WO2016065462A1

WO2016065462A1 - A thermal gate for a melt distribution apparatus

Info

Publication number: WO2016065462A1
Application number: PCT/CA2015/051048
Authority: WO
Inventors: William Steven Keir; Daniel Joseph OSMOKROVIC; Hakimuddin Boxwala; Maxfield Paul Bradshaw; Derek Robertson Mccready; Stephen Daniel Ferenc
Original assignee: Husky Injection Molding Systems Ltd.
Priority date: 2014-10-30
Filing date: 2015-10-19
Publication date: 2016-05-06

Abstract

There is disclosed a nozzle (204) for a molding material distributor (108) for use with a molding system. The nozzle (204) comprises a body (205) defining a hot nozzle portion (214); an annular melt flow channel (216) defined within the hot nozzle portion, the annular melt flow channel (215) for conveying a stream of molten molding material; a spigot (220) located at least partially within the stream of molten molding material, the spigot (220) including an active temperature controller (228), the active temperature controller (228) configured to cool the spigot (220).

Description

A THERMAL GATE FOR A MELT DISTRIBUTION APPARATUS

TECHNICAL FIELD

The present technology relates to injection molding systems in general and specifically to a gate for a melt distribution apparatus.

BACKGROUND

Molding is a process by virtue of which a molded article can be formed from molding material by using a molding system. Various molded articles can be formed by using the molding process, such as an injection molding process. One example of a molded article that can be formed, for example, from Polyethylene Terephthalate (PET) material is a preform that is capable of being subsequently blown into a beverage container, such as, a bottle and the like.

As an illustration, injection molding of PET material involves heating the molding material (ex. PET pellets, etc.) to a homogeneous molten state and injecting, under pressure, the so-melted PET material into a molding cavity defined, at least in part, by a female cavity piece and a male core piece mounted respectively on a cavity plate and a core plate of the mold. The cavity plate and the core plate are urged together and are held together by clamp force, the clamp force being sufficient enough to keep the cavity and the core pieces together against the pressure of the injected PET material. The molding cavity has a shape that substantially corresponds to a final cold-state shape of the molded article to be molded. The so-injected PET material is then cooled to a temperature sufficient to enable ejection of the so-formed molded article from the mold. When cooled, the molded article shrinks inside of the molding cavity and, as such, when the cavity and core plates are urged apart, the molded article tends to remain associated with the core piece. Accordingly, by urging the core plate away from the cavity plate, the molded article can be demolded, i.e. ejected off of the core piece. Ejection structures are known to assist in removing the molded articles from the core halves. Examples of the ejection structures include stripper plates, ejector pins, etc.

It is known in the art to use a hot runner for the purposes of distributing molten molding material from the plasticizer into the one or more molding cavities of the mold. Generally speaking, two types of hot runners are known - a mechanically gated hot runner and a thermally gated hot runner. Within the mechanically gated implementation of the hot runner, a valve stem is used as means to selectively open and close the gate (and, thus, to selectively allow and stop the flow of molding material through the gate). Hence, the valve stem mechanically opens and closes the gate.

One of the challenges faced by the injection molding industry is optimizing the injection process parameters to achieve a good balance between part quality and the cycle time for a given part. For hot runners that are used for molding PET preforms, the most common approach is to use a mechanically gated hot runner, i.e. the one that uses a valve stem. As a moving item, valve stems are generally considered to be a wear and tear item. Furthermore, it is generally known that the valve stem can potentially cause wear or even damage to the gate insert (as well as the valve stem itself) as the valve stem continuously enters the gate region of the gate insert. Replacing valve stems is known to be lengthy and can be a significant expense item. In some scenarios, replacing a worn out or broken valve stem or pin cannot be performed at the customer site, again adding to the downtime and increasing costs.

Thermally gated nozzles, also commonly referred to as "hot tip nozzles", are typically used on applications other than PET preforms (i.e. on applications with different resins and smaller gate diameters to allow quick "freeze off of the gate) so as not to require a mechanical shut-off Thermally gated nozzles have not been widely used on PET preforms due to excessive cooling times required on larger gate diameters associated with PET preform molding. Due at least partially to the insulative properties of the PET resin, the center of the gate nub area takes a long time to cool, in a sense negating the potential benefit of using the thermally gated nozzles for PET preform molding over the use of mechanically gated nozzles.

SUMMARY

According to a broad aspect of the resent technology, there is provided a nozzle for a molding material distributor for use with a molding system, the nozzle comprising: a body defining a hot nozzle portion; an annular melt flow channel defined within the hot nozzle portion, the annular melt flow channel for conveying a stream of molten molding material; a spigot located at least partially within the stream of molten molding material, the spigot including an active temperature controller, the active temperature controller configured to cool the spigot.

