HK1036031A1

HK1036031A1 - Preform post-mold cooling method and apparatus

Info

Publication number: HK1036031A1
Application number: HK01106561A
Authority: HK
Inventors: 费萨尔‧韦斯拉蒂; 维托尔德‧内特尔; 蒂默‧布兰德; 戈登‧埃利奥特; 理查德‧翁德兰德; 格奥尔基‧奥拉鲁
Original assignee: 哈斯基注模系统有限公司
Priority date: 1998-03-31
Filing date: 1998-07-20
Publication date: 2001-12-21
Also published as: KR20030031514A; CN1817606B; CN1294546A; WO1999050039A1; CN1275759C; AU8575698A; CN1817606A; JP2002509817A; AU746598B2; AU746598C; CN1231340C; KR100386415B1; RU2189313C2; IL138727A; CN1375390A; IL138727A0; HK1052156A1; JP4358715B2; JP3665568B2; KR20010042339A

Abstract

The present invention relates to an improved method and apparatus for injection molding and cooling molded articles such as preforms so as to avoid crystallinity. The apparatus and method make use of a take-off plate for removing articles (48) from a mold, which plate may include heat transfer devices for cooling exterior surfaces of the molded articles or preforms (48), and a system for cooling (74) in a controlled manner interior surfaces of the molded articles or preforms (48).

Description

Preform post-mold cooling method and apparatus

The present invention relates to a method and apparatus for mold forming and cooling of plastic molded articles, such as preforms made of one or more materials (e.g., plastic resins). In particular, the present invention relates to a rapid injection molding process in which molded articles, such as PET preforms, are ejected from the mold prior to the cooling step being completed. The present invention utilizes a novel post-mold cooling method and apparatus for convectively cooling the preforms internally after they have been removed from the mold and placed outside the mold. The invention also relates to external cooling by conduction or convection, which can be carried out at least partially simultaneously with the internal cooling.

Proper cooling of the molded article represents a very important aspect of the injection molding process because it affects the quality of the molded article and the length of the entire injection cycle. This is even more important in the case of semi-crystalline resins such as injection moulding of PET preforms. After injection, the PET resin remains in the mold cavity gap, cooling for a time sufficient to prevent the formation of crystallized portions and to solidify the preform before it is ejected.

In order to shorten the cycle time of the injection process, two things generally happen if one preform is quickly ejected from one mold. The first is that the preforms are not cooled uniformly. In most cases, crystallization occurred at the bottom opposite to the model nozzle. The heat accumulated in the preform walls during the injection process is still high enough to cause post-mold crystallization in the preform (especially in the gate area of the preform). The gate area is a very important area because the cooling of the mold in this section is insufficient and the resin in the cavity gap is still in contact with the hot stem of the hot runner injection nozzle. If the area of a preform remains crystalline over a particular size and depth, this will reduce the quality of a blown article. The second thing is that the preform will be too soft and thus may be deformed during a later transfer step. Another important area of a preform is the neck finish portion (neck finish portion), which in many cases has thicker walls and retains more heat than other portions. The neck finish portion needs to be effectively post-mold cooled to prevent crystallization thereof. In addition, effective cooling also enables the neck to solidify sufficiently to withstand further handling.

In the past, attempts have been made to improve the cooling of PET injection molding systems, but still have failed to significantly improve the quality of the molded preforms or reduce cycle times. U.S. Pat. No. 4,382,905 to Valyi, herein incorporated by reference, discloses an injection molding process in which molded preforms are transferred to a first tempering mold for a first cooling step, and then to a second tempering mold for a final cooling step. The two tempering molds are similar to the injection mold and have internal means for cooling the mold wall that is in contact with the preform during cooling. U.S. patent No. 4,382,905, issued to Valyi, does not provide cooling means on the means for transferring the preforms from the molding area or additional cooling means capable of circulating a fluid coolant through the molded preforms.

U.S. Pat. No. 4,592,719 to Bellehache discloses an injection molding process for making PET preforms wherein molded preforms are removed from the injection core by a first movable means comprising vacuum suction means for holding the preforms, the process further comprising air absorption (convection) cooling of the outer surface of the preforms. A second cooling means used in U.S. Pat. No. 4,592,719 to Bellehache, in combination with a second movable means, also utilizes air absorption to further cool the interior of the preform. See fig. 22 here. U.S. Pat. No. 4,592,719 to Bellehache does not disclose blowing cold air into the interior of a preform in a manner that provides better cooling than by drawing or absorbing ambient air, and does not disclose cooling devices that utilize conductive heat transfer and are in intimate contact with the preform walls and air blowing devices toward the dome portion of the preform. This solution proposed by Bellehache has a number of drawbacks, including a low cooling efficiency, a poor cooling uniformity, a long cooling time and a high probability of deformation of the preforms.

U.S. Pat. Nos. 5,176,871 and 5,232,715 disclose a preform cooling method and apparatus. The molded preform is retained by the injection molded core outside of the molding region. Cooling the mold core with a coolant that does not contact the molded preform. A cooling tube larger than the preform is placed around the preform to blow cool air around the preform. The main problem with the devices and methods disclosed in these patents is that the preform is held in the mold core and this greatly increases the cycle time. In addition, direct contact between the coolant and the preforms is not utilized for internal cooling purposes.

U.S. Pat. Nos. 5,114,327, 5,232,641, 5,338,172, and 5,514,309 (incorporated herein by reference) disclose a preform internal cooling method that employs a liquid coolant. Preforms ejected from a mold are transferred to a preform carrier having vacuum means to position the preforms without contact with the preform outer walls. But this preform carrier does not have any cooling means. A cooling core is also introduced inside the preforms held by the carriers and a cooling fluid is blown into the preform interiors to cool the preforms. The coolant is also evacuated from the cavity surrounding the preforms by the same vacuum means used to hold the preforms. These patents do not disclose blowing cold air into the interior of a preform where the air is free to exit the preform after it has been cooled. Neither of these patents disclose simultaneous internal and external preform cooling or a preform carrier with cooling means. See fig. 21 here.

