WO2017214712A1

WO2017214712A1 - Method of producing molded article and apparatus for executing same

Info

Publication number: WO2017214712A1
Application number: PCT/CA2017/050183
Authority: WO
Inventors: Douglas James Weatherall
Original assignee: Husky Injection Molding Systems Ltd.
Priority date: 2016-03-28
Filing date: 2017-02-15
Publication date: 2017-12-21

Abstract

There is disclosed a method of injection molding a flip top closure having a body that includes a base and a lid connected by a hinge. The method is executable in an injection molding machine controlled by a machine controller. The injection molding machine includes a mold defining a mold cavity for producing the flip top closure. The mold cavity has a base defining portion for defining the base and a lid defining portion for defining the lid and at least a portion of the hinge. The method comprises: injecting, via a first gate, a first molding material into the base defining portion; injecting, via a second gate, a second molding material into the mold cavity; controlling, by the machine controller, the injecting of the first molding material and the injection of the second molding material, such that they are executed at least partially sequentially and the injecting of the second molding material is commenced with the first molding material passing the second gate.

Description

METHOD OF PRODUCING MOLDED ARTICLE AND APPARATUS FOR

EXECUTING SAME

FIELD

This application relates to an injection molding process in general and, more specifically, to a method of producing a molded article and an apparatus for executing same.

BACKGROUND

Injection molding is a process by which a molding material is injected into a mold and then cooled to form a solid molded article. A molding material, such as, for example, polyethylene terephthalate (PET) is placed in an injection unit, which heats the molding material into a molten, flowable state. Molten molding material is then conveyed through a distribution network, often referred to as a "hot runner", and delivered to one or more mold cavities through one or more associated nozzles.

Various articles can be produced using the molding process. Examples include but are not limited to: a preform for subsequent blow molding into a final shaped container for a beverage; a closure for such a container; a thin- walled container for food items and the like. Some of the molded articles are produced using a single molded material - such as a preform for a carbonated soft drink, as an example. Other molded articles are produced using two or more materials. For example, a given molded article can be produced from two different resins or from two forms of the same resin (such as virgin and recycled). A particular type of the molded article that can be produced using the injection molding process is a flip top closure. With reference to Figure 1 , there is depicted a prior art flip top closure 100. The flip top closure 100 comprises a base 102 and a lid 104, joined therebetween by a hinge 106. Exact shape of the base 102, the lid 104 and the hinge 106 will vary based on the specific technical requirements for the flip top closure 100. Typically the lid 104 is smaller and, thus, lighter than the base 102. This is due to the fact that the base 102 is a structural element usually made to push onto a bottle (not depicted) and needs thick walls. The lid 104, on the other hand, is required only to provide closing for a product opening (not numbered) and is most commonly thin and light.

US patent 6,305,563 discloses a one-piece dispensing structure that is molded by a process combining a co-injection molding first phase with a bi-injection molding second phase. In the first phase, a skin material and core material are co-injected into a mold cavity first region to form most of the major portion of the closure body. Subsequently, a movable shut- off member is retracted to expose an intermediate region which (1) is adjacent the closure structure hinge area and which (2) establishes communication between the mold cavity first region and another part of the mold cavity defining the closure lid portion. The skin material is injected through a second gate directly into the cavity intermediate region to fill the cavity intermediate region and the closure lid portion of the mold cavity. The skin material in the cavity intermediate region bonds to the previously injected skin material in the cavity first region adjacent the closure hinge.

US patent 6,830,721 teaches a liquid dispensing closure for bottles and the like comprising a one-piece body having an end wall for covering the mouth of the bottle and a depending skirt for threading onto the neck of the bottle. A dispensing aperture in the end wall is surrounded by a spout that affords directional control of a stream of liquid being dispensed and reduced dribbling when dispensing is discontinued. A flap is hinged on the end wall to open and close the aperture with an associated depending plug that fits in the spout. The end wall, spout and hinged flap are arranged in a manner relative to one another that permits the flap to be advantageously molded in an upright position.

US patent 6,682,686 discloses a container closure that can easily be manufactured, has improved drop strength and is convenient for opening operation. The present invention provides a container closure comprises, a substrate having adequate property for retaining an object which is enclosed in a container, a peripheral section formed on the periphery area of the container closure on the opposite side of a side where the substrate is attached to a container body, a panel section covering an area of the substrate surrounding by the peripheral section on the same side where the peripheral section is provided, and a score section formed between the peripheral portion and the panel section to provide a weakened region, the peripheral section and the panel section is a plastic layer formed with the same heat-fusible plastic on the substrate. Substantial area of the score section is constructed of the substrate. Further, the thin layer is formed on at least a part of the substrate of the score section with the heat-fusible plastic that connects the peripheral section and the panel section. US 6,257,431 teaches a dispensing cap which fits on a container containing a fluid product. The cap includes a body provided with a dispensing orifice and a hinged lid which is hinged to the body about an axis. The body and lid are made of a rigid or semi-rigid material. The lid includes a plugging pip for plugging the dispensing orifice when the lid is closed. A coating of elastomeric material is arranged on the outer wall of the pip to produce a seal between the pip and the orifice when the lid is closed.

US 6,152,324 discloses a dispenser head for dispensing a fluid that includes a dispenser endpiece of rigid or semi-rigid thermoplastic material and a flow reducer member of elastically deformable thermoplastic material secured to the endpiece. The member includes at least one slot whose edges are suitable for moving apart under the effect of thrust from the fluid while it is being dispensed. A method of making the dispenser head includes making the flow reducer member by injection molding from one or more injection points situated on one or both sides of the slot. US 6,106,261 teaches a method and apparatus for molding a one-piece article in a single molding operation using two different plastic materials so a first portion of the article is made of one plastic material and a second portion of the article is made of a different plastic material, and the two portions are fused together while hot to create a one-piece article.

US 5,755,360 discloses a closure for a container and includes a base which preferably has an attached lid. The base includes a body for mounting to the container, and the body defines a dispensing orifice and spout. A tamper-evident seal initially closes the dispensing orifice. The body is injection molded from a first molding material. The tamper-evident seal structure is subsequently injection-molded from a second material. The seal structure includes a peripheral portion molded against the base body and attached thereto. The seal structure includes a partition consisting only of the second material extending across the dispensing orifice and connected around its periphery to the seal structure peripheral portion with a frangible, reduced thickness section of the second material. A grip member extends from the partition for being pulled to tear only the partition and grip member together away from the seal structure peripheral portion so as to open the dispensing orifice. US 5,260,012 teaches an apparatus and method for molding plastic articles including oscillating the molten plastic in the mold cavity. The method and apparatus is particularly suitable for use with a plurality of mold cavities supplied from a single feeding means or extruder. The disclosure teaches alternately feeding molten plastic to the mold cavity from at least one shooting pot while the flow of molten plastic to the mold cavity from the feeding means is discontinued.

US 5,112,551 discloses a method of molding a flipper link to reduce or eliminate the tendency of the flipper link to break. The method includes the steps of forming a mold cavity for forming a flipper link having a first end portion, a second end portion and an intermediate necked-down portion. The necked-down portion provides an area between the first and second end portions which more easily twists and absorbs the stress exerted on the flipper link during use. Pins are provided in the cavity for forming an aperture in each of the first and second end portions. Plastic material is injected into the cavity at each end of the first and second end portions such that the plastic material flows into the cavity about the pins and the knit line or lines are formed in the flipper link in a location substantially centrally of the necked-down portion to thereby transfer the stress on the flipper link away from the apertures so as to substantially eliminate the tendency of the flipper link to break about the apertures.

