DE102009003699A1 - Preform for manufacturing can, has neck section carrying circulating snap ring and circulating support ring at outer surface, where neck section is provided with conical inner contour - Google Patents

Abstract

The preform (20) has a neck section (22) carrying a circulating snap ring (28) and a circulating support ring (30) at an outer surface. A preform body (32) is arranged below the neck section, where the neck section is provided with a conical inner contour. Diameter and/or thickness of the snap ring are reduced in such a manner that transportation of the preform is made by the snap ring. The conical inner contour of the neck section is designed with a taper ratio between 1:5 and 1:50. Independent claims are also included for the following: (1) a device for manufacturing a can blank of a can (2) a method for manufacturing a can blank (3) a can consisting of a can blank and a can cover.

Description

The The present invention relates to a preform for production a can. The preform has a neck portion which abuts an outer surface a circumferential locking ring and has a circulating support ring. The circlip and the support ring each have a thickness and a diameter. The preform body from which made the actual box is located below the neck portion.

Furthermore The invention relates to a device for producing can blanks. The device consists of an oven for preheating the preforms. The oven is followed by a blowing machine, in which from the preheated preform a precursor of the can blank produced is, with the precursor of the can blank connected to her Upper part includes. The blow molding machine is at least one laser cutting unit subordinate to a dividing line between the upper part and the actual can blank produced. For releasable mounting a neck section for each preform and / or for Each precursor of the can blanks is provided in each case a mandrel.

Furthermore discloses a method for the production of can blanks, in which the preforms are preheated in an oven. The preheated Preforms become a blower downstream of the furnace fed there to a precursor for can blanks to be formed. The preliminary stage of the can blanks comprises an upper part. The upper part is equipped with at least one laser cutting unit of the Separated precursor of the can blank. For releasable mounting a neck section for each preform and / or for Each precursor of the blanks is used in each case a mandrel.

Farther the invention discloses a can consisting of a can blank and a can lid is assembled.

The publication DE 10 2006 042 711 relates to a method and an apparatus for producing plastic packages. The plastic packages are made by stretch blowing a bottle-like pre-packaging. After completion, the prepackages are cut to size using a laser to form the final packaging. The upper part of the pre-packaging, which contains the thread and the bearing ring, is cut off at a cutting edge. To make the cut clean, the prepackages are held in the cutting module by means of grippers. In a further embodiment, the prepackages are centered and fixed during cutting by a mandrel acting on the prepacking from above.

In the utility model DE 21 2006 000 052 is a preform for the production of plastic bottles, in particular PET bottles, disclosed with a rigid, substantially elongated body. The preform is formed closed at its one longitudinal end and provided at its opposite longitudinal end with a neck portion. The neck portion is provided with a pouring opening. The neck portion is separated from the body of the preform by a radially projecting, flange-like support ring. Furthermore, the neck portion has a guarantee ring and threaded portions. Furthermore, the preform has one or more adjoining the body sections, which are formed at least partially reduced in their wall thickness. These sections may be the neck portion and / or the support ring and / or a transition portion adjacent the support ring to the body. These reductions serve to reduce the use of materials for the production of PET bottles. Furthermore, it is important for the further handling of the preform that the neck portion has a constant inner diameter, even if provided between the support ring and the guarantee ring areas with a reduced outer diameter.

The Utility Model DE 203 19 786 relates to a plastic-molded cup-shaped plastic part for expansion to a plastic bottle by blow molding. Furthermore, a plastic bottle produced from a preform is disclosed, which is provided with a mouth region. The mouth region has a free peripheral edge, which has a rounding on the outside and on the inside.

The German translation DE 693 28 561 T2 the European patent specification EP 0 662 037 B1 describes a blow molding preform and a method and apparatus for blow molding a thermoplastic preform into biaxially oriented molded articles. The blow-preform has a wall thickness in the neck area. Below the neck, the blow-preform has a thickening of the wall, which tapers to the ground again. This increase in material is due to the higher demand for material that occurs when the bottle is blown. For the design of the bottle wall more material is needed in this process than for the design of the soil. The neck area of the blow preform remains unchanged during bottle making and later forms the neck of the bottles.

