JP2010516507A - Apparatus and method for post-cooling a preform - Google Patents

Abstract

  The present invention relates to an apparatus and a method for sizing and post-processing a shape-unstable preform (10) taken from multiple injection molds, the preform being incorporated in a water-cooled cooling sleeve (21) Air cooling for the outside on the open end side of (10) is proposed. In particular special types of preforms, the areas not supported in the preform by the cooling sleeve (21) are taken out from the open mold (8, 9) or from the start of delivery to the cooling sleeve, on the outside, Pre-solidified by cooling with chilled air or refrigerated air. The new construction means also guarantees the highest quality in terms of dimensional accuracy and pressure spot formation under load, in particular by sizing in the cooling sleeve (32) or processing in the region of post-cooling.

Description

  The present invention is a post-cooling device for a preform, in which a still unstable shape preform is removed from a mold of an injection molding machine by a take-out gripper and is at least partially in a water-cooled take-out or cooling sleeve. It relates to what can be post-cooled.

  Furthermore, the present invention is a method for post-cooling a preform comprising a threaded portion, a blow-in portion and a neck ring, wherein the preform is at least partially in a water-cooled cooling sleeve in a shape unstable state at a high temperature. Related to what is to be post-cooled.

In practice, three post-cooling operations are performed to produce a preform.
-In the first process, the still hot preform is delivered directly to the cooling sleeve of the aftercooler. In this case, the post-cooler has several times the cooling position relative to the number of preforms in the injection molding cycle.
-In the second process, the preform is removed from the open mold by a simple take-out robot without cooling action, delivered to a post-cooler and post-cooled.
-In Applicants' third process, the function of the robot is divided into an extraction gripper with a water-cooled extraction sleeve as well as an additional transport gripper for delivery to the post-cooler.

According to recent developments, the injection molding machine-cycle time is further reduced and the preform is removed from the mold in a soft shape unstable state. As a result, problems that have not been recognized so far can be seen. From a physical point of view, cooling is unevenly distributed inside the preform wall.
-As soon as the preform is removed from the open mold half, a temperature difference in the preform, in particular the preform wall, causes a thermal or shrinkage stress on the preform, which changes its shape.
-The shape may be damaged by the action of the machine and the operation of the gripper as a robot.
The same happens with the horizontal position of the preform in the post-cooler.

  Therefore, the operation within the post-cooling range is a very delicate operation. When an injection molded product is manufactured using an injection molding machine, the cooling time is a decisive factor with respect to the total cycle time. The first main cooling is still performed in the injection mold. Since both injection mold halves are intensively water cooled during the injection molding process, the temperature of the injection molded article, for example 280 degrees, can be reduced to a range of about 70 degrees at least in the edge layer. In the outer layer it falls very quickly below the so-called vitrification temperature of about 80 degrees. The actual injection molding process until taking out the injection molded product has been almost halved recently. This is obtained with optimum quality for the preform. The preform needs to solidify strongly in the mold half, and the preform is held by the take-out assisting means without being damaged and delivered to the take-out device. The take-out device has a shape that conforms to the injection molded product-external dimensions. Intensive water cooling in the injection mold halves results in a temperature drop delayed to the core region of the preform wall, physically limited. This means that the aforementioned temperature of about 70 degrees cannot be obtained uniformly over the entire cross section. As a result, when intensive water cooling through the mold is interrupted, immediate return heating from the inside to the outside occurs immediately in the material cross section. The post-cooling of the preform outside the injection mold is very important for two reasons. Not only shape changes but also surface damage, such as pressure spots, need to be avoided during post-cooling. Furthermore, it is necessary to avoid that the cooling in a relatively high temperature range takes place too slowly and that adverse crystallization occurs locally due to back heating. The purpose is a uniform amorphous state in the finished preform material. The residual temperature of the finished preform is desired to be low and it is also desired to be low so that it will not be damaged by pressing and sticking at the point of contact in large packaging containing a large amount of injection-molded product placed without packaging. . The finished injection molded article must not exceed a surface temperature of 40 degrees even after a slight back-heating. Post-cooling after removing a preform that is unstable at high temperatures from an injection mold is extremely important with respect to dimensional accuracy.

  In WO 2004/041510 the applicant has proposed a central cooling station as well as a post-cooling station, in which a cooling pin for internal cooling that can be inserted into a preform is proposed. . The inner shape of the cooling sleeve is matched to the corresponding inner shape of the injection mold so that it can be inserted into the cooling sleeve until it completely contacts the wall with as little play as possible after removal from the injection mold. Harmonized. When the preform occupies a lateral position in the first stage of post-cooling, the preform tends to rest downward on a suitable cooling sleeve portion. By intensive cooling contact in the lower region, the preform is cooled relatively strongly on the lower side, which creates a load on the preform and tends to be elliptical. With the shortened cooling in the first stage of post-cooling, if the individual preforms are slightly deformed in the injection mold, the appropriate shape change can no longer be corrected with the already solidified preforms. With the desired control of the adsorption and blowing air, a preforming pressure is formed on the inside of the preform, based on the advantageous configuration of WO 2004/041510, and the unsolidified preform is It is completely in contact with the entire inner wall surface. After the preform is in close contact with the inner wall surface of the cooling sleeve, the surface contact is maintained for a few seconds, creating a sizing effect for the individual preforms. The sizing effect forms a high product and quality standard when manufacturing preforms, as was not possible with previous prior art. The preform is thus brought back into the correct shape immediately after removal from the injection mold. The dimensional changes that occur in some cases are compensated again after the first treatment, which is a problem from the injection mold to the cooling sleeve. Preform sizing is performed and the preform is still removed from the mold at a high temperature and still a relatively short injection molding cycle time is achieved.

