TWI708672B - Method for co-injection with continuous injection molding - Google Patents

Abstract

A carousel-like continuous co-injection molding system includes an arrangement of upper and lower inclined feed channels. Each of the feed channels has a valve therein positioned upstream of an inlet to an associated mold cavity. The valve is controllable so that adjustments may be made in real time to achieve or maintain delivery of molten polymeric material to the mold cavity at constant pressure.

Description

Co-injection method with continuous injection molding

This application generally relates to an injection molding system and, more specifically, to an apparatus and method for producing a coinjection molded part under a low constant pressure by continuously feeding molten polymer material to a plurality of cavities. A cavity rotates around an axis including at least a first nozzle and a second nozzle.

Injection molding is a technique commonly used for high volume manufacturing of parts made of fusible materials (most often parts made of thermoplastic polymers). The injection molding process mainly used in the industry today is intermittent, which means that all processes occur in a sequential manner and therefore each step must be completed before the next step can start. A plastic resin (most often in the form of beads or pellets) is introduced into an injection molding machine that melts the resin beads under heat, pressure, and shear. The molten resin is forcibly injected into a mold cavity with a specific cavity property. The injected plastic is held in the cavity under pressure, cooled, and then removed as a solidified part having a shape that essentially replicates the cavity shape of the mold. Repeat this procedure to produce multiple parts using the same mold. The mold itself can have a single cavity or multiple cavities. If more than one molten material is injected into a mold, the injection molding procedure refers to coinjection.

US Patent Application No. 13/774,692 (incorporated herein by reference) describes a coinjection procedure in a substantially constant pressure injection molding system. There are several limitations and challenges demonstrated by both intermittent injection molding and co-injection molding. For example, the conventional intermittent injection molding is due to the need to execute each stage or step sequentially, and it is necessary to lengthen a part to form circulation time. In addition, since the clamp tonnage must hold multiple cavities closed at the same time, the use of intermittent injection molding to produce a large number of parts requires large equipment to hold the mold closed. The conventional multi-cavity intermittent injection molding system also occupies a large area to receive multiple mold cavities. The conventional co-injection molding shows the manufacturing challenge of maintaining the synchronous flow front velocity of the material introduced into the cavity to maintain a uniform distribution of one of the materials in the cavity. The conventional co-injection molding further requires: the thickness of the part is at least 1mm to avoid an inner layer from bulging and an outer layer. These and other restrictions and challenges limit the situations where intermittent and co-injection molding procedures can be used.

One way to use intermittent injection molding to solve these problems is to "compress" molded objects. This approach includes: 1) extruding the melted polymer; 2) trimming a "plug" of the extruded polymer to a predetermined length (to achieve a target volume of the polymer); 3) The plug is deposited into a bottom mold cavity; and 4) an upper mold half is compressed to a bottom mold half to form a shaped part. This approach can be done on a continuous rotating platform that allows all steps to be completed at the same time, resulting in very high productivity and lower cost. However, there are several trade-offs. First, when touching the cooled bottom mold half, the polymer "plug" freezes immediately, which results in a significant matte or rough surface texture (a poor quality defect) on the molded part. Second, the design of the mold must be very simple so that when the upper mold half is close to the bottom mold half, the part is formed by compression force, which greatly limits the design of the parts that may use this forming technology.

An alternative approach is to continuously feed the polymer to a plurality of cavities arranged around a central polymer source in a rotating rack. In the existing continuous injection molding system of this nature that has been proposed or practiced, it should be understood that the mold cavities are arranged in a plane, center radiating manner around the central polymer source, and the polymer source outlet or nozzle is located at the same The entrance of each of the cavity is in the same plane. One of the disadvantages of this configuration is the large footprint required to accommodate all the mold cavities. Another disadvantage is the amount of energy necessary to propagate the polymer along the horizontally extending feed channel connecting the nozzle and the cavity. An additional disadvantage is the lack of The ability to adjust pressure instantly. In at least one of the previous disclosures of a rotating rack type continuous forming system, the system has a gate valve actuator for positioning and controllably connecting the forming cavity to a valve pin of a shooting tank. The gate valve operates according to a gate valve cam profile for actuation of the valve pin. Because the actuation of the valve depends on a cam track, when a mold position rotates around the rotating rack, the valve position is specified by the orientation of the mold position. Therefore, there is no ability to adjust the melt flow to increase or decrease the pressure. The only variable to determine the rate and pressure of the melt flow to a given cavity is the degree to which the valve is opened or closed, but is unable to accurately adjust the position of the valve. Any pressure that may be required will have to be This is done by adjusting the output rate of an extruder or other source of molten polymer material.

The present invention provides a solution to the problems of both intermittent injection molding and coinjection by using a substantially constant pressure filling procedure that also features coinjection.

A new continuous injection molding approach is realized by using a newly discovered substantially constant pressure filling procedure (which is suitable for producing a high-quality part even at very low filling pressure). The new continuous injection molding approach uses intermittent injection molding to solve the problem. The new procedure involves: 1) extruding the polymer onto a rotary feeder element on a continuous basis; 2) measuring the flow of molten polymer material into the mold cavity through a valve or measuring plate; 3) in the mold cavity Cool the polymer in the middle; 4) inject the part from the mold cavity; and 5) close the mold cavity to prepare the cavity to receive another "shot" (shot) of molten polymer material. Repeat the procedure on a continuous basis.

The substantially constant, low-pressure injection molding also provides an environment conducive to the use of conventional co-injection molding to solve problems. When the injection system for each of two or more materials co-injecting each other into a mold cavity maintains a constant and equal pressure, the flow rate of each of the materials is also equal in the mold cavity. This provides a more consistent layer thickness and eliminates the need for highly complex control algorithms, expensive equipment, and time-consuming iteration procedures to define acceptable program settings to achieve the desired layer thickness. In addition, when the material is co-injected at a lower constant pressure When used in a mold made of a material with high thermal conductivity, it is not necessary to provide this thick external material to achieve the flow of the second material relative to the first. Therefore, multi-layer coinjection parts can achieve a total thickness of even less than 0.5 mm and materials with inferior physical properties can be used as a core material in injection molded parts with a thin wall.

The present invention involves: 1) supplying one of a first molten polymer material to continuously flow to an upper rotary feeder element by some motive (such as extrusion); 2) supplying a second molten polymer material to continuously flow to a lower part Rotary feeder element; 3) Simultaneously measure the flow of the first molten polymer material to the mold cavity and the flow of the second molten polymer material to the mold cavity through a measuring plate (or measuring gate) or valve; 4) In Cool the polymer in the mold cavity; 4) inject the part from the mold cavity; and 5) close the mold cavity to prepare a mold cavity to receive another "injection" to melt the polymer material. Repeat the procedure on a continuous basis.

The upper feed channel of the continuous coinjection molding system of the present invention provides the first molten polymer material to each mold, and the lower feed channel of the continuous coinjection molding system of the present invention provides the second molten polymer material to each mold . It is recognized that the second molten polymeric material may differ from the first molten polymeric material in one or more of various characteristics or attributes, such as color, viscosity, flow rate, melting point, freezing point, and regrind content. Supplying the first molten polymer material to one of the upper feed channels. The first nozzle is located at a first height higher than the second molten polymer material being supplied to one of the lower feed channels. One of the second nozzles has a second height. The second height of the second nozzle may be a height or a third height equal to the entrance of each of the mold cavities. Therefore, each of the upper feeding channels of the present invention is arranged at a slope. Each of the lower feed channels of the present invention can also be arranged at a slope or alternatively arranged on the same plane as the cavity (such as arranged in a central radial distribution).