Japanese patent publication No. 7-171888, incorporated herein by reference, discloses a preform cooling apparatus and method. An automated molded preform carrier is used to transfer the preforms to a cooling station. The robot is capable of externally cooling the preform walls by conduction heat exchange with a cooling water. The cooling station includes a first movable robotic transfer device having a rotating robot portion including vacuum means for holding the preforms and also for externally cooling the preform walls by conductive heat transfer. The molded preforms are transferred from the robot carrier to the robot portion. The robot section moves from position a to position B where it is rotated through a 90 degree angle to transfer the preforms (which are now only cooled externally) to a cooling tool. The cooling tool has means for holding the preform, means for cooling the inside of the preform by blowing air, and means for cooling the outside of the preform by blowing air or water cooling. Here, the internal cooling employed is shown in fig. 19 and 20. This patent does not disclose a method for internal and external cooling immediately from the moment the preform is ejected from the mold and placed into a carrier plate. Nor is there any disclosure of cooling both the interior and exterior of the preforms simultaneously as they are held by the movable robot carrier. Therefore, this cooling method is not fast enough and cannot prevent crystallization from occurring outside the mold.

Figures 19 and 20 show a known method of internally cooling preforms, wherein a cooling device is located outside the preforms and is used to blow cool air into the interior of the preforms. Because the air nozzle is located outside the preform, the incoming cold air flow necessarily at least partially affects and mixes with the exiting warm air. This will greatly reduce the cooling efficiency. The method of FIG. 19 is ineffective if the cooling means are on the same axis as the preform, since there is no air circulation in the preform. If the cooling device is moved laterally as shown in FIG. 20, air circulation will be achieved, but this is still ineffective because one side of the preform cools well and more quickly than the other. The coolant has a quasi-divergent flow and asymmetric profile. This profile is very inefficient and does not allow the cooling fluid/gas to converge towards the sprue gate or dome portion.

It is a primary object of the present invention to provide a method and apparatus for producing preforms that improves cooling efficiency.

Another object of the present invention is to provide a method and a device for producing preforms of good quality.

Another object of the present invention is to provide a method and a device for producing preforms which allow to reduce the overall production cycle time.

The above objects are accomplished by the apparatus and method of the present invention.

In one embodiment, the novel molding and cooling method of the present invention comprises removing the preform from the mold before the preform in the mold is sufficiently cooled, i.e., the preform retains an amount of heat that may crystallize the sprue gate portion, the neck finish portion, or the entire preform; securing the preform outside of the molding area; and internally cooling the preform by convective heat transfer so that no crystallization occurs in any of the above regions.

In another embodiment of the present invention, the novel molding and cooling method to which the present invention relates comprises removing the preform from the mold before the preform in the mold is sufficiently cooled, i.e., the preform retains an amount of heat that may crystallize the sprue gate portion, the neck finish portion, or the entire preform; securing the preform outside of the molding area; and internally cooling said preforms by convective heat transfer so that crystallization does not occur in any of said regions, said cooling step comprising disposing a coolant in direct contact with said preforms; and externally cooling the preform by convective heat transfer so that no crystallization occurs in any of the above regions. The external cooling step may be simultaneous, at least partially simultaneous, or sequential with respect to the internal cooling step.

In another embodiment of the present invention, the novel molding and cooling method to which the present invention relates comprises removing the preform from the mold before the preform in the mold is sufficiently cooled, i.e., the preform retains an amount of heat that may crystallize the sprue gate portion, the neck finish portion, or the entire preform; securing the preform outside of the molding area; and internally cooling said preforms by convective heat transfer so that crystallization does not occur in any of said regions, said cooling step comprising disposing a coolant in direct contact with said preforms; and externally cooling the preform by conduction heat transfer so that crystallization does not occur in any of the above regions. The external cooling step may be simultaneous, at least partially simultaneous, or sequential with respect to the internal cooling step.

In each of the above embodiments, the preforms are ejected from the mold and held outside the mold by means independent of the mold, such as a movable take-off plate. Such independent holding means may hold one set of said moulded preforms or several sets of preforms simultaneously. When several groups of preforms are held by said independent means, the preforms of these groups are at different temperatures from each other, since they are moulded at different times. According to the present invention, the molded preforms can be cooled from the inside and the outside in different sequences by the cooling method according to the present invention. In each of the above embodiments, the internal cooling is performed by means (such as cooling pins) that are capable of entering at least partially inside the preform and of circulating a coolant inside the preform. Preferably, the cooling is performed by means of a quasi-symmetrical coolant flow that is delivered to the interior of the preform, being directed to portions of the preform that require more cooling than other portions, such as the sprue gate portion and the neck finish portion. In a preferred embodiment of the invention, the coolant is directed toward the bottom or dome portion of the preform to form an annular flow of coolant.

In certain embodiments of the present invention, the new internal cooling of the preforms can be supplemented by external cooling that can be done in several ways. For example, external cooling may be performed on a take-off plate (one or more locations) having cooling means that may operate by conduction heat transfer (cooling water) or convection heat transfer (air/gas). External cooling can also be performed on a take-off plate (one or more locations) without cooling means so that the preforms can only partially contact their holders. Thus, a separate cooling device can be used to deliver the cooling air/gas so that it is in direct contact with the outer surface of the preform.

In another embodiment, the preforms are held in a take-off plate without any cooling means and are only internally cooled using the novel cooling pins of the present invention.

The novel cooling method of the present invention can be achieved in one embodiment by removing the preforms or molded articles from the mold, holding the preforms or molded articles in a take-off plate that is capable of automated operation, the plate having a system for cooling the exterior surfaces of the preforms or molded articles, and then engaging cooling means within the interior of the preforms or molded articles to simultaneously cool the exterior and interior surfaces. According to the present invention, an additional cooling step is introduced to reduce the temperature of the preforms by convective heat transfer (e.g., by circulating a cooling gas within the preforms).

As mentioned above, the method and apparatus according to the present invention are advantageous in preventing crystallization in the most important areas of the preform (i.e. the bottom or dome portion where the sprue gate portion is located and the neck portion). In addition, the cooling method and apparatus of the present invention can be incorporated into an injection-blow molding apparatus where the cooled preforms without crystallization can be further temperature adjusted and blown into bottles.

According to one aspect of the present invention, a method for preventing crystallization in an injection molded preform with improved off-mold cooling includes injecting a molten material into a mold formed of two mold halves or mold plates that are spaced apart from each other in a mold open position to define a molding area; cooling said molten material while in the mold cavity space formed by said mold halves to a temperature very close to the crystalline-glass transition temperature of such molten material so that said molded article can be mechanically removed from the mold without undergoing geometric deformation; opening said mold halves to maintain a spacing between said mold halves sufficient to allow a molded article carrier to move between said mold halves; ejecting said molded articles from said molds and transferring them to said movable carrier; cooling said molded articles by conductive heat transfer while said molded articles are in said movable carrier to reduce crystallization, wherein said cooling agent is a blown air; and internally cooling the molded articles by convective heat transfer until each molded article is substantially free of any crystallized portions. This method can also be supplemented by a movable carrier with convective heat transfer means for external cooling.