  In WO 2004/041510 pamphlet, two configurations for forming a molding pressure are proposed. In the first configuration, a seal ring is disposed on the cooling pin or the blowing nozzle, and the seal ring is brought into contact with the conical transition portion of the preform inner chamber. In the second configuration, the blowing nozzle includes a ring-shaped seal, and the seal is specified to abut on the end face side of the surface edge of the preform. Here, the molding pressure acts on the entire preform. Due to the disadvantages of both arrangements, in practice, for example, multiple injection molding with 100 to 200 cavities, it is necessary to assume very high accuracy with respect to the guide or movement of all blow nozzles.

  European Patent Publication No. 900135 proposes a concept equivalent to the above-described second configuration. The seal at the opening edge presupposes some pressure and sufficient shape stability of the threaded portion. In order to avoid thread shape changes, the preform must be maintained in the injection mold to a relatively high shape stability. However, this counters the reduction in injection molding cycle time.

  As can be seen from extensive testing, the sizing of a still hot, shape-unstable preform immediately after the removal robot has moved away from the open mold half is extremely advantageous. However, the outcome does not occur with all types of preforms. As will become apparent, preforms with unsupported thread portions did not solve the problem of forming accuracy with respect to the cooling sleeve. As has been found by the inventors, the shorter the machine cycle time, the more particularly the end side that is completely open for processing in the post-cooling region is also at risk. This is in particular because the thread portion protrudes from the cooling sleeve and is no longer cooled via the cooling sleeve. This is independent of whether the preform is sized.

  The object of the present invention is therefore to improve the post-cooling device and the method of post-cooling the preform, ensuring the highest quality parameters in the post-cooling area, in particular in terms of processing, at least in conventional preforms, To provide the one that allows the highest form accuracy of the preform with the shortest possible cycle time.

DISCLOSURE OF THE INVENTION According to the post-cooling device according to the present invention, the blowing device is incorporated in the cooling sleeve in the region of the open end side outside the preform, and at least the preform is passed through the blowing device. The outer surface of the unsupported area is solidified with cooling air.

  According to the post-cooling method according to the present invention, at least a part of the outer surface of the unsupported end side opened outside the preform is cooled with cooling air via an air blowing device incorporated in the cooling sleeve. Solidify.

  As clarified by the inventor, sizing after inserting a hot preform into a cooling sleeve with a generally cylindrical or slightly conical blowing portion has made great progress with respect to the production of classic preforms. Bring. For sizing, inevitably, at least the inner chamber of the preform part of the preform must be mechanically sealed. If the open end region of the preform wall section is not supported by the cooling sleeve inner wall, the force of the compressed air already sizing eliminates new problems, at least as well as the mechanical sealing force. Equally important, the outside of the open end of the preform can solidify immediately after the cooling air is received in the cooling sleeve and immediately after it has passed from the already opened mold half to the cooling sleeve. it can. This means that, for example, a time of 1 to 2 seconds is saved in order to bring the desired thread area into a shape-stable state by means of additional external cooling with cooling air. In the blowing part, the proper and immediate external cooling can cause the disadvantage that sizing requires a relatively large air pressure. In the cylindrical area of the blowing area, water cooling of the cooling sleeve is immediately brought about by direct wall contact. This brings great results from the beginning. The entire area of the neck ring is air cooled or solidified from the outside so that mechanical forces do not cause shape damage based on the sealing force. Particularly advantageously, in the case of sizing, the outside air-cooling point is selected against the sealing force of the press or seal ring from the inside, for example.

  The new post-cooling arrangement advantageously starts from the thermos concept for sizing and / or processing. Both applications are the same with unwieldy wall materials. On the one hand it is glass and on the other hand it is still a slightly deformable plastic. According to the configuration of the present invention, the seal portion need not be designed with extremely high accuracy. According to the great advantages of the present invention, a significant reduction in the overall cycle time and a corresponding increase in the output of the injection molding machine by 15% to 20% is achieved while completely achieving all quality problems. The release of the preform can be performed relatively early, with the preform still strong and unstable in shape.

In fact, there are a wide variety of preforms that require specific processing.
A preform with a neck addition portion extending in a conical shape between the cylindrical blowing portion and the neck ring is particularly difficult to handle.
-Another unwieldy preform has an extension at the corresponding neck.

  According to the present invention, it is possible to completely obtain the shape accuracy while greatly shortening the drying operation time. What this means is that there is still room for even shorter machine cycle times due to special air cooling on the outer open end side. Field tests show that for transparent preforms the machine cycle time can be reduced by about 15% and for colored preforms it can be reduced by about 20%.

  The present invention allows many particularly advantageous forms. In this regard, see claims 2-17 and 19-29.

  Advantageously, in the case of sizing, the compressed air can expand steplessly from the beginning of sizing. As a result, shrinkage compensation can be achieved continuously even if the solidification of the preform progresses. Advantageously, the compressed air supply is reproducibly ensured by an increase in the control voltage of the programmed control valve and a corresponding increase in the sizing pressure.

  Particularly advantageously, a cooler is arranged corresponding to the post-cooling device in order to form air that is cooled, in particular, below 0 °. In this case, a pressure generator for the cooling air is arranged corresponding to the post-cooling device, and the pressure generator allows an air pressure below 2 bar, preferably below 1.2 bar, for the cooling air. It can be formed. Advantageously, the process of use is controlled, in which case the post-cooling device is equipped with a control device, by which the air blowing device can be activated immediately from the moment when the preform is taken out or delivered to the cooling sleeve. is there. The use of refrigerated air provides two great advantages. On the one hand, a concentrated and rapid solidification of the outer surface is obtained in the open area immediately after delivering the preform which has been removed from the injection mold, which is still hot. This means that, before any mechanical action due to processing or sizing, particularly the risky parts are strongly solidified and no longer ovalization or local expansion occurs. Refrigerated air allows the added benefit of reducing the amount of cooling air. The air pressure can be reduced to 1 bar, for example instead of 4 bar. The same effect as ambient air can be obtained with a very small amount of air. In particular, the frozen air can be controlled as desired with respect to quantity and temperature.