EP 1 523 405 teaches a tube (1) made of polymer material and injection moulded in one piece, comprising a tube body (2), a tube shoulder (3) and a closure (4) connected to the tube shoulder (3) via a hinge (5), the tube shoulder (3) having an emptying opening (12), the tube shoulder (3) having at least one intake point (20; 21) and the closure having at least one intake point (19), the tube shoulder (3) comprising material which has flowed in through intake points in both the tube shoulder (3) and the closure (4). The invention also relates to a method for manufacturing the tube and also to a tool.

SUMMARY

Developers of the present technology have developed various embodiments thereof based on their appreciation of at least one technical problem associated with the prior art approaches to molding the flip top closures 100 (such as the process described in the above- mentioned US patent 6,305,563). Some of these problems specifically occur when attempting to reduce the molding cycle (i.e. the time required to produce a single batch of the flip top closures 100). In order to speed any injection molding cycle a common method is to attempt to reduce the cooling time required since it typically constitutes a major portion of the molding cycle. Without changing the design of the flip top closure 100 (i.e. reducing wall thickness) a typical strategy is to, for example, lower the mold or melt temperature, or bring the cooling lines closer to the hot spots on the flip top closure 100. These approaches to decreasing the molding cycle can be broadly categorized as reducing cooling time by either increasing the cooling intensity/effectiveness or by decreasing the molten material temperature.

The geometry of the flip top closure 100 itself poses a unique problem associated with attempts to reduce the cooling time since the portion that is being filled first is typically the base 102, which is heavy. Additionally, the lid 104 is typically filled through the hinge 106, which connects the lid 104 to the base 102 (since an injection point is typically located proximate to the base 102). An injection point on the typical flip top closure 100 is shown schematically in Figure 1 at 110.

Developers of the present technology have realized that lowering the melt temperature, as means for decreasing the molding cycle, presents its special challenges when dealing with the flip top closure 100. More specifically, whereas it may be possible to fill the base 102 with the melt of lower temperature, filling the lid 104 through a narrow and/or thin hinge 106 can prove challenging or even not feasible. Additionally, the lid 104 tends to cool off quickly since it is thin, adding to the filling problem through the hinge 106 using molding material at a comparatively lower temperature.

Embodiments of the present technology attempt to mitigate at least some of the technical problems of the prior art approaches to molding the flip top closures 100. Broadly speaking, some embodiments of present technology allows a reduction in cooling time of the molded article (i.e. the flip top closure 100).

In some embodiments, the reduction in the cooling time is achieved through controlling the temperature of the molding materials for filling the base 102 to a lower temperature (the lower temperature so selected such that to be able to fill the base 102, but is potentially too low to fill in the lid 104). Filling of the lid 104 is then done through a second injection point with a molding material controlled to a second temperature, which is higher than the first temperature.

Thus, it can be said that in some embodiments, this reduction in cooling time is achieved through lowering the melt temperature of the molding material filling the base 102, while still be able to fill the lid 104. This is achieved by filling the lid 104 using a separate stream of a molding material, which can be one or more of the following: (i) through a sequentially operated valve gates; (ii) through a sequentially operated valve gate with pre-conditioning of either or both of the streams of the molding material; (iii) through a shooting pot, (iv) through a separate injection unit, and (v) through a separate injection unit where the two streams of the molding material are streams of different type of the molding materials.

Some embodiments of the present technology allow to avoid weld lines (typically at a point where the first and the second molding materials mate and/or overlap) by means of allowing the molding material from the first injection point is to pass the second injection point before the second injection point is opened providing for a smooth and continuous flow of molten resin into the mold cavity. In some embodiments, the temperature of the molding material injected through the second injection point is adjusted through running the hot runner nozzle associated with the second injection point at a different temperature.

The first molding material and the second molding material can be the same molding materials. Alternatively, the first molding material can be different from the second molding material. As an example, in some implementations, the lid 104 and the hinge 106 can be made of the PP resin (PP resin has the integral hinge property) and the base 102 can be made of HDPE for example, which can be run at a lower temperature and ejected at a higher temperature thus reducing cycle time.

In alternative embodiments of the present technology, the reduction in the cooling time is achieved through controlling the temperature of the molding material for filling the base 102 to a lower temperature (the lower temperature so selected such that to be able to fill the base 102, but is potentially too low to fill in the lid 104). Filling of the lid 104 is then done through the same coinjection point with a molding material controlled to a second temperature, which is higher than the first temperature, the second molding material being coinjected as a core layer in the flow of the first molding material to fill the hinge 106 and the lid 104. Filling of the base portion is done while fluidly isolating the mold portion defining the base 102 from the mold portion defining the hinge 106 and the lid 104. Filling the hinge portion and the lid portion is done, while stopping injecting the first material (i.e. with the second molding material only) while fluidly connecting the mold portion defining the base 102 and the mold portion defining the hinge 106 and the lid 104. The selective fluid isolation and connection can be done through positioning of a blocking structure between the mold portion defining the base 102 and the mold portion defining the hinge 106 and the lid 104. The blocking structure can be actuated by an actuator to selectively block and open the fluid passage between the mold portion defining the base 102 and the mold portion defining the hinge 106 and the lid 104.

According to a first broad aspect of the present technology, there is provided a method of injection molding a flip top closure having a body that includes a base and a lid connected by a hinge. The method is executable in an injection molding machine controlled by a machine controller. The injection molding machine includes a mold defining a mold cavity for producing the flip top closure, the mold cavity having a base defining portion for defining the base and a lid defining portion for defining the lid and at least a portion of the hinge. The method comprises: injecting, via a first gate, a first molding material into the base defining portion; injecting, via a second gate, a second molding material into the mold cavity; controlling, by the machine controller, the injecting of the first molding material and the injection of the second molding material, such that they are executed at least partially sequentially and the injecting of the second molding material is commenced with the first molding material passing the second gate.

In some implementations of the method, the first molding material and the second molding material are a same polymer. In some implementations of the method, the controlling further comprises: controlling an injection temperature of the first molding material to a first temperature; controlling an injection temperature of the second molding material to a second temperature.

In some implementations of the method, the second temperature is higher than the first temperature. In some implementations of the method, the first molding material is high density polyethylene and the second molding material is polypropylene.

In some implementations of the method, the controlling further comprises terminating injecting of the first molding material prior to commencing the injecting of the second molding material. In some implementations of the method, the controlling further comprises commencing the injecting of the second molding material before terminating injecting the first molding material, such that the injecting of the second molding material follows the injecting of the first molding material.

In some implementations of the method, the first gate is located in the body defining portion of the mold cavity and the second gate is located proximate to the lid defining portion of the mold cavity.

In some implementations of the method, the second gate is located upstream, relative to the first gate, from the lid defining portion.

In some implementations of the method, the second gate is located downstream from the lid defining portion and the first gate. In some implementations of the method, the first molding material and the second molding material are supplied from a single molding material source.

In some implementations of the method, the first molding material is supplied from a first molding material source and the second molding material is supplied from a second molding material source.

In accordance with another broad aspect, there is provided an injection molding machine for producing a flip top closure having a body that includes a base and a lid connected by a hinge. The injection molding machine comprises: an injection unit for plasticising molding material; a mold defining a mold cavity for producing the flip top closure, the mold cavity having a base defining portion for defining the base and a lid defining portion for defining the lid and at least a portion of the hinge, a machine controller for controlling operations of the injection unit and the mold, the machine controller configured to execute: injecting, via a first gate, a first molding material into the base defining portion; injecting, via a second gate, a second molding material into the mold cavity; controlling, by the machine controller, the injecting of the first molding material and the injection of the second molding material, such that they are executed at least partially sequentially and the injecting of the second molding material is commenced with the first molding material passing the second gate.

In some implementations of the injection molding machine, the first molding material and the second molding material are a same polymer. In some implementations of the injection molding machine, the step of controlling further comprises: controlling an injection temperature of the first molding material to a first temperature; controlling an injection temperature of the second molding material to a second temperature.

In some implementations of the injection molding machine, the second temperature is higher than the first temperature.