According to one aspect of the present invention, an apparatus for forming a non-crystallized injection molded article comprises, a mold having two mold halves movable between a mold closed position and a mold open position; means for injecting molten material into the mold when the mold halves are in the mold closed position; means for cooling said molten material in the mold cavity space formed by said mold halves to a temperature very close to the crystal-glass transition temperature of such molten material so that said molded article can be mechanically moved out of the mold without undergoing geometric deformation; means for opening said mold to maintain a spacing between said mold halves sufficient to allow a molded article carrier to move between said mold halves; means for ejecting said molded articles from said mold; means for transferring said molded articles to said movable carrier; said carrier having means for holding said molded articles and cooling said molded articles by conductive heat transfer to reduce crystallization; and means for cooling said molded articles from the inside by convective heat transfer until each molded article, preferably the entire molded article, is substantially free of any crystallized portions, particularly in the mold gate portion. This method can also be supplemented by a movable carrier with convective heat transfer means for external cooling.

As used herein, the terms "take-off plate," "take-off plate," and "end-of-arm tool" are interchangeable and represent the same structure.

Further details of the method and apparatus according to the invention, as well as other objects and advantages thereof, will be apparent from the following detailed description when read in conjunction with the accompanying drawings, wherein like elements are designated by like reference numerals.

FIG. 1 shows a graph of the temperature of the preform during and after completion of the injection versus time;

FIG. 2 schematically shows a preform in a mold;

FIGS. 3(a) and 3(b) illustrate the temperature gradient across a wall of a molded preform during cooling;

FIG. 3c shows the temperature profile along the preform wall;

FIG. 4 is a cross-sectional view showing an injection mold according to the prior art;

FIG. 5 is a cross-sectional view showing a movable robot including an end of arm tool (EOAT) device positioned in the molding area between the fixed platen and the movable platen;

FIGS. 6(a) and 6(b) are side views showing an embodiment of the present invention comprising an automated and removable plate (or end of arm tool, EOAT) and a frame for holding cooling pins;

FIGS. 6(c) and 6(d) are front views of the embodiment shown in FIGS. 6(a) and 6 (b);

fig. 7(a) -7 (d) show a frame and cooling pins according to a first embodiment of the present invention;

FIGS. 8(a) -8 (g) illustrate several cooling pin designs in accordance with the present invention;

FIGS. 9(a) and 9(b) illustrate in more detail cooling pins according to two embodiments of the present invention;

FIG. 10(a) shows a preform having crystallized regions as produced in a prior art method;

FIG. 10(b) shows a preform without crystallized regions produced after the method of the present invention is utilized;

11(a) -11 (1) illustrate another embodiment of a frame and cooling pin according to the present invention;

FIG. 12 is a cross-sectional view of a system in which air cooling channels are incorporated into the mold halves;

FIGS. 13(a) and 13(b) are side views of another embodiment of the cooling system of the present invention;

FIG. 14 is a top plan view of an injection molding system having another embodiment of the cooling system of the present invention;

FIG. 15 is a cross-sectional view of another embodiment of the cooling system of the present invention showing the mechanism associated with the take-off plate for cooling the interior of the molded articles;

FIG. 16 shows an embodiment of the present invention in which a take-off plate without cooling means is used to remove the molded preforms from the molding area;

FIG. 17 shows another construction of a cooling pin according to the present invention;

FIGS. 18(a) and 18(b) illustrate another form of cooling pin according to the present invention;

FIGS. 19 and 20 illustrate a prior art method for cooling the interior of a preform;

FIG. 21 illustrates another prior art method for cooling the interior and exterior of a preform;

FIG. 22 shows a prior art system for cooling a preform by drawing ambient air; and

FIG. 23 illustrates a frame structure having cooling pins on multiple surfaces of the frame.

Referring now to the drawings, FIG. 1 shows a graph of temperature versus time of a preform during and after completion of injection. Figure 2 schematically shows a preform in a mould. As can be seen in this figure, cooling in the mold is typically accomplished by cooling tubes 12 and 14 located within mold cavity 16 and mold core portion 18, respectively. Thus, cooling is performed from both sides of the preform 11. In addition, as shown in FIG. 2, the cavity plate 16 generally has a sprue gate area 20 formed at the bottom or dome portion 22 of the preform 11. The preform has a neck finish portion 13, sometimes with thicker walls that are difficult to cool to prevent crystallization.

FIGS. 3(a) and 3(b) show the temperature gradient across the wall of a molded preform during cooling. Fig. 3(a) shows the temperature gradient inside the model, and fig. 3(b) shows the temperature gradient outside the model. FIG. 3c shows the temperature profile along the preform wall. The temperature peak represents the temperature in the dome or sprue gate portion of the preform.

Referring now to fig. 4, an injection mold is provided that includes a stationary mold half or platen 32 having an array of mold cavities 34 and a movable mold half or platen 36 having an array of mold cores 38. The cavity plate 32 is in fluid communication with a manifold plate (not shown) that is capable of receiving molten material from an injection assembly (not shown) of an injection molding apparatus. The mold cavity 34 receives molten material from a hot runner nozzle (not shown), such as a valve gate nozzle (not shown), through a mold cavity gate 40. When the mold plates 32 and 36 are in a mold closed position, the mold cavities are surrounded by cooling apparatus 42 for cooling the molten material in the cavity space formed by the mold core 38 and the mold cavity 34. The cooling device 42 is preferably formed by cooling channels embedded in the mold plate 32 for conducting a cooling fluid. As described above, the mold core 38 and the mold cavity 34 form a plurality of cavity spaces (not shown) in the mold closed position, into which molten material is filled through the mold gates 40 during the injection step. The mold core 38 also includes means 44 for cooling the molten material in the cavity space. The cooling device 44 preferably includes a cooling tube in each die. The core plate 36 also includes an ejector plate 46, the ejector plate 46 being used to remove molded preforms 48 from the mold cores 38. The operation of the ejector plate 46 is well known in the art and is not included in the present invention. In fact, the ejector plate 46 may comprise any suitable ejector plate 46 known in the art.

In accordance with the present invention, any molten plastic, metal or ceramic material can be injected into the mold cavity gap using the molding system shown in FIG. 4 and the material cooled to a desired article. In a preferred embodiment of the invention, the molten material is PET and the molded article is a preform. However, according to the present invention, the molded article may also be a preform made of more than one material, such as virgin PET, recycled PET, and a suitable barrier material (e.g., EVOH).