According to another broad aspect of the present technology, there is provided a method of molding a molded article, the method executable in a molding machine having a molding material distributor with a nozzle, the nozzle having an annular melt flow channel defined within a hot nozzle portion, the annular melt flow channel for conveying a stream of molten molding material and a spigot located at least partially within the stream of molten molding material, the spigot including an active temperature controller, the active temperature controller configured to cool the spigot, the spigot defining a portion of an annular gate flow portion; the method comprising: allowing a flow of molten molding material from the annular melt flow channel through the annular gate portion during a first portion of a molding cycle; actuating the active temperature controller to cool the spigot during a second portion of the molding cycle, the actuating resulting in formation of a frozen plug within the annular gate portion.

These and other aspects and features of non-limiting embodiments will now become apparent to those skilled in the art upon review of the following description of specific non-limiting embodiments in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

The non-limiting embodiments will be more fully appreciated by reference to the accompanying drawings, in which:

FIG. 1 depicts a schematic representation of a molding system implemented in accordance with non-limiting embodiments of the present technology.

FIG. 2 depicts a cross-sectional view of a portion of a mold 200 of the molding system of FIG. 1.

FIG. 3 depicts a block diagram of steps of a non-limiting embodiment of a method 300 of molding a molded article, the method executable at the molding machine 100 of FIG. 1. FIG. 4 depicts a cross section taken along an operational axis of a portion of the mold 200, the mold 200 being implemented in accordance with non-limiting embodiments of the present technology.

FIG. 5 depicts a cross section along an operational axis of another portion of the mold 200, the mold 200 being implemented in accordance with other non-limiting embodiments of the present technology.

FIG. 6 depicts a cross section along an operational axis of another portion of the mold 200, the mold 200 being implemented in accordance with yet another non-limiting embodiment of the present technology.

The drawings are not necessarily to scale and may be illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted.

DETAILED DESCRIPTION OF THE NON-LIMITING EMBODIMENTS)

Reference will now be made in detail to various non-limiting embodiment s) of a molding material distributor for use in an injection molding machine of an injection molding system. It should be understood that other non-limiting embodiment s), modifications and equivalents will be evident to one of ordinary skill in the art in view of the non-limiting embodiment(s) disclosed herein and that these variants should be considered to be within the scope of the appended claims.

Furthermore, it will be recognized by one of ordinary skill in the art that certain structural and operational details of the non-limiting embodiment(s) discussed hereafter may be modified or omitted (i.e. non-essential) altogether. In other instances, well known methods, procedures, and components have not been described in detail.

In a non-limiting embodiment, FIG. 1 shows a molding system 100. The molding system 100 includes (but is not limited to): (i) a clamp assembly 102, (ii) an injection unit 104, (iii) a mold assembly 106, and (iv) a molding material distributor 108. It is noted that the molding material distributor 108 is sometimes referred to hose by skill in he art as a "hot runner". In the illustrated embodiments, the molding system 100 is for manufacturing thin wall containers. However, in alternative non-limiting embodiments, the molding system 100 can be configured to manufacture other molded articles - preforms for subsequent blow molding into final shaped containers, medical appliances, closures and the like.

The clamp assembly 102 includes (but is not limited to): (i) a first platen 110, (ii) a second platen 1 12, (iii) a third platen 114, (iv) tie bars 116, and (v) a clamp 118.

The second platen 112 is configured to be movable between the first platen 110 and the third platen 114. Hence, the first platen 110 is a stationary platen that is stationary relative to the third platen 114. The third platen 114 is an end platen that is stationary relative to the first platen 110. The second platen 112 is, therefore, relatively movable vis-a-vis the first platen 110 and the third platen 114. Even though a three-platen assembly has been depicted here, in alternative non- limiting embodiments, the clamp assembly 102 can be implemented as a two-platen assembly, where a first platen is typically a fixed platen and a second platen is typically a movable platen.

The tie bars 116 extend between the first platen 110 and the third platen 114. The second platen 1 12 and the tie bars 116 are slidably connected, such that the second platen 112 is slidable relative to the tie bars 116. The third platen 114 is associated with the clamp 118. Actuation of the clamp 118 applies a clamping force to push the second platen 112 toward the first platen 110 and pull the tie bars 116 toward the third platen 114, such that the clamping force is applied across the first platen 110 and the second platen 112.

The injection unit 104 is configured to plasticize and then inject, under pressure, a molding material. In some embodiments, a separate device, known as a shooting pot, can be used for injecting the molding material. In that case, the injection unit 104 can be responsible for exclusively plasticizing the molding material.

The molding material distributor 108 is configured to receive the molding material from the injection unit 104 (or the shooting pot, where used) and to distribute the molding material to a mold cavity 120 defined by the mold assembly 106. The molding material distributor 108 is associated with the first platen 110. The mold assembly 106 includes a stationary mold portion 122 and a movable mold portion 124. The stationary mold portion 122 is associated with the first platen 110. The movable mold portion 124 is associated with the second platen 112.