  In a particularly advantageous form of the invention, the air blowing device is formed as an air guide directed towards the open end side outside the preform. Advantageously, the post-cooling device is equipped with a connection and disconnection control device by means of which the air blowing device can be activated during the sizing phase from the point of delivery or delivery of the preform to the cooling sleeve. is there. The form according to the present invention can be used in any part of the post-cooling region where there is a risk of damage due to processing.

  In a particularly advantageous form, the gripper comprises a number of nipples having inserts into the preform and a press or seal ring that radially expands the insert of the nipple that can be inserted into the preform. The press ring is advantageously formed as a radially inflatable seal ring, through which the forming pressure is applied to the nipple in the inner chamber of the blow-in part of the preform. A sealing force toward the inner wall of the preform can be formed on the nipple. Particularly advantageously, the molding pressure is controlled so that it also starts at a minimum pressure and increases to an optimum pressure.

  According to another important idea, the nipple can be inserted into the preform with a controlled positioning at the optimum selectable seal location in the region between the threaded portion and the blow-in portion. This takes into account the various shapes of the transition between the threaded part and the blowing part. An optimum seal location is required at the start of production each time. After inserting the nipple, the outer wall of the preform blowing part contacts the corresponding inner wall of the extraction sleeve. Thus, advantageously, the preform is inserted into the take-out sleeve during delivery, until the closed bottom enclosure and the entire blowing part are fully and fully inwardly wall-contacted. The preform is post-cooled in the water-cooled cooling sleeve of the post-cooler for the duration of multiple injection molding cycles, and sizing takes place within the duration of one injection molding cycle, or one injection molding cycle Limited by the duration of Removal of the preform from the cooling sleeve can be carried out without problems.

  In the device according to the invention, each nipple comprises two tube members that can move relative to each other, and a holding shoulder is fixedly attached to the end of the tube member. In both the above-mentioned forms, each nipple is provided with an air passage, and controlled compressed air can be supplied to the inner chamber of the blowing portion of the preform through the air passage. By means of controlled adjustment means, the actuating plate moves relative to the platform in order to actuate the press or seal ring simultaneously. The adjusting means has a pure support function during sizing. The press or seal ring is held on the inner surface of the preform in a pressed state. For a good sealing, already a slight force of the adjusting means of the actuating plate is sufficient. Advantageously, the nipple is arranged on the platform via a common actuating plate, through which the nipple is inserted into the preform and moved away from the preform and the nipple in the take-out sleeve. Positioning is performed. For this purpose, controlled drive means are arranged for positioning the press or seal ring at the optimum penetration depth or at the optimum location corresponding to the platform.

  According to a first advantageous embodiment, the removal of the preform from the take-out sleeve and the delivery of the post-cooler to the cooling sleeve is achieved within a time of one injection molding cycle while achieving sufficient shape stability. . After sizing, the press or seal ring is relaxed and the pressure in the inner chamber of the blowing part is released. A negative pressure is created through the air passage through the nipple and the preform is delivered by the nipple to the aftercooler. For this reason, the nipple does not have a cooling function. Advantageously, there is no ventilation between the preform and the ambient air during a short sizing time. The nipple is provided with an air passage, and a negative pressure for taking out the preform can be formed in the preform via the air passage. Inside the nipple, the air passage for compressed air and the air passage for adsorbed air are the same. Advantageously, the tube members are arranged so as to enter each other, in which case the inner tube member comprises at least one air passage. With regard to the configuration of the first embodiment, the device according to the present invention comprises a controllable take-out gripper and is provided with a number of take-out sleeves corresponding at least to the number of injection molding positions of the injection mold. The apparatus according to the present invention comprises a controllable compressed air connection and a controllable connection for adsorbed air to form a molding pressure inside the preform for sizing the preform. After switching to negative pressure instead of molding pressure, the preform can be taken out from the take-out sleeve by means of a nipple. In such a configuration, the device according to the invention, in addition to the take-out gripper, puts the preform from the take-out grip to the post-cooler in order to completely cool the preform independently of the injection molding cycle. It has a transport gripper to deliver or replace.

  According to an advantageous second embodiment, the device according to the invention comprises a cooler formed as a take-out robot, which has several cooling positions with respect to the injection position of the injection mold. In this case, the preform to be delivered at a high temperature is inserted into a free cooling position, sized, centrally cooled and released after complete cooling. Here, the discharge of the cooled preform from the take-out sleeve and delivery to the conveyor belt is assisted by controlled adsorption and compressed air. According to the second form, after sizing, the press or seal ring is relaxed, the pressure in the inner chamber of the blow-in part is released, the nipple is separated and held in the standby position, which is also a subsequent injection molding cycle. Until the new cooler repositions the new cooler.

For both configurations, the preform is sized with compressed air and the duration of the injection cycle is limited. The pressing and sizing of still soft preforms has great advantages.
First, maximum heat transfer and maximum cooling action is ensured by pressing the outer surface of the preform firmly against the inner water-cooled take-off sleeve.
-Secondly, the outer dimensions of the preform are precisely formed by sizing and maintained during subsequent solidification.
Thirdly, physical quality parameters are ensured by the rapid passage of the so-called vitrification temperature.
Fourth, sufficient form stabilization of the preform for subsequent processing from the take-off sleeve to the cooler sleeve of the post-cooler and subsequent discharge to the conveyor belt by the formation of a strongly cooled and solidified outer material layer Sex is obtained.