As is known in the art, a preform molding process includes the steps of closing the mold, injecting molten material into the mold cavity gap, initiating cooling of the mold cavity gap, filling the mold cavity gap with molten material, maintaining the molten material under pressure, performing final mold cooling, opening the mold, ejecting the solidified article or preform from the mold core and transferring the article or preform to a take-off plate. According to the invention, in order to reduce the cycle time, the residence time of the preforms in the mould must be minimized in order for the mould to produce groups of preforms as quickly as possible. The problem with reducing the residence time in the mold is that the cooling time must be reduced and the degree of solidification of the molded articles or preforms can be sufficient to withstand all subsequent transfer steps without deformation. Shortening the cooling time is a problematic option because adequate and uniform cooling of the molded articles or preforms is not achieved by the cooling devices 42 and 44. The amount of heat retained within the molded article or preform after cooling within the mold for a relatively short period of time, followed by opening the mold, is very large and depends on the thickness of the molded article or preform. Such internal heat may form crystallized portions at the sprue gate or dome portion of the molded article or preform, at the neck finish portion of the molded article or preform, or throughout the preform. In order to prevent crystallization of the molded articles or preforms, an efficient cooling method must be employed. During cooling, it is necessary to control the shrinkage of the molded article, which may adversely affect the final dimensions of the molded article.

FIG. 5 shows one embodiment of a robotic take-off plate 60 that may be used in the cooling method of the present invention. The removed plate 60 includes a plurality of hollow fixtures or receptacles 62, and the hollow fixtures or receptacles 62 may be water cooled tubes. Conventional take-off plates that can be used as the take-off plate 60 are shown in U.S. Pat. No. 5,447,426 to Gessner et al and U.S. reissue Pat. RE 33,237 to Delfer, III, both of which are incorporated herein by reference. In operation, the openings of the plurality of fixtures 62 are aligned with the mold cores 38 of the mold plate 36. The molded articles 48 are transferred to the fixture 62 by operation of the ejector plate 46. According to the invention, the take-off plate 60 can be provided with a plurality of fixing means 62, the number of fixing means 62 being equal to the number of mould cores 38 or a multiple of the number of mould cores, for example three or four times the number of mould cores. In the event that the number of fixtures 62 is greater than the number of mold cores 38, some of the molded articles can be held for a period of time longer than one molding cycle, thereby allowing increased cooling time while maintaining a higher yield of molded articles. The method of the present invention can be performed regardless of the number of molded articles held by the holding device 62. However, in the preferred embodiment of the invention, the robotic take-off plate 60 has three times as many holders 62 as there are cores 38. This means that the take-off plate 60 does not always carry the same number of preforms or molded articles as the number of holders 62. This also means that a group of preforms can be returned more than once to pick up other groups of molded articles in the molding area between the core and cavity plates as they are cooled by intimate contact between the hollow tubes 64 within the take-off plate and the outer walls of the preforms, the tubes 64 carrying a cooling liquid, such as water, as shown in detail in the aforementioned U.S. Pat. No. 5,447,426. Heat exchange between the tubes 64 and the hot molded articles exiting the mold is by conduction. In particular, any solid material capable of being made into a lubricating cooling device may be used and brought into intimate contact with the exterior walls of the molded article to cool the molded article. Because a cooling system operating by conduction heat transfer cools the molded articles or preforms by intimate contact between the molded articles or preforms and the cooling device, the shape of the molded articles or preforms can be maintained without deformation or scratching due to handling.

If desired, the conductive cooling means 64 used in the take-off plate may be replaced by a convective heat transfer means. Any suitable convective heat transfer means known in the art can be used in conjunction with the take-off plate 60 to cool the exterior surfaces of the molded articles or preforms carried by the take-off plate 60.

Referring now to FIGS. 6(a) and 6(b), an additional cooling device 70 is used in conjunction with the take-off plate 60 to simultaneously cool the interior and exterior surfaces of the molded articles or preforms by convective heat transfer, thereby improving the post-mold cooling effect, reducing cycle time, and improving preform quality. The additional cooling device 70 includes an array of elongated cooling pins 74, the function of the pins 74 being to deliver a cooling fluid to the interior of the molded articles held by the take-off plate 60. In a preferred embodiment of the present invention, the cooling fluid is directed primarily toward and delivered directly into the dome portion (sprue gate portion) 22 of the molded article or preform, which dome portion (sprue gate portion) 22 is most likely to be crystallized due to the shortened cooling time in the mold. The cooling fluid is introduced in the form of a circular flow. According to the invention, the cooling fluid may be any suitable coolant, such as a liquid or a gas. In a preferred embodiment of the present invention, the cooling fluid is compressed air delivered through a passage 90 located within the cooling pin 74. This aspect of the invention is shown in more detail in fig. 9 (a).

FIG. 9(a) shows a cooling pin 74 according to the present invention, the pin 74 being located within a preform or molded article 48 that requires cooling. In order to optimize the flow of the coolant, the cooling pin 74 is introduced deep into the preform 48 to enable the coolant to reach the dome or sprue gate portion 22. In addition, the cooling pin 74 may also serve as an additional cooling core. The cooling pin 74 also facilitates the creation of a circular flow that has a cooling effect that is superior to other flow patterns. The use of this new cooling pin 74 also allows the incoming blown cool air and the outgoing warm air to be completely separated, thereby preventing their mixing.

As shown in FIG. 9(a), the cooling pin 74 is centrally located within the preform or molded article, preferably such that the central axis 220 of the cooling pin 74 is centered with respect to the central axis 222 of the preform. As can be seen in this figure, the outer wall 224 of the cooling pin 74 is maintained at a distance D from the inner wall 226 of the preform in an upper region UP. In addition, a spacing d is maintained between the outlet nozzle 92 of the cooling pin 74 and the inner wall 228 of the dome portion 22. In order to form the desired circular flow pattern of the cooling fluid, it is preferred that the ratio between D and D is in the range of 1: 1 to 10: 1. Preferably, the cooling pin outlet nozzle 92 is a diverging nozzle configuration. The outlet nozzle 92 may be a straight wall nozzle, although a diverging nozzle is preferred for the outlet 92.

Because the cooling pin 74 enters deep into the preform and also acts as a cooling core, the free flow of warm air from the preform is also in the form of an annulus.

Although one preferred configuration of the cooling pin is shown in fig. 9(a), the cooling pin 74 may have various sizes and shapes to achieve various cooling effects, as shown in fig. 8(a) through 8(g), 17, and 18. For example, as shown in FIG. 8(a), the lower portion LP of the cooling pin 74 may have a diameter D2 that is different from the diameter D1 of the upper portion UP of the cooling pin. As shown in fig. 8(a) to 8(c), the upper portion UP of the cooling pin may have different shapes. Referring to fig. 8(d), cooling pin 74 may have lateral outlets 82 for discharging a cooling fluid onto the sidewalls of the molded article where crystallization may occur. As shown in fig. 8(e), the cooling pin 74 may have a helical groove 84 to achieve a particular cooling effect. Similarly in fig. 8(f) and (g), the cooling pin 74 may have a plurality of ribs 86 or a plurality of contact elements 88 around its periphery.