Movement of the second platen 112 closes the mold assembly 106. The stationary mold portion 122 and the movable mold portion 124 cooperate to define the mold cavity 120. In a typical implementation, several ones of the mold cavity 120 are provided. Typical cavitation of the mold assembly 120 can be implemented as 72, 96, 126 and the like.

In operation, the second platen 112 is moved toward the first platen 110, moving the mold assembly 120 to a closed position. The clamp 118 and the tie bars 116 then apply the clamping force across the first platen 1 10 and the second platen 112. The clamping force squeezes the mold assembly 106 together as the injection unit 104 injects the mold cavity 120 with the molding material via the molding material distributor 108.

In those embodiments where the clamp assembly 102 is implemented as a two-platen clamp assembly, it is typical to use a clamp column (not depicted) in lieu of tie bars 116. In yet alternative non-limiting embodiments of the present technology, the clamp assembly 102 can be implemented as a toggle clamp.

Referring now to FIG. 2, there is depicted a cross-sectional view of a portion of a mold 200. The portion of the mold 200 includes a gate insert 202 and a nozzle 204. Naturally, the mold 200 has a number of additional components, all of which are well known in the art and have been omitted from FIG. 2 for the sake of simplifying the illustration. The mold 200 can be part of the mold assembly 106 of FIG. 1, but for the specific modifications pursuant to embodiments of the present technology, as described herein below.

The gate insert 202 includes a nozzle interface portion 206 and a molding surface 208. The nozzle interface portion 206 is for accepting, in use, the nozzle 204. The molding surface 208 is for defining, in use, a portion of a molded article or, more specifically in this case an outer surface of a preform 210. The gate insert 202 further defines a gate 212. The gate 212 provides a flow path for the molding material from the nozzle 204 into a molding cavity (not separately numbered) that defines the preform 210.

The nozzle 204 comprises a body 205. The body 205 includes a hot nozzle portion 214. The hot nozzle portion 214 incudes a heater 215, the heater 215 for maintaining a desired operational temperature of the hot nozzle portion 214. The hot nozzle portion 214 defines an annular melt flow channel 216, the annular melt flow channel 216 for delivering the stream of molten molding material towards the gate 212. The desired temperature maintained by the heater 215 depends on the type of the material being used and in the specific example of PET, the operational temperature can be approximately 280 degrees Celsius. Needless to say, within various implementations the operating temperature can be varied and those skilled in the art will easily appreciate proper operating temperature settings for a given material, be it PET or other types of molding material.

According to embodiments of the present technology, the nozzle 204 further includes a spigot 220. It is noted that the spigot 220 is not movable (i.e. it does not reciprocate up or down, the direction being as seen in Figure 2). Put another way, the spigot 220 is stationary relative to the nozzle 204 and/or the gate insert 202. Some embodiments of the present technology lead to a technical affect, whereby due to the spigot 220 being stationary (as opposed for example, to the valve stem mentioned above, which reciprocates), the spigot 220 can be associated with less wear and tear and/or be associated with a simpler construction (for example, not requiring actuators similar to those required for moving the valve stem).

As is seen within the illustration of FIG. 2, the spigot 220 is located coaxially centrally within the hot nozzle portion 214. Put another way, the spigot 220 is located coaxially centrally within the annular melt flow channel 216. Put yet another way, a portion of the spigot 220 is located coaxially centrally within the gate 212. Also, as is seen within the region of the gate 212, the spigot 220 is located coaxially centrally within the molding material flow. Hence, it can be said that the spigot 220 is located within the molding material flow. Also, as can be seen in FIG. 2, the lowermost portion of the spigot 220 defines a portion of a molding surface of the preform 210. Specifically, the spigot 220 defines a portion of a gate nub of the preform 210. It can be said that the spigot 220 is thermally insulated from the remainder of the nozzle 204. In some embodiments of the present technology, the spigot 220 comprises an insulator 222. In some embodiments of the present technology, the insulator 222 is implemented as an annular ceramic ring. In alternative embodiments, the insulator 222 can be implemented as an annular VESPEL ring (VESPEL being a trade-mark of Dupont of Wilmington, Delaware, United States of America. Alternatively, those skilled in the art will be able to select a number of additional isolative materials for the insulator 222. Additionally or alternatively, there is provided an insulative gap 224. The insulative gap 224 can be implemented as an air gap or as a vacuum gap.

In accordance with various embodiments of the present technology, the spigot 220 is provided with active temperature controller 228. Generally speaking, the active temperature controller 228 is configured to actively control the temperature of the spigot 220. In some embodiments, the active temperature controller 228 can control the temperature of the spigot 220 in both directions. In other words, within those embodiments the active temperature controller 228 can selectively increase or decrease the temperature associated with the spigot 220. Put another way, the active temperature controller 228 can be configured to selectively heat or cool the spigot 220.

