DE2557192A1 - DEVICE FOR THE CONTINUOUS MANUFACTURING OF ORIENTED HOLLOW BODIES FROM THERMOPLASTIC MATERIAL - Google Patents

Description

Device for the continuous production of oriented hollow bodies made of thermoplastic material

Di® invention relates to a device for continuous Production of oriented hollow bodies made of thermoplastic material, which device enables the achievement of very high levels Productivity rates possible.

It is known to use hollow bodies made of a thermoplastic material manufacture that have improved mechanical properties by contributing to the elongation and final shape of the preforms a temperature which leads to a molecular orientation. In general, the preforms are at produced at a temperature below the crystalline melting point of the thermoplastic material from which it is made will.

For the production of oriented hollow bodies made of thermoplastic Material on an industrial scale are numerous technologies

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been caught in the eye. One of the most popular techniques is there in the production of the preforms by inflating a section of a tubular structure in a Preform mold, in a conditioning of these preforms to a temperature suitable for their orientation and in their subsequent incorporation in molds that ensure the final shape by inflation.

One device making use of this technique is disclosed in U.S. Patent No. 3,767,747.

This device consists of two molding units, each of which has a preform and a mold for final inflation have, both of which are arranged on both sides of an extrusion device that emits a tubular structure. Every such a unit shifts alternately in such a way that it takes its preform shape under the extrusion head and then under Blowing nozzles moved, also on both sides of the extrusion device are arranged.

However, this type of device can be due to the successive Movement of the forming units, the severely limited number of molds and the need to keep each preform in its own to leave the associated preform mold for a period of time, sufficient to enable its thermal conditioning, only low production rates.

The invention has set itself the goal of creating a device for the continuous production of oriented hollow bodies made of thermoplastic material starting from preforms, which are deformed by inflation, which device enables extremely high production rates.

The device according to the invention has a device for producing a continuous tubular structure from the thermoplastic material, a machine for inflating preforms, which creates the continuous tubular structure is fed and their shapes end to end seamlessly on one

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first rotation beams are aligned what the manufacture of individual preforms allows their neck in his final shape is produced, a device for deburring the neck of the preforms, a device for thermal Conditioning of the preforms to an optimal orientation temperature, a machine for the final inflation, which has a plurality of molds arranged on a second rotating support, and means for Continuation of the preforms from the machine for inflating the preforms to the machine for the final inflation, by moving them through the deburring device and the thermal conditioning device, in which apparatus the device for continuing the preform rings consists of an endless chain with carriers arranged in such a way that the preforms are supported below their already formed neck.

The preforms carried by the endless chain are generally cylindrical in shape. Your bottom part can be a have any shape. For example, the bottom part can end in an edge like a tube of toothpaste, or it can be hemispherical be designed like the tubes used in chemistry laboratories for experimental purposes. Your neck part already has the final shape of the neck of the final hollow body. Its central part is essentially cylindrical.

The carriers have vertically arranged seats open at least at their upper part, which are also generally one cylindrical in shape and preferably have a diameter slightly larger than that of the central part of the preforms in order to be able to introduce them there in a loose manner without damaging them. Preferably These seats have no bottom so that the bottom areas of the preforms are not damaged. In this case, the Preforms can be equipped with an annular bead on their neck area. This bead is not for the preforms disadvantageous as it was sent in exactly the same form to the final

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Hollow bodies must be provided to enable their closure.

There is a particularly advantageous embodiment of the carrier in forming this with the help of two jaws that are mutually exclusive apart from each other and which are suitable and are intended to form a bottomless cylindrical seat between each other - in the closed position. The cheeks will moved apart, so as to allow the preforms to be placed in the carriers and removed again, which is necessary for the Passing on to the machine for final inflation is necessary. The jaws enclose the central part of the preforms. Their height is not important.

The carriers are attached to an endless chain at regular intervals. The endless chain preferably with vertical ones The pin can be stored, driven and guided without difficulty, with the help of gears. Furthermore it enables a correct arrangement of the carriers with respect to the various devices and machines. However, in in the same way any other continuation means can be used which is capable of the same functions as that of the Ensure an endless chain, for example a toothed belt.

Obviously, it is desirable that the distances between the carriers and the speed of movement of the endless chain should be chosen so that all preforms can be passed on or transferred from the machine for inflation to the machine for final inflation, each carrier of the chain having a preform between the two Machines. So it is necessary that the two blow molding machines and the endless chain are able to work with equal power.

