US 6,713,013 B2 · Single-row and multi-row stretch blow molding method and apparatus therefor

Abstract

In a single-row and expandable into a multi-row stretch blow molding method and apparatus, at least one row of tray plates in a tray unit is used to collect molded preforms ejected from the opening clamp of a preform-molding unit, transfer the preforms with or without transfer beads out of the molding area and align them with the center row distances of the downstream processing units. At least one robot having a universal gripper assembly is used to pick up either all or consecutively fractions of the preforms align them to the center distances of the blow mold cavities to place them at variable time intervals into a conditioning, stretch blow molding and oriented discharge unit, releases finished hollow articles and returns to a waiting position at the preform-molding and tray unit again at the preform mold's center distance independent of the preform-molding cycle. Simultaneously, component transfer devices may pick up external components, i.e. labels, valves or handles during the stretch blow molding phase and release the components into the blow-mold cavities while the universal gripper assembly is in the waiting position. The universal gripper assembly can alternatively also be pivoted to pick up preforms from a lateral reheat unit to supplement the molded preform supply. A modular stack-blow-mold clamp assembly is equipped with at least one row of blow mold cavities and with a plurality of pivoting spacing platens which in conjunction with helical spindles and nuts open and close the blow-mold halves and align their respective parting lines to correspond with the center-row distances of the transfer tray plates, conditioning and stretch blow means. Prior to the transfer of the molded preforms to a conditioning unit, internal components, i.e. sleeves or liners can be inserted into the neck and body portion of the preforms. Further, a secondary robot with a gripper assembly can pick up pretreated preforms from the first set of blow molds and transfer them into one or several consecutive blow mold assemblies all to obtain heat stable hollow articles or improved hollow article barrier performance prior to discharging.

Claims17

Dependent claims

Method for the preparation of hollow thermoplastic articles in a stretch blow-molding apparatus including a plasticizing unit and a preform-molding unit comprising a preform mold having a neck-ring clamp and an injection-core clamp, a tray unit with at least one row of telescoping tray plates and a robot having a universal gripper assembly conditioning unit, a stretch blow-molding unit having a blow-core clamp, a stretch-rod clamp, and a stack blow-mold clamp with at least one row of blow-mold cavities, and a discharge unit, comprising the steps of

(a) plasticizing raw material in the plasticizing unit to form a molten material,
(b) transferring the molten material from the plasticizing unit into the closed preform mold of the preform-molding unit,
(c) molding preforms in the preform-molding unit,
(d) opening the neck-ring clamp of the preform-molding unit
(e) introducing the tray unit in-between the molded preforms during the preform-mold-clamp opening stroke,
(f) collecting the ejected molten preforms by their transfer rings in the openings of at least one row of tray plates of the tray unit while retracting the injection-core clamp, and spreading the neck-ring assembly,
(g) transferring the preforms with the tray unit out of the preform molding area,
(h) closing the preform mold clamp assembly to start a new preform molding cycle,
(i) lifting the transferred molten preforms with the universal gripper assembly of the robot out of the tray unit in an upright position and bring the preforms to the conditioning unit,
(j) conditioning the preforms in the conditioning unit at a freely programmable time interval,
(k) transferring the preforms with the universal gripper assembly of the robot in an upright position to the stretch blow molding unit,
(l) stretchblow-molding the preforms in the blow molding unit in at least one row of blow-mold cavities into hollow articles at a freely programmable time interval,
(m) transferring the hollow articles with the universal gripper assembly of the robot in an upright position to the discharge unit,
(n) releasing the finished hollow articles from the universal gripper assembly of the robot onto the discharge unit, and
(o) returning the universal gripper assembly of the robot to a waiting position at the preform-molding unit and the tray unit prior to completion of the preform-molding cycle.

