Abstract:
The invention relates to a pressurized-fluid workhead (66) for permanent bell-forming end portions (50) of plastic pipes (51), comprising: a die (52) exhibiting a cavity (80) for receiving a thermally plasticized end portion (50) of a pipe (51), being provided with flow conduits (54) for a pressurized fluid; a forming mandrel (55), insertable into the end portion (50) of the pipe (51) and arranged centrally to the die (52) and further exhibiting flow pipes (58) for a pressurized fluid; a flange (60) mounted coaxially and slidably with respect the the mandrel (55) and die (52), and having a striking surface (82) which is associable to an edge (62) of the end portion (50) of the pipe (51); sealing elements (59) located on the die (52) and the mandrel (55), destined to interact with an external surface (84) and an internal surface (83) of the end portion (51) of the pipe (50). The die (52), the mandrel (55) and the flange (60) together peripherally define a forming chamber (72) of the end portion (50) of the pipe (51), said forming chamber (72) being subdivided by the pipe (51) into a first and a second pressure chamber (63,64) of a fluid; the first pressure chamber being arranged between the lateral surface (81) of the mandrel (55) and the internal surface (83) of the pipe (51); the second chamber (64) being arranged between the external surface (84) of the pipe (51) and the internal surface (53) of the die (52); the pressure chambers (63,64) being fed by the conduits (54,58) such as circumferentially and successively to dilate and contract the end portion (50) of the pipe (51), to produce a yielding, of the pipe (51).
Abstract:
Apparatus and methods for forming dilatation balloons and catheters including same are provided. The balloons are fabricated of a biaxially orientable material such as a nylon or a polyamide material, and they have an inflated, non-distended working profile as well as a stretched inflated profile which is achieved by applying pressure through a dilatation catheter or the like that is in excess of that needed to achieve the inflated, non-distended profile and which is adequate to effect dilatation or the like up to a maximum pre-bursting pressure application. The maximum pre-bursting size of the balloon can be tailored depending upon the needs of the particular balloon within a wide range of possible maximum pre-bursting sizes. The apparatus and methods facilitate fabrication of the balloons which are subjected to longitudinal elongation or axial orientation and biaxial or radial orientation.
Abstract:
Es wird eine Einrichtung zum drehbaren Transportieren von Vorformlingen durch eine Aufheizstation einer Streckblasmaschine aufgezeigt, mit der ohne lange Umrüstzeiten Vorformlinge mit verschiedenen Halsdurchmessern sehr gleichmäßig und gezielt aufgeheizt werden können. Erreicht wird dieses Ziel durch zwei parallel zueinander laufende, endlose Mitnahmetrums mit daran befestigten Aufnahmeeinrichtungen, zwischen denen die Vorformlinge während ihres Durchlaufs durch die Heizeinrichtung gehalten werden und die zusammen mit den Heizeinrichtungen in ihrem gegenseitigen Abstand zueinander einstellbar sind. Durch zwei weitere endlose Treibriemen werden die Vorformlinge während des Durchlaufs mit gezielter Umfangsgeschwindigkeit in Drehbewegung gehalten, um die Temperaturvergleichmäßigung zu unterstützen.
Abstract:
A method of producing a tubular article, such as a can body or a bottle, of a biaxially oriented crystallisable thermoplastic polymer such as polyethylene terephthalate from a tubular article of smaller dimensions, such as a preform, having at least one open end, comprises heating the smaller tubular article to a temperature above the glass transition temperature but below the melting temperature of the polymer, stretching the tubular article axially by mechanical means such as an extending push rod (122) or a drawing chuk element, and simultaneously or sequentiall stretching the tubular article both axially and transversely by internal fluid pressure introduced through the open end (13), without any external mould or other external constraint. The stretched and biaxially oriented article (10) may be subsequently heated further to anneal the polymer and thereafter cooled before removal from the stretching apparatus, the internal pressure being reduced during such annealing and cooling. For polyethylene terephthalate, the stretching temperature is from 75oC to 120oC and the internal fluid pressure from 7 to 15 bars, while the annealing temperature is from 110oC to 240oC and the reduced internal fluid pressure used during annealing and/or cooling is from 2 to 4 bars.