The preforms are then inflated by the machine

given at regular time intervals. It is appropriate that

every time a preform is presented, a carrier

is ready to be accepted. Thus it is necessary that the

Discharge of the preforms and the movement of the carriers completely

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are synchronized with each other. To ensure this synchronicity, the geometry of the various elements must of course correctly selected.

On the other hand, the preforms should be received by the carrier realizable at different rotation speeds of the rotation support of the machine for inflating the preforms be. This result can be achieved in an advantageous manner in that the endless chain is driven by the same motor which is the rotation support of the inflation machine the preforms set in rotation.

In this way it is ensured that the linear speed of movement the endless chain is always proportional to the speed of rotation of the machine for inflating the preforms changed, and the endless chain as a result at the location of this machine regardless of the speed of rotation of the same correctly performed its task.

Of course, it is also useful that the The final inflation machine is designed to include the sequential ones brought about by the endless chain Resumes pre-form rings and inflates them.

Proper supply of the final inflation machine by means of the endless chain results in a Synchronicity between the movements of the carriers of the endless chain at the point of this supply and the movements of the Means for removing the preforms for their introduction into the machine for final inflation.

This result could be achieved by using the propulsion of the machine for final inflation endless chain is ensured. However, the machine's very large moment of inertia for final inflation could make the use of an oversized endless chain necessary. In the context of the invention it is therefore preferred to meet this condition in that the machine is driven by the same motor for the final inflation.

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which drives the machine to inflate the preforms, with the interposition of suitable transmissions,

According to a preferred embodiment variant, therefore, are the two Rotary support of the blow molding machines by means of a single motor driven, and this motor also drives the endless chain for passing on the preforms. With such a Operation can ensure correct overall operation of the device and its performance can thereby be modified be that only a single control is carried out, namely the single drive motor.

According to the preferred embodiment of this variant the endless chain is equipped with tensioners, and it is indirect and double with the interposition of each of the two Blowing machines driven.

In the context of the invention it has actually been found that when the endless transport or continuation chain is direct is driven by the motor or with the interposition of only a single blow molding machine, the synchronicity between the endless chain at the point of the machines that do not participate in their drive is not always guaranteed. Indeed it has been observed that they then change periodically in slight changes in the movement of the carriers of the chain the place of the blow molding machines. These changes are based in particular on the game that moves between the various Elements of the device, and on the thermal cycle to which the endless chain is subjected, the passes through the thermal conditioning device simultaneously with the preforms.

The proposed mode of operation controls the arrangement the carrier has been secured at the point of each of the two blow molding machines. The small temporary changes in speed the endless chain near the two blow molding machines are eliminated and compensated for by an automatic Adjustment of the tensioner. This prevents any risk of chain breakage. In addition, contacts can be provided that

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stop the motor automatically if one of the clamps exceeds the permitted adjustment.

In a preferred manner, two tensioners are provided, and are each provided on one of the sections of the endless chain that lie between the two drives of the chain.

With the machine for inflating the preforms, it is important to that the sequential and end-to-end shapes are as closely spaced as possible because of the fact that this machine is supplied with a continuous tubular structure and that consequently every two space separating successive forms entails a loss of material.

In contrast, with the final inflation machine, the molds can be spaced apart, since each of these molds is designed to receive an independent preform.

The device according to the invention is further detailed in the following description of a preferred one practical embodiment explained. However, it is it goes without saying that this description is in no way to be understood as restrictive.

In this description, reference is made to the figures of the drawings taken, in which shows:

Figure 1 is a schematic plan view of a device according to the invention,

Figure 2 is a schematic and perspective view to illustrate the drive system of the device,

FIG. 3 shows a partial section through a stationary preform half-mold to show the device for controlling the hollow blow needle,

FIG. 4 shows a side view and a top view of one and 5 sections of the endless transport or continuation chain for the preforms to represent a

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the carrier and arranged on this chain

FIG. 6 shows a partial section through a stationary preform half-mold to represent a variant of the Ausxtferf ens.