The continuous forming system of the present invention is particularly suitable for operating at a substantially constant pressure when filling each cavity. The present invention also recognizes that it is desirable to make small adjustments to the pressure of molten polymer material entering individual mold cavities based on real-time measurements. These feed channels may have The measuring gate or controllable valve (such as a ball valve, needle valve or measuring plate) actuated by the pressure increase of the molten polymer material at the entrance of the cavity associated with the inclined feed channel while maintaining substantially The molten polymer material is conveyed to the inlet of the mold cavity in fluid communication with the feed channel upstream of the mold cavity (between the plurality of closed mold cavities) under constant pressure.

A substantially constant pressure injection molding system allows the filling stage of injection molding to occur simultaneously under the same (or substantially the same) pressure as the filling stage of injection molding, which advantageously reduces cycle time and avoids the need to increase pressure at the end of filling, In order to avoid the adverse effects of shrinkage after the cooling of the injection molded product. However, even in a substantially constant pressure multi-cavity injection molding system, it is still desirable to be able to have a limited ability to adjust the pressure of the molten polymer material introduced into the mold cavity. Some injection molding systems control the pressure by adjusting a nozzle and manifold or the rate of rotation upstream of an extruder system in the feed system. One of the disadvantages of these systems is a sensing condition (for example, pressure, temperature, viscosity, or flow rate) at a specific location (such as a gate, a mold cavity entrance) or a location along an inside of a mold cavity There is an inherent lag between the pressure adjustment and the pressure adjustment. This is because the pressure adjustment takes some time (even assuming that the controller can instantaneously process a signal from a sensor that indicates a change in the pressure and a sensing condition) And instruct the extruder system to change its compensation speed; due to the time it takes for the molten polymer material to travel from the extruder system to the sensing position, the pressure before the resulting pressure change is achieved at the sensing position Adjusting takes some time). U.S. Patent Application No. 13/476,047 entitled "Alternative Pressure Control for a Low Constant Pressure Injection Molding Apparatus" (the entirety of which is incorporated herein by reference) discloses and describes the use of an active closed loop controller to regulate and To achieve a substantially constant pressure for melting one of the polymeric materials, and other pressures that use adjustment devices to maintain a substantially constant melt pressure. For example, a pressure relief valve is disclosed in which a set point of the pressure relief valve is lower than the melt pressure on the melt holder side of the pressure relief valve, when the pressure of the molten polymer material exceeds a set point of the pressure relief valve At this time, the pressure relief valve discharges part of the molten polymer material through a pressure relief outlet.

Using the ability to actuate the controllable valves of the individual feed channels of the present invention, the continuous molding system facilitates more instantaneous correction or pressure adjustment than a closed loop controller that adjusts the rotation rate of an extruder system in an injection molding system This is because the pressure adjustment is implemented by placing a valve immediately upstream of an inlet of the cavity. In this respect, the controllable valves of the individual feed channels of the continuous forming system of the present invention provide a pressure adjustment very close to the inlet of the mold cavity, similar to the one achieved by the pressure relief valve of US Application No. 13/476,047 advantage. In addition, since the control valves that can be individually actuated are not limited to a single set point, but can be variably opened or closed to the desired degree to adjust the pressure in real time, the control valves that can be individually actuated provide better performance in forming operations. Great flexibility. An extruder system (if necessary) of the continuous forming system can also add a boost in addition to the pressure generated by the rotation. In addition, using one of the valves in a step-by-step filling procedure can provide better injection control. The opening/closing (valve control) can be located at the extruder, at the nozzle or at each cavity.

In continuous injection molding, each cavity can be fed through a rotary feeding system. In the feeding system, each feeding pipeline can be adjusted by a hydraulic or pneumatic valve. This rotary feeding system has the ability to limit or close.

10: Exemplary low constant pressure injection molding device

12: Injection system

14: Clamping system

16: Thermoplastic pellets

18: Funnel

20: heating sleeve

22: Extruder system/screw

24: Melting thermoplastic materials

25: The first mold part

26: Nozzle

27: The second mold part

28: Mould

30: Gate

32: Mould cavity

34: Press or clamping unit / clamping system

36: Screw control

50: Active, closed loop controller

52: Sensor

54: Wired connector

56: Wired connector

180: Exemplary low constant pressure coinjection manifold

182: First machine nozzle path

184: first material

186: Second machine nozzle path

188: second material

190: Co-injection tip

192: Heat pipe tip hole

194: Mould Cavity

196: Opposite End

200: The first screw pump

202: The second screw pump

204: Rotating motor

206: Funnel

208: Screw

210: The first nozzle

212: second nozzle

214a: Upper feed channel

214b: Upper feed channel

214c: upper feed channel

216a: Lower feed channel

216b: Lower feed channel

216c: Lower feed channel

220: Mould Cavity

220a: mold cavity

220b: mold cavity

220c: mold cavity

220n: mold cavity

222: Mold cavity/core board

224: Co-injection manifold

226: Single entrance/first entrance

228: Second Entrance

230: mold core

230a: core

230b: core

230c: core

230n: core

232: Cam follower roller

234: cam track

236: Measuring gate or valve

A: Arrow

Y ₁ : first height

Y ₂ : second height

Y ₃ : third height

Although this specification ends with the scope of patent application, the scope of patent application is specifically pointed out and clearly regarded as the subject of the present invention, but it is believed that the present invention will be more fully understood from the following description with the accompanying drawings. Some figures may have been simplified by omitting selected components for the purpose of showing other components more clearly. Such omission of elements in some figures does not necessarily indicate the presence or absence of a particular element in any of the illustrative embodiments, unless it can be explicitly depicted in the corresponding written description. No scheme is necessarily drawn to scale.

As used herein, the term "injection point" refers to the position in the forming device where the injection of molten thermoplastic material enters the cavity. For example, for a forming device having a single cavity coupled to a nozzle, the injection point may be located at or adjacent to the nozzle. Alternatively, for mold cavities having a plurality of mold cavities and for transferring the molten thermoplastic material from the nozzle to the molds Each of the cavities is a forming device of the runner system, and the injection point may be the contact point between the runner system and each of the individual mold cavities. When the molten thermoplastic material is transported through the runner system, the shot including the molten thermoplastic material is maintained at a substantially constant melt pressure. Generally, the runner system is a heating runner system that maintains the melt temperature of the shot including the molten thermoplastic material when the molten thermoplastic material is transported to the mold cavities.

As used herein, the term "low pressure" with respect to the melt pressure of a thermoplastic material means the melt pressure near a nozzle of an injection molding machine of about 15,000 psi and lower.

As used herein, the term "melt" refers to a molten material, which is usually a polymeric material that is transported to the mold cavity through a feed system, where the polymeric material solidifies into a finished part.