In some implementations of the injection molding machine, the first molding material is high density polyethylene and the second molding material is polypropylene.

In some implementations of the injection molding machine, the step of controlling further comprises terminating injecting of the first molding material prior to commencing the injecting of the second molding material. In some implementations of the injection molding machine, the step of controlling further comprises commencing the injecting of the second molding material before terminating injecting the first molding material, such that the injecting of the second molding material follows the injecting of the first molding material. In some implementations of the injection molding machine, the first gate is located in the body defining portion of the mold cavity and the second gate is located proximate to the lid defining portion of the mold cavity.

In some implementations of the injection molding machine, the second gate is located upstream, relative to the first gate, from the lid defining portion. In some implementations of the injection molding machine, the second gate is located downstream from the lid defining portion and the first gate.

In some implementations of the injection molding machine, the first molding material and the second molding material are supplied from a single molding material source.

In some implementations of the injection molding machine, the first molding material is supplied from a first molding material source and the second molding material is supplied from a second molding material source.

In accordance with another broad aspect of the present technology, there is provided a method of injection molding a flip top closure having a body that includes a base and a lid connected by a hinge. The method is executable in an injection molding machine controlled by a machine controller, the injection molding machine including a mold defining a mold cavity for producing the flip top closure, the mold cavity having a base defining portion for defining the base and a lid defining portion for defining the lid and at least a portion of the hinge. The base defining portion and the hinge defining portion are separated by a blocking structure for selectively blocking flow of molding material therebetween. The method comprises: actuating the blocking structure to block a passage between the base defining portion of the hinge defining portion; injecting, via a coinjection gate, a first molding material into the base defining portion to fill, at least partially, the base defining portion; coinjecting, through the coinjection gate, a second molding material as a core flow within the flow of the first molding material; terminating the flow of the first molding material; actuating the blocking structure to open the passage between the base defining portion and the hinge defining portion; continuing injecting only the second molding material to fill the hinge defining portion and the lid defining portion. In some implementations of the method, the first molding material is high density polyethylene and the second molding material is polypropylene.

In some implementations of the method, the first molding material and the second molding material are a same polymer. In some implementations of the method, the method further comprises: controlling an injection temperature of the first molding material to a first temperature; controlling an injection temperature of the second molding material to a second temperature.

In some implementations of the method, the second temperature is higher than the first temperature. In some implementations of the method, the first molding material is supplied from a first molding material source and the second molding material is supplied from a second molding material source.

In accordance with yet another broad aspect of the present technology, there is provided an injection molding machine for producing a flip top closure having a body that includes a base and a lid connected by a hinge. The injection molding machine comprises: an injection unit for plasticising molding material; a mold defining a mold cavity for producing the flip top closure, the mold cavity having a base defining portion for defining the base and a lid defining portion for defining the lid and at least a portion of the hinge, the mold further including: a blocking structure positioned between the base defining portion and the hinge defining portion for selectively blocking flow of molding material therebetween; a machine controller for controlling operations of the injection unit and the mold. The machine controller is configured to execute: actuating the blocking structure to block a passage between the base defining portion of the hinge defining portion; injecting, via a coinjection gate, a first molding material into the base defining portion to fill, at least partially, the base defining portion; coinjecting, through the coinjection gate, a second molding material as a core flow within the flow of the first molding material; terminating the flow of the first molding material; actuating the blocking structure to open the passage between the base defining portion and the hinge defining portion; continuing injecting only the second molding material to fill the hinge defining portion and the lid defining portion. BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present technology, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where: Figure 1 depicts a prior art flip top closure.

Figure 2 a top schematic view of an injection molding machine.

Figure 3 depicts a non-limiting example of implementation of a given one of the nozzles of the injection molding machine of Figure 2, the implementation being in accordance with non-limiting embodiments of the present technology. Figure 4 depicts a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a first phase of filling) to produce the flip top closure similar to that depicted in Figure 1.

Figure 5 depicts a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a second phase of filling) to produce the flip top closure similar to that depicted in Figure 1.

Figure 6 depicts a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a third phase of filling) to produce the flip top closure similar to that depicted in Figure 1.

Figure 7 depicts a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a fourth phase of filling) to produce the flip top closure similar to that depicted in Figure 1.

Figure 8 depicts a block diagram of a method executable in the injection molding machine of Figure 2.

Figure 9 depicts a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a first phase of filling) to produce the flip top closure similar to that depicted in Figure 1, the filling being implemented in accordance with another embodiment of the present technology. Figure 10 depicts a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a second phase of filling) to produce the flip top closure similar to that depicted in Figure 1, the filling being implemented in accordance with another embodiment of the present technology.

Figure 11 depicts a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a third phase of filling) to produce the flip top closure similar to that depicted in Figure 1, the filling being implemented in accordance with another embodiment of the present technology.

Figure 12 depicts a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a fourth phase of filling) to produce the flip top closure similar to that depicted in Figure 1, the filling being implemented in accordance with another embodiment of the present technology.

Figure 13 depicts a block diagram of a method executable in the injection molding machine of Figure 2, the method being executed in accordance with another 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 implementations or that render other details difficult to perceive may have been omitted.

DETAILED DESCRIPTION

Reference will now be made in detail to various non-limiting implementations for producing a flip-top closure. It should be understood that other non-limiting implementations, modifications and equivalents will be evident to one of ordinary skill in the art in view of the non-limiting implementations disclosed herein and that these variants should be considered to be within 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 implementations discussed hereafter may be modified or omitted (i.e. nonessential) altogether. In other instances, well known methods, procedures, and components have not been described in detail. It is to be further expressly understood that the injection mold and its components are depicted merely as an illustrative implementation of the present technology. Thus, the description thereof that follows is intended to be only a description of illustrative examples of the present technology. This description is not intended to define the scope or set forth the bounds of the present technology. In some cases, what are believed to be helpful examples of modifications to the injection mold and/or its components may also be set forth below. This is done merely as an aid to understanding, and, again, not to define the scope or set forth the bounds of the present technology. These modifications are not an exhaustive list, and, as a person skilled in the art would understand, other modifications are likely possible. Further, where this has not been done (i.e. where no examples of modifications have been set forth), it should not be interpreted that no modifications are possible and/or that what is described is the sole manner of implementing that element of the present technology. As a person skilled in the art would understand, this is likely not the case. In addition it is to be understood that the injection mold and/or its components may provide in certain instances simple implementations of the present technology, and that where such is the case they have been presented in this manner as an aid to understanding. As persons skilled in the art would understand, various implementations of the present technology may be of a greater complexity. Furthermore, where specific details of the different implementations are presented with reference to discrete implementations, a person skilled in the art is expected to combine specific implementational details of one discrete implementation with specific implementational details of another discrete implementation, even though such a combination may not be expressly disclosed herein below.

Figure 2 depicts an example embodiment of an injection molding machine 200 for forming molded articles from molding material. In the example of Figure 2, the molded article is a flip top closure similar to the flip top closure 100 of Figure 1, albeit manufactured using the injection molding machine 200 and the associated method implemented in accordance with non- limiting embodiments of the present technology.

Injection molding machine 200 has a stationary platen 202 and a movable platen 204. A hot runner 206 and a mold 208 are typically mounted in-between the stationary platen 202 and the movable platen 204. Mold 208 comprises a mold cavity plate 210 mounted to the hot runner 206, and a mold core plate 212 mounted to movable platen 204.

Movable platen 204 is movable between a closed position, depicted in Figure 1, and an open position (not shown) in which the movable platen 204 is withdrawn away from the stationary platen 202 along axis "a-a" (hereinafter referred to as an "operational axis" of the injection molding machine 200).

With the movable platen 204 in the closed position, the mold cavity plate 210 and the mold core plate 212 abut one another and may be pressed together by a force exerted on the stationary platen 202 and the movable platen 204.