As can be seen from FIG. 1, the device according to the invention has via a device 1 for producing a continuous tubular structure, via a rotation carrier 2 with a horizontal axis of rotation, the. carries adjacent or interrelated preform molds that End to end arranged around the continuous tubular Record structure, via a device 3 for demolding, the removal of the successive preforms from its shape and its insertion into the hinged jaws of the successive beams that are arranged on the endless transport or continuation chain 4. The endless chain 4 represents a further movement of the successive Preforms to a device 5 for deburring their neck and to a room 6 for thermal conditioning secure. The endless chain 4 also provides the correct presentation of the deburred and thermally conditioned preforms with a view to their introduction in molds for final inflation, which on a second rotary support 7 with a vertical axis of rotation are arranged.

As will be described further below, the device can by a device 8 for cooling the preforms, which is located between the deburring device 5 and the thermal conditioning space 6 is arranged, and be supplemented by a reheating furnace 9, which is based on the device 7 for the final Inflation follows and is intended to receive the oriented hollow body removed from the latter.

The endless chain 4 is driven twice in the area of the demolding device 3 or the deburring device 5 and in the area of the device 10 for continuing the preforms into the molds for the final inflation. The endless chain

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is finally equipped with two tensioners 11 and 12, which are each arranged on a section of the endless chain 4, which are arranged between the two drives of the chain 4.

As can be seen very clearly from Figure 2, the mechanical drive of the various moving parts of the device is realized with the help of a shaft 13, which is set in rotation by a motor / gear group 14, which the represents the only source of energy to ensure the drive of the entire device.

Thus, the first relation is carrier 2, which by means of its drive ring gear 15 is shown schematically, driven directly by means of a pinion 16 which is keyed onto the shaft 13 is and engages in the ring gear 15.

A toothed wheel 17, again keyed on the shaft 13, drives the device via a chain 18 and an angular transmission 19 for the continuation of the cast preforms on the continuation chain 4 at.

Another gear 20 keyed on the shaft 13 drives the device 5 via a chain 21 and angled transmission 22 Enfejxatung the necks of the preforms.

Finally, a last gear 23 drives, again on the shaft 13 keyed, via a chain 24 and a gear 25 to an intermediate cardan shaft 26. This shaft 26 provides an angle reduction gear 27 on the one hand the drive of a toothed ring 18, 20 connected to the second rotary carrier 7 Gears 29, 30, 31 and the chain 32 and on the other hand a first drive of the continuation chain 4 via a shaft 33, Gears 34 and 35, a chain 36 and a gear 37, which is provided on the chain 4, securely.

The continuation chain is also at the location of the blower unit driven for the preforms. This drive can by means of the deburring device 5, by means of the device be ensured for demolding the preforms or by means of these two devices.

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The trajectory of the continuation chain 4 is large Gears 38 determined, and the two tensioners 11 and 12 are each individually on one of the between the two drives Continuing chain 4 located segment of the endless chain is provided.

The position of the tensioners 11 and 12 is not important as far as each of these two is on one of the sections the endless chain 4 is located, which is arranged between the drives. Thus, in Figure 1, tensioners 11 and 12 take different ones Positions.

The arrows in FIG. 2 indicate the direction of rotation or movement of all drive elements.

It can also be clearly seen that all the movement organs of the device are operated by the single motor 14 under Zv / ischenschaltung the shaft 13 are driven, which allows to ensure complete synchronicity in the functional sequence.

In addition, the continuation chain 4 is driven in two places, which are located in places where the chain picks up the molded preforms or where they hold these preforms to the machine for final inflation, and this chain is thus in contact with the at these points completely synchronized with other organs of the device, regardless of any extension of the chain.

In Figures 1 and 2 are the details of the practical embodiment each constituent element of the device has been deliberately omitted for the sake of clarity. The details are described below.

The extrusion device 1 shown schematically in FIG. 1 for the continuous tubular structure does not have a real one Special feature compared to well-known classic facilities. However, it is desirable to choose an extruder that has a productivity capacity possesses, which with the high production capacity of the device for the production of oriented hollow bodies, which is to be supplied is comparable. Furthermore

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can extrusion direction with a programming system the wall thickness of the continuous tubular shape produced Be equipped.

The first rotation carrier 2 is, as already stated, equipped with adjacent molds arranged end to end and their inner cavity the desired shape reproduces the preform.

According to the preferred variant shown, the rotary carrier 2 driven by means of the toothed ring 15 rotates at a constant speed around a horizontal axis, and this carrier offers 2 successively those on its Circumferentially arranged various shapes at right angles to the continuously extruded tubular structure and tangential to this rotation carrier.