As used herein, the term "melt pressure" refers to the pressure of a shot including molten thermoplastic material when the molten thermoplastic material is injected into and fills a cavity of a forming device. During the filling of substantially the entire mold cavity, the melt pressure of the shot including the molten thermoplastic material remains substantially constant. As used herein, the term "cavity pressure" refers to the pressure in a closed cavity. For example, a pressure sensor placed inside the cavity can be used to measure the cavity pressure. In an embodiment of the method, before injecting the shot including the molten thermoplastic material into the mold cavity, the cavity pressure is different from the pre-injection pressure of the shot including the molten thermoplastic material. For example, the cavity pressure may be less than the pre-injection pressure of the shot including the molten thermoplastic material. In another embodiment, the cavity pressure may be greater than the pre-injection pressure of the shot including the molten thermoplastic material. For example, before injection, the cavity pressure may be different (greater than or less than) the pre-injection pressure of the shot including the molten thermoplastic material by at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, At least 40% or at least 50%. In one embodiment, the cavity pressure is different from (greater than or less than) the pre-injection pressure of the shot including the molten thermoplastic material by at least 15 psi. In various embodiments, the cavity pressure can be atmospheric pressure before injection. In other embodiments, the cavity pressure may be greater than One of atmospheric pressure. In yet another embodiment, the cavity can be maintained in a vacuum before injection.

As used herein, the term "motivation" refers to a means by which a melt is produced to move from a press nozzle to a part cavity. This can be achieved by positive displacement or positive pressure means or a combination thereof.

As used herein, the term "non-fluid temperature" refers to the temperature at which the viscosity of the thermoplastic material is so high that the thermoplastic material is effectively unable to be forced to flow.

As used herein, the term "pre-injection pressure" with respect to the shot including molten thermoplastic material means that after the thermoplastic material has been heated to a molten state in a heating sleeve and prepared into the shot, and just after The pressure of the thermoplastic material before injecting the shot including the molten thermoplastic material into the mold cavity or forming a runner or feed system in fluid communication with the nozzle and the mold cavity. The pre-injection pressure of the shot including the molten thermoplastic material may not be equal to the pressure of the cavity before injection. In one embodiment, prior to injection, the cavity may be, for example, under atmospheric pressure. In another embodiment, the cavity may have a slight positive pressure. In yet another embodiment, a vacuum can be induced in the cavity.

As used herein, the term "substantially constant pressure" with respect to a melt pressure of a thermoplastic material means that a deviation from a baseline melt pressure does not produce a meaningful change in the physical properties of the thermoplastic material. For example, "substantially constant pressure" includes, but is not limited to, pressure changes for which the viscosity of the molten thermoplastic material does not change meaningfully. In this regard, the term "substantially constant" includes a deviation of approximately 30% from a baseline melt pressure. For example, the term "a substantially constant pressure of about 4600 psi" includes pressures that fluctuate up to about 6000 psi (up to 30% above 4600 psi) to about 3200 psi (up to 30% below 4600 psi). As long as the melt pressure fluctuation is not more than 30% from the listed pressure, a melt pressure is considered to be substantially constant.

The term "valve" refers to a mechanism that regulates the mass flow of melt through a point in a feed system, which includes the ability to completely block the flow. One valve can use one rotatable ball Valve, gate valve, butterfly valve, needle valve, aperture type valve, tongue valve, reed valve, flap valve, diaphragm valve, disc valve, check (ball type) valve, check (ring type) valve, duckbill Valve or some other type of valve.

Fig. 1 shows a schematic front view of an exemplary low constant pressure injection molding apparatus; Fig. 2 is a cross-sectional view of a molding assembly including a multi-cavity mold and a co-injection manifold; Fig. 3 is the present invention A perspective view of a continuous co-injection molding system. The continuous co-injection molding system includes: a first pump that provides a continuous supply of a first molten polymer material and a plurality of positions arranged at a steep angle relative to the molds A combination of two upper feeding channels; and a second pump that provides a continuous supply of a second molten polymer material and a combination of a plurality of lower feeding channels arranged at a smaller angle relative to one of the molds; 3A is a top view of the embodiment of FIG. 3 and shows a rotating cavity/core plate with a cam track therein; FIG. 3B shows one of the cores surrounding the nozzle of the continuous supply of molten polymer material in FIG. 3 A curve diagram of the radius of the cam track over time during rotation; Fig. 4 is an exploded view of the continuous coinjection molding system of the present invention depicted in Fig. 3; Fig. 5 is an exploded view of the continuous coinjection molding system of the present invention In a perspective view, the continuous coinjection molding system includes: a first pump that provides a combination of a continuous supply of a first molten polymer material and a plurality of upper feed channels arranged at an angle relative to the molds; And a second pump, which provides a continuous supply of a second molten polymer material and a combination of a plurality of lower feed channels arranged on the same plane as the molds; FIG. 6 is a combination of the present invention depicted in FIG. 5 An exploded view of the continuous coinjection molding system; FIG. 7 is a perspective view of a continuous coinjection molding system according to an alternative embodiment of the present invention.

The embodiments of the present invention may use materials, structures, and/or any and all embodiments of the features, methods, and materials used for injection molding under a substantially constant pressure as disclosed in the following U.S. patent applications: "Apparatus and Method for Injection Molding at Low Constant Pressure" U.S. Patent Application No. 13/476,045 (Application Reference 12127); U.S. Patent Application No. 13/ entitled "Apparatus and Method for Injection Molding at Low Constant Pressure" No. 601,307 (reference 12127D of the application); U.S. Patent Application No. 13/476,047 named "Alternative Pressure Control for a Low Constant Pressure Injection Molding Apparatus" (reference 12128 of the application); named "Injection Molding System Having Simplified Cooling" U.S. Patent Application No. 13/774,571 (application reference 12129); U.S. Patent Application No. 13/476,073 named "Non-Naturally Balanced Feed System for an Injection Molding Apparatus" (the application Reference 12130), U.S. Patent Application No. 13/476,197 named "Method for Injection Molding at Low, Substantially Constant Pressure" (reference 12131Q of the application), named "Method for Injection Molding at Low, Substantially Constant Pressure" US Patent Application No. 13/476,178 (Application Reference 12132Q); US Patent Application No. 13/601,338 titled "Method for Injection Molding at Low, Substantially Constant Pressure" (Application Reference: 1213D2Q) ; U.S. Patent Application No. 13/774,692 named "High Thermal Conductivity Co-Injection Molding System" No. (Application reference: 12361); U.S. Patent Application No. 13/601,359 named "Injection Mold Having A Simplified Evaporative Cooling System or a Simplified Cooling System With Exotic" (Application reference: 12453); Name is "Injection Mold Having A Simplified Evaporative Cooling System or a Simplified Cooling System With Exotic Cooling Fluids" U.S. Patent Application No. 13/765,425 (Application Reference: 12453M); U.S. Patent Application entitled "Method and Apparatus for Substantially Constant Pressure Injection Molding of Thinwall Parts" Case No. 13/476,584 (Reference of Application: 12487); U.S. Patent Application No. 13/601,514 (Reference of Application: 12487D) entitled "Method and Apparatus for Substantially Constant Pressure Injection Molding of Thinwall Parts"; U.S. Patent Application No. 13/672,246 named "Injection Mold with Failsafe Mechanism" (reference to the application: 12659); U.S. Patent Application No. 13/ named "A Method for Operating A High Productivity Injection Molding Machine" No. 682,456 (reference to the application: 12673R); U.S. Provisional Application No. 61/728,764 entitled "Methods of Molding Compositions of Thermoplastic Polymer and Hydrogenated Castor Oil" (reference to the application: 12674P); titled "Reduced Size Runner for an Injection Mold System" US Provisional Application No. 61/729,028.