In alternative embodiments of the present technology, the active temperature controller 228 is configured to control the temperature of the spigot 220 to cool the spigot 220. In yet alternative embodiments, a portion of the active temperature controller 228 is configured to cool a portion of the spigot 220 and another portion of the active temperature controller 228 is configured to heat a portion of the spigot 220.

In a specific implementation depicted in Figure 2, the active temperature controller 228 is implemented as an internal cooling channel 230 defined within the spigot 220. In use, in some embodiments of the present technology, a cooling fluid can be circulated through the internal cooling channel 230. In some embodiments, a temperature of the cooling fluid circulated through the internal cooling channel 230 can be instrumental in causing active temperature control. In these embodiments, a thermulator or other means (both not depicted) can be used to control the temperature of the cooling fluid. In other embodiments, a flow rate of the cooling fluid circulated through the internal cooling channel 230 can be instrumental in active temperature control. Within these embodiments, a flow control device such as a valve (shown in Figure 4) can be provided to regulate the rate of flow of the cooling fluid. The lower the temperature of the cooling fluid being circulated through the internal cooling channel 230 and the faster the cooling fluid is circulated through the internal cooling channel 230, the lower the temperature cooling affected by the spigot 220.

With reference to FIG. 4, there is depicted a cross section along an operational axis of a portion of the mold 200, the mold 200 being implemented in accordance with non-limiting embodiments of the present technology. Briefly, FIG. 4 depicts the aforementioned gate insert 202. There is also depicted a manifold plate 402, a backing plate 404 and a back up pad 406 located between the manifold plate 402 and the backing plate 404. It is noted that the general construction of the manifold plate 402, the backing plate 404 and the back up plate 406 are generally known in the art and, as such, will not be described here at much length. It is also noted that the depiction of the manifold plate 402, the backing plate 404 and the back up plate 406 is for illustration purposes only and should not be used as a limitation of all embodiments of the present technology.

Within the illustration of FIG. 4, the active temperature controller is implemented as the internal cooling channel 230, which has been briefly described above. Depicted in FIG. 4 are further details for implementing the internal cooling channel 230. According to embodiments of the present technology, there is provided a cooling tube 410 disposed within the internal cooling channel 230. The cooling tube 410 is fluidly coupled to a cooling fluid intake 412 and, indirectly, to a cooling fluid outlet 414. In a sense, it can be said that the combination of the cooling tube 410 and the internal cooling channel 230 is implemented as a bubbler tube (i.e. a hollow tube within a tube). The internal cooling channel 230 is fluidly coupled to the cooling fluid outlet 414.

The cooling fluid intake 412 is fluidly coupled to a cooling fluid source 415. Within the illustrated embodiment, the source of cooling fluid 415 comprises a cooled water supply 416 and a heated water supply 418. In alternative embodiments, the source of cooling fluid 415 can be implemented as a temperature-controlled single source of cooling/heated fluid. In some embodiments of the present technology, ability to provide cooling fluid of different temperatures (whether from the cooled water supply 416 and the heated water supply 418 or from a single source of cooling/heated fluid) can provide ability to selectively circulate a cooling fluid of different temperature through the cooling tube 410. Also provided is a flow control device 419 for regulating the flow rate of the cooling fluid (i.e., the flow control device 419 can provide variable flow control). The flow control device 419 may also include a sequence valve 417 for selectively combining fluids from different supplies (e.g., the cooled water supply 416 and the heated water supply 418) to provide the cooling fluid. The flow control device 419 may consist of a single component or multiple components.

Within these implementations of the technology, the active temperature controller 228 operates as follows. A cooling fluid flows from the cooling fluid intake 412 inside the cooling tube 410 in a direction of an arrow 420. The cooling fluid then flows on the outside of the cooling tube 410 and inside the internal cooling channel 230 towards the cooling fluid outlet 414 in the direction of an arrow 422. It should be noted that in alternative embodiments of the present technology, the direction of flow can be reversed between the direction of the arrow 420 and the arrow 422.

Within these embodiments, the cooling rate of the active temperature controller 228 can be controlled by means of controlling, by the flow control device 419, the flow rate of the cooling fluid. Additionally (or alternatively), the cooling rate of the active temperature controller 228 can be controlled by means of controlling the temperature of cooling fluid.

It is noted that the arrangement of the cooling fluid path depicted with reference to FIG. 4 can be varied. An alternative is depicted with reference to FIG. 5, which depicts a cross section along an operational axis of another portion of the mold 200, the mold 200 being implemented in accordance with other non-limiting embodiments of the present technology.

