DUAL SIGNAL ADDITIVE FEEDING METHOD AND APPARATUS

Abstract

Injection molding plastic parts includes furnishing resin material to a screw barrel having a rotatable screw therewithin, rotating the screw to work the resin material into a molten state, furnishing additive such as liquid color or another additive to the screw barrel interior at a first rate during screw rotation and driving the screw longitudinally from a first position to a second position to force an additive-resin material mixture resulting from screw rotation into a mold while furnishing additive with resin to the screw barrel interior at a second additive addition rate.

Claims

1. An injection molding machine comprising: a) a barrel; b) a rotatable screw residing within the barrel and being longitudinally movable therewithin; c) a liquid color pump for furnishing liquid color to the screw within the barrel; d) a transducer for sensing position of the rotatable screw within the barrel and providing a signal indicative thereof; e) a processor receiving the signal and controlling pump speed according to sensed position of the screw.

2. An injection molding machine comprising: a) a barrel; b) a rotatable screw residing within the barrel and being longitudinally movable therewithin; c) a liquid color pump for furnishing liquid color to the screw within the barrel; d) a transducer for sensing rotation of the rotatable screw within the barrel and providing a signal indicative thereof; e) a processor receiving the signal and controlling pump speed according to sensed rotation of the screw.

3. In a method for supplying colorant to an injection molding machine having a rotatable reciprocable screw within a barrel, the improvement comprising furnishing liquid color to the injection molding machine barrel at a first rate during screw rotation and at a second rate during material injection.

4. An injection molding press for injection molding resin into plastic parts, comprising: a) a barrel having a throat for resin feed into the barrel; b) a rotatable, longitudinally movable screw within the barrel; c) a first sensor providing a signal indicative of screw rotation; d) a second sensor providing a signal indicative of screw longitudinal advancement injecting molten resin into a mold; e) a feeder, providing additive to the resin at the throat during resin feed into the barrel, in response to the first sensor signal and thereafter in response to the second sensor signal.

5. The press of claim 4 further comprising the second sensor providing a signal indicative of screw longitudinal advancement injecting molten resin into a mold and of screw position maintenance while molten resin is cooling in the mold.

6. The press of claim 5 further comprising the second sensor signal being indicative of screw longitudinal advancement injecting molted resin into a mold and cessation of such advancement.

7. The press of claim 4 wherein the feeder apportions the additive in response to the sensor signals.

8. The press of claim 4 further comprising a processor receiving said first sensor signal, recording time duration of screw rotation, computing time based thereon for screw injection of molten resin into the mold and controlling the feeder to regulate the rate of additive addition during screw rotation and during injection.

9. A method of providing additive to an injection molding machine, comprising: a) rotating the machine screw while concurrently feeding resin and additive into the screw barrel through the barrel throat at a first selected rate, rotation of the screw converting the resin-additive mixture into molten material and driving the molten material forward into space in front of the screw, filling the space with molten material, pressure from the molten material in the space on the screw causing the rotating screw to retract longitudinally; b) halting screw rotation upon the screw retracting to a preselected position; c) driving the screw longitudinally forward thereby injecting the molten plastic material into the mold while concurrently feeding resin and additive at a second selected rate into the barrel through the throat.

10. The method of claim 9 further comprising allowing molten material in the mold to cool.

11. The method of claim 10 wherein the step of allowing molten material in the mold to cool further includes continuing to feed resin and additive at the second selected rate.

12. A method of providing additive to an injection molding machine, comprising: a) feeding the additive at a first selected rate together with resin into the screw barrel through the barrel throat while the screw is rotating; b) rotating the machine screw, rotation of the screw converting the additive and resin into molten material and driving molten material forward into space in front of the screw, filling the space with molten material, with pressure from the molten plastic on the screw in the space causing the rotating screw to retract; c) halting screw rotation upon the screw retracting to a preselected position; d) filling additive at a second selected rate together with resin into the barrel through the throat while driving the screw forward thereby injecting a preselected volume of the molten material into the mold; e) continuing filling additive at the second selected rate together with resin into the barrel through the throat while allowing molten material in the mold to cool; f) opening the mold for removal of solidified plastic.