12 more elements

Method for the preparation of hollow thermoplastic articles in a stretch blow-molding apparatus including a plasticizing unit and a preform-molding unit comprising a preform mold having a neck-ring clamp and an injection-core clamp, a tray unit with at least one row of tray plates with catch baskets mounted beneath and a robot having a universal gripper assembly, a conditioning unit, a stretch blow-molding unit having a blow-core clamp, a stretch-rod clamp, and a stack blow-mold clamp with at least one row of blow-mold cavities, and a discharge unit, comprising the steps of

(a) plasticizing raw material in the plasticizing unit to form a molten material,
(b) transferring the molten material from the plasticizing unit into the closed preform mold of the preform-molding unit,
(c) molding preforms in the preform-molding unit,
(d) opening the neck-ring clamp of the preform-molding unit,
(e) introducing the tray unit in between the molded preforms during the preform-mold-clamp opening stroke,
(f) collecting the ejected molten preforms without transfer beads by their bottom areas in at least one row of baskets mounted beneath the tray plate openings of the tray unit while retracting the injection-core clamp, and spreading the neck-ring assembly,
(g) transferring the preforms with the tray unit out of the preform molding area,
(h) closing the preform mold clamp assembly to start a new preform molding cycle,
(i) lifting the transferred molten preforms with the universal gripper assembly of the robot out of the tray unit and bring the preforms in an upright position to the conditioning unit,
(j) conditioning the preforms in the conditioning unit at a freely programmable time interval,
(k) transferring the preforms with the universal gripper assembly of the robot to the blow molding unit,
(l) stretch blow-molding the preforms in the blow molding unit in at least one row of blow-mold cavities into hollow article at a freely programmable time interval,
(m) transferring the hollow articles with the universal gripper assembly of the robot to the discharge unit,
(n) releasing the finished hollow articles from the universal gripper assembly of the robot onto the discharge unit, and
(o) returning the universal gripper assembly of the robot to a waiting position at the preform-molding unit and the tray unit prior to completion of the preform-molding cycle.

12 more elements

Method for the preparation of hollow thermoplastic articles in a stretch blow-molding apparatus including a plasticizing unit and a preform-molding unit comprising a preform mold having a neck-ring clamp and an injection-core clamp, a take-out tray unit with at least one row of tray plates and a robot having a universal gripper assembly, a conditioning unit, a stretch blow-molding unit having a blow-core clamp, a stretch-rod clamp, and a stack blow-mold clamp with at least one row of blow-mold cavities, and a discharge unit, comprising the steps of

(a) plasticizing raw material in the plasticizing unit to form a molten material,
(b) transferring the molten material from the plasticizing unit into the closed preform mold of the preform-molding unit,
(c) molding preforms in the preform-molding unit,
(d) opening the neck-ring clamp of the preform-molding unit,
(e) introducing the tray unit in between the molded preforms during the preform-mold-clamp opening stroke,
(f) collecting the ejected molten preforms in the openings of at least one row of tray plates in the tray unit while retracting the injection-core clamp, and spreading the neck-ring assembly,
(g) transferring the preforms with the tray unit out of the preform molding area,
(h) closing the preform mold clamp assembly to start a new preform molding cycle,
(i) lifting up the transferred molded preforms with the universal gripper assembly of the robot and bringing the preforms in an upright position to the conditioning unit,
(j) conditioning the preforms in the conditioning unit at a freely programmable time interval,
(k) transferring the preforms with the universal gripper assembly of the robot in an upright position to the blow molding unit,
(l) stretch blow-molding the preforms in the blow molding unit in at least one row of blow-mold cavities into hollow article at a freely programmable time interval,
(m) transferring the hollow articles with the universal gripper assembly of the robot in an upright position to the discharge unit,
(n) releasing the finished hollow articles from the universal gripper assembly of the robot in an upright position into the discharge unit,
(o) returning the universal gripper assembly of the robot to a waiting position at the preform-molding unit and the tray unit prior to completion of the preform-molding cycle, and
(p) laterally moving the upper blow-mold clamp assembly on linear bearings to facilitate mold and tooling change over.