The implementation of the mold 200 depicted in FIG. 5 is substantially similar to that depicted in FIG. 4, other than for the specific differences discussed herein below. Within the depiction of FIG. 5, there is provided a cooling fluid intake 512 and a cooling fluid outlet 514 with a path of cooling fluid (not separately numbered) defined there between. It is noted that within the depiction of FIG. 5, the path of cooling fluid between the cooling fluid intake 512 and the cooling fluid outlet 514 only spans a portion of the spigot 220. More specifically, the path of cooling fluid between the cooling fluid intake 512 and the cooling fluid outlet 514 only spans an upper (as viewed in the orientation of FIG. 5) portion of the spigot 220, while a lower portion of the spigot 220 is cooled by conduction with the cooled upper part of the spigot 220. There is also provided a thermal insulating ring 502 to provide thermal insulation between the spigot 220 (being cooled) and the heated portion of the nozzle portion 214.

It should be noted that even though both FIG. 4 and FIG. 5 illustrate that the spigot 220 is cooled by means of cooling fluid being circulated within the internal cooling channel 230 (which internal cooling channel 230 can span at least a portion as in FIG. 5 or all of the spigot 220 as in FIG. 4), in alternative embodiments of the present technology, the spigot 220 can be cooled by means of a cooling fluid being circulated around an outer portion of the spigot 220. For example, the cooling fluid can alternatively be circulated around an outer upper (as viewed in the orientation of FIG. 5) portion of the spigot 220.

In alternative embodiments, rather than circulating cooling fluid within the internal cooling channel (230) or outside of a portion of the spigot 220, a reciprocating cooling rod can be provided within the internal cooling channel 230.

With reference to FIG. 6, there is depicted a cross section along an operational axis of another portion of the mold 200, the mold 200 being implemented in accordance with yet another non- limiting embodiment of the present technology. The implementation of the mold 200 depicted in FIG. 6 is substantially similar to that depicted in FIG. 4, other than for the specific differences discussed herein below.

Within these embodiments of the present technology, there is provided a reciprocating cooling rod 602, which reciprocates up and down (as viewed in the orientation of FIG. 6), within the internal cooling channel 230. It is noted that even though not depicted in FIG. 6, there is provided an actuator to actuate the reciprocating cooling rod 602. In some embodiments of the present technology, the actuator to actuate the reciprocating cooling rod 602 can be implemented in the same manner as an actuator used for actuating valve pins in mechanically actuated gates of hot runners.

Within a specific embodiment of the present technology, the path of travel of the reciprocating cooling rod 602 in the vertical direction as viewed in the orientation of FIG. 6 is approximately 0.5 mm. However, in alternative embodiments of the present technology, the length of the path of travel for the reciprocating cooling rod 602 can be different.

There is provided a reciprocating cooling rod cooling channel 604 defined within the reciprocating cooling rod 602, the reciprocating cooling rod cooling channel 604 being fluidly coupled to a cooling water intake 606 and a cooling water outlet 608. The reciprocating cooling rod cooling channel 604 can be implemented using concepts similar to the description above related to the internal cooling channel 230 and the cooling tube 410. It is noted that the diameter of the cooling water intake 606 is larger than the diameter of the reciprocating cooling rod cooling channel 604. An additional technical advantage of this configuration of diameters is that the reciprocating cooling rod cooling channel 604 and the cooling water intake 604 stay fluidly connected during the movement of the reciprocating cooling rod 602.

Generally speaking, when the reciprocating cooling rod 602 is actuated downwardly (as viewed in the orientation of FIG. 6) so that it touches the spigot 220, cooling of the spigot 220 is affected. When the reciprocating cooling rod 602 is actuated upwardly (as viewed in the orientation of FIG. 6) so as to break contact with the spigot 220, cooling of the spigot 220 is terminated.

In some embodiments of the present technology, the spigot 220 can be made of a conductive material. In some embodiments of the present technology, the reciprocating cooling rod 602 can also be made of conductive material. It should be understood, however, that the spigot 220 and the reciprocating cooling rod 602 do not need to (but can, if desired or otherwise needed) be made of the same material. For example, in some embodiments of the present technology, the spigot 220 can be made of a more wear resistant material than the reciprocating cooling rod 602. An example of the conductive material used can be copper. Other conductive materials can also be used. These conductive materials can include, but are not limited to, TPhc, copper alloys, BECU3 HT, aluminum alloy 1100, aluminum alloy 6061, beryllium-copper alloys and the like. In alternative embodiments of the present technology, instead of the reciprocating cooling rod 602, a "heat pipe" can be used (also sometimes referred to as a "thermal pin" or a "heat pin"). As is known, the heat pipe relies both on conduction and phase transition to transfer heat. In some embodiments, the internal cooling channel 230 is considered to be a first portion of the above-mentioned active temperature controller 228. Even though not depicted in Figure 2, the spigot 220 can also be associated with a heater located, for example, at a tip 240 of the spigot 220. Within those embodiments, the heater located at the tip 240 could be considered to be a second portion of the active temperature controller 228. Within these embodiments, the heater located at the tip 240 can be implemented as a micro-heater and can be configured to provide pulse heating during appropriate portions of the molding cycle (as will be described in greater detail herein below).