In the closed position, a plurality of mold cavities 214 are defined between the mold cavity plate 210 and the mold core plate 212. Molten molding material may be injected under pressure into mold cavities 214 and cooled to form molded parts. Two such cavities are depicted in Figure 1, but the mold 108 may have any number of cavities. As such, the number of the plurality of mold cavities 214 is not particularly limited and will depend on the particular implementation of the mold 208.

Mold cavities 214 receive molten molding material from an injection unit 216 through the hot runner 206. Injection unit 216 heats molding material to a desired temperature sufficient to render the molding material in a flowable state. Injection unit 216 may, for example, compress solid pellets of molding material with a screw, heating the material and urging it toward the mold cavities 214. Other types of the injection unit 216 are well known to those skilled in the art.

Hot runner 206 comprises a backing plate 218 mounted to the stationary platen 202. A sprue bushing 226 is received through the backing plate 218 and coupled to a manifold 224, for example using bolts or the like. The sprue bushing 226 has an inner passage for receiving molten molding material from the injection unit 216.

A manifold plate 220 is mounted to the backing plate 218, for example, using bolts or other suitable fasteners. A manifold pocket 222 is defined between the manifold plate 220 and the backing plate 218. The manifold 224 is disposed within manifold pocket 222. The manifold 224 is attached to the backing plate 218 and the manifold plate 220 using alignment pins (not shown). The alignment pins may align the manifold 224 to the backing plate 218 but may allow the manifold 224 to float in the longitudinal direction of injection molding machine 200. Thermally-insulating spacers (not shown) may be provided between the manifold 224 and the backing plate 218 and/or the manifold plate 220. The manifold 124 has an inlet (not numbered) in fluid communication with the sprue bushing 226 to receive the molding material. The inlet branches into a plurality of conduits (not shown) that run internally within the manifold 224 from the sprue bushing 226 to each of a plurality of nozzles 228, to deliver molding material thereto. Nozzles 228 may form part of larger assemblies, which may for example include one or more heaters (not shown) or seals (not shown).

Nozzles 228 are mounted to manifold 224, by conventional methods, well-known to those skilled in the art. Nozzles 228 may, for example, be mounted using preloaded spring packs and aligning features such as pins. Each nozzle 228 extends through a passage 244 in the manifold plate 220 to a corresponding mold cavity 214 to supply molding material thereto. Two nozzles 228 are depicted in FIG. 1, however any number may be present - as will be described in greater detail herein below. An interface between a given one of the nozzles 228 and the associated mold cavity 214 is typically referred to as a "gate" and is numbered in Figure 2 at 240. Within embodiments of the present technology, the "gating style" of the gate 240 can be mechanical (i.e. by use of a valve step to open or block the flow of the molten molding material through the gate 240) or thermal (i.e. by use of localized cooling to block the flow of the molten molding material through the gate 240 during appropriate portions of the molding cycle).

Each of the manifold plate 220, the mold cavity plate 210 and the mold core plate 212 have alignment bores 203 extending longitudinally therethrough. Alignment pins 201 are mounted to the backing plate 218, for example, using bolts or other suitable fasteners (not shown). Alignment pins 201 extend through alignment bores 203 to maintain relative alignment between the backing plate 218, the manifold plate 220, the mold cavity plate 210 and the mold core plate 212.

Within the embodiment depicted in Figure 2, there is also provided a machine controller 242. Within various embodiments of the present technology, the machine controller 242 can be implemented as a computing apparatus having a processor (not separately numbered). The processor may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software.

The processor can execute one or more functions to control operations of one or more of the components of the injection molding machine 200. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. In some embodiments of the present technology, the processor may be a general purpose processor, such as a central processing unit (CPU) or a processor dedicated to a specific purpose. Moreover, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), read-only memory (ROM) for storing software, random access memory (RAM), and non- volatile storage. Other hardware, conventional and/or custom, may also be included.

The machine controller 242 has access to a memory (not depicted) that stores computer executable instructions, which computer executable instructions, when executed, cause the processor to control operation of one or more of the components of the injection molding machine 200. Examples of such operations controlled by the machine controller 242 include (but are not limited to): (i) controlling plasticising of the molding material by the injection unit 216; (ii) controlling temperature of the heaters within the hot runner 206, including nozzle heaters (not depicted) associated with the nozzles 228; (iii) controlling molding material flow through the gate 240 (by either controlling the valve stem in the mechanically controlled gate 240 or controlling temperature in the thermally controlled gate 240), (iv) controlling mold opening / closing, controlling ejection of the molded parts, controlling post-mold handling equipment, other auxiliary equipment and the like.

Within the illustrated embodiment, the mold cavities 214 are configured to produce flip top closures, similar to the flip top closure 100 depicted in Figure 1 albeit produced using methods to be described below.

With reference to Figure 3, there is depicted a non- limiting example of implementation of a given one of the nozzle 228, the implementation being in accordance with non-limiting embodiments of the present technology. Depicted in Figure 3 are portions of: the mold core plate 212 (including a mold core 312) and the hot runner 206. There is also depicted the flip top closure 100 (including the base 102, the lid 104 and the hinge 106), the flip top closure 100 being produced using embodiments of the present technology.

In accordance with embodiments of the present technology, each mold cavity 214 is provided with two instances of the nozzle 228 - a first nozzle 228a and a second nozzle 228b. The first nozzle 228a is provided in association with a first gate 240a and the second nozzle 228b is provided in association with a second gate 240b. Within the illustration of Figure 3, both the first nozzle 228a and the second nozzle 228b are depicted as valve gated nozzles. However, this needs not be so in every embodiment of the present technology. As such, in alternative embodiments of the present technology, one or both of the first nozzle 228a and the second nozzle 228b can be implemented as thermally gated nozzles.

In accordance with embodiments of the present technology, the first gate 240a is configured for supplying molding material into a base defining portion of the mold cavity 214, the base defining portion being the portion of the mold cavity 214 for defining the base 102 of the flip top closure 100. The second gate 240b is configured for supplying molding material into a lid defining portion of the mold cavity 214, the lid defining portion being the portion of the mold cavity 214 for defining the lid 104. Depending on location of the second gate 240b, one or both of the first gate 240a and the second gate 240b can be configured for supplying molding material to at least a portion of the hinge 106 of the flip top closure 100. To that end, the first gate 240a is disposed in proximity to the base defining portion, while the second gate 240b is located in proximity to the lid defining portion. In the depicted embodiment, the second gate 240b (and, thus, the second nozzle 228b) is located just downstream of the hinge 106. Thus, in these embodiments, at least a portion of the hinge 106 is filled by the first gate 240a. However, in alternative embodiments of the present technology, the second gate 240b (and, thus, the second nozzle 228b) can be located just upstream of the hinge 106 (i.e. closer to the first gate 240a). In other words, in alternative embodiments of the present technology, the second gate 240b (and, thus, the second nozzle 228b) can be moved closer to the first gate 240a in a left- ward direction as viewed in the orientation of Figure 3. Thus, in these embodiments, at least a portion of the hinge 106 is filled by the second gate 240b.

Thus, in various embodiments of the present technology the location of the first gate 240a and the second gate 240b can be executed as follows. The first gate 240a can be located proximate to the body defining portion of the mold cavity 214 and the second gate 240b can be located proximate to the lid defining portion of the mold cavity 214. In some implementations, the second gate 240b can be located upstream, relative to the first gate 240a, from the lid defining portion. In other implementations, the second gate 240b can be located downstream from the lid defining portion and the first gate 240a.

In some embodiments of the present technology, a first molding material flowing through the first nozzle 228a and a second molding material flowing through the second nozzle 228b can be the same molding materials, such as, for example, Popylpropelene (PP) or the like.

In other embodiments, the molding materials flowing through the first nozzle 228a and the second nozzle 228b can be different molding materials. As an example, a first molding material flowing through the first nozzle 228a can be High Density Polyethylene (HDPE) and a second molding material flowing through the second nozzle 228b can be PP. Other combinations are, of course possible.

