Plastic and nonmetallic article shaping or treating: processes – Mechanical shaping or molding to form or reform shaped article – Plural sequential shaping or molding steps on same workpiece
Patent
1997-12-19
1999-10-19
Silbaugh, Jan H.
Plastic and nonmetallic article shaping or treating: processes
Mechanical shaping or molding to form or reform shaped article
Plural sequential shaping or molding steps on same workpiece
264230, 264322, 264327, 425384, 425392, 425393, 425398, B29C 5700, B29C 5712, B29C 6102
Patent
active
059684380
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to a method and an apparatus for processing a thinly walled tube of thermoplastic resin to produce a tubular container having an inwardly directed flange section at an end of the thinly walled tube.
There are containers fabricated by applying a lid typically made of a filmy material to an end of a tube for each container. Such a container is normally used by peeling off the lid from the tube so that the content may be squeezed out. Of containers of the above described type, some are provided with an outwardly extending flange section arranged at an end of the tube, to which a lid is applied.
Generally, the process of manufacturing a tubular container made of a resin material and containing a given amount of a product comprises steps of preparing a tube main body from a thinly walled tube, filling it with the content and sealing the hole of the tubular container containing the contents typically by melting/bonding the open end of the container with heat or by means of an ultrasonic wave. In the above process, there are cases where tubes are laid flat in order to move the tubular container from a processing step to the next.
However, when tubes provided with the outwardly extending flange section are laid flat to transfer the tubular containers to the next processing station, there arises a problem that they rotate around the end opposite to the one where the flange section is arranged, so that the tubes would not be fed to the next processing step properly.
In view of the above identified problem, it is therefore the object of the present invention to provide a method and an apparatus for processing a thinly walled tube efficiently that is adapted to transfer it from a processing step to the next when it is held to a flatly laid state.
SUMMARY OF THE INVENTION
(1) According to the invention, the above problem is remedied by providing a method for processing a thinly walled tube of thermoplastic resin to produce a tubular container having an inwardly directed flange section arranged along the periphery of the hole at an end of the thinly walled tube, comprising: provided with a male mold for molding the flange section having a hole and forming an opening located inside the flange section, the front end of the thinly walled tube being arranged to project by a predetermined distance from a front end of the tube holder; walled tube at and near the front end thereof and cooling an outer wall surface of the thinly walled tube also at and the front end thereof, to produce a temperature difference between an inside and an outside of the thinly walled tube, so as to deform the front end of the thinly walled tube into a flange projecting radially; and walled tube into the flange section showing a predetermined shape and forming an opening located inside the flange section by means of a female mold cooperating with said male mold.
In the first embodiment of the invention, hot air is blown to the inner wall surface at and near the end of the thinly walled tube to heat the inner wall surface to a temperature lower than a melting point of the inner layer of the tube, while the outer wall surface of the thinly walled tube is cooled at and near the end, to produce the temperature difference between the inside and the outside of the thinly walled tube in the above described second step, so as to deform the front end of the thinly walled tube into a flange section projecting radially inwardly.
In the above described first embodiment of the invention, it is considered that because hot air is blown to the inner wall surface of the thinly walled tube from the inside to heat the inner wall surface to a temperature lower than the melting point of the inner layer of the tube, the inner wall surface is heated above the glass transition point thereof, so that it instantaneously contracts to restore the original shape according to its memory, whereas the outer wall surface does not contract at all due to its memory, because it is cooled, so that consequently the end of the thinly
REFERENCES:
patent: 3570107 (1971-03-01), Denzler Von Matt
patent: 4032281 (1977-06-01), Rakovsky
patent: 4559197 (1985-12-01), Dick et al.
patent: 4907958 (1990-03-01), Jones
patent: 5069856 (1991-12-01), Holoubek et al.
Poe Michael
Silbaugh Jan H.
Yoshino Kogyosho Co. Ltd.
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