The machine for inflating the preforms can have the same general design as the rotary machine for inflating of hollow bodies, which is described in BE-PS 723 419, with the proviso that each shape is only a single preform and not two preforms are connected to one another via the neck.

The Rctationträger 2 consists of a number of equidistant and arms arranged radially in a plane perpendicular to the rotary shaft, the end of each of these arms being equipped with a shaping unit, which preferably consists of one with the Arm firmly connected to the stationary half-mold and from a movable one, which is articulated to the stationary half-mold via a hinge Half forra consists. Control cams are provided to shoot the successive shapes in at the moment that their rotation makes them at a right angle to the continuous hose-shaped dispensed from the extrusion device Structure steepens to lock the molds in the closed position to allow the shaping by inflating the molds To control contained sections of the tubular structure in order to unlock the forms before their opening and to unlock the Open molds to allow the molded preforms

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can be taken.

Preferably, the interior of each mold reproduces the shape of a preform that has a closed false neck and has a hemispherical bottom, as described in French patent application 74 09380 and in FIG 1 of the same is shown.

Devices for deburring the bottom of the preforms, such as these are described in the aforementioned French patent application, can advantageously between each other adjacent molds provided on the rotation support be arranged and controlled with the help of cams in such a way that a direct production of separate Vorfirmlingen is possible, whose hemispherical bottom is completely deburred.

The interior of each shape can also advantageously correspond to the shape of the preforms used in the French Patent application 74 05 461 described and particularly shown in Figures 1 to 5 of the same. Deburring the bottom of these preforms is not a problem because it is in the form of a straight edge.

The diameter of the interior of the molds and thus that of the preforms produced is only slightly larger than that Diameter of the tubular structure used as the starting product, around the radial extension of this tubular structure v / to keep at a value below 20% during the formation of the preform. It is actually useful for this purpose at this stage to limit the stretching of the tubular structure, since this stretching because of the relative high temperature of its thermoplastic material does not lead to any molecular orientation.

The preform is preferably shaped by inflation by means of a hollow needle which is connected to a pressurized fluid source is connected and which pierces the tubular structure at a point / beyond the desired cast Neck lies, i.e. in a region of the tubular

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Structure to be deformed into a closed false neck, which in turn is eventually removed.

The hollow blow needle is preferably on a movable Cultivated control block, which is arranged to the side of the stationary half-mold, the movements of this block from the Rotation of the rotatable support that carries the molds and is controlled by cams.

A variant of the preferred embodiment of this device is shown in FIG.

As can be seen from this figure, the stationary half-form 39, the interior 40 of which reproduces the shape of a preform with a hemispherical bottom, with an inflation device equipped, which is formed in particular by a movable hollow needle which has a conical foot surface 42. These The needle 41 is inserted into a seat provided in a control block 43, the bottom of which has a conical area which the conical foot surface 42 of the needle 41 corresponds. The needle is in the bottom of the seat by means of a tension screw 44 held. The end of this screw is equipped with a central channel that is in extension of the central channel of the needle and which is connected to the walls of the screw via radial channels 45. It also owns the end the clamping screw 44 has a diameter such that an annular space or an annular chamber 46 between the circumference of the seat of the Control block 43 and the circumference of the end of the clamping screw 44 consists. A channel 47 provided in the control block 43 opens into the annular space 46. This channel 47 is connected to a pressure fluid source via a control valve, not shown. The control block 43 is arranged on a carrier 48 fastened to the side wall of the stationary half-mold 39 in such a way that he can move in this carrier. The displacement of the control block 43 on this carrier 48 and in one direction perpendicular to the axis of the stationary half-mold 39 takes place in both directions by pivoting a control lever that is on a carrier 49 fastened to the stationary half-mold 39 is arranged. One arm 50 of the lever, the one with a loose one

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Roller 51 is equipped, for example, under the action of not shown, stationary cams when rotating move the rotation support carrying the preform molds, 'the other arm 52 acts on the position of the control block 43 **). Furthermore, it can be seen from Figure 3 that the Needle 41 is arranged such that it enters the interior 40 in the area 53, which is the formation of a closed False neck limited on the molded preform. The assembly system of the needle 41 allows in case of need quick removal of the blow needle, as it is sufficient to loosen the clamping screw 44 to remove the needle from its Remove the seat in the control block 43. Attaching a new needle is easy by using the its tip is inserted into the seat and the clamping screw 44 is tightened again. The provision of the chamber 46 and of the radial channels 45 eliminates any need for a particular arrangement of the needle 41 in its seat.

