DE2517981A1 - Forming machine - for pre-stretching, compressed air deep drawing, and prod. stacking in a single station - Google Patents

Abstract

In the prodn. of articles e.g. beakers, from thermo plastic film by first heating this and then forming the articles, stamping them out and stacking them in a single station, the articles are delivered after stamping out by the locally fixed top cutter of the laterally displaceable stacking shafts behind this, the shaft and the auxiliary stretching unit being pushed alternately over the moult array. Used for prodn. of relatively deep articles from a thermoplastic film by mechanical pre-drawing and compressed air-forming in a single station in which they can also be stamped out and stacked.

Description

METHOD AND DEVICE FOR MANUFACTURING ARTIKEIJ.4 FROM THERMOPLASTIC PLASTIC FILM The invention relates to a method for manufacturing articles made of thermoplastic Y # unststoff-olie, whereby the film is peeled off the roll, cyclically transported, heated and the articles from it in a station by means of Differential pressure shaped, punched out and stacked. It also concerns a Device for carrying out the process.

There are several advantages to having plastic items in one station shape, punch and stack. For this purpose, it is suggested in DT-PS 1 779 568, to form a stationary upper knife with a narrowing edge over which the punched out Article to be pushed.

With the tool described there, however, it is only possible relatively to produce flat articles stacked, as only vacuum deformation is possible. Modern machines deform deeper containers using compressed air, as this creates a faster and sharper shaping is achieved. The result is better articles in shorter time.

In the case of a tool according to the cited patent specification, it is not either possible to use a stretching aid, which is important for cup-type objects Achieving a uniform wall thickness is absolutely necessary.

It was the object of the invention to provide a method and apparatus for production of articles made of thermoplastic plastic film so that also relatively deep articles by means of compressed air deformation and mechanical pre-stretching in one Station can be shaped, punched and stacked.

This is achieved according to the invention in that the article after Punching out through the fixed upper knife in it can be displaced behind it arranged stacking shafts are passed, with these stacking shafts alternating be moved with the stretching aid over the upper knife. The transfer takes place mechanically by sliding parts of the bottom of the article shape.

The device is characterized by a behind the upper knife Slidable bridge on which the stretching aid and stacking shafts are arranged. Included carry the stacking shafts at least locally latches or similar parts, so that the articles pushed over it are held back.

An embodiment of the invention is based on the schematic Drawings described in more detail.

It shows: FIG. 1: a longitudinal representation of the device after the stacking process Fig. 2: a partial representation of the forming station after the shape of the article Fig. 3: an enlarged view of the stacking shafts in the lower area.

Fig. 4: an advantageous embodiment of the entire stacking shafts Die The device for carrying out the method consists essentially of the frame 1, the roll holder 2 to take on the film roll 3, a clockwise working Transport 4, a heater 5 and the forming station 6. This forming station 6 has a relative to the rigid upper table 7 moves union table 8, which is the actual molding tool 9 wears.

It consists essentially of the mold cavities lo, their outer edge as, cutting edge in cooperation with # the upper knife 12 and the spring-loaded Scraper ii. This upper knife 12 is rigidly attached to the stationary upper table 7.

Behind the upper table 7, a bridge 13 is arranged on guides 14 can be moved The bridge 13 on the one hand carries a structure 15 for attachment a cylinder 16 which moves the stretching aid 17. On the other hand are at the bridge 13, the stacking shafts 18 are arranged. They carry feathered ones at their lower end Latches 49 to hold back the articles 20.

For the lifting movement of the table 8, a lifting cam 21 is used, which is of a Gear 22 is moved The movement of the bridge 13 should be mechanically inevitable be controlled depending on the stroke movement of the table 8, therefore is a second cam 23 is provided, which is mounted on the same drive shaft 24 and a lever 25 moves, which on the one hand rotatably mounted in the bearing 26 on the other hand is hinged to the bridge 13 at the pivot point 36.

A third curve 27, also attached to the drive shaft 24, controls the lifting movement of a bridge 28 to which the rods 29 are attached, the the other end carries the bottoms 30 of the mold cavities 10.

In an advantageous embodiment of the invention, the stacking shafts 18 rotatably mounted on the bridge 13 in a pivot point 31, on the other side a pivotable lever 32 forms a support. In this way accomplish this end the stacking shafts 18 only a slight pivoting movement, so that removal of the stacked article 20 is possible during the operation of the device.

The procedure is as follows: From the transport 4, the Film web 33 is pulled off the roll 3 and first fed cyclically to the heater 5, which causes warming up to the deformation temperature. A warmed up section the film web 33 is brought into the forming station 6 and after the closing of the The molding tool 9 is used to shape the article 20 by means of mechanical pre-stretching Via the stretching aid 17 and by compressed air that is fed into the via port 34 closed space 35 is passed, which the structure 15 forms. This procedural status is shown in FIG.

After the article 20 has cooled down, it is pressed through a short punching stroke of the table 8 punched out. At the same time the bridge 13 is moved so that the Stacking shafts 18 come to rest over the article 20. The handover of the punched out Article 20 in the stacking shafts 18 is carried out by extending the floors 30 through the Upper knife 12 through it. The edges of the article 20 are thereby separated from the pawls 19 held back.

While the floors 30 are still retreating, the bridge 13 is over the Move lever 25 to the side so that the stretching aid 17 over the mold cavities 10 come to rest and the mold 9 is moved in the direction of the upper knife 12 so the next work cycle can then run immediately afterwards.

The device is shown in a vertical construction, as opposite the horizontal construction, the stacking shafts 18 are much more easily accessible are. Of course, the horizontal construction is also possible; by appropriately designed stacking shafts can put the articles in an accessible position be convicted.

Claims (6)

P A T E N T A N 5 P R Ü c ii E Xperience for the production of articles from thermoplastic plastic film, whereby this plastic film is first heated and then the articles from it in a station shaped, punched out and stacked, characterized in that the articles (20) after punching out through the fixed upper knife (12) in behind this laterally displaceable stacking shafts (18) are transferred, the stacking shafts be shifted alternately with the stretching aids (17) over the mold cavities (10) 2) Device for performing the method according to claim 1 with a roll holder, a cycle-based transport, a heater and a forming station with one rigid upper knife and a table (8) that can be moved to this, which the forming tool (9), characterized by sliding shelves ¢ 30) and one behind the Oberniesser (12) displaceable bridge (13) with spaced apart from its displacement path on it Stacking shafts (.18) and stretching aid (17). 3) Device according to claim 2 characterized by a synchronous with the lifting cam (21) moving cam (23) which controls the lifting movement of the floors (30). 4) Device according to claim 2 or 3 characterized by a synchronous with the lifting cam (21) moving cam (27) via a lever (25). the postponement the bridge (13) controls. 5) Device according to one of claims 2-4, characterized in that that the stacking shafts (18) are pivotally attached to the bridge (13) and on the other side using a pivoting lever # (32) on the floor. 6) Device according to one of claims 2-5 characterized by on the stacking shafts (18) attached pawls (19) that the pushed over Support the edges of the article (20).