FIGS. 18a and 18b illustrate a cooling pin 74 having a plurality of radial conduits 230 for delivering coolant to other areas of the preform (such as the neck finish portion or body portion) than the dome portion 22. The radial conduits 230 may be spaced along the length of the cooling pins to direct coolant to specific areas of one preform 48.

The cooling pin 74 may be made of any suitable thermally conductive or thermally insulating material. If desired, as shown in FIG. 17, the cooling pin 74 can be made of a porous material 232 to spread additional coolant in a very uniform manner over the area of a preform other than the dome or sprue gate portion 22.

In a preferred embodiment of the invention, the cooling pin 74 is designed to maximize cooling at the sprue gate or dome portion 22 of the molded article 48, thereby achieving an effective concentration of cooling fluid to cool that region. In this way, a molded article (such as a preform) having no crystallized region in the gate portion or dome portion 22 can be formed.

Another pin structure with a cool air blowing system that can be used in the apparatus of the present invention is shown in fig. 19 (b). As shown in this figure, the pin 74 has a cool air blowing passage 90, the cool air blowing passage 90 having an outlet 92 for directing cool air toward the interior surface of the molded article 48, preferably the dome or sprue gate portion 22 of the molded article. The passageway 90 communicates with a source of cold air (not shown) through an inlet 94. The cooling pin 74 is also provided with a vacuum passage 96 for exhausting cooling air from the interior of the molded articles 48. The vacuum channel 86 may be connected to any desired vacuum source (not shown). As can be seen in fig. 19(b), the cooling pin 74 is mounted to a portion of a frame 98 using sliding pads 100 and a fastening device, such as nuts 102, the sliding pads 100 being used for automatic adjustment of the pin. The nut 102 may be secured to a member 104 (not shown) having an externally threaded portion.

Referring now to fig. 6 and 7, the cooling pin array 74 is mounted on a cooling frame 98, which cooling frame 98 may be made of a lightweight material such as aluminum. According to the invention, the cooling frame 98 can operate in a vertical position or in a horizontal position. In both cases, when the take-off plate 60 reaches its final molded position, the frame 98 is moved toward the take-off plate 60. The frame 98 may be moved to advance at high speed using any suitable means known in the art so that the cooling pins 74 may be immediately introduced into the molded articles. In a preferred embodiment of the present invention, the frame 98 is moved using a hydraulic cylinder 110. According to the present invention, the number of cooling pins 74 may be the same as or less than the number of receptacles 62 in the take-off plate 60. According to the present invention, the take-off plate 60 is provided with means (not shown) for securing the molded articles or preforms 48 in the containers 62, such as suction means, and also with means for ejecting the preforms from the take-off plate. The securing means and the expelling means may be of the kind disclosed in the above mentioned US patent 5,447,426, which is hereby incorporated by reference. As shown in fig. 6(c) and 6(d), the cooling frame 98 is provided with a plurality of gaps 112. The gap 112 allows the finally cooled molded articles or preforms ejected from the take-off plate 60 to fall onto a conveyor 114 for removing the resulting products from the system. In a preferred embodiment of the present invention, the fully cooled preforms 48 are dropped onto the conveyor 114 by moving the cooling pins 74 laterally relative to the containers 62 holding the preforms that must be ejected from the take-off plate 60. This is the case when the cooling frame is in a horizontal position. When the cooling frame is in a vertical position, it does not hold the preforms that have fallen from the take-off plate.

Referring now to fig. 7(a) and 7(b), a first row of cooling pins 74 is shown. As can be seen in FIG. 7(b), each cooling pin 74 has a cooling passage 90, the cooling passages 90 communicating with a source of cooling air (not shown) through passages 122. A plurality of air valves 124 are disposed in the passage 122, and the air valves 124 may be used to regulate the flow of cooling air. In this way, a variable flow rate of cooling air can be supplied to the cooling pin 74.

Referring now to fig. 7(c), each cooling pin 74 may also be provided with air directly from a source of cooling air (not shown) through a simple passage 126. In addition, as shown in fig. 7(d), the passage 126 is connected to the fluid conduit 120 in each cooling pin, if necessary, through a flexible conduit 128.

According to one embodiment of the invention, the cooling pins 74 provide access to the preforms held by the take-off plate 60 in a very small number of steps, and the preforms molded at different times during each step have different temperatures. In order to optimize the overall cooling step and to avoid waste of coolant, in the first cooling step the preforms are very hot, so that the maximum amount of cooling air is delivered by the cooling pins. In the second and subsequent steps, the amount of cooling air directed by the cooling pins engaging the first molded preform is substantially less than the amount of cooling air directed to the new and hotter molded preforms. To further optimize the cooling process, the pre-and post-cooling temperatures of the preforms may be sensed using any suitable known temperature sensor, such as a thermocouple, to allow adjustment of the cooling flow rate in the event of an interruption of the molding cycle. In a preferred embodiment, thermocouples (not shown) are connected to control devices (not shown) located in the take-off plate 60 adjacent to each preform. By monitoring the temperature of each preform, some adjustment can be made to the amount of cooling air delivered to all or some of the cooling pins 74. This also compensates for cooling inefficiencies or non-uniformities of the conductive cooling means located in the take-off plate.

Referring now to fig. 10(a) and 10(b), fig. 10(a) shows, in cross-section, a preform 48 molded using a prior art system. As can be seen in this figure, the preform 48 may have crystallized portions in four different regions including the dome portion 22 and the neck portion 13. FIG. 10(b), on the other hand, shows in cross-section a preform 48 molded using the system of the present invention. As can be seen from this figure, there are no crystallized areas in the preform.

