Plastic article or earthenware shaping or treating: apparatus – Female mold and means to shape parison directly by internal... – With heating or cooling means
Patent
1994-08-23
1996-04-23
Housel, James C.
Plastic article or earthenware shaping or treating: apparatus
Female mold and means to shape parison directly by internal...
With heating or cooling means
425534, 425537, B29C 4900
Patent
active
055097960
DESCRIPTION:
BRIEF SUMMARY
The invention is related to a machine for manufacturing hollow bodies from thermoplastic preforms by blow molding. More specifically, the invention is intended for the production of biaxially-oriented thermoplastic receptacles, such as bottles or flasks.
It is known to manufacture biaxially-oriented thermoplastic bottles from preforms obtained, for example, by injection.
A preform is generally shaped like a tube closed at one end, whereas its other open end is provided with a ring, possibly equipped at its base with a counter-ring in the shape of a projecting flange. Apart from its ring and counter-ring, the preform must be subject to an expansion during a molding operation, known as stretch-blow molding.
For this, after manufacturing, the thermoplastic preforms must be subject to an appropriate thermal treatment, prior to the molding operation by stretch-blow molding in order to bring their material to a proper forming temperature and molecular orientation. Certain characteristics of the finished product, such as resistance, transparency, etc., especially depend upon this thermal treatment.
Bottles are generally molded by means of a mold which grips each preform, and a molding and stretching blow pipe which is introduced into the open portion of said preform to ensure the stretching and expansion thereof by blow molding under pressure.
The machines provided for this type of manufacturing are displayed, for example, in a straight line; this limits the number of molds, which the shot rates depend upon.
This is why we have contemplated rotating machines enabling better rates.
These known machines are generally composed of an apparatus for feeding and heating the preforms, and a wheel for blow molding. The heating apparatus is, for example, of the rotary unwinding type, and even more specifically, also in the shape of a wheel, such as for example, the molding machine described in FR-A-2 510 470.
In addition, this type of apparatus has transfer means, especially for transferring the preforms from the heating apparatus towards the molding wheel to evacuate the product after molding, or else for feeding the preforms.
However, for this type of operation, a mold and the means it is equipped with, are relatively heavy and a wheel equipped with several molds has a very substantial moving mass.
Also envisioned in the area of blow molding (without stretching), is the machine described in U.S. Pat. No. 2,792,593 which comprises an apparatus for heating preforms and an assembly of molding stations fixedly arranged in an arc of a circle.
In this machine, the heating station is in the form of a sort of a tunnel in an arc of a circle, in which the preforms are displaced by means of a rotating carriage, whereas the molds are located on a concentric arc of a circle having the same radius as that described by the preforms.
In addition, with such a machine, the finished products issuing from the preforms cool in their molds before being conveyed to the other stations for evacuation.
Therefore, it is clear that with this machine it is impossible to obtain a continuous operation, and in addition, that the number of molding stations is very limited due to the space requirement of the heating apparatus.
The inventor has sought to design a continuously operational machine which benefits from the advantages of the rotating machines without having the disadvantages of large moving masses.
The machine according to the invention, of the aforementioned type, and therefore comprising at least one apparatus for heating the preforms and an assembly of molding stations fixedly arranged in an arc of a circle, is especially characterized in that the molding stations each comprise a finished product ejection means, whereas a rotary transfer device is provided between said heating apparatus and said molding stations for transfer of the heated preforms.
Thus, since the molding stations are fixed, it suffices for example, to rotationally drive only the control cams, of a negligible weight, contrary to the known technique where the molding station
REFERENCES:
patent: 2792593 (1957-05-01), Hardgrove
patent: 3832101 (1974-08-01), Rainville
patent: 3850566 (1974-11-01), Moore
patent: 4214860 (1980-07-01), Kleimenhagen et al.
patent: 4233010 (1980-11-01), Suzuki
patent: 4479772 (1984-10-01), Kleimenhagen
patent: 5110282 (1992-05-01), Voss
ADS
Housel James C.
Thornton Krisanne M.
LandOfFree
Machine for manufacturing hollow bodies by blow molding does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Machine for manufacturing hollow bodies by blow molding, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Machine for manufacturing hollow bodies by blow molding will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2304590