  According to another particularly advantageous form of the device according to the invention, the water-cooled take-off sleeve provides a ventilation path between the threaded part and the blow-in part for appropriate outer cooling of the corresponding preform region. And an air connection for the air passage. Depending on the geometry of the preform, the air passages are arranged in the transition region between the threaded portion and the neck ring and / or in the transition region between the neck ring and the blowing portion. Advantageously, the water-cooled extraction sleeve is formed from a standardized part, optionally with a guide ring for the air passage, a transition region between the thread part and the neck ring, and / or the neck ring And is used to cool the transition area between the blowing part.

  With regard to the method according to the invention, immediately after the preform has been delivered to the cooling sleeve of the take-out gripper, the outer cooling of the preform with air takes place in the region between the threaded part and the blowing part until the end of sizing. Advantageously, for sizing, a press or seal ring attached to the nipple is positioned to the transition region between the threaded portion and the neck ring and / or to the transition region between the neck ring and the blowing portion. Controlled and inserted into the preform. The preform is cooled from the outside in the transition region between the threaded portion and the neck ring and / or to the transition region between the neck ring and the blowing portion during sizing after already being inserted into the cooling sleeve. And then solidified. According to a special advantage, the outer surface of the preform is immediately and strongly solidified after passing from the open mold half to the cooling sleeve in the unsupported part of the preform prior to sizing, The mechanical holding force does not adversely affect the corresponding area. In a preform with an expanding neck, the transition region between the threaded portion and the neck ring is air cooled from the outside. Here, the preform is inserted on the end face side of the cooling sleeve except for the stopper of the neck ring, in which case the cooling sleeve is formed so that a minimum gap remains between the bottom of the preform and the corresponding bottom of the cooling sleeve. The minimum gap remains advantageously in the hundredth millimeter range, which is eliminated by sizing.

  The present invention will be described in detail based on examples.

FIG. 3 schematically shows the present invention at a preparation position before sizing a preform. It is a figure which shows the nipple inserted in the preform optimally in the area | region of the open edge part side of a preform. It is a figure which expands and shows the nipple provided with the press or seal ring by which rocking | fluctuation arrangement | positioning was carried out. FIG. 5 shows the outer cooling of the transition region between the thread portion and the blow portion of the preform. It is a figure which expands and shows a part of FIG. 3a. It is a figure which expands and shows a part of air-outside cooling. FIG. 5 shows air-outside cooling in a preform with an expanding neck portion. FIG. 5 schematically shows the optimum entry point of the press or seal ring and the outer cooling. FIG. 6 schematically shows the optimum entry point of the press or seal ring as well as the outer cooling, additionally providing air-out cooling of unwieldy, unsupported areas. FIG. 6 schematically shows the optimum entry point of the press or seal ring as well as the outer cooling, additionally providing air-out cooling of unwieldy, unsupported areas. FIG. 5 shows a thick preform having an alternative configuration with the nipple or seal ring properly positioned. It is a figure which shows the form shown in FIG. 6a in the state which the molding pressure was extracted and the seal ring was relaxed. It is a figure which shows taking out the preform by the nipple as a holding nipple. It is a figure which shows an example of the 1st form provided with the additional aftercooler. It is a figure which shows an example of the 2nd form in which the taking-out robot was formed as a postcooler. FIG. 4 shows a thermal profile recorded in a preform made without sizing. It is a figure which shows the experiment example which has preform-sizing. FIG. 3 shows an errored preform having a transition region that is not supported in the cooling sleeve without solidification according to the present invention.

FIG. 1 shows a state after the take-out device 11 moves away from the open mold halves 8 and 9, and the start of sizing and centralized cooling. Here, the platform 17, together with the nipple 30, is already in a ready position for an approach movement into the preform 10 along the arrow 31. The platform 17 is supported by the sliding device 32 and the linear guide rail 33 provided on the support console 36 via the arm 14, and is moved in parallel to the machine axis 37 via the linear drive device 34. It is done. The linear drive device 34 is fixed to the additional portion of the support plate 4 on the back side. By operation of the linear drive device 34, the nipple 30 is moved toward and away from the take-out device 11 (along arrow 31). Adjusting means 18 is disposed on the actuating plate 16, and the adjusting means 18 has the only function of compressing and releasing the press or seal ring 56.

FIG. 1 and FIG. 7 schematically show an injection molding machine for a preform having a main element (mechanical bed 1). On the mechanical bed 1, a support plate 4 and an immobile mold clamping plate are shown. 2 and the injection unit 3 are supported. The movable mold clamping plate 5 is supported on the machine bed 1 so as to be slidable in the axial direction. Both plates 2 and 4 are mutually connected by a bar 6, and the bar 6 is guided through a movable clamping plate 5. A drive unit 7 for forming a closing pressure is provided between the support plate 4 and the movable mold clamping plate 5. The stationary mold clamping plate 2 and the movable mold clamping plate 5 support the mold halves 8 and 9, respectively, and produce an appropriate number of sleeve-shaped injection molded products between the mold halves 8 and 9. A large number of cavities are formed. The injection molded product 10 is manufactured in a cavity between the mandrel 26 and the cavity 27. After the mold halves 8 and 9 are opened, the sleeve-like injection molded product 10 is held by the mandrel 26. The same injection-molded product 10 in the state where the cooling is completed is shown in the upper left in FIG. 7, where the injection-molded product 10 is just released from the post-cooling device 19. The upper bar 6 is shown interrupted between the open mold halves to better show details. In the form shown in FIGS. 1 and 7, the four method steps for the injection molded article 10 after finishing the injection molding process according to the first aspect are as follows.
“A” is removal of the injection molded product or preform 10 from both mold halves. The still plastic part is accommodated by the take-out device 11 lowered in the space between the open mold halves (FIG. 1) and lifted to position “B” by the take-out device 11.
“B” is the stage of sizing and central cooling.
“B” / “C” are delivery of the preform 10 from the take-out device 11 to the transport gripper 12 and delivery of the preform 10 from the transport gripper 12 to the post-cooling device 19 based on the first mode.
“D” is the removal from the post-cooling device 19 of the preform 10 that has been cooled and brought into a stable state.