Another embodiment of the present invention is shown in FIGS. 11(a) through 11(1), wherein the take-off plate 60' is maintained in a vertical position throughout the molding cycle. This eliminates a complicated motor and makes the plate lighter so that it can be moved more quickly into and out of the cavity gap formed between the mold halves or mold plates 32 and 36. The cooling frame 98' used in this system has an additional function and is capable of additional movement. First, the cooling pins 74 'cool the molded articles or preforms using blown air and eject the molded articles and preforms from the take-off plate 60' using drawn air. The preforms are held on the cooling pins 74 ' by vacuum and can be ejected from the tubes 62 ' in the take-off plate 60 ' during a return process. The cooling frame 98 'can be moved to and from the take-off plate 60' and rotated back from the plate 60 ', the cooling frame 98' also being rotated from a vertical position to a position parallel to a conveyor 114 'to eject the preforms from the cooling pins 74' with the evacuation disabled. Any suitable means known in the art may be used to rotate the cooling frame 98 'and cooling pin 74' in accordance with the present invention. According to a preferred embodiment of the invention shown in fig. 11(a) to 11(1), a fixed cam 130 acts as a very simple device capable of converting the translation of the frame into rotation so as to allow the preforms held by the cooling frame to fall onto a conveyor 114'. As shown in FIG. 11(h), the cooling pins 74 'can engage the preforms using a vacuum and eject the preforms from the take-off plate 60'. The preforms are then dropped from the pins 74' into a conveyor.

The operation of the novel cooling device according to the invention can be seen in fig. 6(a) to 6 (d). After the in-mold cooling, which shortens to the point where the molded articles or preforms reach a solid state that prevents their deformation, the mold is opened and the take-off plate 60 is moved into the molding region between core plate 36 and cavity plate 32. The relative movement between the core plate and the cavity plate may be carried out in any suitable manner known in the art using any suitable means (not shown) known in the art. After the take-off plate reaches the molding position, the cooling pins 74 engage the molded articles to cool the molded articles, particularly at the dome portion 22 of each molded article or preform.

Although the take-off plate 60 described above has water cooling means for conduction cooling of the outer surface of the preforms in the holders 62, there are many instances when the preforms are first placed in the take-off plate, it is not desirable to begin cooling the outer surface. To this end, means for controlling cooling can be provided in the take-off plate to initiate external cooling until after internal cooling of the preforms has begun and/or is complete. For example, suitable valves (not shown) may be provided in the take-off plate to prevent the flow of cooling fluid until a desired time is reached. Thus, the internal and external cooling of the preform can be performed simultaneously, at least partially simultaneously, or sequentially.

FIG. 16 shows another embodiment of a take-off plate 60 "without cooling means for ejecting the molded preforms from the molding area. The take-off plate 60 "can have a number of preform holders 62", the number of preform holders 62 "being sufficient to accommodate one set of preforms or multiple sets of preforms. The preforms are held by a vacuum device (not shown) that draws through an opening 240 over the sprue gate or dome portion 22 of the preforms 48. The preforms are also held by holders 62 ", the holders 62" can have any desired configuration, and the holders 62 "can utilize one type of cooling air to directly cool the preforms. The fixture 62 "is preferably rigid enough to hold the preform and has holes or other openings 242 and 244 in which the fixture cannot directly contact the preform. With fixtures having these only partially covering the outer surfaces of the preforms, the preforms can be cooled on their outer surfaces while they are also internally cooled with the cooling pins 74. In this case, the cooling step includes transferring the preforms from the mold to the take-off plate 60 ", which take-off plate 60" moves outside the molding area and to a cooling area adjacent to the molding area. At the cooling zone, the preforms 48 are internally cooled by the frame 98 and the cooling pins 74 that are at least partially inside the preforms. At the same time, the preforms 48 held by the take-off plate 60 "have outer surfaces convectively cooled by an additional cooling station 250, the cooling station 250 blowing a coolant fluid toward the preform holders. As shown in FIG. 16, the additional cooling station 250 is shown having a plurality of nozzles 252, 254 and 256 for blowing coolant against the outer surfaces of the preforms, the nozzles 252, 254 and 256 blowing cooling fluid through windows 258 into the take-off plate 60 "and through windows or openings 242 and 244 in the preform holders onto the outer surfaces of the preforms. The nozzles 252, 254 and 256 blow cooling fluid through the openings 242 and 244 into the preform holders 62 "and onto the outer surface of the preforms. Although the additional cooling station 250 described above has nozzles for cooling two preforms, it should be understood that the cooling station 250 may have as many nozzles as needed to cool the outer surfaces of any desired number of preforms in an implementation.

The additional cooling station 250 allows for simultaneous cooling of the preforms 48 from the inside and outside using a cooling device separate from the take-off plate 60 ". This solution makes the take-off plate 60 "very light, very fast and easy to maintain. If desired, the preform holders 62 "can simply grip the preforms at the neck, leaving more windows for blowing cooling fluid to cool the exterior of the preforms.

According to another embodiment of the present invention, the take-off plate may or may not include an external cooling device using blown air. In both cases, internal cooling is performed using the novel cooling method and apparatus of the present invention.

The novel cooling method and apparatus of the present invention are particularly advantageous for cooling preforms molded in high-cavity molds. It is well known that the temperature of molten resin flowing through a mold can vary greatly for a number of reasons, including: (a) non-uniform heating of the hot runner manifold; (b) forming a confinement sheet within the melt channel of the manifold; (c) cooling the uneven die cavity; (d) cooling at the nozzle portion is ineffective in modeling. One consequence of the temperature variation across the mold is that the cooling time must be adjusted at a local level to cool the hottest preforms before crystallization occurs in the final preform. In order to prevent the formation of crystallized regions, the cooling system according to the present invention can provide a different cooling method, which can be varied according to the temperature characteristics of each mold. A sensor may be provided in the take-off plate 60 to adjust the amount of cooling of each cooling pin 74. Another consequence of the non-uniform temperature distribution within the mold is that the sprue gate, which is located on the dome portion 22 of the preform in most cases, is the hottest part of the molded preform. Because the sprue gate portion cools more slowly in the mold closed position, it will likely be crystallized if the cooling time in the mold is too long or if no additional cooling is provided outside the mold. According to the invention, blowing cold air into the preform by means of the cooling pin 74 and in the vicinity of the nozzle area is a new operation which very effectively prevents the formation of crystallized areas in the preform.

The inventive cooling method and apparatus of the present invention is also beneficial in compensating for inefficiencies in cooling the removable sheet. The temperature of the molded articles held by the removable plate may vary across the plate due to incomplete contact between the heated molded articles and the cooling tube. According to the present invention, temperature sensors located within the take-off plate and cooling frame may be used to provide information to a cooling control unit that varies the amount of cooling flow supplied to each preform.

The adaptive cooling method described above has also been beneficial to date because it is contemplated that the mold temperature of the molded preform may vary throughout the day, utilizing the function of special resins, the function of mechanical devices, or due to local variations in preform thickness caused by improper valve stem actuation within the heated nozzle or due to a core pin within the mold cavity. These situations are neither predictable nor easily determinable; the present invention, however, provides a mechanism to adjust the post-mold cooling step for each cavity based on the temperature of each molded article or preform.