FIG. 1 shows an exemplary low constant pressure injection molding device 10 used to produce thin-walled parts with high volume (for example, a type 101 or 102 injection mold, or a "ultra-high productivity mold"). The injection molding device 10 generally includes an injection system 12 and a clamping system 14. A thermoplastic material may be introduced into the injection system 12 in the form of thermoplastic pellets 16. The thermoplastic pellets 16 are placed in a hopper 18 that feeds the thermoplastic pellets 16 to a heating sleeve 20 of the injection system 12. After being fed to the heating sleeve 20, the thermoplastic pellets 16 can be driven to the heating sleeve 20 by an extruder system 22. The heating of the heating sleeve 20 and the thermoplastic pellets 16 are compressed by the extruder system 22 to cause the thermoplastic pellets 16 to melt to form a molten thermoplastic material 24. The molten thermoplastic material is generally processed at a temperature between about 130°C and about 410°C.

The extruder system 22 forces the molten thermoplastic material 24 toward a nozzle 26 to form a shot of thermoplastic material, which will be injected into a cavity 32 of a mold 28. Melting thermoplastic material 24 The injection may pass through a gate 30 which directs the flow of molten thermoplastic material 24 to the cavity 32. The mold cavity 32 is formed between the first mold part 25 and the second mold part 27 of the mold 28, and the first mold part 25 and the second mold part 27 are held together under pressure by a press or clamp unit 34 . When the molten thermoplastic material 24 is injected into the mold cavity 32, the press or clamping unit 34 exerts a clamping force in the range of about 1000 psi to about 6000 psi during the forming process to connect the first mold part 25 and the second mold part 27 held together. To support these clamping forces, the clamping system 34 may include a mold frame and a mold base formed of a material having a surface hardness greater than about 165BHN and preferably less than about 260BHN, However, as long as the material can be easily processed, a material with a surface hardness BHN value of about 260 can be used, as discussed further below.

Once the shot including the molten thermoplastic material 24 is injected into the cavity 32, the extruder system 22 stops moving forward. The molten thermoplastic material 24 takes the form of a mold cavity 32 and the molten thermoplastic material 24 is cooled inside the mold 28 until the thermoplastic material 24 solidifies. Once the thermoplastic material 24 has solidified, the press 34 releases the first mold part 25 and the second mold part 27, the first mold part 25 and the second mold part 27 are separated from each other, and the finished part can be injected from the mold 28. The mold 28 may include a plurality of mold cavities 32 to increase the overall productivity.

A controller 50 is communicatively connected with a sensor 52 and a screw control member 36. The controller 50 may include a microprocessor, a memory, and one or more communication links. The controller 50 can be connected to the sensor 52 and the screw control member 36 via wired connections 54 and 56 respectively. In other embodiments, the controller 50 may be connected via a wireless connection, a mechanical connection, a hydraulic connection, a pneumatic connection, or a person familiar with the ordinary skill in allowing the controller 50 and the sensor 52 and screw control. 36 Any other type of communication connection between the two is connected to the sensor 52 and the screw control element 36.

In the embodiment of FIG. 1, the sensor 52 is a pressure sensor that measures (directly or indirectly) the melt pressure of the melted thermoplastic material 24 in the nozzle 26. The sensor 52 generates an electric signal which is transmitted to the controller 50. Next, the controller 50 commands the screw connector 36 to maintain the nozzle 26 One of the molten thermoplastic materials 24 advances the screw 22 at a rate at a substantially constant melt pressure. Although the sensor 52 can directly measure the melt pressure, the sensor 52 can measure other characteristics of the molten thermoplastic material 24 (such as temperature, viscosity, and flow rate indicating the melt pressure). Likewise, the sensor 52 does not need to be located directly in the nozzle 26, but the sensor 52 can be located anywhere in the injection system 12 or the mold 28 that is in fluid connection with the nozzle 26. If the sensor 52 is not located in the nozzle 26, an appropriate correction factor can be applied to the measured characteristics to calculate the melt pressure in the nozzle 26. In still other embodiments, the sensor 52 need not be in fluid connection with the nozzle. Instead, the sensor can measure the clamping force generated by the clamping system 14 at a mold parting line between the first mold part 25 and the second mold part 27. In one aspect, the controller 50 can maintain the pressure based on the input from the sensor 52. The sensor can be secured as a stationary sensor or can be a moving sensor. The sensor can be used to sense all cavities instead of one or two cavities. In addition, the sensors can be used on a variety of molds.

Although an active, closed loop controller 50 is shown in FIG. 1, other pressure regulating devices can be used instead of the closed loop controller 50. For example, a pressure regulating valve (not shown) or a pressure relief valve (not shown) can replace the controller 50 to regulate the melt pressure of the molten thermoplastic material 24. More specifically, the pressure regulating valve and the pressure releasing valve can prevent the mold 28 from being over-pressurized. Another alternative mechanism for preventing over-pressurization of the mold 28 is to activate an alarm when an over-pressurization condition is detected.

FIG. 2 shows an exemplary low constant pressure coinjection manifold 180. The manifold includes: a first machine nozzle path 182 for a first material 184 to form the inner and outer walls or "skin layers" of a shaped product; and a second machine nozzle for a second material 188 Path 186 is used to form a core of the shaped product. The co-injection manifold 180 includes a co-injection tube tip 190, which nests the second machine nozzle path 186 in the first machine nozzle path 182 at the heat pipe tip hole 192 for allowing the first material 184 and the second material 188 to enter Each mold cavity 194. Because the injection molding assembly operates under a low constant pressure (ie, less than one injection pressure of 15,000 psi), the first material 184 and the second material 188 are introduced into the mold cavity at a constant flow rate In 194, a uniform flow front of the filling cavity 194 from the heat pipe tip hole 192 to the opposite end 196 of the cavity is formed.

The first material 184 can be shaped to have a skin thickness of at least 0.1 mm without the second material 188 surging or swelling the skin layer. The ability to co-inject materials with this thin skin layer allows greater use of polylactic acid (PLA), starch, acrylic acid, post-consumer recyclables (PCR) and post-industrial recyclables (PIR) in injection molded products because These materials (which are adopted as the second (core) material 188) protect the field of vision, protect from contact with consumable products to be dispensed in consumer product containers, and are protected from contact with one by the skin layer. The user's skin contact (it can be an initial material with excellent physical properties (such as EVOH or nylon)), so regardless of its internal physical properties (such as the brittleness of PLA, the moisture sensitivity of starch and acrylic acid, and the smell in PCR) And discontinuity).

Figure 3 illustrates: a first screw pump 200, which is suitable for supplying a continuous flow of one of a first molten polymer material; and a second screw pump 202, which is used for supplying a continuous flow of one of a second polymer material to a plurality of A mold cavity 220. The first screw pump 200 and the second screw pump 202 may each include a rotating motor 204, a hopper 206, and a screw 208. The first screw pump 200 can further include a first nozzle 210, and the second screw pump 202 can further protect a second nozzle 212. The first screw pump 200 and/or the second screw pump 202 can be in the form of or similar to an extruder. The first nozzle 210 is arranged at a first height Y ₁ and is in fluid communication with a plurality of inclined upper feed channels 214 (which are numbered 214a, 214b...214n from left to right in the drawing), and The feeding channel 214 at least partially surrounds and is arranged in a conical distribution downwardly from the first nozzle 210. The plurality of upper feeding channels 214a, 214b...214n may be supported by a first rotating conical feeding channel plate (not shown). The second nozzle 212 is arranged at a second height Y ₂ (which is smaller than Y ₁ ), and is in fluid communication with a plurality of lower feed channels 216. The lower feed channels 216a, 216b...216n may be supported by a second rotating conical feed channel plate (not shown). In the embodiment depicted in FIG. 3, the lower feed channel 216 is also inclined, and at least partially surrounds and is arranged in a conical distribution downwardly from the second nozzle 212. Alternatively, the lower feed channel 216 may be in the same horizontal plane as the second nozzle 212 and extend horizontally outward from the second nozzle 212 in a radial configuration that at least partially surrounds a center of the second nozzle 212.