The invention has for its object to provide a preform for producing a can body, with which it is possible, high Maßhaltig speed of a circumferential dividing line between the can body and the unneeded part of the molded preform to ensure.

The The above object is achieved by a preform which the features of claim 1 comprises.

A second object of the invention is to provide a device with which it is possible to make a can blank characterized by a high dimensional accuracy of the circumferential Dividing line between the can body and the unneeded Upper part of the molded preform distinguishes.

These Task is solved by a device that has the features of claim 8.

Farther the object of the invention is to provide a method with which a can blank can be produced, which is characterized by a high dimensional stability the circumferential dividing line between the can body and the unneeded top of the molded preform distinguished.

These Task is solved by a method that has the characteristics of claim 14.

characteristics Advantageous developments of the invention will become apparent from the respective dependent claims.

Of the inventive preform for producing a The box has a neck section at the top. At the outer surface of the neck are a circumferential Circlip and a circumferential support ring arranged. The circlip and the support ring both have a thickness and a diameter on. The thickness and the diameter of the retaining ring and the Wear rings are of the requirements of the transport systems in dependent on the processing machines. The preform body, produced from the later in the production of the can blank is located below the neck portion. The neck section of the preform is provided with a conical inner contour. The Conical design of the inner contour serves to the preform exactly on a holding pin in the production machine for to position the can blanks.

The conical inner contour of the neck portion is designed with a taper ratio between 1: 5 and 1:50. In a preferred embodiment, the conical inner contour of the neck portion is configured with a taper ratio of 1:20. This taper ratio corresponds to the taper ratio of a tool cone DIN 228 , It is clear to the person skilled in the art that the cone ratios specified here do not represent a limitation of the invention; depending on the production conditions, the person skilled in the art can also choose other cone ratios.

A another way, the required amount of material to save for the production of the preform, is the reduction the diameter and / or thickness of the circlip. In the Reduction, however, is to pay attention that the diameter and / or the thickness are only reduced such that transport of the preform continue to be practicable using the circlip is.

By the reduction of the diameter and / or the thickness of the support ring a further reduction of the material requirement is possible. Again, make sure that the transportability of the preform is maintained.

One another point by which it is possible weight and production costs saving is the saving of threads in the neck area of the preform. As is known in the art, are Plastic cans currently made from the same preforms like plastic bottles. For the preparation of the doses, however, after blistering the precursor of the can blanks the shell that holds the Neck of the preform and contains the threads, away. The can blank will be filled after filling Cover attached. Thus, the threads of the preform have for the later use of the can any Importance. For this reason, the threads can without Effects on the production of the can and on its later Use can be saved.

Around a further material reduction for the preform reach, the preform is designed such that the neck portion of the preform in at least one section a reduced Outside diameter has. In a further embodiment of the preform is the outer diameter for weight reduction of the neck section gradually reduced. By the gradual Reduction of the outside diameter makes it possible the outer diameter of different neck sections To reduce different levels. Because of the neck section divided by the circlip and the support ring in three sections is, are the sections where the different degrees of reduction the amount of material is made, given. Thus, it is possible the material thickness between the outside diameter of three sections and the inner cone of the neck steadily increasing reduce. Furthermore, by reducing the wall thickness the individual sections of the neck section made sure that the stability needed for further processing preserved.

A Reduction in the amount of material used to make the preform is for the production of a huge financial advantage. At the high volumes, in which cans made of PET can be reductions in the amount of material in tenths of a tenth very quickly lead to material savings in the tonne range.