Within the embodiments of the present technology, the machine controller 242 is configured to control the flow of the first molding material and the second molding material, such that: (i) the injection of the first molding materials and the second molding material are executed at least partially sequentially and (ii) the injecting of the second molding material is commenced with the first molding material passing the second gate 240b. A special technical effect attributable to at least some of these embodiments is at least partial reduction of weld lines between the first molding material and the second molding material in the cooled flip top closure 100.

In some embodiments of the present technology, the machine controller 242 is further configured to control the temperature of the first molding materials and the temperature of the second molding material to different temperature settings. In some embodiments, the machine controller 242 can execute this by causing a heater (not depicted) associated with the first nozzle 228a to heat the first molding material to a first temperature and a heater (not depicted) associated with the second nozzle 228b to heat the second molding material to a second temperature. In some embodiments of the present technology, the second temperature can be higher than the first temperature. A special technical effect attributable to at least some of these embodiments is at ability to fill the base 102 with the first molding material with comparatively lower temperature (allowing it to cool comparatively faster), while providing ability to still fill in the hinge 106 and the lid 104 by relying on the second molding material having comparatively higher temperature (thus, be more flowable and allowing for filling relatively thinner parts, i.e. the hinge 106 and the lid 104). In some embodiments of the present technology, the machine controller 242 is further configured to control injection of the first molding material and the second molding material, such that injection of the first molding material is terminated prior to commencing the injecting of the second molding material. Alternatively, the machine controller 242 can be configured to trigger injecting of the second molding material before terminating injecting the first molding materials, such that the injecting of the second molding material follows the injecting of the first molding material. How the machine controller 242 is configured to initiate and stop flowing of the molding material is generally known and will depend on the type of gating within the given gate 240. In those embodiments where the first molding material and the second molding material are the same molding material, the first molding material and the second molding material can be supplied from a single molding material source - such as for example, from the injection unit 216. In those embodiments, where the first molding material and the second molding material are different materials, the first molding material can be supplied from a first molding material source and the second molding material can be supplied from a second molding material source. Either the first molding material source or the second molding material source can be the injection unit 216. The other one of the first molding material source or the second molding material source can be another injection unit (similar to the injection unit 216), a shooting pot (not depicted) or the like.

The sequence of filling the flip top closure 100 in accordance with non limiting embodiments of the present technology will now be described with reference to Figures 4-7. Notably, the filling of the hinge 106 will be done at least partially through the second gate 240b.

Figure 4 depicts a schematic cross section of a portion of the mold cavity 214 as it is being filled with the molding material (during a first phase of filling) to produce the flip top closure 100. For sake of reference, portions of the mold cavity 214 have been marked with numbers for the associated portions of the flip top closure 100 - the base 102, the lid 104 and the hinge 106. Also shown in Figure 4 are the first gate 240a and the second gate 240b. The first gate 240a is in a gate open state - so a first molding material 402 has started filling the base 102. The second gate 240b is in a gate closed state, so no flow of molding material through the second gate 240b happens at this stage.

Figure 5 depicts a schematic cross section of a portion of the mold cavity 214 as it is being filled with the molding material (during a second phase of filling) to produce the flip top closure 100. During the second phase of filling, the first gate 240a is still in the gate open state - so the first molding material 402 has filled the base 102 and the hinge 106, as well as a portion of the lid 104. The second gate 240b is still in the gate closed state, so no flow of molding material through the second gate 240b happens at this stage. A melt front 404 of the first molding material 402 has reached the position of the second gate 240b. In some embodiments of the present technology, the melt front 404 reaching the second gate 240b can be used as a trigger for opening the second gate 240b. Figure 6 depicts a schematic cross section of a portion of the mold cavity 214 as it is being filled with the molding material (during a third phase of filling) to produce the flip top closure 100. During the third phase of filling, the second gate 240b is in a gate open state, so a second molding material 406 starts to fill the lid 104. Within some embodiments of the present technology, once the second molding material 406 starts to flow, the first gate 240a is controlled to the gate closed state so the first molding material 402 ceases to flow.

Figure 7 depicts a schematic cross section of a portion of the mold cavity 214 as it is being filled with the molding material (during a fourth phase of filling) to produce the flip top closure 100. During the fourth phase of filling, the second gate 240b is still in the gate open state, so the second molding material 406 has completed filling the lid 104.

As is clear from the above description and particularly from the illustration of Figure 7, the second molding material 406 starts to flow as the first molding material 402 reaches the second gate 240b - thus creating a single molding material front flowing through the remainder of the body of the flip top closure 100 - thus, providing for continuous flow of the first molding material 402 and the second molding material 406.

It should be recalled that in alternative embodiments, the second gate 240b can be located upstream of the hinge 106 - thus the sequence described with reference to Figures 4-7 would be modified accordingly.

Given the architecture described above, it is possible to execute a method of injection molding the flip top closure 100 having a body that includes the base 102 and the lid 104 connected by the hinge 106. With reference to Figure 8, there is depicted a block diagram of a method 800. The method 800 is executable in the injection molding machine 200 controlled by the machine controller 242. The injection molding machine 200 comprises inter alia: the mold 208 defining a mold cavity 214 for producing the flip top closure 100. The mold cavity 214 can have a base defining portion for defining the base 102 and a lid defining portion for defining the lid 104 and at least a portion of the hinge 106.

Step 802 - injecting, via a first gate, a first molding material into the base defining portion

The method 800 begins at step 802, where the machine controller 242 executes the step of injecting, via the first gate 240a, a first molding material 402 into the base defining portion. In some embodiments of the present technology, the injecting at step 802 is executed through the first gate 240a. The flow of the first molding material 402 during step 802 is depicted in Figure 5 and Figure 5, as described above.

Step 804 - injecting, via a second gate, a second molding material into the mold cavity 214 Next, at step 804, the machine controller 242 executed injecting, via the second gate 240b, a second molding material 406 into the mold cavity.

In some embodiments of the present technology, the second gate 240b is located upstream, relative to the first gate 240a. In other embodiments of the present technology, the second gate 240b is located downstream from the lid defining portion and the first gate 240a. In some embodiments of the present technology, the second gate 240b can be located adjacent the lid defining portion.

The flow of the second molding material 406 during step 804 is depicted in Figure 7, as described above.

Step 806 - controlling, by the machine controller, the injecting of the first molding material and the injection of the second molding material, such that they are executed at least partially sequentially and the injecting of the second molding material is commenced with the first molding material passing the second gate.

At step 806, the machine controller 242 executes controlling the injecting of the first molding material 402 and the injection of the second molding material 406, such that they are executed at least partially sequentially. The step 806 includes causing injecting of the second molding material 406 to commence with the first molding material 402 passing the second gate 240b.

In some embodiments of the present technology, the machine controller 242 can acquire an indication of the first molding material 402 passing the second gate 240b by receiving a signal from a melt-presence-sensing device (not depicted) located within the molding material flow path proximate to the second gate 240b. The melt-presence-sensing device can be implemented as a pressure transducer, as a temperature sensing device, as an on/off switch for determining melt presence and the like. The melt-presence-sensing device can be located immediately upstream from the second gate 240b or immediately downstream from the second gate 240b. In the above illustrated embodiments, the two instances of the nozzle 228 - the first nozzle 228a and the second nozzle 228b (and the associated the first gate 240a and the second gate 240b) are located remote from each other. It will be recalled that in the illustrations provided above, the first gate 240a is disposed in proximity to the base defining portion, while the second gate 240b is located in proximity to the lid defining portion.

In alternative embodiments, the first nozzle 228a and the second nozzle 228b can be implemented as a coinjection nozzle configured to inject, through a single coinjection gate two (or more) different types of the same molding material or two (or more) different molding materials. It is noted that coinjection nozzles are generally known to those of ordinary skill in the art and, as such, will not be described here at any length.