The first nozzle 210 and the second nozzle 212 are aligned with the same vertical axis. A plurality of mold cavities 220a, 220b...220n rotate along a mold cavity/core plate 222 at least partially around the vertical axis including the first nozzle 210 and the second nozzle 212. The cavity 220 may include a measurement plate (which includes a valve or measurement gate 236), and may also include a coinjection manifold 224 (such as the coinjection manifold depicted in FIG. 2). Because the total injection manifold 224 introduces two or more polymer materials at the same time (the choice of which changes the proportion of polymer materials passing through a single inlet 226 to the mold cavity 220), when a layered structure is desired to pass through the wall of a part At this time, a total of injection manifold 224 is advantageous. When using sequential coinjection (which changes the distribution of each polymeric material along the flow direction), the coinjection manifold 224 may or may not be used. Sequential coinjection is used to, for example, coinject two polymeric materials (they are the same, but different colors).

Each of the mold cavities is at least partially defined by a wall. If a coinjection manifold 224 is used, the upper feed channel 214 supplies the first molten polymer material to the coinjection manifold 224 and the lower feed channel 216 feeds the second molten polymer material to the coinjection manifold 224. If the goal is to achieve a layered structure through the wall of a part, then a single inlet 226 (such as a runner located between the co-injection manifold 224 and the respective mold cavity 220), and then the first polymer material and the second Both polymeric materials are supplied to the mold cavity 220. If instead sequential coinjection occurs (where a coinjection manifold is used), a first inlet 226 (such as a runner located between the coinjection manifold 224 and the respective cavity 220) supplies the first molten polymer material To the mold cavity 220, and a second inlet 228 (such as a second runner disposed between the coinjection manifold 224 and the respective mold cavity 220) supplies the second molten polymer material to the mold cavity 220.

If no coinjection manifold is used, a first inlet 226 (such as a first runner located between each of the upper feed channel 214 and the respective mold cavity 220) supplies the first molten polymer material to the mold Cavity 220, and a second inlet 228 (such as a second runner located between each of the lower feed channel 216 and the respective mold cavity 220) supplies the second molten polymer material to the mold cavity 220. To this end, at one of the lower ends of each of the inclined upper feeding channels 214, the inclined upper feeding channel 214 and the first inlet 226 of the mold cavity 220 form selective or permanent fluid communication. Similarly, at one end of each of the lower feeding passages 216, the lower feeding passage 216 is in communication with the second inlet 228 of the mold cavity 220. The first entrance 226 and the second entrance 228 of the cavity 220 are located at or close to a third height Y ₃ , the third height Y _{3 is} lower than the first height Y _{1 of the} first nozzle 210 and may be lower than or equal to the second nozzle 212 The second height Y ₂ . Although the first entrance 226 and the second entrance 228 are shown at the top of the mold cavity 220 in FIG. 3, it is recognized that the first entrance 226 and the second entrance 228 of the mold cavity 220 can be positioned at any desired position of the mold cavity 220. At height (such as at the bottom of cavity 220 or at a midpoint).

In one embodiment, as shown in FIG. 3, the mold cavities 220a, 220b...220n are arranged in a complete circle or rotated around the vertical axis containing the first nozzle 210 and the second nozzle 212. Each mold cavity 220a, 220b...220n has a respective mold core 230a, 230b...230n associated with it, and each of the mold cavity 220a, 220b...220n and the mold core 230a, 230b...230n At least one of them can be actuated relative to the respective mold core 230 or mold cavity 220, so that the mold cavity 220 and the mold core 230 are at least during a portion of the rotation of the mold cavity/core plate 222 (during this period by a respective inclined feeding The passage 214 conveys the first molten polymer material and the lower feed passage 216 conveys the second molten polymer material) to form a tightly sealed forming chamber. For example, although according to this embodiment, each mold cavity 220 travels (ie, rotates) with a fixed radius around the vertical axis containing the first nozzle 210 and the second nozzle 212, each of the mold cores 230a, 230b...230n It may have a cam follower roller 232 riding in a cam track 234 in the cavity/core plate 222 associated with it.

As shown in FIG. 3A, the cam track 234 has an angular position that extends from an angular position at least immediately upstream (ie, just before) from the initial forming to at least immediately beyond an angular position (in which the angular position is filled or Fill at least one mold cavity 220) with a constant maximum radius CMR of a portion of the cavity/core plate 222. Along the portion of the cam track 234 corresponding to the non-forming portion (ie along an arc area of the cavity/core plate 222 during which no filling or filling of the cavity 220 occurs), the cam track 234 The radius is reduced to a pause area along which the mold core 230 is completely separated from the respective mold cavity 220. The area of the cam track 234 (where the radius of the cam track 234 decreases from R _CMR to R _DWELL ) causes the mold core 230 to move radially inward, resulting in the separation of the mold cavity 220 and the mold core 230, thereby promoting the cooling of the formed part and Injection from the mold cavity 220. After the molded parts are ejected from each of the mold cavities 220, each of the respective mold core 230 and the mold cavity 220 starts a new rotation or cycle, thereby closing together to form and the respective upper feeding channel 214 and lower feeding The material channel 216 is in fluid communication with a tightly sealed forming chamber to receive additional molten polymer material (ie, to form an additional part).

As used herein, when describing the disposition of the mold cavity 220 relative to the nozzles 210 and 212 along the cam track 234, the term "arc" refers to having at least 15° (up to and including 360°) relative to the nozzle. A circular configuration)) an arc length and a substantially constant radius area.

In FIG. 3B, the radius of the cam track 234 is depicted as completing a given cavity 220 and the respective mold core 230 completely rotating around one of the vertical axes containing the first nozzle 210 and the second nozzle 212 over time, where identification will be along the cam track The forming operations in the respective areas of 234. If necessary, instead of pairs of mold cavities and mold cores can travel along different cam tracks, it may be desirable to facilitate simultaneous execution of a specific operation on multiple mold cavities. For example, the odd-numbered cores 230a, 230c, 230e ... 230n may have 234 _odd riding along the cam of a first cam follower 232 _odd tracks and the even-numbered core 230b, 230d, 230f ... 230n + 1 may have riding along the cam 234 _even track of a second cam follower 232 _even, a second cam track 234 _even similar to the first cam profile of the cam track of the cam profile 234 _odd, but slightly offset, such that pairs of odd and even The cores 230n and 230n+1, through a rotating part or through a complete rotation, surround the core 230 containing the vertical axis of the first nozzle 210 and the second nozzle 212 and simultaneously undergo the same operation. The second cam track 234 _even may have a maximum radius CMR that is smaller than the first cam track 234 _odd , and the link between the cam follower 232 _even and its respective mold cores 230b, 230d, 230f...230n+1 may be comparable to the cam The link between the follower 232 _odd and its respective mold cores 230a, 230c, 230e...230n is long to prevent the cam follower from switching from one of the cam tracks to another cam track or hinder the mold core 230 Smooth rotation around the vertical axis containing the first nozzle 210 and the second nozzle 212.