The Device for the production of can blanks consists of a Furnace for preheating the preforms, which is a blow molding machine for manufacturing is followed by precursors of the can blanks. The preliminary stages the can blanks include after being manufactured in the blow molding machine the can blank and an associated top. To create a circumferential dividing line between the upper part and the can blank the blow molding machine is followed by at least one laser cutting unit. For the detachable mounting of a neck section for each preform and / or for each precursor of the blanks each a mandrel is provided. The conical inner contour the neck portion of the preform is designed such that it interacts with the conical outer contour of the mandrel. Through this interaction are the preforms and / or the precursors the can blanks automatically about a respective longitudinal axis centered.

The Generation of the circumferential dividing line between the upper part and the Canned blank is made by the at least one laser cutting unit. The circumferential dividing line lies in the cutting of the can blank perpendicular to the longitudinal axis of the mandrel.

Between the laser cutting unit and the precursors of the can blanks lies a rotational relative movement before. By the rotational relative movement is it possible a circumferential dividing line between the To produce upper part and the can blank.

For the expert it is understood that the rotary Relative movement can be generated in various ways. A possibility, producing them is the mandrel with the one on top Pre-stage of the can blank to rotate. By passing by the rotating precursors of the can blanks on the laser cutting unit arises the circumferential dividing line. Another way, the Rotary relative movement is to create the laser cutting unit to drive around the precursors of the can blanks. Through the movement The laser cutting unit is the precursors of the blanks then generates the circumferential dividing line.

Around the tops of the precursors of the can blanks from the mandrel take off, is on the apparatus for the production of can blanks Wedge segment arranged. The tops of the precursors of the can blanks run past the mandrels on this wedge segment. there strips the upper edge of the neck portion along the wedge segment, whereby the upper part of the precursors of the can blanks of the Pick-up mandrel lifts off. The lifted shells are for the further production of can blanks is no longer needed. One way to continue using the tops would be to to re-supply them to preform production as recycled material.

The conical outer contour of the mandrel is with a cone ratio between 1: 5 and 1:50. In a particular embodiment is the conical outer contour of the mandrel with a Cone ratio of 1:20 designed. This embodiment is configured analogously to the conical inner cone of the preform, so that the two cones interact.

The inventive method is used for the production of can blanks in which the preforms are preheated in an oven become. The preheated preforms are connected downstream of the furnace Blowing machine fed there to a preliminary stage for Cans blanks to be formed. The precursor of the blanks consists from the top and the can blank. The top will come with at least a laser cutting unit, which is downstream of the blow molding machine, separated from the precursor of the can blank. To detachable Mounting a neck section for each preform and / or For each precursor of the blanks is a receiving mandrel used. For this purpose, the neck portion of the preform with his conical inner contour on a conical outer contour of the Mount mandrel mounted so that they interact. By the Interaction are the preforms and / or the precursors of Can blanks automatically around a respective longitudinal axis centered.

While the production of the circumferential dividing line between the upper part and the can blank by the laser cutting unit is the can blank aligned such that the circumferential dividing line perpendicular to Longitudinal axis of the mandrel is located. The preliminary stage of can blanks is used to generate the circumferential dividing line in a rotary Relative movement to the laser cutting unit moves. According to the method with a respective associated laser cutting unit several blanks simultaneously separated from the preliminary stages for can blanks.

It is obvious to a person skilled in the art that for this purpose the laser cutting unit has to be equipped with a plurality of cutting devices. The design of these laser cutting devices will not be explained in detail here, since they is sufficiently known from the prior art and does not represent a limitation of the invention.

The Upper part, which after the removal of the can blank on the mandrel remains, is lifted from this by at least one wedge segment.

The can according to the invention is made from a can blank and a can lid assembled. The can blank is with produced by the method described above. The can lid will open pressed the circumferential dividing line of the can blank. For It is obvious to a person skilled in the art that the can is filled before pressing the can lid. The can lid can be made of metal (preferably aluminum) or of a plastic material (preferably the same material as the can body) exist. Furthermore, it is clear that the can lid not necessarily with the Dose must be pressed to close these tight. The can lid can also be replaced by other methods such as by crimping or welding tight with the can get connected. To the usual welding procedures include laser welding and / or ultrasonic welding. The way the can lid is tightly connected to the can is not a final restriction of the invention. From packaging technology are other methods known for tightly sealing containers which can also be used.