  FIG. 1 and FIG. 7 show so-called instantaneous shooting (rapid shooting) of the main steps related to the processing based on the first mode. At position “B”, the injection molded products 10 arranged vertically up and down are received by the transport gripper 12 or 12 ′, and the standing position shown at stage “C” by turning the transport device in the direction of arrow P. Brought to you. The transport gripper 12 includes a platform 17 that can pivot about an axis 13. The platform 17 supports an operation plate 16, and the platform 17 and the operation plate 16 are spaced apart from each other in parallel. Has been placed. The actuating plate 16 can be pushed out parallel to the platform 17 via a drive or adjusting means 18, so that at position "B", the sleeve-like injection-molded article 10 is taken out from the take-out device 11, It is slidable to the rear cooling device 19 located above at the position turned to the position “C”. Each delivery is performed by changing the distance “S” between the working plate 16 and the platform 17. The high-temperature injection-molded article 10 is completely cooled in the post-cooling device 19 and is pushed out after the post-cooling device 19 has moved to the position “D” and released to the conveyor belt 20. Reference numeral 23 denotes a water-cooling section by an appropriate inflow or outflow pipe, and the inflow or outflow pipe is indicated by an arrow for simplification of illustration, and is regarded as a known one. Reference numeral 24/25 indicates an air side, 24 is a blowing part or a compressed air supply part, and 25 is a vacuum part or an intake part (FIGS. 6a and 6c).

  From FIG. 2a, the direct relationship between the function of the nipple 30 as a sizing nipple and the conical section 47 of the preform 10 can be seen. A suitable conical outer part of the preform 10 is first specially cooled immediately after removal from the open mold halves 8, 9, and the unsupported outer wall layer is solidified inside the cooling sleeve 21 ( FIG. 3b). This provides sufficient shape stability for all preforms at the tapered transition 47. On the outside, the air guide ring 114 is held inside the head portion 143 of the cooling sleeve 21. At the time of assembly, the air guide ring 114 is pushed from the right to the left together with the sleeve 144 inside the cooling sleeve 21. Cooling air is indicated by arrows 145 and 145 '. As shown in FIG. 2a or 3b, the cooling air acts before the press or seal ring 56 contacts the preform.

  In FIG. 2b, the introduction part of the nipple 30 shown in FIG. 6a is shown enlarged. A floating support of the press or seal ring 56 is a particularly advantageous configuration. The press ring 56 is held by loose support rings 100 on both end sides. Both loose support rings 100 have an inner diameter D, and the inner diameter D is larger than the outer diameter d of the support tube 52 by a slight gap. In the longitudinal direction, a play Sp between the support ring 100 and the coupling member 80 is formed. This provides the press or seal ring 56 with a degree of freedom of movement that is in a non-actuated state and slightly rocking or floating. The press or seal ring 56 automatically produces optimum ring-shaped seal points, for example 57, 57 ', 57 ".

  FIGS. 3 a and 3 b show the outer cooling of the preform 10xx at the inconvenient transition 47 between the threaded portion 44 and the blowing portion 43. A number of preforms 10xx have an outer conical taper 110 in this section. The conical taper 110 is disadvantageous in that the tapered region 47 is not supported against the cooling sleeve 21. There is no contact with the inner wall 111 of the cooling sleeve. Cooling air is blown in through the air connection portion 112 and is discharged again to the outside air through the cooling passage 113. This additional cooling is advantageous, and cooling can be effectively performed over the entire sizing time from the moment the preform 10 is delivered to the cooling sleeve 21. The additional solidification of the relevant preform outer surface counteracts deformations that may be caused by the pressing force of the press or seal ring 56. According to a clear structural difference from the “normal” cooling sleeve, an air guide ring 114 is arranged in the open open area. Inside the air guide ring 114, a ring-shaped cooling passage is disposed around the corresponding preform from the air connection portion 112 side to the discharge point 113 '. This allows the cooling air to act along the entire corresponding conical outer surface of the preform to the end face of the neck ring 137 as desired.

  4a and 4b show a preform 10x having a neck portion 136 that is conically expanded. In this type of preform, the expanded neck portion is included in the blowing portion and abuts the inner wall of the cooling sleeve 130 during sizing. The inner wall of the cooling sleeve gives the final shape to the preform 10x. The entire blowing portion of the preform 10x extends to the neck ring 137. The optimum sealing location of the press or seal ring 56 is located in the region of the cylindrical section in the region of the neck ring 137 (FIG. 5b). However, this portion may be deformed when the press or seal ring 56 is expanded. Because this part. This is because it is only partially supported from the outside. Here, additional outside air cooling (KL) acts. Due to the air cooling of the thread portion 44 as well as the neck ring 137, the outer surface of the thread 44 obtains a relatively high stability. This is independent of whether the preform is sized.

  FIG. 4b shows another related configuration. The cooling sleeve is assembled from standardized components and comprises an inner cooling sleeve 130, an outer cooling sleeve 131, an outer sleeve 132 and a head ring 133, by means of the head ring 133, an air passage (gap Sp). ) Is formed. Depending on the shape of the preform 10, 10x, 10xx, the inner cooling sleeve 130 is configured and a suitable head ring 133 or 114 is fitted over it. Reference numeral 138 indicates the lowest thread, reference numeral 134 indicates the base of the working plate, and reference numeral 135 indicates the seal ring. As shown in FIGS. 4a and 4b, the cooling sleeve 10x is configured such that a minimum gap 139 of sufficient millimeters remains at the bottom after the preform is inserted into the cooling sleeve. In contrast, the neck ring 137 preferably abuts the end face of the cooling sleeve completely when already inserted.