13 more elements

Apparatus for producing finished hollow articles in a single and multi-row stack blow mold clamp assembly including

(a) a plasticizing unit for plasticizing raw material,
(b) a preform molding unit having a frame-type clamp platen to mount neck-split holding bars adapted with neck splits at freely adjustable center row distances in accordance with the equivalent preform-mold-center distances, the molding unit sliding on tie-bars between a fixed upper platen and a base machine platen,
(c) a clamp platen housing mounted on the frame-type clamp platen which holds the clamp platen for the different rows of injection cores according to the center-distance rows of the neck split bars and neck splits,
(d) a tray unit with a multitude of tray plate rows at freely adjustable center-row distances according to the equivalent center-row distances of the preform mold and the down stream processing units,
(e) a conditioning unit with a clamp platen and holding bars for mounting conditioning rods at freely adjustable center-row distances and heat-pots at center-row distances according to the equivalent center-row distances of the downstream processing units,
(f) a stretch blow unit having a frame-type clamp platen to mount blow core holding bars with blow cores at freely adjustable center-row distances sliding on tie-bars between a fixed upper platen and a base machine frame,
(g) a frame-type housing mounted onto the frame-type clamp platen holding the clamp platen for the different rows of stretch rods according to the center-distance rows of the blow-core bars and blow cores,
(h) a stretch blow unit having a stretch rod and blow core assembly movable laterally on linear bearings to facilitate mold and tooling mounting,
(i) a modular stack blow mold clamp assembly having a plurality of pivoting spacing platens and a plurality of lateral helical spindles with nuts to open, close, hold, accelerate and align a multitude of blow mold halves with the corresponding blow core, stretch rod, and bottom plug rows,
(j) a stack-blow-mold clamp assembly movable synchronously with a plurality of pivoting spacing platens with pivoting means and a plurality of lateral helical spindles with nuts and a multitude of stack-blow-mold halves which maintain the corresponding center row distances of the external means entering the blow-mold cavities during operation,
(k) a multitude of pivoting spacing platens variable in size according to the desired stack-blow-mold cavity opening strokes
(l) a multitude of pivoting spacing platens variable in number according to the desired number of blow-mold cavity rows,
(m) a multitude of lateral helical spindles with nuts according to the desired number of blow-mold cavity rows,
(n) a multitude of tie bar nuts connected to tie bars and the blow mold assembly back platen is turned by driving means and a toothed belt for mold height adjustment,
(o) an oriented discharge unit to release finished hollow articles,
(p) a take out tray unit with retracted tray plates to collect molten preforms during the opening stroke of the preform mold unit at the preform mold center row distances to guide the molten preforms out of the preform mold unit and to extend the tray plate center row distances during transfer of the molten preforms to align with the center row distances of the down stream processing units,
(q) a robot having a universal gripper assembly and opening and closing means to pick up molten preforms from the extended tray unit and to guide the preforms through a multitude of processing units which transform the preforms into finished hollow articles,
(r) a robot with a universal gripper assembly and gripper components telescopically retractable and extendable to vary the center distances of the gripper component preform holding cut outs according to the center distances of the preform mold and the blow mold cavity center distances,
(s) a robot with a universal gripper assembly to pick up pretreated hollow articles and guide them into secondary blow mold units for transformation into finished hollow articles prior to release onto an oriented discharge unit,
(t) a component transfer device assembly to pick up external components from dispensing cartridges and release them into open blow mold cavities simultaneously during other processing phases,
(u) a component inserting unit to place internal components inside molten preforms prior to completion of their shrinkage phase, and a component-inserting unit to place internal liners inside molten preforms to form a multi-layer hollow article, and
(v) all processing units being independently turnable in relation to each other to minimize the number of universal gripper assemblies and to speed up the mold change-over procedure.

19 more elements

Dependencies are inferred from the claim text.

Single-row and multi-row stretch blow molding method and apparatus therefor

Life of this patent

Single-row and multi-row stretch blow molding method and apparatus therefor

Life of this patent

Abstract

Claims17