Broadly speaking and with reference to Figure 9, there is depicted a schematic cross section of a portion of a mold cavity of the injection molding machine of Figure 2 as it is being filled with the molding material (during a first phase of filling) to produce the flip top closure similar to that depicted in Figure 1. It is noted that the mold cavity 214 can be implemented substantially similar to the above- described mold cavity 214 and the associated mold 108 can be implemented substantially similar to the above-described mold 108, other than the specific differences described above.

For sake of reference, portions of the mold cavity 214 have been marked with numbers for the associated portions of the flip top closure 100 - the base 102, the lid 104 and the hinge 106.

Also shown in Figure 9 are the first nozzle 228'a and the second nozzle 228'b. in this embodiment, the first nozzle 228'a and the second nozzle 228'b are implemented as a co- injection nozzle 228' for injection molding material(s) through a single coinjection gate 240'. As has been alluded to above, structure and implementation of the co-injection nozzles 228' is known to those of ordinary skill in the art and, as such, will not be described here at any length. Furthermore, associated changes to the mold 108 and the injection molding machine 200 (such as provision of shooting pots, provision of additional manifolds for flow of the additional materials to the secondary nozzles, etc.) are known to those of ordinary skill in the art and will not be described here at any length.

Within the embodiment of Figure 9, there is also provided a blocking structure 980. Generally speaking, the blocking structure 980 is positioned between the base defining portion that defines the base 102 and the hinge defining portion that defines the hinge 106. In the embodiment of Figure 9, the blocking structure 980 is positioned just upstream of the hinge defining portion. However, in alternative embodiments of the present technology, the blocking structure 980 can be located within the hinge defining portion. Generally speaking, the blocking structure 980 is configured to selectively block flow of molding material between the base defining portion and the hinge defining portion. More specifically, in the closed configuration, as depicted in Figure 9, the blocking structure 980 (such as a dam member or the like) is positioned to obstruct the molding material flow path into the hinge defining portion to prevent a molding material flow from the base defining portion into the hinge defining portion (and, therefore, into the lid defining portion). In an open configuration (will be described below), the blocking structure 980 is actuated to un- obstruct the molding material flow path from the hinge defining portion to allow the molding material flow from the base defining portion into the hinge defining portion (and, therefore, into the lid defining portion). In other words, the blocking structure 980 is actuatable between the closed configuration and the open configuration to selectively prevent and allow molding material flow from the base defining portion to the hinge defining portion (and, therefore, into the lid defining portion). To that end, the blocking structure 980 is coupled to an actuator (not depicted), which can be implemented as a servo motor, a pneumatic actuator, a mechanical actuator and the like. The actuator is configured to open and close the blocking structure 980, under control of the machine controller 242.

Within the illustration of Figure 9, the first nozzle 228' a is in a closed state - so the first molding material 402 has started filling the base 102 and, as can be appreciated from Figure 9, has at least partially filled in the base 102. The second nozzle 228'b is in a closed state, so no flow of molding material through the second nozzle 228'b happens at this stage.

Figure 10 depicts a schematic cross section of a portion of the mold cavity 214 as it is being filled with the molding material (during a second phase of filling) to produce the flip top closure 100. During the second phase of filling, the first nozzle 228 'a is still in the open state - so the first molding material 402 has filled the base 102 almost entirely. The second nozzle 228'b is in the open state so that the second molding material 406 starts to flow. Recalling that the first nozzle 228'a and the second nozzle 228'b are implemented as the coinjection nozzle 228', the second molding material 406 flows through the same gate as the first molding material 402, i.e. the single coinjection gate 240'. More specifically, the second molding material 406 is injected as a core flow within the flow of the first molding material 402.

The exact timing of actuating the second nozzle 228 'b into the open state is not particularly limited. For example, the machine controller 242 can trigger actuation of the second nozzle 228 'b into the open state based on an indication of a pre-determined point of time of the filling cycle, which can be entered by an operator based on empirical observations. Alternatively, the machine controller 242 can trigger actuation of the second nozzle 228 'b into the open state based on a melt front of the first molding material 402 reaching a pre- determined point within the base 102. Other variations are, of course, possible.

Figure 11 depicts a schematic cross section of a portion of the mold cavity 214 as it is being filled with the molding material (during a third phase of filling) to produce the flip top closure 100. As can be appreciated by comparing the illustration of Figure 11 and Figure 10, the blocking structure 980 has been actuated into an open configuration to allow molding material from the base defining portion and the hinge defining portion

During the third phase of filling, the first nozzle 228'a is in the closed state (so no additional first molding material 402 flows in) and the second nozzle 228b is still in the open state, so the second molding material 406 continues to fill the lid 104. The exact time of actuating the first nozzle 228'a into the closed state is not particularly limited and can for example, by triggered by the machine controller 242 when the first molding material 402 has fully filled the base 102 (based on a reading of an on/off switch positioned in the base 102, as an example). Alternatively, the machine controller 242 can cause the first nozzle 228'a to be actuated into the closed state at a pre-determined time point within the filling cycle.

Figure 12 depicts a schematic cross section of a portion of the mold cavity 214 as it is being filled with the molding material (during a fourth phase of filling) to produce the flip top closure 100. During the fourth phase of filling, the first nozzle 228'a is in the closed state (so no additional first molding material 402 flows in) and the second nozzle 228 'b is still in the open state, so the second molding material 406 has completed the filling of the lid 104.

After filling, the second molding material 406 can be further injected during the packing phase, at which point the second nozzle 228'b is also actuated into a closed state.

In some embodiments of the present technology, the machine controller 242 is further configured to control the temperature of the first molding material and the temperature of the second molding material to different temperature settings. In some embodiments, the machine controller 242 can execute this by causing a heater (not depicted) associated with a melt flow conduit feeding the first nozzle 228 'a to heat the first molding material to a first temperature and a heater (not depicted) associated with a melt flow conduit feeding the second nozzle 228 'b to heat the second molding material to a second temperature.

In some embodiments of the present technology, the second temperature can be higher than the first temperature. A special technical effect attributable to at least some of these embodiments is at ability to fill the base 102 with the first molding material with comparatively lower temperature (allowing it to cool comparatively faster), while providing ability to still fill in the hinge 106 and the lid 104 by relying on the second molding material having comparatively higher temperature (thus, be more flowable and allowing for filling relatively thinner parts, i.e. the hinge 106 and the lid 104).

With reference to Figure 13, there is depicted a block diagram of a method 1300. The method 1300 is executable in the injection molding machine 200 controlled by the machine controller 242. The injection molding machine 200 comprises inter alia: the mold 208 defining a mold cavity 214 for producing the flip top closure 100. The mold cavity 214 can have a base defining portion for defining the base 102 and a lid defining portion for defining the lid 104 and at least a portion of the hinge 106. Within these embodiments of the present technology, the mold cavity 214 is further provided with a blocking structure 980, the blocking structure 980 for selectively fluidly separating the hinge defining portion from the base defining portion for selectively blocking flow of molding material therebetween.

Step 1302 - actuating the blocking structure 980 to block a passage between the base defining portion of the hinge defining portion

The method 1300 begins at step 1302, where the machine controller 242 causes actuation of the blocking structure 980 to block a passage between the base defining portion of the hinge defining portion.

Step 1304 - injecting, via a coinjection gate 240', a first molding material 402 into the base defining portion to fill, at least partially, the base defining portion

At step 1304, the machine controller 242 causes injection, via a coinjection gate 240' , a first molding material 402 into the base defining portion to fill, at least partially, the base defining portion. Step 1306 - coinjecting, through the coinjection gate 240', a second molding material as a core flow within the flow of the first molding material

At step 1306, the machine controller 242 causes coinjection, through the coinjection gate 240', a second molding material as a core flow within the flow of the first molding material 402.