  As shown in FIG. 5a, outer cooling can often be omitted at the blow-in part of the true cylinder. If the machine cycle time is to be further reduced, it is advantageous to solidify the thread part early, even with a preform having a cylindrical blow-in part, so that the thread breaks in processes within the range of post-cooling. Does not occur.

  FIG. 5b shows a preform having an expanded diameter in the open end region. The preform is no longer supported by the cooling sleeve in the neck ring 137 as well as in the threaded region. It is therefore very advantageous here that the outer surface of the described region is solidified with cooling air as soon as it is delivered from the injection mold to the take-off gripper.

  FIG. 5c shows a mode in which deformation, particularly indentation of the corresponding portion, can be prevented when the appropriate blowing portion is tapered (FIG. 10b). This is achieved with a relatively thick preform wall thickness, especially with very short cycle times of less than 10 seconds. In conventional preforms for PET bottles with a capacity of 1-2 liters, the section to be treated with cooling air is usually 3 cm to 5 cm, in which case the thread itself is about 2 cm.

As can be seen from the above description, with respect to the preforms 10, 10 x, 10 xx, from the moment they are taken out from the open mold half,
-The optimum cooling characteristics are always formed,
-The preform is pressed against the cooling surface inside the extraction sleeve 40 during the sizing phase, until the nipple enters, immediately after moving from the open mold half to the cooling sleeve, except for a short break,
The short break due to 100% abutment of the preform 10 is again compensated by a relatively long lasting sizing,
-After sizing, the preforms 10, 10x, 10xx are already in a shape-stable state entirely. Thus, preforms 10, 10x, 10xx are dimensioned with the outer geometry until sizing and cooling is complete.

In the maximum design of the water cooling circuit,
-Injection mold,
The area of the injection molding cavity and the injection molding mandrel,
-Extraction sleeve,
A maximum concentration effect is formed. The purpose here is not to completely cool the preforms 10, 10x, 10xx within the injection molding cycle. However, it is intended to bring the preforms 10, 10x, 10xx into a state where they can be loaded, stored and transported by the end of cooling after lasting 2-3 times longer.

The resulting great benefits:
-Conditions for significant reduction in cycle time,
-As a result, the productivity of injection molding machines is greatly improved,
-Maximum dimensional accuracy of the preform,
-And the highest quality properties of the preform, for example with regard to crystallization, dimensional accuracy and damage-free,
Is obtained.

  6a, 6b and 6c show sizing and removal of the preform 10 from the take-out sleeve 40 using the nipple 30 which functions as a holding nipple. The inner chamber of the blowing part is exposed to negative pressure via the nipple 30 (FIG. 6a) or the preform 10 is adsorbed to the nipple 30 (-sign) (FIG. 6b). A positioning (centering) ring 58 is attached to the rear end of the support tube 52, and the positioning ring 58 is accurately attached to the open end of the preform 10 in order to securely hold the preform 10 in the nipple 30. It fits. On the opposite side of the preform 10, compressed air is applied to the closed preform end (+ sign) (FIG. 6c). The preform 10 extends to the stopper 50 towards the working plate 16 and is completely removed from the take-off sleeve 40 and delivered, for example, to post-cooling or, in the second aspect, by switching to compressed air. The

  FIG. 6a schematically shows the adjustment of the compressed air supply. Via a voltage-regulated control valve 35, 38, the control device 39 adjusts the supply of compressed air for sizing in terms of voltage (volts), in this case advantageously from the start of sizing to shaping (expansion). A continuous increase in pressure is desired. As a result, the shrinkage of the preform 10 caused by the cooling action of the cooling sleeve 21 can be counteracted, and rapid solidification of the outer surface is obtained. The preform 10 is optimally pressed against the inner wall of the cooling sleeve for the duration of the sizing so that deformation (expansion) in the unsupported region or failure due to operation of the preform does not occur.

  FIG. 7 shows an end state of the injection molding process in which the mold halves 8 and 9 are opened. The temperature of the preform 10 is lowered in the mold having the maximum cooling effect. Accordingly, the preform 10 may still be unstable in shape to such an extent that it can be deformed by a very small external force during rapid release after mold release. At the end of the injection molding process, the take-out device is already in the starting position (FIG. 1) and can be lowered between the mold halves opened after the mold opening without time lag. In the embodiment shown in FIG. 7, an independent post-cooling device 19 is used in which the still hot preform 10 is completely cooled during 3-4 injection molding cycles. The transport gripper 12 delivers the preform 10 to the post-cooling device 19 at the stage “B” / “C” in FIG. Post-cooling of the preform is performed in a water-cooled sleeve.

  In FIG. 7, the horizontal plane is indicated by EH, and the vertical plane is indicated by EV. The horizontal plane EH is defined by both coordinates X and Y, and the vertical plane is defined by coordinates YZ. The Z coordinate is vertical and the X coordinate is oriented perpendicular to the Z coordinate. The transport gripper 12 performs a turning motion and a linear motion on the X coordinate. The transport gripper 12 can additionally be formed with a controlled movement on the Y coordinate. Since the transport gripper 12 already has a controlled movement on the X coordinate, the precise positioning of the preform 10 located on the nipple 30 of the transport gripper 12 in the X direction is appropriately controlled / adjusted. Can be done by exercise. Here, in order to deliver the preform 10 to the post-cooling device 19, the post-cooling device 19 is moved to a specified position in the X direction, and the transport gripper 12 is controlled / adjusted in the Y direction to be in a desired position. Brought about. In an advantageous manner, the movement means for the post-cooling device 19 can be controlled / adjusted with respect to the two coordinates XY for precise positioning with respect to the delivery of the preform 10. In this case, the transport gripper 12 is brought to a specified delivery position.