For It is further clear to the person skilled in the art that the can is not exclusive can be filled with liquids. It can also solids are filled. Furthermore, it is conceivable that the can is not strictly for food must be used. There may be other products as well such as oil of fats are filled. Even in the non-food sector, it is possible to use the can with liquids and / or solid substances. The filling the can of the invention with drinks thus does not constitute a final restriction of the invention.

in the Below are embodiments of the invention and their advantages with reference to the accompanying figures closer explain. The proportions of the individual elements to each other in the figures do not always correspond the real size ratios, as some Simplified shapes and other shapes for better illustration increased in proportion to other elements are shown.

1 shows a schematic representation of an apparatus for producing can blanks.

2 shows the schematic sectional view of a preform.

3 shows a schematic representation of a receiving mandrel.

4 shows the schematic structure of the neck portion of a preform.

5 shows the dimensions of the retaining ring and the support ring.

6 schematically shows how the outer diameter of the neck portion of the preform is gradually reduced.

7 shows schematically how the mandrel and the top of the precursor of the can tube interact.

8th shows the schematic structure of the precursor of the can blank.

9 shows schematically the can blank and cut off from the can blank top.

10 shows a box with its lid.

11 shows a box with pressed-on lid.

For the same or equivalent elements of the invention will be identical Reference numeral used. Furthermore, for clarity's sake only reference numerals in the individual figures shown for the description of the respective figure are required. The illustrated Embodiments are merely examples, such as the device according to the invention or the inventive Procedures can be designed and provide no final Limitation.

1 shows a schematic view of a device 1 in which can blanks (not shown) are made essentially by a stretch blow molding process. The device 1 consists essentially of an oven 2 in which preforms (not shown) for the can blanks to be produced are brought to a specific temperature in order that the blanks can be produced from these preforms by the blow molding or stretch blow molding method. With the oven 2 is a blowing machine 3 connected. In the oven 2 is a conveyor 4 provided a variety of preforms to a heater 5 passes. To the interior of the oven 2 there is the transport device 4 using heat-reflecting tiles 6 shielded. At a transfer position 7 the preforms are placed in the oven 2 initiated. At an issue position 8th become the heated preforms to an input position 9 for the blowing machine 3 to hand over. At an issue position 10 the blowing machine 3 The generated preliminary stages of the can blanks are output for further processing. During further processing, the actual can blanks are produced from the precursors of the can blanks. For this purpose, the precursors of the can blanks with the transport path 15 in the transport direction 17 on a laser cutting unit 16 past. With this laser cutting unit 16 The tops are separated from the precursors of the can blanks, so that the can blanks arise. The resulting can blanks are used for further processing, eg. B. for cleaning and / or filling, to further production units (not shown) transported on.

In the in 1 The illustration shown includes the blow molding machine 3 a transport device 11 on which the variety of mold carriers 12 is arranged. In the schematic illustration of the blow molding machine shown here 3 , is the transport device 11 designed as a wheel. It is also conceivable that the transport device 11 is designed as a substantially linear transport device. The blowing machine 3 is of several walls 14 enclosed.

The 2 shows the schematic sectional view of a preform 20 , In the area of the neck section 22 is a circulating carrying ring 30 arranged, to which the preform 20 is transported through the production. Above the carrying ring 30 is a circlip 28 arranged. This circlip 28 is with this preform 20 only for the transport of the preform 20 significant. Below the neck section 22 closes the preform body 32 from where the can blank 21 (not shown) is made by stretch blow molding. The longitudinal axis 40 of the preform 20 runs through this center. Around this longitudinal axis 40 becomes the preform 20 rotated during the production of the can blank.