Step 1308 - terminating the flow of the first molding material

At step 1306, the machine controller 242 causes termination of the flow of the first molding material 402.

Step 1310 - actuating the blocking structure 980 to open the passage between the base defining portion and the hinge defining portion

At step 1310, the machine controller 242 causes actuation of the blocking structure 980 to open the passage between the base defining portion and the hinge defining portion.

Step 1312 - continuing injecting only the second molding material to fill the hinge defining portion and the lid defining portion At step 1312, the machine controller causes continuation of injecting only the second molding material 406 to fill the hinge defining portion and the lid defining portion.

Of course, the above described embodiments are intended to be illustrative only and in no way limiting. The described embodiments are susceptible to many modifications of form, arrangement of parts, details and order of operation. The invention, rather, is intended to encompass all such modification within its scope, as defined by the claims.

As such, embodiments of the present technology can be summarized as follows, structured in numbered clauses.

CLAUSE 1. A method (800) of injection molding a flip top closure (100) having a body that includes a base (102) and a lid (104) connected by a hinge (106), the method (800) executable in an injection molding machine (200) controlled by a machine controller (242), the injection molding machine (200) including a mold (208) defining a mold cavity (214) for producing the flip top closure (100), the mold cavity (214) having a base defining portion for defining the base (102) and a lid defining portion for defining the lid (104) and at least a portion of the hinge (106), the method (800) comprising: injecting (802), via a first gate (240a), a first molding material (402) into the base defining portion; injecting (804), via a second gate (240b), a second molding material (406) into the mold cavity (214); controlling (806), by the machine controller (242), the injecting of the first molding material (402) and the injection of the second molding material (406), such that they are executed at least partially sequentially and the injecting (804) of the second molding material (406) is commenced with the first molding material (402) passing the second gate (240b).

CLAUSE 2. The method (800) of clause 1 , wherein the first molding material (402) and the second molding material (406) are a same polymer.

CLAUSE 3. The method (800) of any one clause 1 or 2, wherein the controlling (806) further comprises: controlling an injection temperature of the first molding material (402) to a first temperature; controlling an injection temperature of the second molding material (406) to a second temperature.

CLAUSE 4. The method (800) of clause 3, wherein the second temperature is higher than the first temperature.

CLAUSE 5. The method (800) of any one of clauses 1 to 4, wherein the first molding material (402) is high density polyethylene and the second molding material (406) is polypropylene.

CLAUSE 6. The method (800) of any one of clauses 1 to 5, the controlling (806) further comprises terminating injecting of the first molding material (402) prior to commencing the injecting of the second molding material (406). CLAUSE 7. The method (800) of any one of clauses 1 to 5, wherein the controlling (806) further comprises commencing the injecting of the second molding material (406) before terminating injecting the first molding material (402), such that the injecting of the second molding material (406) follows the injecting of the first molding material (402).

CLAUSE 8. The method (800) of any one of clauses 1 to 7, wherein the first gate (240a) is located in the body defining portion of the mold cavity (214) and the second gate (240b) is located proximate to the lid defining portion of the mold cavity (214).

CLAUSE 9. The method (800) of clause 8, wherein the second gate (240b) is located upstream, relative to the first gate (240a), from the lid defining portion. CLAUSE 10. The method (800) of clause 8, wherein the second gate (240b) is located downstream from the lid defining portion and the first gate (240a).

CLAUSE 11. The method (800) of any one clause 1 to 4, wherein the first molding material (402) and the second molding material (406) are supplied from a single molding material source (216). CLAUSE 12. The method (800) of any one clause 1 to 4, wherein the first molding material (402) is supplied from a first molding material source (216) and the second molding material (406) is supplied from a second molding material source.

CLAUSE 13. An injection molding machine (200) for producing a flip top closure (100) having a body that includes a base (102) and a lid (104) connected by a hinge (106), the injection molding machine (200) comprising: an injection unit (216) for plasticising molding material; a mold (208) defining a mold cavity (214) for producing the flip top closure (100), the mold cavity (214) having a base defining portion for defining the base (102) and a lid defining portion for defining the lid (104) and at least a portion of the hinge (106), a machine controller (242) for controlling operations of the injection unit (216) and the mold (208), the machine controller (242) configured to execute the method of any one clause 1 to 12.

CLAUSE 14. A method (1300) of injection molding a flip top closure (100) having a body that includes a base (102) and a lid (104) connected by a hinge (106), the method (800) executable in an injection molding machine (200) controlled by a machine controller (242), the injection molding machine (200) including a mold (208) defining a mold cavity (214) for producing the flip top closure (100), the mold cavity (214) having a base defining portion for defining the base (102) and a lid defining portion for defining the lid (104) and at least a portion of the hinge (106), the base defining portion and the hinge defining portion being separated by a blocking structure (980) for selectively blocking flow of molding material therebetween, the method (800) comprising: actuating (1302) the blocking structure (980) to block a passage between the base defining portion of the hinge defining portion; injecting (1304), via a coinjection gate (240'), a first molding material (402) into the base defining portion to fill, at least partially, the base defining portion; coinjecting (1306), through the coinjection gate (240'), second molding material (406) as a core flow within the flow of the first molding material; terminating (1308) the flow of the first molding material (402); actuating (1310) the blocking structure (980) to open the passage between the base defining portion and the hinge defining portion; continuing (1312) injecting only the second molding material (406) to fill the hinge defining portion and the lid defining portion.

CLAUSE 15. The method (1300) of clause 14, wherein the first molding material (402) is high density polyethylene and the second molding material (406) is polypropylene. CLAUSE 16. The method (1300) of clause 14, wherein the first molding material (402) and the second molding material (406) are a same polymer.

CLAUSE 17. The method (1300) of any one clauses 14 to 16, the method further comprises: controlling an injection temperature of the first molding material (402) to a first temperature; controlling an injection temperature of the second molding material (406) to a second temperature.

CLAUSE 18. The method (1300) of clause 17, wherein the second temperature is higher than the first temperature. CLAUSE 19. The method (1300) of any one of clauses 14 to 18, wherein the first molding material (402) is supplied from a first molding material source (216) and the second molding material (406) is supplied from a second molding material source. CLAUSE 20. An injection molding machine (200) for producing a flip top closure (100) having a body that includes a base (102) and a lid (104) connected by a hinge (106), the injection molding machine (200) comprising: an injection unit (216) for plasticising molding material; a mold (208) defining a mold cavity (214) for producing the flip top closure

(100), the mold cavity (214) having a base defining portion for defining the base (102) and a lid defining portion for defining the lid (104) and at least a portion of the hinge (106), the mold (208) further including: a blocking structure (980) positioned between the base defining portion and the hinge defining portion for selectively blocking flow of molding material therebetween; a machine controller (242) for controlling operations of the injection unit (216) and the mold (208), the machine controller (242) configured to execute the method of any one of clauses 14 to 19. It is noted that the foregoing has outlined some of the more pertinent non-limiting implementations. It will be clear to those skilled in the art that modifications to the disclosed non-limiting implementations can be effected without departing from the spirit and scope thereof. As such, the described non-limiting implementations 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 implementations in a different manner or modifying them in ways known to those familiar with the art. The mixing and/or matching of features, elements and/or functions between various non-limiting implementations are expressly contemplated herein as one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one implementation may be incorporated into another implementation as appropriate, unless expressly described otherwise, above. Although the description is made for particular arrangements and methods, the intent and concept thereof may be suitable and applicable to other arrangements and applications.