The rate of molten polymeric material introduced into one of the upper feed channel 214 or the lower feed channel 216 of a respective mold cavity 220 can be controlled by a measuring gate or valve 236 . The valve 236 may take the form of a rotatable ball gate valve. Alternatively, gate valves, butterfly valves, needle valves, aperture type valves, tongue valves, reed valves, flap valves, diaphragm valves, disc valves, check (ball type) valves, check (ring type) Valve, duckbill valve or some other type of valve. Ball gate valves and needle valves are the easiest to allow precise control of the flow rate, but other types of valves can be used. The position of the valve 236 can be controlled by a controller (such as a servo drive controller) so that the upper feed channel 214, the lower feed channel 216 and the cavity 220 reach a specific length along the arc length of the cavity/core plate 222 The position of the valve 236 is dynamically adjusted during the position. Alternatively, the rotating conical feed channel plate, measuring plate or some external structure may be provided with a cam system or trigger mechanism (such as an electromagnetic switch), which gives a given position along the arc length of the cavity/core plate 222 The change of the valve position.

When the valve 236 is fully opened, the molten polymer material flows freely from the upper feed channel 214 and/or the lower feed channel 216 to the respective mold cavity 220 under a nominal pressure. When the valve 236 is actuated from its fully open state to a partially closed state, this configuration causes the pressure of the molten polymer material downstream of the valve 236 (ie, the pressure of the melt when flowing to the mold cavity) to decrease.

In order to detect the pressure of the molten polymer material entering each mold cavity to ensure that a constant pressure is maintained in each mold cavity 220, and to adjust any unacceptable variance from the desired constant pressure as necessary, it can be provided with the mold The inside of each cavity 220 is fluidly connected to one or more pressure sensors (not shown). In a rotating rack type multi-cavity injection molding system as disclosed herein, it is necessary to enable the pressure signal to be transmitted by each of the pressure sensors, although the fact is that the pressure sensors and the mold cavity 220 Rotate together. Self-existence Alternatives to fixed-line communication of pressure signals of the plurality of pressure sensors associated with the cavity 220. For example, each of the pressure sensors can use a radio frequency relay (for example, RFID) to transmit a pressure signal, or can use a BLUTOOTH or Wifi signal to transmit the pressure signal to a central controller (which is based on the pressure signal) The valve position of the valve 236 can be adjusted as needed to obtain the desired pressure in the individual cavity 220). In a specific embodiment, instead of a wired connection, a pressure sensor can be combined with a plurality of pressure sensor contact pads (not shown) positioned in a series of at least one arc portion of the rotating material rack An intermittent contact, which corresponds to a signal of the pressure measured by the pressure sensor of the contact pad of the pressure sensor instantaneously after the contact, which then transmits the sensed pressure data to the Central controller.

As an alternative to providing wireless communication with a plurality of pressure sensors that move dynamically from the rotating mold cavity 220, a plurality of static pressure sensors can be used, which have a fixed line with a central controller Or wireless communication. For example, a pin (not shown) formed in fluid communication with one of the inside of a mold cavity 220 can ride along a rotating rack with a mold cavity, but can apply pressure to a stationary one positioned at a predetermined position on the periphery of the rotating rack On the sensor (not shown). The pressure applied by the pin on the stationary sensor will be proportional to the pressure of the melt in the cavity 220, so that the pressure detected by the stationary sensor can be transmitted to the central controller and interpreted to determine the cavity Whether the pressure in 220 needs any change, and if it needs to be changed, the central controller can send an appropriate command to reposition a valve 236 associated with an upper feed channel 214 and/or with a valve corresponding to the cavity The lower feed channel 216 is associated with a valve 236 to complete the desired pressure change.

It is recognized that the pressure in each upper feed passage 214 and lower feed passage 216 upstream of the valve 236 can be accurately predicted by one of the pressures in each relevant mold cavity. For example, when there is an adjustment of a valve position, an increase in the detected pressure in the upper feed passage 214 or the lower feed passage 216 upstream of the valve 236 indicates a decrease in the pressure in the cavity 220. Therefore, in addition to the pressure sensor in the mold cavity 220 or instead of the pressure sensor in the mold cavity 220, it is recognized that the advanced The pressure sensor in each of the upper feed channel 214 and the lower feed channel 216 upstream of the valve 236 in the feed channel 214 and the lower feed channel 216 to collect information for determining whether the adjustment of the valve position is in the mold cavity Useful pressure data necessary to achieve or maintain a desired constant pressure within 220. In view of the similar rotating rack configuration of the upper feed channel 214 and the lower feed channel 216, the pressure sensors placed in the upper feed channel 214 and the lower feed channel 216 will similarly benefit from being fixed to a central controller Some alternatives to wireless communication (such as radio frequency relay (for example, RFID), BLUTOOTH or Wifi).

In addition to the mold cavity 220 near the valve 236 and/or the pressure sensors in the upper feed passage 214 and the lower feed passage 216, it is desirable to have the upper feed passage near the first screw pump 200 and the second screw pump 202 Each of 214 and the lower feed channel 216 has an additional pressure sensor to detect the pressure of the melted polymer material when the melted polymer material is introduced into the upper feed channel 214 and the lower feed channel 216. The data from the pressure sensor (which indicates the pressure of the molten polymer material introduced into the upper feed channel 214 by the first screw pump 200 and the pressure of the molten polymer material introduced into the lower feed channel 216 by the second screw pump 202) will be usefully provided for Whether the pressure transmitted by the first screw pump 200 and the second screw pump 202 is high enough to transmit the desired constant pressure to a central controller of all downstream cavity 220 information.

4 is an exploded view of the continuous coinjection molding system of the present invention depicted in FIG. 3. 4 illustrates the first nozzle 210 (the upper feed passage 214 extends downwardly from the first nozzle 210) and is located on the second nozzle 212 (the lower feed passage 216 extends downwardly from the second nozzle 212). Below the nozzles 210 and 212 are a mold cavity 220 and a mold core 230. The mold core 230 is located in the mold cavity 220 radially inward. The portion of the mold cavity 220 including the valve or measuring gate 236 and/or the coinjection manifold 224 is located on the portion of the mold cavity 220 including the first inlet 226 and the second inlet 228.

Fig. 5 is a perspective view of a continuous coinjection molding system of the present invention, similar to the continuous coinjection molding system disclosed in Fig. 3, but the lower feed channels 216a, 216b, 216c...216n are arranged in the same mold The cavity 220 is in a central radial configuration on the same plane. The first height Y ₁ of the first nozzle 210 is greater than the second height Y _{2 of the} second nozzle 212, which is equal to the height Y ₃ of the first inlet 226 and the second inlet 228 of the mold cavity 220.

6 is an exploded view of the continuous coinjection molding system of the present invention depicted in FIG. 5. The upper feed channels 214a, 214b, 214c...214n are dependently downward, while the lower feed channels 216a, 216b, 216c...216n extend in a flat central radial configuration.

