region 
and no shoulder region, but only with 13.5 mm diameter die openings in the 
flat die surface. The laminate between the retaining tool and the die is 
therefore not only clamped in the edge region, but also in the shoulder 
region, i.e. over the whole surface outside the die opening. A laminate as 
described in the first example is processed to a base for blister packs 
under the same conditions of die opening stamp diameter (12.8 mm) and 
depth of penetration (3.4 mm) of the stamp into the die opening. The 
measured pore-free, permanent depth of deformation amounted to 3.0 mm. 
4. In a further trial a series of base parts for blister packs was 
manufacture. The stamp was lowered by 4.4 mm. The forming conditions were 
chosen such that using a state-of-the-art die as described in example 3 a 
reject rate of 100% was obtained with respect to pore-free, permanent 
deformation. Using the same test equipment and the same trial 
conditions--with the exception, however, that a die according to the 
invention as described in example 1 was employed--the reject rate was 
reduced to 88%. Using the same test equipment and the same test 
conditions--with the exception that a die according to the invention as 
described in example 2 was employed--the reject rate was reduced to 58%.