In the 3 is schematically the structure of a receiving mandrel 34 shown. The mandrel 34 is on a mold carrier 12 appropriate. Directly to the mold carrier 12 closes the mandrel body 36 at. At the mold carrier 12 opposite end of the mandrel body 36 This is followed by the area at which the preform (not shown) is picked up. This area has a conical outer contour 35 on. Around the longitudinal axis 41 of the mandrel 34 becomes the mandrel 34 in the preparation of precursors 18 the can blanks (not shown) turned.

4 shows the schematic structure of the neck portion 22 a preform 20 , The neck section 22 is from the neck section body 26 educated. The neck section body 26 is through the circlip 28 in a first section 26a and a second section 26b divided. Between the carrying ring 30 and the preform body 32 is a third section 26c educated. The inner contour 24 of the neck section 22 is conical. The outer wall 23 of the neck section 22 is formed such that over the entire length of the neck portion 22 an outer diameter 27 is equal to. In other words, the outer wall is 23 over the entire length of the neck section 22 parallel to the longitudinal axis 40 of the preform 20 ,

In the 5 are the dimensions of the retaining ring 28 and the bearing ring 30 shown. The circlip 28 and the bearing ring 30 run all around the neck section 22 perpendicular to the longitudinal axis 40 of the preform 20 , The circlip 28 has a diameter 29a and the thickness 29b on. The circlip 30 has a diameter 31a and a thickness 31b on. The dimensions of the retaining ring 28 and those of the bearing ring 30 are dependent on the requirements of the processing machines (not shown).

In the 6 is shown schematically as the outer diameter 27a of the first section 26a of the neck section 22 of the preform 20 gradually reduced. The reduction is made such that the outer diameter 27a of the neck section 22 at the second section 26b on the outside diameter 27b is reduced. In the area of the third section 26c is the outside diameter 27a of the neck section 22 again on the outside diameter 27c reduced. The outside diameter 27a . 27b and 27c However, they can only be reduced so far that a certain wall thickness 25 of the neck section 22 not fallen below. This is necessary because of the neck section 22 otherwise it is no longer dimensionally stable enough to handle it safely in further processing.

The 7 schematically shows how the mandrel 35 and the top 19 the preliminary stage 18 the can blank (not shown) cooperate. The neck section 22 of the top 19 lies with its conical inner cone 24 positive fit on the conical outer contour 35 of the mandrel 34 at. Through this positive connection creates a detachable connection using a wedge segment 39 can be solved again. To release the connection, the upper part 19 and the mandrel 34 on the wedge segment 39 in a transport direction 17 (please refer 1 ) passed by. By doing that, the wedge segment 39 firmly on the device 1 attached, the shell becomes 19 from the mandrel 34 lifted. This happens because the distance between the mandrel 34 and the top 19 is increased by driving past, until the conical outer contour 35 of the recording hawthorn 34 and the conical inner contour 24 in the neck section 22 of the top 19 no longer interact.

The 8th shows the schematic structure of the precursor 18 of the can blank 21 , The preliminary stage 18 of the can blank 21 consists of the can blank 21 and a top 19 on which the neck section 22 located. Below the top 19 there is a circumferential dividing line 42 , Along this circumferential dividing line 42 becomes the shell 19 from the can blank 21 disconnected.

In the 9 is schematically a tailored can blank 21 shown. The can blank 21 was from the top by the laser cutting unit (not shown) 19 at which the neck portion 22 is located, separated. By cutting with the laser cutting unit is the circumferential dividing line 42 emerged.

The 10 shows a schematic representation of a erfindugsgemäßen tin 44 with associated lid 46 , The lid 46 will after filling the can 44 on the circulating dividing line 42 put on and pressed so hard that he cans 44 closes.

The 11 shows a can 44 with pressed-in lid 46 , The tin 44 is up to a level 48 filled. The lid 46 is at the circumferential dividing line 42 on the can 44 placed. The lid 46 Depending on the material with the appropriate method with the can 44 get connected. The possible method is pressing, welding (laser, ultrasound) and / or beading.