FIG. 7 shows another embodiment, in which the mold cavities 220a, 220b...220n and the respective mold cores 230a, 230b...230n are only along an arc portion of the mold cavity/core plate 222 (such as along a semicircle) Splice. Along the arc area, at least one of the mold cavities 220a, 220b...220n and each of the respective mold cores 230a, 230b...230n is actuated to be fixedly engaged with its respective mold core or cavity, so that the mold cavity 220 and the core 230 form a tightly sealed forming chamber at least during the rotation of the cavity/core plate 220 (during this period, the molten polymer material is conveyed through the upper feeding channel 214 and the lower feeding channel 216). As in the previous embodiment, a cam track 234 may be provided to actuate each mold core 230 relative to a respective mold cavity 220.

As discussed above, a controller and feedback loop are used to adjust the speed of an extruder system upstream of a nozzle, and the manifold or feed system provides for the melt polymerization delivered to a cavity of a multi-cavity forming system One possible way of limited adjustment of material pressure. Alternatively or in addition, a pressure relief valve can be used just upstream of one of the inlets of a mold cavity, which has a set point, when the pressure exceeds the set point, causing the relief valve to discharge the molten polymer material through a pressure relief outlet Part. In a continuous co-injection molding system of the present invention, the need and advantages of the ability to control pressure in the cavity immediately adjacent to the entrance are even more severe. Since each individual mold cavity only has a finite period of the arc length of the mold cavity/core plate 222 around the rotating material frame (along which can receive molten polymer material), it can be effectively tuned by the upper feeding One of the channel 214 and/or the lower feed channel 216 feeds the pressure of the molten polymer material at the inlet(s) of a respective cavity 220. The limited adjustment of the position of the valve(s) 236 results in an immediate change in the nominal pressure of the molten polymeric material in the upper feed channel 214 and/or the lower feed channel 216 when the molten material enters the mold cavity 220. Can respond to the parameters sensed in the cavity 220 or in the upper feeding channel 214 or the lower feeding channel 216 Or conditions (such as pressure, temperature, viscosity, or flow rate) to make these adjustments instantly. Alternatively or in addition, these adjustments may be made based on predetermined conditions that require a specific deviation from the nominal (substantially constant) pressure within the upper feed channel 214 or the lower feed channel 216.

For example, it may be desirable to use cavities of different volumes and/or shapes in various cavities 220a, 220b, 220c...220n to form a plurality of different products or different parts of products. For example, in order to facilitate the downstream assembly of a multi-part cover (not shown) of a container for a sanitary product or the like, a first plurality of mold cavities (such as odd-numbered mold cavities 220a, 220c...) Can be sized and shaped to form a first, relatively large component of the cover, and a second plurality of cavities (such as even-numbered cavities 220b, 220d...) can be sized and shaped To form a second, relatively small component of the cover. The time when each of the odd-numbered and even-numbered mold cavities is joined with their respective upper feeding channel 214 and lower feeding channel 216 along a part of the mold cavity/core plate 222 (during which forming can occur) similar to the rotating rack identical. Therefore, it may be necessary to operate the valves 236 of the upper feed channel 214 and the lower feed channel 216 associated with the second plurality of mold cavities (ie 220b, 220d...), so that the mold cavities can be The opening of the valve 236 associated with the upper feeding passage 214 and the lower feeding passage 216 is shorter than the duration of the first plurality of mold cavities (ie, the odd-numbered (relatively larger) 220a, 220c...) valves 236 associated with them.

In addition, it may be desirable to fill the plurality of mold cavities 220a, 220c... of the first and odd number marks at a higher or lower pressure than the plurality of mold cavities 220b, 220d... of the second and even number marks. To complete this filling, the valve 236 of the upper feed channel 214 and the lower feed channel 216 associated with the first plurality of mold cavities 220a, 220c... can be along the mold cavity/core plate 222 ( During this period, forming can occur) adjusted to a different position relative to a valve 236 of the upper feed passage 214 and the lower feed passage 216 associated with the second plurality of mold cavities 220b, 220d...

Another advantage of being able to change the pressure by a controlled amount during filling is the ability to compensate or balance the expansion in the region of varying thickness of the cavity, and/or to make adjustments to compensate for thermal contraction close to the cavity wall. When forming thin-walled products or thin-walled areas of products The adjustment of the nominal pressure of the molten polymeric material conveyed by an inclined feed channel can be particularly advantageous.

Some or all of the embodiments disclosed herein can be combined with some or all of other injection molding embodiments known in the art, including the embodiments described below.

The embodiment of the present invention can be used together with the embodiment for injection molding under low constant pressure, such as the US patent application filed on May 21, 2012 under the title "Apparatus and Method for Injection Molding at Low Constant Pressure" The case No. 13/476,045 (case 12127 of the application case) is disclosed and published as US 2012-0294963 A1, which is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments for pressure control. For example, US Patent Application No. 13/476,047 filed on May 21, 2012 entitled "Alternative Pressure Control for a Low Constant Pressure Injection Molding Apparatus" As disclosed in No. (Application Case 12128), it is now US Patent No. 8,757,999, which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for the unnaturally balanced feeding system, such as the US patent application filed on May 21, 2012 entitled "Non-Naturally Balanced Feed System for an Injection Molding Apparatus" The 13/476,073 (case 12130 of the application) is disclosed and published as US 2012-0292823 A1, which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for injection molding at low (substantially constant) pressure, such as the one filed under the title "Method for Injection Molding at Low, Substantially Constant Pressure" on May 21, 2012 The US Patent Application No. 13/476,197 (application case 12131Q) is disclosed and published as US 2012-0295050 A1, which is hereby incorporated by reference.

The embodiment of the present invention can be compared with the actual injection molding under low (substantially constant) pressure. The examples are used together, as disclosed in the US Patent Application No. 13/476,178 (Application Case 12132Q) entitled "Method for Injection Molding at Low, Substantially Constant Pressure" filed on May 21, 2012 and It is published as US 2012-0295049 A1, which is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments for coinjection procedures. For example, US Patent Application No. 13/774,692 filed on February 22, 2013 entitled "High Thermal Conductivity Co-Injection Molding System" ( As disclosed in the case 12361) of the application, it is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment aimed at using a simplified cooling system for forming. For example, the name of the application on February 12, 2013 is "Injection Mold Having a Simplified Evaporative Cooling System or a Simplified Cooling System with Exotic Cooling Fluids" It is disclosed in US Patent Application No. 13/765,428 (Application Case 12453M), which is now US Patent No. 8,591,219, which is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments for forming thin-walled parts. For example, the US patent application titled "Method and Apparatus for Substantially Constant Pressure Injection Molding of Thinwall Parts" filed on May 21, 2012 It is disclosed in No. 13/416,584 (Application Case 12487), which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for forming using a fail-safe mechanism, such as the US Patent Application No. 13/672,246 filed on November 8, 2012, entitled "Injection Mold With Fail Safe Pressure Mechanism" No. (Application Case 12657), which is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments for high-productivity molding. For example, the US Patent Application No. "Method for Operating a High Productivity Injection Molding Machine" filed on November 20, 2012 It is disclosed in No. 13/682,456 (Application Case 12673R), which is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments for forming specific thermoplastics. For example, the US Patent Application No. 14 entitled "Methods of Molding Compositions of Thermoplastic Polymer and Hydrogenated Castor Oil" filed on November 20, 2013 It is disclosed in No. /085,515 (Application Case 12674M), which is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments for forming specific thermoplastics. For example, US Patent Application No. 14/085,515 filed on November 21, 2013 and titled "Reduced Size Runner for an Injection Mold System" (Case 12677M of the application), which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for the mobile forming system. For example, the US Patent Application No. 61 filed on May 13, 2013 entitled "Low Constant Pressure Injection Molding System with Variable Position Molding Cavities:" /822,661 (case 12896P of the application), which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for the injection molding control system, such as the United States of America which was named "Injection Molding Machines and Methods for Accounting for Changes in Material Properties During Injection Molding Runs" on August 20, 2013 It is disclosed in Patent Application No. 61/861,298 (case 13020P of the application), which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for the injection molding control system, such as the United States of America which was named "Injection Molding Machines and Methods for Accounting for Changes in Material Properties During Injection Molding Runs" on August 20, 2013 It is disclosed in Patent Application No. 61/861,304 (case 13021P of the application), which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for the injection molding control system, such as the United States of America which was named "Injection Molding Machines and Methods for Accounting for Changes in Material Properties During Injection Molding Runs" on August 20, 2013 Patent Application No. 61/861,310 (case 13022P of the application) is disclosed, which is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments directed to the use of injection molding to form covered objects. For example, US Patent Application No. 61/918,438 filed on December 19, 2013 entitled "Methods of Forming Overmolded Articles" No. (Case 13190P of the application), which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for controlling the forming process. For example, the US Patent No. 5,728,329 entitled "Method and Apparatus for Injecting a Molten Material into a Mold Cavity" was issued on March 17, 1998 ( It is disclosed in the application case 12467CC), which is hereby incorporated by reference.