This, achieved peculiarity, the concept and the functionality the device for shaping by inflating the preforms are practically identical to those in BE-PS 723 described; so it is not necessary to go further to complain about.

The demolding and removal of the cast preforms when the preform molds are opened are preferably included Realized with the help of a device for demolding, which is described in BE-PS 772 264. However, the preforms, those resulting from the cooperation between the ejectors of the preform molds and the devices for detection, which are arranged on the arms belonging to the demolding device, not placed on a transport device, as described in BE-PS 772 264, but simply in the articulated with Transferring to each other connected jaws equipped carrier, which on the endless continuation chain 4 are provided. This continuation does not pose any particular synchronization problem since the endless chain 4 is in the vicinity the demolding device 3 is driven, in turn by *) during

**) on its carrier 48 - χ5 -

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the rotating plate of the machine for inflating the foregrounds is driven. This guarantees complete synchronization of the movements of the gripping organs of the demoulding units with those of the supports equipped with hinged jaws, which are arranged on the endless chain 4 are.

The dimensions of the demolding device are preferably the distance between the carriers on the endless chain and the reduction of the transmission between the demolding device and the endless chain chosen so that the preforms assume the same linear speed in exactly the moment at which they leave the demolding device and at the moment at which they are led away from the endless chain 4 will. This enables the device to operate in an overall manner that could not have been foreseen.

Figures 4 and 5 of the drawings show a segment of the endless Chain equipped with a carrier with hinged jaws.

As can be seen from these figures, the carrier 54 with the hinged jaws connected to one another is arranged on a bracket 55, which is attached to the links of the endless chain 4. This carrier 54 has two movable jaws 56 and 57, the are articulated on bolts 58 and 59 attached to the bracket 55. A spring 60 tends to keep the jaws closed To hold position. One jaw 56 is equipped with a lever arm 61 which carries a loose steering wheel 62. Of In addition, there are two gearwheels 63 and 64 which are in engagement with one another, each individually on one of the jaws 56 and 57 in the area the bolt fastened.

The opening of the jointly connected jaws is achieved by the mutual encounter between the control roller 62 and a stationary profiled cam, not shown causes, which is arranged on the movement path. This cam causes the jaw 56 to pivot under the action of the Lever arm 61, and this pivoting calls with the aid of

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would take the gears 6 3 and 64 at the same time pivoting the other jaw 57 in the opposite direction. The cam is arranged, for example, so that the Open jaws present at the moment a preform is captured from the preform inflation machine taken by the demolding device, and that the cam causes a sudden closure of the jaws causes the action of the spring 60 at the moment at which the preform has been exposed by the demolding device.

The preforms are removed from the arms of the demolding device captured just below the neck. When released from these arms, they fall under the action of gravity into the seat, which is formed by the previously closed jaws of the wearer. You are then from the ring bead her neck part held.

When the preform molds are opened, it is advisable to that the cast preforms always remain suspended in the stationary half-mold in order to be removed from the demolding device to be included. In the context of the invention it has been found that this condition can easily be converted into a safe Way can be met by the blow needle 41, which is inserted into the interior 40 of the stationary half-mold 39, up there remains at the moment the mold is partially open. In this way, the needle 41 holds the preform in place stationary half-form 39 actually fixed.

This result is achieved, for example, by such an arrangement the retraction of the needle 41 controlling the cam achieved that this only on the lever 50 after partial Acts opening the corresponding shape. In this case it is obviously useful to inflate it before opening the mold to interrupt. This condition can furthermore be met with the aid of ejectors of the form such as that in FIG mentioned BE-PS 723 419 is described. In this case, the ejector is in its rest position on the

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Way back in his seat in the area of the floor of the interior.

Another technique that also uses the ejectors power is shown in FIG.