Therefore, it can be said that the spigot 220 and the gate 212 define an annular gate flow portion 242. The annular gate flow portion 242 is generally donut shaped. During the appropriate portions of the molding cycle (such as the injections and/or packing), the molding material flows through the annular gate flow portion 242. Within these portions of the molding cycle, the cooling function of the active temperature controller 228 can be turned off or decreased. During other appropriate portions of the molding cycle (such as cooling, for example) the active temperature controller 228 is actuated to cool the spigot 220. Cooling of the spigot 220, in turn, results in cooling of the molten material within the annular gate flow portion 242. That results in a formation of a frozen plug 244 within the annular gate flow portion 242.

The frozen plug 244 is also associated with a donut shape. In some embodiments, the frozen plug 244 has an annular shape with an outside diameter of approximately 6 mm and an inside diameter of approximately 4 mm. Naturally, the frozen plug 224 can have other dimensions, depending on the specific implementation and, as such, these dimensions are provided as an example only.

In some embodiments of the present technology and recalling that the active temperature controller 228 can be configured to selectively heat or cool the spigot 220 (and more precisely, that a portion of the active temperature controller 228 can be implemented as a heater located, for example, at the tip 240 of the spigot 220), during appropriate portions of the molding cycle (such as at the end of the cooling or beginning of the injection), the heater located, for example, at the tip 240 of the spigot 220 can be turned on. Activation of the heater located, for example, at the tip 240 of the spigot 220 can help to melt the frozen plug 224. Recalling that the active temperature controller 228 is located within the molten molding material stream, it can be said that the active temperature controller 228 is configured to cool the molten molding material from within the molten material stream. As is known in the art, the gate insert 202 also implements cooling, for example, by means of circulating cooling fluid within cooling channels defined in the gate insert 202 (not depicted in FIG. 2). Therefore, it can be said that the molten molding material, within these implementations if cooled both from outside and from within the molten molding material flow.

Recalling that the frozen plug 244 has a donut shape defined between the spigot 220 and the gate 212, the area that has to be frozen is substantially reduced compared to the traditional hot tip implementations. Furthermore, since the cooling can be affected from both outside and from within the molten molding material flow, the overall cooling time can be reduced compared to the traditional hot tip implementations. At the same time, the amount of flow area in-between the spigot 220 and the gate 212 is substantially unchanged from the traditional hot tip implementations. For example, in some implementations, the amount of flow in-between the spigot 220 and the gate 212 is substantially unchanged from the 3.4 mm hot tip gate implementation. Within these embodiments, a special technical effect may include unchanged pressure drop compared to traditional valve gated implementation.

By provision of the spigot 220 with the active temperature controller 228, embodiments of the present technology allow for potential elimination of the mechanical shut off requirement for PET preform molding, while maintaining acceptable cycle time. Additionally or alternatively, embodiments of the present technology allow for expansion of use of thermally gated nozzles for molding material distributors 108 for use for PET preforms molding. Additionally or alternatively, embodiments of the present technology may allow for improved processing window, at least partially due to reduced variance in valve stem actuation timing and/or the removal of the molding material splitting around the valve stem. Additionally or alternatively, embodiments of the present technology may result in cost savings resultant at least partially from the removal of moving parts within the nozzle 200 and/or the molding material distributor 108. Additionally or alternatively, embodiments of the present technology may result in cost savings from potentially making thinner plates that accommodate the molding material distributor 108, the thinner plates at least partially due to removal of the valve stem and/or removal of actuation of the valve stem. Additionally or alternatively, embodiments of the present technology may result in reduced wear and tear of portions of the molding material distributor 108. Additionally or alternatively, embodiments of the present technology may result in an increase in service intervals for the molding material distributor 108.

Additionally or alternatively, embodiments of the present technology may result in better cooling in the center of the gate nub of the preform, an area generally indicated at 280 in Figure 2. This can be particularly beneficial, but not limited to, for those implementations where the preform 210 is a gate limited preform. Generally speaking, thinner walled preforms are considered to be gate limited.

Given the architecture of the nozzle 204 of FIG. 2, it is possible to implement a method of molding a molded article. The method can be executable in the molding machine of Figure 1, the molding machine 100 having a molding material distributor 108 with a nozzle 204, the nozzle 204 having an annular melt flow channel 216 defined within a hot nozzle portion, the annular melt flow channel 215 for conveying a stream of molten molding material and a spigot 220 located at least partially within the stream of molten molding material, the spigot 220 including an active temperature controller 228, the active temperature controller 228 configured to cool the spigot 220, the spigot 220 defining a portion of an annular gate flow portion 242.