The embodiment of the present invention can be used together with the embodiment for the control forming procedure, as disclosed in the US Patent No. 5,716,561 (the case of the application 12467CR) entitled "Injection Control System" issued on February 10, 1998 , Which is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments for forming preforms, such as in US Patent Application No. 61/952281 (Application Case 13242P) entitled "Plastic Article Forming Apparatus and Methods for Using the Same" As disclosed, it is hereby incorporated by reference.

The embodiments of the present invention can be used together with the embodiments for forming preforms, such as in US Patent Application No. 61/952283 (Application Case 13243P) entitled "Plastic Article Forming Apparatus and Methods for Using the Same" As disclosed, it is hereby incorporated by reference.

The dimensions and values disclosed herein are not to be understood as strictly limited to the exact values listed. Rather, unless otherwise specified, these dimensions are intended to mean both the recited value and the functionally equivalent range surrounding one of the values. For example, the one size disclosed as "40mm" means "about 40mm".

Unless expressly excluded or otherwise limited, the entire content of each document (including any cross-references or related patents or applications) cited herein is hereby incorporated by reference. The citation of any document is not a license: it is relative to any invention disclosed or applied for herein, or is independent or with any other reference, teaching, suggestion, or prior art that forms any combination of any such invention. In addition, as far as any meaning or definition of a term in this document conflicts with any meaning or definition of the same term incorporated by reference in a document, the meaning or definition assigned to the term in this document shall be managed Or definition.

Although specific embodiments of the present invention have been illustrated and described, those skilled in the art should know that various other changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, it is intended to cover all such changes and modifications within the scope of the present invention in the scope of the attached patent application.

200: The first screw pump

202: The second screw pump

204: Rotating motor

206: Funnel

208: Screw

210: The first nozzle

212: second nozzle

214a: Upper feed channel

214b: Upper feed channel

214c: upper feed channel

216a: Lower feed channel

216b: Lower feed channel

216c: Lower feed channel

220a: mold cavity

220b: mold cavity

220c: mold cavity

222: Mold cavity/core board

224: Co-injection manifold

226: Single entrance/first entrance

228: Second Entrance

230a: core

230b: core

230c: core

232: Cam follower roller

236: Measuring gate or valve

Y ₁ : first height

Y ₂ : second height

Y ₃ : third height

Claims (13)

A co-injection method with continuous injection molding includes: continuously feeding one of a first molten polymer material to a first nozzle (210) that is selectively connected to a plurality of mold cavities (220a); continuously feeding a second One of the molten polymer materials is supplied to a second nozzle (212) in selective communication with the plurality of mold cavities, wherein (i) the first nozzle is disposed at a first inlet than at least one of the plurality of mold cavities (226) A third height (Y ₃ ) is higher than a first height (Y ₁ ), and wherein the second nozzle is arranged at a second one equal to or higher than at least one of the plurality of mold cavities The third height (Y ₃ ) of the inlet (228) is a second height (Y ₂ ) and is lower than the first height (Y ₁ ) of the first nozzle, (ii) the first molten polymer material is continuously fed The supply to the first nozzle in fluid communication with the plurality of mold cavities includes allowing the first molten polymer material to flow into a plurality of upper feed channels (214a), each of the upper feed channels passing through the molds The first entrance of the cavity is selectively communicated with one of the mold cavities, and each of the upper feed channels is inclined from the first height (Y ₁ ) of the first nozzle down to the The third height (Y ₃ ) of the first inlet of each of the mold cavities, (iii) continuously feeding the supply of the second molten polymer material to the second nozzle in fluid communication with the plurality of mold cavities includes The second molten polymer material is flowed into a plurality of lower feed passages (216a), and each of the lower feed passages is selectively communicated with one of the mold cavities through the second inlet of each mold cavity. Such as the method of claim 1, wherein a first runner is arranged between each of the upper feeding channels and the respective mold cavity, and a second runner is arranged between each of the lower feeding channels Between the respective cavity. The method of claim 1, wherein the first nozzle and the second nozzle are in the same vertical axis, and the mold cavities, the upper feed channel and the lower feed channel surround the first nozzle and the second nozzle The vertical axis rotates. Such as the method of claim 3, and while the mold cavities and the upper feeding channel and the lower feeding channel are rotated around the vertical axis of the first nozzle and the second nozzle, the mold cavities are relative to the The vertical axis of the first nozzle and the second nozzle are arranged in an arc shape, and the upper feed passages are arranged in a conical shape at least partially surrounding the first nozzle. The method of claim 4, wherein the mold cavities are arranged in a circular configuration relative to the vertical axis of the first nozzle and the second nozzle. The method of claim 4, wherein the lower feed channels are arranged in a conical distribution at least partially around one of the second nozzles. Such as the method of claim 5, wherein the lower feed channels are arranged in a radial distribution at least partially around a center of the second nozzle. The method of claim 1, and the supply of the first polymer material is continuously fed to the first nozzle, the first molten polymer material is squeezed, and the supply of the second polymer material is continuously fed to the first nozzle In the second nozzle, the second polymer material is extruded. The method of any one of claims 1 to 8, further comprising measuring the first polymer material, the second polymer material, or the first polymer material and the second polymer through one of a valve or a measuring plate The flow of material to at least one of the cavities. The method of claim 9, further comprising cooling the polymeric material in at least one of the mold cavities. The method of claim 10, further comprising injecting a formed part from each of the at least one mold cavity after cooling the polymeric material in the at least one mold cavity. The method of claim 11, wherein injecting the part includes: opening at least one wall partially defining the at least one mold cavity. The method of claim 12, further comprising, after ejecting the part from the at least one mold cavity, closing the at least one wall that partially defines the mold cavity.

Images