As can be seen from this figure, the ejector 65 shown in its rest position is aligned in the area of the bottom of the interior 40 of the stationary half-mold 39, and it has a recess in the shape of a half dovetail in its upper area. In this way, when the preform 66 is inflated, part of the thermoplastic material enters the cavity 67, which is formed by this recess, and when the mold is subsequently opened, the preform remains suspended in the stationary half-mold 39 Problem; because as soon as the ejector has inserted the neck of the preform into a pair of tongs belonging to the demolding device, the arm carrying these tongs ensures that the preform is released from the notch of the ejector.

The demolded and in the carrier 54, which is equipped with hinged jaws and attached to the endless chain 4 are arranged, transferred preforms are then fed to a deburring device that is used for cutting of the wrong neck.

This can be done in an advantageous manner by means of a deburring device based on the principle described in BE-PS 673 913.

In such a device, the ridge or false neck is cut off by means of a stationary knife, during the Preforms a translational movement along the knife and a simultaneous rotational movement around its longitudinal axis is communicated «

The transition movement can be achieved with the help of a Rotary plates equipped with loose rollers with a suitable profile is which profile corresponds to that of the false neck. These preforms are then placed in the area of your neck held in place across the deburring device

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moved and between two loose roles and one stationary Guide with suitable geometry set in rotation around itself. The plate can by means of the endless chain 4 and be set in rotation at such a speed that the translational speed of the preforms is exactly equals the linear speed of travel of the chain. According to another variant, the plate can be taken directly from the Be driven by a motor that drives the two blow molding machines. In this case, the disk can be the endless chain propel at a speed equal to the speed of rotation is comparable or compatible with blow molding machines. This drive can supplement or replace the drive, which is provided in the area of the demolding device, which in this case can be uncoupled from the endless chain.

This thus leads to the fact that the drive of the endless chain at the point of the first blow molding machine either with the aid of Demoulding device or with the aid of the deburring device or by means of any other connected to the motor Which motor drives the two blow molding machines can help.

The rotation plate is preferably profiled loose rollers to adapt to the profile of the false necks of the preforms and the fixed guide is also profiled in the same way in order to achieve a correct arrangement of the preforms when cutting off the burr.

The preforms can be in their carriers during their passage be held by the Entgratungsexnrichtung. They can also be raised slightly during this pass and no longer rest on the ring bead of your neck part.

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around the rotational movement communicated to the preforms in this case not to hinder during their deburring, it is obviously appropriate that the preforms in the with articulated interconnected jaws equipped carriers of the endless continuation chain 4 at least during their Passage through the deburring device not tight are held. For this purpose, the articulated interconnected jaws are preferably designed such that they'in Ihra: closed position only loosely surround the body of the preforms, which are received in the cheeks and retained by their cast neck. To enable or facilitate The rotation of the preforms can be provided with a fixed profile cam around the opening of the hingedly interconnected To effect baking at the moment the preforms enter the deburring device and around the To cause closure around the preforms at the moment they leave this deburring device In the latter case, the retaining rollers provided on the rotating plate and the circular, stationary guide must be profiled be in order to hold the preforms not only by means of the false neck, but also in the area of this neck during the Deburring in such a way that the preforms are retained between these elements after the false neck has been completely cut off remain and thus of the supports equipped with hinged jaws at the exit of the deburring device can be resumed. However, this modification is not necessary if the cam is designed for a Reclosing the jaws of the carrier is profiled at the exact moment at which the cutting of the ridge of the Neck is running.

When shaping them by inflating them into the first blow molding machine belonging to molds, the cast preforms are noticeably cooled, for example by means of one in the mold walls circulating cooling fluids in order to enable them to be removed from the mold without the risk of deformation. In addition, it is a consequence the fact that these preforms must finally be subjected to an orientation treatment, expediently, the

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Cooling after shaping or casting of the preforms to regulate this in such a way that the demolded preforms have an average wall temperature that is in the temperature range which is suitable and expedient for their subsequent orientation. In fact, the outer wall of the preform, which is in contact with the wall of the interior of the mold during the shaping or casting, considerably cooled more than the inner wall.

Thus, for example, when water at ambient temperature is used as the cooling fluid, the temperature is the Outer wall of the preform after demolding in the vicinity of 30 C, while the inner wall continues to maintain a temperature in the Near the extrusion temperature. From this it follows that that the preform at the moment of its removal from the mold has a tempera hair gradient in its thickness which is from the ambient temperature (outer wall) based on up to

can run to the extrusion temperature (inner wall).