Abstract:
A container of a food or beverage product, characterised in that it is constructed from a tubular wall portion open at both ends, the dimensions of the open ends being substantially the same as the transverse dimensions of the remainder of the tubular wall portion, that the tubular wall portion is of biaxially oriented thermoplastics material and is transparent, that the container further comprises end closures (30, 31) formed separately from the tubular wall portion but sealingly secured thereto to close its ends, and that a food or beverage product is hermetically sealed within the container and displayed through the tubular wall portion.
Abstract:
Biaxially oriented tubular articles which are destined to provide bodies for processable food containers are made from an elongate tube of thermoplastics material as it emerges from an extruder. The manufacturing process comprises repeatedly performing a cycle of operations each including the following steps: engaging the tube by a first clamping means (11,12) over a first region at a leading end of the tube (10) and by a second clamping means (13,14) over a second region at a spacing from the first region, so as to define between the clamping regions a portion of the tube to be longitudinally stretched and radially expanded; moving the clamping means apart to stretch the tube portion longitudinally and admitting pressure fluid to the tube portion to expand it radially, such stretching and expansion forming a bubble (100) of biaxially oriented thermoplastics material adjacent the leading end of the tube; and severing (at 22) at least a substantial part of the bubble from the tube to form the tube with a new end as the said leading end of the tube for the succeeding cycle of operations.
Abstract:
Apparatus for use in the manufacture of socketed thermoplastics pipe by the radial expansion of a pipe blank. The apparatus includes an openended central mould portion 12 which can be raised or lowered on stanchions 10, 11 to three predetermined positions: a pair of mould end portions 15, 17 each having a supporting mandrel 19, 20 engageable with the pipe blank 28, end portions 15, 17 being advanceable to and retractable from the central mould portion 12. One of the mould end portions 15 is internally contoured to provide part of the socket-forming portion of the mould. The mould end portions 15, 17 can be held in an intermediate position, partially advanced towards the central portion 12 to locate the blank 28 on mandrels 19, 20 before closing of the mould.
Abstract:
Le procédé comprend l'étirage bidirectionnel dans un moule d'un tube préformé en matière thermoplastique chauffée à la température d'orientation de la matière, sous l'action d'une pression interne de fluide; cet étirage est limité à une valeur déterminée et est suivi d'un étirage transversal supplémentaire. Le procédé permet d'obtenir des profilés biorientés de grande longueur, de sections droite et transversale quelconques, et qui présentent d'excellents caractéristiques.
Abstract:
Ein Verfahren und eine Vorrichtung zur Blasformung molekular orientierter hohler Behälter aus rohrförmigen Rohingen (26-26'), wobei ein Rohrstrang plastischen Materials bei geeigneter Orientierungstemperatur mittels einer Zufüheinrichtung (22) einer Schneideeinrichtung (24) zugeführt wird. Das freie Ende des Rohrstrangs wird von einer Rohlingüberagbeeinrichtung (28) erfasst, worauf Rohlinge von dem Bohrstrang abgetrennt und durch die Übergabeeinrichtung in eine Position für die Aufnahme in Blasformen (30, 32) gebracht werden. Die erste von zwei Blasformen bewegt sich zur Aufnahme eines Rohlings von einer Blasstellung in Richtung auf die Rohrstrangachse. Die Rohlingübergabeeinrichtung wird ausgefahren, um den Rohling zwischen den Formhöhlungen (66, 66a) der offenen Blasform zu bringen. Das freie Ende des Rohlings wird von Klemmbacken ergriffen, und während des Einziehens der Rohlingübergabeeinrichtung wird der Rohling vor dem Formschluss gereckt. Die geschlossene Blasform kehrt in ihre Blasstellung zurück, um die Blasformung eines fertigen orientierten Behälters zu vollenden. Die Rohlingübergabeeinrichtung übernimmt einen anderen Rohling und bringt ihn in die Stellung zur Aufnahme in einer zweiten Blasform, die aus ihrer Blasstellung bewegt wurde, und die Schritte werden wiederholt.