  With respect to this form, all the contents of WO 2004/041510 pamphlet and further PCT 2007/000319 are applied.

  7 and 8, the mold halves 8 and 9 occupy an open state, so that the post-cooling device 60 can move to the free intermediate space 62 between the mold halves. . The post-cooling device 60 has a total of three motion axes, a horizontal motion axis on the Y coordinate, a vertical motion axis on the Z coordinate, and a rotation shaft 63 (the rotation shaft 63 is adjusted by the machine control device 90). ing. The rotary shaft 63 is used exclusively for discharging the completely cooled preform 10 onto the conveyor belt 20. The rotating shaft 63 is supported with respect to the substrate. The movement means for the vertical movement is a vertical drive device 65. The vertical driving device 65 is slidably disposed along the substrate 66 of the horizontal driving device 67. The horizontal drive device 67 includes an AC servo motor having a vertical axis. The substrate 66 is supported through four slide bodies so as to be able to reciprocate along two parallel slide rails. The substrate 66 includes a vertically upward substrate portion on the right side of the drawing, and a vertical driving device 65 is fixed to the substrate portion. Similarly, the vertical driving device 65 includes an AC servo motor having a horizontal axis.

  The post-cooling device shown in FIG. 8 has a plurality of rows arranged in parallel. In the illustrated embodiment, twelve cooling sleeves 21 are shown in each vertical row. The cooling sleeve 21 can be arranged very narrow with respect to the state in the injection molded product. Therefore, not only a plurality of parallel rows but also an additional row shift is proposed. That is, for the first injection molding cycle, the cooling pipe is numbered 1 and for the second injection molding cycle, the cooling pipe is numbered 2 and so on. For example, if all three rows are numbered 3 in 4 parallel rows, the row having the number 1 is prepared for delivery to the conveyor belt 20 as described. The rest proceeds regularly throughout the production time. In the illustrated embodiment, the total post cooling time is 3-4 times the injection molding time. The air pressure or negative pressure state in the post-cooling device 19 can be controlled for each column, whereby all the columns 1 or 2 can be operated simultaneously at a specific time. In addition to the distance adjustment accuracy of the post-cooling device 19 and the platform 17, it is important to optimally control the acceleration and deceleration functions. Visualization is performed in the machine control device or the command device of the machine computer 90. The exercise process is optimized from all points of view. This applies, for example, to start and stop, and in particular to acceleration and deceleration with respect to speed and distance.

  FIG. 9 shows the thermal profile that occurs without sizing (recorded in preform 10xx). What should be noted is a large temperature difference of 62.8 degrees to 45.7 degrees. There is a 17.1 degree radial temperature difference at the end of the preform shaft. This causes ovalization of the outer shape in the first cooling process. Undesired ovalization can only be suppressed or avoided by a relatively long cooling time in the mold tool. In the illustrated example, the illustrated thermal profile was measured at a cycle time of 13.5 seconds. The quality is about 0.2 mm, which is still within the tolerance range.

  FIG. 10a shows a test example with sizing of a preform 10xx with cooling air. The temperature distribution is in a very small range of 3.9 degrees. Here, the cycle time was reduced from 13.5 seconds to 11.5 seconds. The ovalization is only 0.05 mm, not 0.2 mm. Therefore, according to the present invention, a more accurate preform can be manufactured in a relatively short cycle time.

  FIG. 10b shows a preform 10xx, where no external cooling according to the present invention was used. The sizing pressure was too high so that the preform expanded in the unsupported conical region.

Claims (29)