With reference to FIG. 3, there is depicted a non-limiting embodiment of a method 300 of molding a molded article, the method executable at the molding machine 100 of FIG. 1, the molding machine 100 having the molding material distributor 108 with the nozzle 204, the nozzle 204 having the annular melt flow channel 216 defined within a hot nozzle portion, the annular melt flow channel 215 for conveying a stream of molten molding material and the spigot 220 located at least partially within the stream of molten molding material, the spigot 220 including the active temperature controller 228, the active temperature controller 228 configured to cool the spigot 220, the spigot 220 defining a portion of an annular gate flow portion 242.

Step 302 - Allowing a flow of molten molding material from the annular melt flow channel 215 through the annular gate portion 242 during a first portion of a molding cycle. The method 300 starts at step 304, where the molding machine is configured for allowing a flow of molten molding material from the annular melt flow channel 215 through the annular gate portion 242 during a first portion of a molding cycle. The first portion of the molding cycle can be an injection portion and/or portions of the holding portion of the molding cycle.

Step 304 - Actuating the active temperature controller 228 to cool the spigot 220 during a second portion of the molding cycle, said actuating resulting in formation of a frozen plug 242 within the annular gate portion 242.

Next, at step 304, the molding machine is configured for actuating the active temperature controller 228 to cool the spigot 220 during a second portion of the molding cycle, said actuating resulting in formation of a frozen plug 242 within the annular gate portion 242. The second portion of the molding cycle can be the cooling portion of the molding cycle.

In some variants of the present technology, where the active temperature controller 228 is further configured to heat the spigot 220, the method 300 further includes actuating the active temperature controller 228 to execute a pulse heating during a third portion of the molding cycle.

In some variants of the present technology, where the active temperature controller 228 comprises an internal cooling channel 230 defined within the spigot 220 for accepting cooling fluid, the step 304 comprises at least one of (i) changing temperature of the cooling fluid and (ii) changing a flow rate of the cooling fluid.

In some variants of the present technology, where the active temperature controller 228 comprises an internal cooling channel 230 defined within the spigot 220 for accepting a reciprocating cooling rod, the step 304 comprises causing insertion of the reciprocating cooling rod into the internal cooling channel 230.

In some variants of the present technology, where the spigot 220 is located coaxially centrally within the stream of molten molding material, the step 302 comprises allowing the molten molding material to flow around the spigot 220. It should be noted that even though above examples have used preform 210 as an example of the implementation, embodiments of the present technology should not be so limited. As such, the nozzle 204 having the spigot 220 with the active temperature controller 228 can be used for other applications. Such applications include but are not limited to closures, medical applications and the like.

Even though the above description has been presented using the molding system 100, it should be understood that embodiments of the present technology can be implemented in other types of molding systems, such as compression molding systems, transfer molding systems, injection- compression molding systems and the like. By the same token and generally speaking, it can be said that embodiments of the present technology can be implemented within any systems that uses molten material (resin, plastic or otherwise) to produce final or semi-final (i.e. intermediary) articles.

It is noted that the foregoing has outlined some of the more pertinent non-limiting embodiments. It will be clear to those skilled in the art that modifications to the disclosed non-embodiment(s) can be effected without departing from the spirit and scope thereof. As such, the described non- limiting embodiment(s) ought to be considered to be merely illustrative of some of the more prominent features and applications. Other beneficial results can be realized by applying the non- limiting embodiments in a different manner or modifying them in ways known to those familiar with the art. This includes the mixing and matching of features, elements and/or functions between various non-limiting embodiment(s), which is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one embodiment may be incorporated into another embodiment as one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one embodiment may be incorporated into another embodiment as appropriate, unless described otherwise, above. Although the description is made for particular arrangements and methods, the intent and concept thereof may be suitable.

Claims

WHAT IS CLAIMED IS:

1. A nozzle (204) for a molding material distributor (108) for use with a molding system, the nozzle (204) comprising: a body (205) defining a hot nozzle portion (214); an annular melt flow channel (216) defined within the hot nozzle portion, the annular melt flow channel (215) for conveying a stream of molten molding material; and a spigot (220) located at least partially within the stream of molten molding material, the spigot (220) including an active temperature controller (228), the active temperature controller (228) configured to cool the spigot (220).

2. The nozzle (204) of claim 1, wherein the active temperature controller (228) is further configured to heat the spigot (220).

3. The nozzle (204) of claim 2, wherein the active temperature controller (228) comprises a first portion configured to cool a portion of the spigot (220) and a second portion configured to heat the spigot (220).

4. The nozzle (204) of claim 3, wherein the second portion is implemented as a micro heater.

5. The nozzle (204) of either 2 or 3, wherein the second portion is located at a tip of the spigot

(220).

6. The nozzle (204) of any one of claims 1 to 5, wherein the active temperature controller (228) comprises an internal cooling channel (230) defined within the spigot (220).