A significant reduction in cycle time to increase the benefit of mold cooling time can be achieved by a simple design and movement of the take-off plate and cooling frame. This also allows for very rigorous assembly, maintenance and operation to constrain the rigidity, accuracy of movement, positioning, etc. between the cooling pins and the molded articles and preforms on the take-off plate and oscillating table. The location of the cooling frame with the locating pins also depends on such a way to reduce the "footprint" of the entire machine.

In this regard, and also with reference to fig. 13(a) and 13(b), fig. 13(a) and 13(b) illustrate another embodiment of the present invention where the take-off plate 60 is maintained in a vertical position, i.e., parallel to the mold plates 32, 36, during the additional air cooling step. The cooling frame 98 is transferred to the take-off plate 60 and the cooling pins 74 enter the molded articles or preforms 48. After all of the preforms have cooled, the cooling frame 98 is retracted, the take-off plate 60 is rotated 90 ° parallel to the conveyor 114, and the cooled preforms are removed from the plate 60. This method simplifies the design of the cooling frame, which does not require rotating means and means to avoid interference of the cooling frame with the preforms ejected from the plate.

Referring also to FIG. 14, which shows another embodiment of the present invention, the robot take-off plate 60 includes additional translation means 150 to move the preforms along an axis parallel to the axis of rotation of the preforms. The additional movement of the preforms simplifies the cooling frame 98, which remains stationary during cooling. As shown in FIG. 14, the take-off plate 60 or other means for holding the preforms is moved along axis X toward a stationary cooling frame 98. After the cooling step, the take-off plate 60 is rotated through a 90 degree angle toward the transfer device 114 to eject the cooled preforms.

Reference is now made to FIG. 15 which shows the new air cooling arrangement in connection with the take-off plate 60. The solution shown in the figures does not require a separate frame for fixing the cooling pins, thus reducing the size of the cooling system and of the injection-moulding apparatus. The new cooling pins 174 are U-shaped and can simultaneously move all the preforms parallel to each other so that they can be introduced into the preforms and removed from the preforms by means of a thin strip driven by the piston BB or any other known means. The pins 174 are also rotatable about an axis "A" parallel to the preforms so that they can be brought into or removed from alignment with the preforms. This simultaneous rotation of all the pins 174 may be accomplished using any suitable means known in the art. According to the invention, the U-shaped cooling pin 174 has an arm "A" which can enter the preform, an arm "C" parallel to arm "A" for moving arm "A" and an arm "B" connecting arms "A" and "C". The rotation of the pin about the axis a of the arm "C" can be performed in different ways. This may be accomplished, as shown in FIG. 15, by an elongated rack 178 operated by a piston AA which is centered on a piston 180 attached to the arm "C" of each cooling pin. The same rotation, one translational and the other rotational, can be accomplished by friction means. During the movement of the preforms 48 from the mold cores 38 to the cooling tubes 62 of the take-off plate 60, the U-shaped cooling pins 174 can "dwell" at a specific location adjacent each cooling tube 62 so that they do not interfere with the moving preforms and require less space to open the mold. Immediately after the preforms 98 are held in the take-off plate 60, the cooling pins 174 attached to the plate 60 are advanced by the piston BB and the strip 176 and when they reach a height such that the arm "A" is on top of the preform, they are rotated in alignment with the preform and finally introduced into the preform by the return of the piston BB. The fixed contact between the band 176 and each arm "C" can be made by a coil spring 182 or any other suitable means that presses against the shoulder 181. Blown air is provided to each cooling pin by an arm "C" with a hose 184. Such cooling pins associated with the take-off plate have the following advantages: the cooling system is simplified and reduced in size, and the cooling efficiency is improved because the preforms are internally cooled immediately after the preforms are in the take-off plate, the internal cooling can be performed during the movement of the take-off plate, and the preforms can be cooled particularly continuously by the take-off plate for a long period of time. During the ejection of the cooled preforms, the cooling pins must be turned again to their initial position so that they are no longer aligned with the preforms.

Referring now to FIG. 12, there is shown an air cooling arrangement 210 comprising cooling channels 210, said cooling channels 210 cooling preforms held by the mold cores in said mold halves 32, 36 prior to entry of said take-off plate into the molding area during and after opening of the mold. This additional cooling step will further solidify the preforms before the take-off plate is brought into the molding area and before it is transferred to the take-off plate.

According to another embodiment of the invention, as can be readily understood from the other figures in this application, the automated take-off plate retains only one set of preforms. After the injection step, the take-off plate stays outside the molding area and cooling air or cold air is blown from the cooling pins into each preform. The cooled preforms ejected from the take-off plate will be brought back into the molding area without preforms.

Fig. 23 shows another configuration of a frame 98 for securing the cooling pin 74. As shown in this figure, the frame 98 may have cooling pins 74 on two opposing surfaces. In addition, the frame is rotatable about a first axis 300 and a second axis 302 perpendicular to the first axis 300. Any suitable means (not shown) known in the art may be used to rotate the frame 98 about the axes 300 and 302.

With this arrangement, the first set of cooling pins 74 can engage the preforms 48 in one take-off plate 60 and begin internal cooling of the preforms. The preforms 48 can then be moved from the holders 62 of the take-off plate 60 onto the cooling pins 74. The space 98 may then be rotated about one or more of the axes 300 and 302 while internal cooling of the preforms 48 is performed using the cooling pins 74. The second set of cooling pins 74 can engage the second set of preforms 48 held in the take-off plate 60 when the first set of preforms reaches the left-hand position shown in FIG. 23. If desired, the left-hand preforms 48 may be externally cooled by conduction through a cooling station 304, the cooling station 304 having a plurality of nozzles (not shown) to blow cool air onto the outer surface. If desired, the frame 98 may have a preform hold down plate 308 attached thereto.