The Invention has been described with reference to a preferred embodiment described. However, it is conceivable for a person skilled in the art that made modifications or changes of the invention can, without losing the scope of the following To leave claims.

1

contraption

2

oven

3

blow molding machine

4

Conveyor

5

heater

6

warmth reflective tiles

7

Transfer position

8th

output position

9

input position

10

output position the blowing machine

11

transport means

12

mold carrier

14

walls

15

transport path

16

Laser cutting unit

17

transport direction

18

preliminary stage of the can blank

19

top

20

preforms

21

can blank

22

neck section

23

outer wall

24

inner contour

25

Wall thickness of the neck section

26

Neck section body

26a

first section

26b

second section

26c

third section

27

outer diameter of the neck section

27a

outer diameter of the preform

27b

outer diameter of the second section

27c

outer diameter of the third section

28

circlip

29a

diameter of the circlip

29b

thickness of the circlip

30

support ring

31a

diameter of the carrying ring

31b

thickness of the carrying ring

32

Preform body

34

arbor

35

conical outer contour

36

Arbor body

38

direction of rotation

39

wedge segment

40

longitudinal axis of the preform

41

longitudinal axis of the mandrel

42

encircling parting line

44

can

46

can end

48

level the can

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102006042711 A [0005]
• - DE 212006000052 U [0006]
• - DE 20319786 U [0007]
• - DE 69328561 T2 [0008]
• - EP 0662037 B1 [0008]

Cited non-patent literature

• - DIN 228 [0017]

Claims (20)