During the subsequent continuation of the preforms, a progressive degradation of this gradient takes place and has the wall of the preforms finally has a constant or practically constant mean temperature over its entire Thickness extension.

It is obviously appropriate for each thermoplastic used Material that cools the molds of the preforms to be regulated in such a way that this mean final temperature is compatible with or on the subsequent orientation treatment is matched.

However, due to the rapid rhythm of preform production especially when working with relatively thick tubular structures, the case occurs, that the cooling of the molds turns out to be insufficient, for the preforms to ultimately have a sufficiently low level Have a medium temperature in order to enable an effective subsequent orientation.

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In order to improve the effectiveness of the cooling during the shaping of these preforms, it may be possible at the end of the inflation an internal rinsing of the preforms can be carried out by means of a very cold fluid, for example with the aid of liquid Nitrogen, which is injected through the hollow needle in a relaxed state.

However, this technique proves to be ineffective because of the small volume of the preform. In addition, with such a procedure, the internal cooling is limited to the false neck zone, and the subsequent severing is associated with greater randomness. '

In order to improve the cooling of the preforms in case of need it has been found and this is one of the Aspects of the present invention that an internal rinsing of the preforms by means of a cold fluid after removal of the is preferable to false necks.

This result can be achieved in that in the freed from their necks preforms to a source of a very cold fluids, e.g. for relaxed liquid nitrogen, *) nozzles are introduced. By influencing the speed the introduction and / or retraction of the nozzles and the spacing of the introduction, it is also possible to use a temperature gradient adjust along the axis of the preforms, which can prove beneficial in certain cases.

This mode of operation following the cooling can advantageously be carried out on a circular carousel, like this is shown schematically by 8 in Figure 1 and that of the continuation chain for the preforms or of the same motor how the blow molding machine is powered. In this case, the movement of the cooling nozzles arranged on the carousel can be stationary Cams are controlled.

Should this be desired, the outer wall can also be cooled by blowing a cold fluid will. - - -

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*) connected * · * ■

After running through the endless chain of continuation 4 carried preforms through the deburring device and possibly the device for cooling by internal rinsing, the preforms pass through a thermal conditioning room, that at a temperature chosen with a view to performing the final inflation, or at a is kept slightly lower or slightly higher temperature. In fact, the temperature of this room will be experimentally adjusted so that the preforms leaving this space an optimal temperature in view of have the orientation and that their temperature is practically identical at every point of their thickness.

At the exit of this furnace, the preforms are introduced into the final inflation molds on the second Rotation carriers are arranged and their arrangement is arbitrary.

This last carrier rotates in a preferred manner about a vertical axis and carries shaping units that consist of two consist of axially separable half-molds, the molding units not necessarily being adjacent or must be connected to each other.

The transfer of the preforms into the blow molds is more preferred Way with the help of blow nozzles which are attached to the Rdationträger and which the preforms by means of of her poured neck at the moment of opening her with Detect jointly connected jaws equipped carrier controlled by a stationary profiled cam and the preforms vertically enter the successive final inflation molds below the endless one Run through the continuation chain, with these movements being controlled, for example, by stationary cams.

As stated earlier, there is complete synchronicity This continuation ensured due to the fact that on the one hand the rotation carrier of the machine to the final Inflation from the same engine as the rotating support of the machine

6098 _28/2 § B88

ne is driven to inflate the preforms and that on the other hand the endless continuation chain at the location of the machine for the final inflation by means of an attached to this machine connected drive device is driven.

For the final inflation machine, it is more pus desirable with regard to a smooth operation of the device that the geometry and the speed of rotation are chosen such that the linear speed of the nozzles is equal to that of the endless chain.

After each mold has been closed for final inflation, the associated blow nozzle provides the final shape safe by inflating the conditioned preform.

The preforms preferably have a shorter length than the desired oriented hollow bodies and the ratio between the final length of the hollow body and that of the preform can be in the range between 1 and 5. In this way, the preforms are simultaneously stretched axially and radially during inflation, making them biaxial Orientation and thus to extraordinary mechanical properties leads.

The blower nozzles can advantageously be equipped with a movable, central piston, which ensures the correct centering of the bottoms of the preforms during the final inflation ensures.

After inflation and cooling, the oriented hollow bodies are removed from the blow mold after the blow mold has been opened, and they fall out under gravity.