Claims

1. A method of cooling a molded article (48) having a first region (22) at a relatively high heat and an adjacent region at a relatively low heat, said method comprising:

removing a molded article (48) from a mold comprising mold halves (16, 18, 32, 36), the molded article (48) being moved into a fixture (62) of an end-of-arm tooling (60) while the molded article retains a certain amount of heat, the end-of-arm tooling operating between a first position and a second position, the first position being a position between the mold halves (16, 18, 32, 36) where the fixture (62) is adapted to receive the molded article (48), the second position being outside of the mold halves (16, 18, 32, 36);

withdrawing the end-of-arm tooling from between the mold halves (16, 18, 32, 36) to a second position;

inserting cooling pins (74, 174) into the molded articles (48) at a time after the end-of-arm tooling (60) is withdrawn from between the mold halves (16, 18, 32, 36) to the second position while the molded articles are secured within the fixture;

the method is characterized in that:

forming an open system with respect to the cooling pins and the molded articles, the open system having channels that allow venting of gaseous cooling fluid from an interior of the molded articles (48) to an ambient environment, the open system being formed by: positioning a cooling pin relative to an open end of the molded article (48) to define a space between an outer surface area of the cooling pin and the open end of the molded article (48) adjacent the outer surface area, wherein the space defines the channel; and is

Forcing a flow of gaseous cooling fluid along an interior passage (90) of the cooling pin, the interior passage (90) terminating in a tip (92), the tip (92) being spaced from the first region (22) upon insertion into the molded article (48), the gaseous cooling fluid exiting the tip (92) primarily in the direction of the first region to begin enhanced cooling in at least the first region (22) to allow the gaseous cooling fluid to flow from the interior of the molded article and exit through the passage to the ambient environment, and the interior passage and tip together concentrating the cooling fluid on the first region when located within the molded article.

2. The method of cooling molded articles (48) of claim 1 wherein said gaseous cooling fluid is cooled compressed air supplied along an interior passage (90).

3. The method of cooling molded articles (48) of claim 1 or 2, further comprising applying cooling to exterior portions of the molded articles (48) while the molded articles are secured in the fixture, wherein said applying cooling to exterior portions of the molded articles (48) occurs either simultaneously, not completely simultaneously, or sequentially with forcing a cooling fluid along the interior passage.

4. The method of cooling molded articles (48) of claim 1 or 2, further comprising varying the amount of cooling fluid delivered by the cooling pin over time.

5. A method of cooling molded articles (48) as claimed in claim 1 or 2, wherein the tips are used to generate a diffuse flow of cooling fluid therefrom.

6. A method of cooling a molded article (48) as claimed in claim 1 or 2, wherein the tip of the cooling pin is introduced to the preform to a depth to allow the coolant to reach and cool the inner dome portion of the preform.

7. The method of cooling molded articles (48) of claim 1 or 2, further comprising:

spacing the tip (92) a first distance d from a first region of the molded article (48); and

spacing a sidewall (224) of the cooling pin (74, 174) a second distance D from an inner sidewall (228) of the molded article (48);

wherein the ratio D: D of the first distance to the second distance is in the range of about 1: 1 to about 10: 1.

8. An apparatus for cooling a molded article (48), the molded article (48) being manufactured in an injection mold formed from mold halves (16, 18, 32, 36), the molded article having a first region (22) at a relatively high heat and an adjacent region at a relatively low heat, the apparatus comprising:

an end-of-arm tooling (60) having at least one fixture (62), the end-of-arm tooling (60) operating, in use, between a first position to accommodate a molded article (48) between the mold halves (16, 18, 32, 36) of a corresponding one of the at least one fixture (62) and a second position outside of the mold halves (16, 18, 32, 36); in use, placing the molded article (48) into a corresponding one of the at least one fixture (62) while the molded article retains an amount of heat;

a cooling pin (74, 174) on the frame (98) adjacent the second location, the cooling pin having a tip (92), and the frame (98) being adapted in use to be moved relative to the end of arm tooling (60) to insert the cooling pin (74, 174) into the molded article after the end of arm tooling (60) reaches the second location; the method is characterized in that:

the cooling pin (74, 174) having an internal passage (90) terminating in a tip (92), the tip (92) being located within the moulded article but spaced from the first region (22) when inserted into the moulded article (48) by relative movement of the frame (98) and the end-of-arm tool (60), wherein the cooling pin (74, 174) is connectable, in use, to a cooling fluid delivery system for forcing a gaseous cooling fluid to flow along the internal passage (90) to expel the gaseous cooling fluid from the tip (92) primarily in the direction of the first region to enhance cooling within at least the first region;

during expulsion of the gaseous cooling fluid from the tip (92), positioning the frame (98) relative to the end-of-arm tooling to define, in use, an open system having a passage that allows venting of the gaseous cooling fluid from an interior of the molded articles (48) into an ambient environment; and is

The apparatus is operable to space the frame from the end-of-arm tooling (60) during expulsion of gaseous cooling fluid from the tip (92), the passage of the open system being created by forming a space between a region of the outer surface of the cooling pin (74, 174) and the open end of the molded article which, in use, is located in its respective fixture.

9. The apparatus of claim 8, wherein the apparatus is configured to introduce the tip of the cooling pin into the preform to a depth to allow the coolant to reach and cool the inner dome portion of the preform.

10. The apparatus of claim 8 or 9, wherein the frame positions cooling pins within the molded articles (48) to:

i) the tip (92) is spaced a first distance d from a first region of the molded article (48);

ii) the sidewall (224) of the cooling pin (74, 174) is a second distance D from an interior sidewall (228) of the molded article (48);

and a ratio D: D of the first distance to the second distance is in a range of about 1: 1 to about 10: 1.

11. The apparatus of claim 8 or 9, wherein the gaseous cooling fluid is cooled compressed air supplied along the internal passage (90).

12. The apparatus of claim 8 or 9, further comprising a valve for supplying a metered amount of gaseous cooling fluid to the cooling pin (74, 174).

13. The apparatus of claim 8 or 9, wherein the tip has one of a diverging nozzle configuration and a straight-walled nozzle configuration, the internal passage and the tip focusing the gaseous cooling fluid toward an area that primarily surrounds the first region (22) when located within the molded article.

14. The apparatus of claim 8 or 9, wherein the cooling pin has one of:

i) a diameter that varies along its length;

ii) a transverse fluid outlet (82) or radial conduit (320) at the side of the cooling pin, the transverse fluid outlet (82) or radial conduit (320) being joined to the internal passage (90) and serving to direct cooling fluid to one of the neck portion (13) and the body portion of the molded article;

iii) a groove along the outer surface of the cooling pin (74, 174);

iv) ribs spaced around the periphery of the cooling pin (74, 174) projecting from the cooling pin to reduce, in use, dimensional separation of the outer surface of the cooling pin to the inner wall of the molded article (226, 228) over the length of each rib; and

v) a plurality of contact elements (88) along an outer surface of the cooling pin (74, 174).

15. The apparatus of claim 8 or 9, wherein;

the end of the arm tool (60) supports a plurality of fixtures; and

the frame includes fewer cooling pins (74, 174) than the fixtures on the end-of-arm tooling;

thus, in use, only selected ones of the molded articles in the respective fixtures are cooled by inserting the tips of the cooling pins into each selected molded article in alignment therewith.