13. The method of claim 12 wherein the second rate is a continuously calculated percentage of the first rate.

14. In a method for operating an injection molding machine for molding granular resin into solid parts, the machine including a barrel having a throat for resin feed into the barrel, a rotatable, longitudinally movable screw within the barrel and a feeder at the throat providing an additive to the resin, the method including: a) feeding the resin-additive mix into the barrel through the throat; b) rotating the screw thereby converting granular resin and additive into molten material collecting at a mold end of the barrel, while the screw retreats longitudinally due to force exerted on the screw by molten material collecting in the barrel at the mold end; c) longitudinally advancing the screw thereby injecting molten material collected at the screw end into the mold; d) maintaining the screw at the longitudinally advanced position for time to allow cooling of the molten material in the mold; the improvement comprising: e) recording the time for performance of step “b”; f) determining the time for performance of steps “c” and “d” based on the recorded time for performance of step “b”; and g) apportioning the amount of additive provided to the resin according to the times determined in steps “e” and “f”.

15. A method for operating an injection molding machine for molding granular resin into solid parts, the machine including a barrel having a throat for resin feed into the barrel, a rotatable, longitudinally movable screw within the barrel and a feeder at the throat providing an additive to the resin, comprising: a) feeding the resin-additive mix into the barrel through the throat; b) rotating the screw thereby converting granular resin and additive into molten material collecting at a mold end of the barrel, while the screw retreats longitudinally due to force exerted on the screw by molten material collecting in the barrel at the mold end; c) longitudinally advancing the screw thereby injecting molten material collected at the screw end into the mold; d) maintaining the screw at the longitudinally advanced position for time to allow cooling of the molten material in the mold; e) measuring the time for the screw to retreat longitudinally while rotatably converting granular resin and additive to molten material f) measuring the time for screw longitudinally advancing molten material injection and screw position maintenance during at least a portion time for molten material cooling; g) regulating the feeder providing additive to the resin at the throat in response to the times measured in steps “e” and “f”.

16. In a method for controlling a feeder furnishing an additive to an injection molding press molding granular resin into solid parts, the press including a barrel having a throat for resin feed into the barrel, a rotatable, longitudinally movable screw within the barrel, the feeder being located at the throat of the press for contributing an additive to the resin to produce a resin-additive mix fed into the barrel, including: h) feeding the resin-additive mix into the barrel through the throat; i) rotating the screw thereby converting the resin-additive mix into molten material collecting at a mold end of the barrel, while the screw retreats longitudinally due to force exerted on the screw by molten material collected at the mold end of the barrel; j) longitudinally advancing the screw thereby injecting molten material collected at the screw end into the mold; k) maintaining the screw at the longitudinally advanced position for time to allow for at least some cooling of the molten material in the mold; l) repeating steps “a” through “d”; the improvement comprising: m) recording the time for performance of step “b”; n) determining the time for performance of steps “c” and “d”; and o) regulating the feeder to apportion the amounts of additive added to the resin during performance of step “b” and during performance of steps “c” and “d”, according to the times determined in steps “f” and “g”.

17. The method of claim 16 wherein step “h” is based on the recorded time for performance of step “b”.

18. The method of claim 16 wherein step “g” further comprises measuring the time for performance of steps “c” and “d”.

19. The method of claim 18 in which step “h” is performed by calculation using the times found in the course of performing steps “f” and “g”.

Description

DESCRIPTION OF THE DRAWINGS

[0064] FIG. 1 is a schematic sectional view in elevation of an injection molding machine with the screw at an advanced position, having forced viscous, molten resin material into the cavities of a mold.

[0065] FIG. 2 is a schematic section view in elevation of the injection molding machine shown in FIG. 1 where the screw has moved to the right in the drawing, away from the mold, into a retracted position as the screw has rotated and filled the space between the front of the screw and end of the screw barrel with molten material. The screw is in position ready to move to the left to advance viscous, molten polymeric resin material residing in front of the screw into the cavities of the mold.