A post-cooling device for the preform (10),
The preform (10) that is still unstable in shape is taken out from the open mold halves (8, 9) of the injection molding machine by the take-out gripper (11) and at least partly in the water-cooled take-out or cooling sleeve (21). In the post-cooling device that is to be post-cooled automatically,
In the region of the open end side outside the preform (10), a blowing device is incorporated in the cooling sleeve (21), and at least the preform (10) is supported through the blowing device. Post-cooling device for the preform (10), characterized in that the outer surface of the non-region is solidified with cooling air.   The post-cooling device according to claim 1, wherein a cooler is arranged corresponding to the post-cooling device to form frozen cooling air.   3. A post-cooling device according to claim 2, wherein a pressure generator for the cooling air is arranged in the post-cooling device, the compressed air being generated by the pressure generator below 4 bar. .   The post-cooling device comprises a control device, by means of which the blowing device can be actuated from the point of taking out or delivering the preform to the cooling sleeve (21). The post-cooling device according to any one of 3 to 3.   The post-cooling device according to claim 4, wherein the cooling air amount and / or the cooling air temperature are controllable, and the maximum value is adjustable immediately after the preform is delivered.   The aftercooling device according to any one of claims 1 to 5, wherein the blowing device is formed as an air guide or cooling passage (113) directed towards the open end of the preform.   A water-cooled take-out sleeve is provided in the region between the threaded portion (44) and the blow-in portion (43) or the cylindrical shaft, with a cooling passage (113) for proper outer cooling of the preform (10). A post-cooling device according to any one of claims 1 to 6, comprising an air connection (112) for the cooling passage (113).   Depending on the geometry of the preform (10), the air passages may be in the region between the threaded portion (44) and the neck ring (137) and / or the neck ring (137) and the cylindrical blowing portion. The post-cooling device according to any one of claims 1 to 7, wherein the post-cooling device is disposed in a transition region between (43) and (43).   A water-cooled take-out sleeve is formed so that the entire preform blowing part, excluding the thread portion (44) and the neck ring (137), is completely inserted into the take-out sleeve. The after-cooling apparatus of any one of Claims.   The water-cooled take-out sleeve is formed from a standardized part, and in some cases, a guide ring (114) is provided between the threaded part (44) and the neck ring (137) and / or the neck. Post-cooling according to any one of the preceding claims, wherein the post-cooling is adapted for an air passage for cooling the transition region between the ring (137) and the blowing part (43). apparatus.   The post-cooling device includes a device having a plurality of nipples (30) each having an insertion portion for the preform (10), and an insertion portion of the nipple (30) that can be inserted into the preform (10) in the radial direction. A post-cooling device according to any one of the preceding claims, comprising a press or seal ring (56) for inflating.   The press ring is formed as a seal ring (56) which is radially inflatable, in particular supported in a floating state, through which the blowing part (43) of the preform (10) is inserted. 12. The rear of claim 11, wherein a mechanically formable and adjustable sealing force is formed towards the inner wall of the preform (10) to create a molding pressure in the inner chamber of the preform (10). Cooling system.   The nipple (30), in particular with a press or seal ring (56) supported in a floating state, is positioned at a selectable and optimal seal location in the region between the threaded portion (44) and the blowing portion (43). 13. A post-cooling device according to claim 11 or 12, which is controlled and inserted into the preform (10).   The preform (10) is still in a hot and unstable state, and is delivered from the injection mold to a water-cooled take-out sleeve for post-cooling, and can be inserted into the preform (10). The post-cooling device according to any one of claims 11 to 13, wherein the post-cooling device is sized according to (30) with compressed air to an accurate outer size.   The nipple (30) is located on a common actuating plate (16) and has the optimum location for optimum penetration depth or seal ring (56) in the preform (10) or extraction cooling sleeve. 15. A controllable drive means is arranged corresponding to the actuating plate (16) for inserting and positioning a press or seal ring (56) in the housing. After-cooling system.   The post-cooling device is provided with a controllable take-out gripper (11) and corresponds at least to the number of injection molding positions of the injection mold, preferably 3 to 4 times the number of injection molding positions in the injection mold. The post-cooling device according to any one of claims 1 to 15, wherein a number of water-cooled take-out sleeves are provided.   The post-cooling device corresponds to a take-out gripper (11) having a water-cooled take-out sleeve, a transport gripper (12, 12 ') having a nipple (30), and a number three to four times the number of injection molding positions. And a rear cooler (19) having a number of cooling positions, the blow-in part (43) of the preform (10) being sized in the take-out sleeve, and the preform (10) Are delivered to the post-cooler (19) by the transport gripper (12, 12 ') and to the unloader (20) after complete cooling within each injection molding cycle in a predetermined precise shape. The aftercooling device according to any one of claims 1 to 16. A method of post-cooling a preform (10) comprising a thread portion (44), a blowing portion (43) and a neck ring (37),
In a method of post-cooling the preform, the preform (10) is at least partially post-cooled in a water-cooled cooling sleeve (21), still in a hot, unstable state,
Cooling at least a part of the outer surface of the unsupported end side opened outside the preform (10) with cooling air via an air blowing device incorporated in the cooling sleeve (21) to solidify. A method for post-cooling a preform.   The compressed air for sizing is expanded steplessly from the start of sizing, and the outer surface of the preform (10) is continuously cooled until the maximum molding pressure is obtained to compensate for the shrinkage. 19. The method of claim 18, wherein the method is achieved by increasing the control voltage of the control valve in the compressed air supply.   20. A method according to claim 18 or 19, wherein the cooling air is preferably cooled air having a temperature in the range below 0 degrees.   21. The method according to claim 20, wherein cooling air below 4 bar is used.   The method according to any one of claims 18 to 21, wherein the cooling air usage is controlled such that the maximum cooling effect is effected immediately after delivery of the preform.   Immediately after delivering the preform (10) to the cooling sleeve (21), in the region between the thread portion (44) and the cylindrical blowing portion (43), the outside of the preform (10) using air The method according to any one of claims 18 to 22, wherein cooling is performed.   24. In the case of a preform (10) with an expanding neck, the transition region between the threaded portion (44) and the neck ring (137) is air-cooled from the outside. The method described.   24. Method according to any one of claims 18 to 23, wherein in the case of a preform (10) with a neck portion extending outwardly, the region of the preform (10) is air cooled from the outside. a) A press or seal ring (56) attached to the nipple (30) is position controlled and inserted into each preform (10) in the region between the threaded portion (44) and the blowing portion (43). And
b) bringing a press or seal ring (56) into contact with the inner wall of the preform (10);
26. A method according to any one of claims 18 to 25, wherein c) the inner chamber of the blowing part (43) is sealed outwardly by creating a force directed radially towards the inner wall.   The blow-in part (43) of the preform (10) is separated from the mold halves (8, 9) opened during the duration of the injection molding cycle by inserting the preform (10) into the cooling sleeve (21). 27. After that, the preform (10) is sized to the exact outer dimension along the inner wall of the cooling sleeve (12) by continuously expanding compressed air. the method of.   The nipple (30) equipped with a press or seal ring (56) is controlled in position to a selective optimum sealing point in the region between the thread part (44) and the blowing part (43), and the preform ( 28. The method according to any one of claims 18 to 27, wherein the method is inserted into 10).   Immediately after inserting the preform (10) from the outside into the cooling sleeve (21) in the transition region between the thread portion (44) and the neck ring (137) and / or blowing with the neck ring (137) Immediately after insertion to the transition area between the parts (43), after cooling from the outside and separating the cooling sleeve (21) from the open mold halves (8, 9), it is attached to the nipple (30). Controlled by a separate press or seal ring (56) to the transition region between the thread portion (44) and the neck ring (137) or between the neck ring (137) and the blowing portion (137) 29. Method according to any one of claims 18 to 28, wherein the process is introduced to the preform (10) up to the region and sized in an injection molding cycle.

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