Preform ( 20 ) for producing a can ( 21 ) with a neck portion ( 22 ), which on an outer surface a circumferential retaining ring ( 28 ) and a circulating support ring ( 30 ), both of which have a thickness ( 29b . 31b ) and a diameter ( 29a . 31a ) and that a preform body ( 32 ) below the neck portion ( 22 ), characterized in that the neck portion ( 22 ) of the preform ( 20 ) with a conical inner contour ( 24 ) is provided. Preform ( 20 ) according to claim 1, characterized in that the diameter ( 29a ) and / or the thickness ( 29b ) of the retaining ring ( 28 ) are reduced such that a transport of the preform is carried out by means of the securing ring. Preform ( 20 ) according to claim 1, characterized in that the diameter ( 31a ) and / or the thickness ( 31b ) of the carrying ring ( 30 ) are reduced such that a transport of the preform is possible on the support ring. Preform ( 20 ) according to one of claims 1 or 3, characterized in that the neck portion ( 22 ) of the preform ( 20 ) has a reduced outside diameter in at least one section. Preform ( 20 ) according to claim 4, characterized in that the outer diameter ( 25a ) of the neck portion ( 22 ) is gradually reduced. Preform ( 20 ) according to one of claims 1 to 5, characterized in that the conical inner contour ( 24 ) of the neck portion ( 22 ) is designed with a taper ratio between 1: 5 and 1:50. Preform ( 20 ) according to claim 6, characterized in that the conical inner contour ( 24 ) of the neck portion ( 22 ) is designed with a cone ratio of 1:20. Contraption ( 1 ) for the production of can blanks ( 21 ), consisting of a furnace ( 2 ) for preheating the preforms ( 20 ), one oven ( 2 ) downstream blowing machine ( 3 ), in which from the preheated preform ( 20 ) a preliminary stage ( 18 ) of the can blank ( 21 ), the precursor ( 18 ) the Do senrohling ( 21 ) and an associated upper part ( 19 ) and at least one of the blowing machines ( 3 ) downstream laser cutting unit ( 16 ) which has a dividing line ( 42 ) between the upper part ( 19 ) and the can blank ( 21 ), wherein for detachable mounting of a neck portion ( 22 ) for each preform ( 20 ) and / or for each precursor ( 18 ) the can blanks ( 21 ) each a mandrel ( 34 ) is characterized in that the neck portion ( 22 ) of the preform ( 20 ) a conical inner contour ( 24 ) has formed in such a way with a conical outer contour ( 35 ) of the mandrel ( 34 ) cooperates, that the preforms ( 20 ) and / or the precursors ( 18 ) the can blanks ( 21 ) automatically about a respective longitudinal axis ( 40 . 41 ) are centered. Contraption ( 1 ) according to claim 8, characterized in that the laser cutting unit ( 16 ) the circumferential dividing line ( 42 ) between the upper part ( 19 ) and the can blank ( 21 ), wherein the circumferential dividing line ( 42 ) perpendicular to the longitudinal axis ( 41 ) of the mandrel ( 34 ) lies. Contraption ( 1 ) according to one of claims 8 or 9, characterized in that between the laser cutting unit ( 16 ) and the preliminary stages ( 18 ) the can blanks ( 21 ) a rotational relative motion is present around a dividing line ( 42 ) between the upper part ( 19 ) and the can blank ( 21 ) to create. Contraption ( 1 ) according to one of claims 8 to 10, characterized in that a wedge segment ( 39 ) on the device ( 1 ) is arranged that the tops ( 19 ) of preliminary stages ( 18 ) the can blanks ( 21 ) from the mandrel ( 24 ) takes off. Contraption ( 1 ) according to one of claims 8 to 11, characterized in that the conical outer contour ( 35 ) of the mandrel ( 34 ) is designed with a taper ratio between 1: 5 and 1:50. Contraption ( 1 ) according to claim 12, characterized in that the conical outer contour ( 35 ) of the mandrel ( 34 ) is designed with a cone ratio of 1:20. Method for producing can blanks ( 21 ), in which preforms ( 20 ) in an oven ( 2 ) are preheated, that the preheated preforms ( 20 ) one of the furnace ( 2 ) downstream blowing machine ( 3 ) are fed there to egg ner precursor ( 18 ) for can blanks ( 21 ), whereby the precursor ( 18 ) the can blanks ( 21 ) an associated upper part ( 19 ), that the upper part ( 19 ) with at least one laser cutting unit ( 16 ) from the preliminary stage ( 18 ) of the can blank ( 21 ) is separated, wherein for the detachable mounting of a neck portion ( 22 ) for each preform ( 20 ) and / or for each precursor ( 18 ) the can blanks ( 21 ) each a mandrel ( 34 ) is characterized in that the neck portion ( 22 ) of the preform ( 20 ) a conical inner contour ( 24 ) has formed in such a way with a conical outer contour ( 35 ) of the mandrel ( 34 ) cooperates, that the preforms ( 20 ) and / or the precursors ( 18 ) the can blanks ( 21 ) automatically about a respective longitudinal axis ( 40 . 41 ) are centered. A method according to claim 14, characterized in that the circumferential dividing line ( 42 ) during the process of generating the circumferential dividing line ( 42 ) between the upper part ( 19 ) and the can blank ( 21 ) by the laser cutting unit ( 16 ) perpendicular to the longitudinal axis ( 41 ) of the mandrel ( 34 ) lies. Method according to one of claims 14 to 15, characterized in that the precursors ( 18 ) the can blanks ( 21 ) for generating the circumferential dividing line ( 42 ) in a rotational relative movement to the laser cutting unit ( 16 ) are moved. Method according to one of claims 14 or 16, characterized in that the upper parts ( 19 ) by at least one wedge segment ( 39 ) from the mandrel ( 24 ) are lifted. Method according to one of claims 14 or 17, characterized in that each with an associated laser cutting unit ( 16 ) several can blanks, ( 21 ) simultaneously from the preliminary stages ( 18 ) for can blanks ( 21 ) are separated. Can ( 44 ) from a can blank ( 21 ) and a can lid ( 46 ), characterized in that the can blank ( 21 ) is produced by a method according to at least one of claims 14 to 18. Can ( 44 ) according to claim 19, characterized in that the can lid ( 46 ) on a circumferential dividing line ( 42 ) of the can blank ( 21 ) is pressed.