[0066] FIG. 3 is a schematic sectional view in elevation of an injection molding machine with an additive feeder in position to supply additive to resin entering the feed throat of the injection molding machine.

DESCRIPTION OF THE INVENTION AND IMPLEMENTATION OF THE SAME

[0067] Referring to the drawings, in FIG. 1 an injection molding machine is denoted generally 10. Injection molding machine 10 includes a barrel 12 of generally cylindrical configuration with a heater 14 wrapped about barrel 12. A mold 16 is located at one end of barrel 12 and receives molten thermoplastic material provided by action of a rotatable, longitudinally reciprocable screw 18. Mounted at the end of screw 18 close to mold 16 is a check valve 20.

[0068] A hopper 22 is provided to hold and supply granular resin material to be molded by molding machine 10, with the granular resin material being supplied to the interior of barrel 12. Rotatable reciprocable screw 18 has a shaft portion 34 which extends out of barrel 12, at the end of barrel 12 opposite from mold 16. Shaft 34 has a driven gear 30 mounted thereon. A drive gear 28 meshes with driven gear 30. Drive gear 28 is rotatably driven by a motor 26. The end of shaft 34 remote from mold 16 is connected to a ram 24, which reciprocates within a housing 50.

[0069] Ram 24 is hydraulically driven from right to left in FIG. 1, thereby moving rotatable reciprocable screw 18 longitudinally from the position illustrated in FIG. 2 to the position illustrated in FIG. 1. In that regard, it is to be understood that FIG. 1 illustrates the position of screw 16 at the completion of a “shot”, namely upon completion of filling the cavities within mold 16 with viscous molten resin material with that material reaching those cavities from the interior of barrel 12 via passageway 36 in the end of barrel 12.

[0070] In FIGS. 1 and 2, a liquid color pump is depicted schematically and designated 40. Pump 40 is controlled by a processor 42. A storage drum for liquid color is designated 48 with an unnumbered conduit being provided for pump 40 to draw liquid color out of drum 48. Pump 40 supplies liquid color through a conduit 44 to the interior of barrel 12.

[0071] The position at which conduit 44 communicates with the interior of barrel 12 is not critical. An alternate position for conduit 44 to communicate with the interior of barrel 12 has been indicated in dotted lines as an alternate conduit 46 in the drawings. A further alternate and preferred position for conduit 44 to communicate with barrel 12 is at throat 56, where hopper 22 empties into barrel 12. This configuration is not illustrated in FIG. 1 or in FIG. 2.

[0072] Ram 24 resides within a housing 50 and is movable therewithin, back and forth between the positions illustrated in FIG. 1 and FIG. 2. Ram 24 moves to the position illustrated in FIG. 1, which is to the left with respect to the interior of housing 50, in response to high pressure hydraulic fluid 32 supplied to the interior of housing 50 via passageway 52.

[0073] Injection molding machine 10 preferably runs continuously, with reciprocable rotating screw 18 moving back and forth and rotating to supply viscous, molten resin material to mold plastic parts in the cavities of mold 16. Granular polymeric resin material is fed into the interior of barrel 12 by downward flow of granular polymeric resin material from hopper 22. Optionally and desirably, a valve may be provided to shut off downward flow of granular polymeric resin material from hopper 22; such a valve has not been illustrated in the drawings to enhance drawing clarity.

[0074] Screw 18 is rotatably driven by a motor 26 via a drive gear 28 meshing with a driven gear 30. Driven gear 30 is fixedly mounted on shaft 34 of rotatable reciprocable screw 18.