Claims

WHAT IS CLAIMED:

1. A method (800) of injection molding a flip top closure (100) having a body that includes a base (102) and a lid (104) connected by a hinge (106), the method (800) executable in an injection molding machine (200) controlled by a machine controller (242), the injection molding machine (200) including a mold (208) defining a mold cavity (214) for producing the flip top closure (100), the mold cavity (214) having a base defining portion for defining the base (102) and a lid defining portion for defining the lid (104) and at least a portion of the hinge (106), the method (800) comprising: injecting (802), via a first gate (240a), a first molding material (402) into the base defining portion; injecting (804), via a second gate (240b), a second molding material (406) into the mold cavity (214); controlling (806), by the machine controller (242), the injecting of the first molding material (402) and the injection of the second molding material (406), such that they are executed at least partially sequentially and the injecting (804) of the second molding material (406) is commenced with the first molding material (402) passing the second gate (240b).

2. The method (800) of claim 1, wherein the first molding material (402) and the second molding material (406) are a same polymer.

3. The method (800) of claim 2, wherein the controlling (806) further comprises: controlling an injection temperature of the first molding material (402) to a first temperature; controlling an injection temperature of the second molding material (406) to a second temperature.

4. The method (800) of claim 3, wherein the second temperature is higher than the first temperature.

5. The method (800) of claim 1, wherein the first molding material (402) is high density polyethylene and the second molding material (406) is polypropylene.

6. The method (800) of claim 1, the controlling (806) further comprises terminating injecting of the first molding material (402) prior to commencing the injecting of the second molding material (406).

7. The method (800) of claim 1, wherein the controlling (806) further comprises commencing the injecting of the second molding material (406) before terminating injecting the first molding material (402), such that the injecting of the second molding material (406) follows the injecting of the first molding material (402).

8. The method (800) of claim 1, wherein the first gate (240a) is located in the body defining portion of the mold cavity (214) and the second gate (240b) is located proximate to the lid defining portion of the mold cavity (214).

9. The method (800) of claim 8, wherein the second gate (240b) is located upstream, relative to the first gate (240a), from the lid defining portion.

10. The method (800) of claim 8, wherein the second gate (240b) is located downstream from the lid defining portion and the first gate (240a).

11. The method (800) of claim 1 , wherein the first molding material (402) and the second molding material (406) are supplied from a single molding material source (216).

12. The method (800) of claim 1, wherein the first molding material (402) is supplied from a first molding material source (216) and the second molding material (406) is supplied from a second molding material source.

13. An injection molding machine (200) for producing a flip top closure (100) having a body that includes a base (102) and a lid (104) connected by a hinge (106), the injection molding machine (200) comprising: an injection unit (216) for plasticising molding material; a mold (208) defining a mold cavity (214) for producing the flip top closure (100), the mold cavity (214) having a base defining portion for defining the base (102) and a lid defining portion for defining the lid (104) and at least a portion of the hinge (106), a machine controller (242) for controlling operations of the injection unit (216) and the mold (208), the machine controller (242) configured to execute: injecting (802), via a first gate (240a), a first molding material (402) into the base defining portion; injecting (804), via a second gate (240b), a second molding material (406) into the mold cavity (214); controlling (806), by the machine controller (242), the injecting of the first molding material (402) and the injection of the second molding material (406), such that they are executed at least partially sequentially and the injecting (804) of the second molding material (406) is commenced with the first molding material (402) passing the second gate (240b).

14. The injection molding machine (200) of claim 13, wherein the first molding material (402) and the second molding material (406) are a same polymer.

15. The injection molding machine (200) of claim 14, wherein the step of controlling (806) further comprises: controlling an injection temperature of the first molding material (402) to a first temperature; controlling an injection temperature of the second molding material (406) to a second temperature.

16. The injection molding machine (200) of claim 15, wherein the second temperature is higher than the first temperature.

17. The injection molding machine (200) of claim 13, wherein the first molding material (402) is high density polyethylene and the second molding material (406) is polypropylene.

18. The injection molding machine (200) of claim 13, the step of controlling (806) further comprises terminating injecting of the first molding material (402) prior to commencing the injecting of the second molding material (406).

19. The injection molding machine (200) of claim 13, wherein the step of controlling (806) further comprises commencing the injecting of the second molding material (406) before terminating injecting the first molding material (402), such that the injecting of the second molding material (406) follows the injecting of the first molding material (402).

20. The injection molding machine (200) of claim 13, wherein the first gate (240a) is located in the body defining portion of the mold cavity (214) and the second gate (240b) is located proximate to the lid defining portion of the mold cavity (214).

21. The injection molding machine (200) of claim 20, wherein the second gate (240b) is located upstream, relative to the first gate (240a), from the lid defining portion.

22. The injection molding machine (200) of claim 20, wherein the second gate (240b) is located downstream from the lid defining portion and the first gate (240a).

23. The injection molding machine (200) of claim 13, wherein the first molding material (402) and the second molding material (406) are supplied from a single molding material source (216).

24. The injection molding machine (200) of claim 13, wherein the first molding material (402) is supplied from a first molding material source (216) and the second molding material (406) is supplied from a second molding material source.

25. A method (1300) of injection molding a flip top closure (100) having a body that includes a base (102) and a lid (104) connected by a hinge (106), the method (800) executable in an injection molding machine (200) controlled by a machine controller (242), the injection molding machine (200) including a mold (208) defining a mold cavity (214) for producing the flip top closure (100), the mold cavity (214) having a base defining portion for defining the base (102) and a lid defining portion for defining the lid (104) and at least a portion of the hinge (106), the base defining portion and the hinge defining portion being separated by a blocking structure (980) for selectively blocking flow of molding material therebetween, the method (800) comprising: actuating (1302) the blocking structure (980) to block a passage between the base defining portion of the hinge defining portion; injecting (1304), via a coinjection gate (240'), a first molding material (402) into the base defining portion to fill, at least partially, the base defining portion; coinjecting (1306), through the coinjection gate (240'), a second molding material (406) as a core flow within the flow of the first molding material; terminating (1308) the flow of the first molding material (402); actuating (1310) the blocking structure (980) to open the passage between the base defining portion and the hinge defining portion; continuing (1312) injecting only the second molding material (406) to fill the hinge defining portion and the lid defining portion.

26. The method (1300) of claim 25, wherein the first molding material (402) is high density polyethylene and the second molding material (406) is polypropylene.

27. The method (1300) of claim 25, wherein the first molding material (402) and the second molding material (406) are a same polymer.

28. The method (1300) of claim 27, the method further comprises: controlling an injection temperature of the first molding material (402) to a first temperature; controlling an injection temperature of the second molding material (406) to a second temperature.

29. The method (1300) of claim 28, wherein the second temperature is higher than the first temperature.

30. The method (1300) of claim 25, wherein the first molding material (402) is supplied from a first molding material source (216) and the second molding material (406) is supplied from a second molding material source.

31. An injection molding machine (200) for producing a flip top closure (100) having a body that includes a base (102) and a lid (104) connected by a hinge (106), the injection molding machine (200) comprising: an injection unit (216) for plasticising molding material; a mold (208) defining a mold cavity (214) for producing the flip top closure (100), the mold cavity (214) having a base defining portion for defining the base (102) and a lid defining portion for defining the lid (104) and at least a portion of the hinge (106), the mold (208) further including: a blocking structure (980) positioned between the base defining portion and the hinge defining portion for selectively blocking flow of molding material therebetween; a machine controller (242) for controlling operations of the injection unit (216) and the mold (208), the machine controller (242) configured to execute: actuating (1302) the blocking structure (980) to block a passage between the base defining portion of the hinge defining portion; injecting (1304), via a coinjection gate (240'), first molding material (402) into the base defining portion to fill, at least partially, the base defining portion; coinjecting (1306), through the coinjection gate (240'), a second molding material (406) as a core flow within the flow of the first molding material; terminating (1308) the flow of the first molding material (402); actuating (1310) the blocking structure (980) to open the passage between the base defining portion and the hinge defining portion; continuing (1312) injecting only the second molding material (406) to fill the hinge defining portion and the lid defining portion.