7. The nozzle (204) of claim 6, wherein the internal cooling channel (230) is for receiving cooling fluid.

8. The nozzle (204) of claim 7, wherein temperature control is affected by at least one of controlling a temperature of the cooling fluid and controlling a flow rate of the cooling fluid.

9. The nozzle (204) of claim 7 or 8, wherein the internal cooling channel (230) further comprises a cooling tube (410) disposed within the internal cooling channel (230).

10. The nozzle (204) of claim 9, wherein the cooling tube (410) is fluidly coupled to a cooling fluid intake (412) and the internal cooling channel (230) is fluidly coupled to a cooling fluid outlet (414).

11. The nozzle (204) of claim 6, wherein the internal cooling channel (230) is for receiving a reciprocating cooling rod.

12. The nozzle (204) of any one of claims 1 to 1 1, wherein a portion of the spigot defines a portion of a molding surface for a molded article manufactured using the molding system.

13. The nozzle (204) of any one of claims 1 to 12, wherein the spigot (220) is located coaxially centrally within the annular melt flow channel (216).

14. The nozzle (204) of any one of claims 1 to 13, wherein the spigot (220) is located coaxially centrally within the stream of molten molding material.

15. The nozzle (204) of any one of claims 1 to 14, wherein the spigot (220) defines a portion of an annular gate flow portion (242) defined between the spigot (220) and a gate insert (202).

16. The nozzle (204) of claim 15, wherein the annular gate flow portion (242) is donut shaped.

17. The nozzle (204) of claim 15 or 16, wherein when the active temperature controller (228) is actuated to cool the spigot (220), a frozen plug (242) is formed within the annular gate flow portion (242).

18. The nozzle (204) of claim 17, wherein the active temperature controller (228) is further configured to heat the spigot (220) and wherein when the active temperature controller (228) is actuated to heat the spigot (220), the frozen plug (242) is melted.

19. The nozzle (204) of claim 18, wherein the active temperature controller (228) is configured to selectively actuate cooling and heating during appropriate portions of a molding cycle of the molding system.

20. The nozzle (204) of claim 1, wherein the molding system is an injection molding system.

21. The nozzle (204) of claim 1, wherein the molding system is configured for production of

PET preforms.

22. The nozzle (204) of claim 1, wherein the molding system is configured for production of closures.

23. The nozzle (204) of claim 1, wherein the molding system is configured for production of medical appliances.

24. A method (300) of molding a molded article, the method executable in a molding machine having a molding material distributor (108) with a nozzle (204), the nozzle having an annular melt flow channel (216) defined within a hot nozzle portion, the annular melt flow channel (215) for conveying a stream of molten molding material and a spigot (220) located at least partially within the stream of molten molding material, the spigot (220) including an active temperature controller (228), the active temperature controller (228) configured to cool the spigot (220), the spigot (220) defining a portion of an annular gate flow portion (242); the method comprising: allowing (302) a flow of molten molding material from the annular melt flow channel (215) through the annular gate portion (242) during a first portion of a molding cycle; actuating (304) the active temperature controller (228) to cool the spigot (220) during a second portion of the molding cycle, said actuating for formation of a frozen plug (242) within the annular gate portion (242).

25. The method of claim 24, wherein said actuating cools the molten molding material from within the stream of molten molding material.

26. The method of claim 25, wherein the molding machine further includes a gate insert (202), the gate insert (202) configured to define a second portion of the annular melt flow channel (215) and the method further comprising causing a portion of the gate insert (202) to cool the molten molding material within the annular melt flow channel (215) from outside.

27. The method of claim 24, wherein the active temperature controller (228) is further configured to heat the spigot (220), and the method further comprises actuating the active temperature controller (228) to execute a pulse heating during a third portion of the molding cycle.

28. The method of any one of claims 24 to 27, wherein the active temperature controller (228) comprises an internal cooling channel (230) defined within the spigot (220) for accepting cooling fluid, and wherein said actuating comprises at least one of (i) changing temperature of the cooling fluid and (ii) changing a flow rate of the cooling fluid.

29. The method of any one of claims 24 to 27, wherein the active temperature controller (228) comprises an internal cooling channel (230) defined within the spigot (220) for accepting a reciprocating cooling rod, and wherein said actuating comprises causing insertion of the reciprocating cooling rod into the internal cooling channel (230).

30. The method of any one of claims 24 to 29, wherein the spigot (220) is located coaxially centrally within the stream of molten molding material, and wherein said allowing comprises allowing the molten molding material to flow around the spigot (220).

31. The method of any one of claims 24 to 30, wherein the molding system is for production of

PET preforms.

32. The method of any one of claims 24 to 30, wherein the molding system is for production of closures.

33. The method of any one of claims 24 to 30, wherein the molding system is for production of medical appliances.