According to a preferred variant, this is facilitated or made possible in that the blower nozzle at the beginning of the opening of the associated Form is withdrawn, this in such a way that the molded hollow body sitting on the blow nozzle from the upper shoulders is retained in its shape and thus removed from the nozzle. Removing the nozzle can also be done in a safe manner.

609828/0588

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will act that an additional amount of the blowing fluid upon withdrawal of the nozzles is injected and / or a supplementary displacement of the centering pistons belonging to the nozzles is communicated.

The demolded, oriented hollow bodies can, if this is considered appropriate, in a reheating furnace after removal from the mold, which oven is kept at a temperature lower than the temperature the dimensional stability under heat. Indeed, it has been found that this reheating treatment improves the durability the oriented hollow body can significantly improve against cracking and tension.

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609828/0588

Claims (1)

-. 25 - Claims Device for the continuous production of oriented hollow bodies made of thermoplastic material with a Device for producing a continuous tubular Structure made of the thermoplastic material, with a machine for inflating preforms, which the continuous tubular structure is fed and the shapes of which are aligned end to end without gaps on a first rotation carrier, which the production of individual Allows preforms, the neck of which is produced in its final shape, with a device for deburring of the neck of the preforms, with a device for thermal Conditioning of the preforms to an optimal orientation temperature, with a machine for the final An inflator having a plurality of shapes arranged on a second rotating support and having a Device for continuing the preforms from the machine for inflating the preforms to the machine for the final Inflate by going through the deburring device and the thermal conditioning device, one after the other are moved, characterized in that the device for continuing the preforms from an endless chain (4) with supports (54) arranged in such a way that the preforms are carried below their neck, which has already been formed can be. Device according to Claim 1, characterized in that the endless chain (4) is driven by the motor (14) which the rotating support (2) of the machine for inflating the preforms drives. Device according to claim 1, characterized in that the machine (7) for the final inflation of the Motor (14) is driven which drives the machine (2) for inflating the preforms. - 26 609828/0588 4. Apparatus according to claim 1, characterized in that the machine (2) for inflating the preforms, the endless Chain (4) and the machine (7) for final inflation are driven by the same motor (14). 5. Apparatus according to claim 4, characterized in that the endless chain (4) indirectly at the same time from the machine (2) for inflating the preforms and the machine (7) is driven for final inflation. 6. Apparatus according to claim 5, characterized in that the chain (4) is equipped with tensioners (11, 12). 7. Apparatus according to claim 6, characterized in that two tensioners (11, 12) are provided and that these two Tensioners (11, 12) are each distributed individually to one of the sections of the endless chain (4), which sections are between the two drives of the chain (4). 8. The device according to claim 1, characterized in that the preform molds (39) which are arranged on the first rotation carrier (2) are equipped with a blowing device are made up of a movable hollow needle (41) which is able to enter the interior (40) of the molds, and consists of means (50) which cause the needle to be withdrawn after the molds have been partially opened. 9. Apparatus according to claim 8, characterized in that the blowing device has a hollow needle (41) which is attached to a control block (43) which can be moved relative to the mold (39) is attached. 10. The device according to claim 1, characterized in that further means (8) for internal cooling of the successive preforms by rinsing with the aid of a cold fluid is provided that this device (8) driven by the continuation chain (4) or by the same motor (14) as the blow molding machine and between the device (5) for deburring the neck of the preforms and the device (6) for thermal conditioning 609828/0588 - 27 - is arranged. 11. The device according to claim 1, characterized in that a reheating furnace (9) is further provided, in which the oriented hollow bodies reside after their removal from the molds for the final inflation can. 12. The device according to claim 1, characterized in that the carrier (54) with vertically arranged seats of im essentially cylindrical in shape, which seats are open at their upper part. 13. The apparatus according to claim 12, characterized in that the seats are bottomless and articulated by two related jaws (56, 57) are formed which can move apart. 14. The apparatus according to claim 13, characterized in that the movement of the jaws (56, 57) apart from one another Cam is controlled, which acts on a lever (61) which is fixedly connected to one (56) of the jaws (56, 57). 15. Apparatus according to claim 4, characterized in that the drive of the machine (2) for inflating the preforms, the endless chain (4) and the machine (7) for final inflation from a single control shaft (13) ensured which is driven by the motor (14). 609828/0 5 88