[0075] A single “shot” of viscous, molten resin material filling the cavities in mold 16 may be considered to commence with rotatable, reciprocable screw 18 at the position illustrated in FIG. 2 of the drawings. With rotatable reciprocable screw 18 at the position illustrated in FIG. 2, a ram 24 affixed to an end of screw shaft 34 remote from the screw flight 54 of rotatable reciprocable screw 18 is in the position illustrated in FIG. 2. When rotatable reciprocable screw 18 is at the position illustrated in FIG. 2, rotatable reciprocable screw 18 has rotated and “worked” the polymeric resin material supplied from hopper 22 so that the interior volume of barrel 12 is filled with viscous molten polymeric resin material. Ram 24 is then moved by application of hydraulic fluid pressure thereto by pumping hydraulic fluid through a passageway 52 formed in housing 50, with the hydraulic fluid being under high pressure. The high pressure hydraulic fluid moves ram 24 and rotatable reciprocable screw 18 to the left in FIG. 2, to the position illustrated in FIG. 1.

[0076] The leftward movement of rotatable reciprocable screw 18 along the interior of barrel 12 forces the viscous, molten material out of the interior of barrel 12, through passageway 36, and into mold 16, specifically into the cavities of mold 16.

[0077] Check valve 20, affixed to the end of rotatable reciprocable screw 18, prevents back flow of any viscous molten material from mold 16 into the interior of barrel 12 when rotatable reciprocable screw 18 is at the longitudinally advanced position illustrated in FIG. 1. Desirably, rotatable reciprocable screw 18 is maintained at the longitudinally advanced position illustrated in FIG. 1 only for such time as required for the viscous, molten thermoplastic resin material in mold 16 to harden sufficiently so that there is no back flow into the interior of barrel 12.

[0078] Rotatable reciprocable screw 18 then rotates, being rotatably driven by motor 36; such rotation serves to “work” granular resin material entering barrel 12 from hopper 22 into a viscous molten state. The thread 54 of rotatable reciprocable screw 18, “works” and advances the granular resin material to the left in FIGS. 1 and 2 with such working raising the temperature of the material whereupon it transforms into a viscous, molten state. As rotatable reciprocable screw 18 continues to turn, with screw thread 54 working and forcing the molten plastic material forward, namely to the left in FIGS. 1 and 2, rotatable reciprocable screw 18 is displaced to the right from the position illustrated in FIG. 1 to the position illustrated in FIG. 2 as more and more granular resin material is transformed into a viscous, molten state and fills space between end 60 of rotatable reciprocable screw 18 and the shaped end portion 58 of the interior portion of barrel 12. Once the molten material has filled space between end 60 of rotatable reciprocable screw 18 and shaped end portion 58 of the interior of barrel 12, and rotatable reciprocable screw 18 has been displaced to the position illustrated in FIG. 2, the cycle repeats itself with rotatable reciprocable screw 18 moving to the left in response to the force of ram 24 produced by high pressure hydraulic fluid filling cavity 62 within housing 50.

[0079] During operation, injection molding machine 10 illustrated in FIGS. 1 and 2 proceeds with molding colored plastic parts by furnishing resin material to screw barrel 12 having rotatable reciprocable screw 18 therewithin. Molding machine 10 proceeds by rotating screw 18 to work the resin material into a molten state within screw barrel 12. Liquid color is furnished to the screw barrel 12 interior at a first rate during the rotation of screw 18. Screw 18 is driven longitudinally from a first position to a second position to force the viscous, molten color-resin material mixture, resulting from the rotation of screw 18, into mold 16 while furnishing liquid color to the interior of screw barrel 12 at a second rate. The liquid color is most preferably provided to the interior of screw barrel 12 via a throat 56 through which the resin material is furnished to screw 18 within screw barrel 12; this configuration has not been illustrated in FIGS. 1 and 2 to ensure drawing clarity. Alternatively, liquid color may be furnished to the interior of screw barrel 12 at a position displaced from where the resin material is furnished to the screw barrel, as illustrated by the positions at which conduits 44 and 46 connect with screw barrel 12 in FIGS. 1 and 2, as explained above.

[0080] Desirably, the second rate at which liquid color is supplied, namely during the injection of the “shot” into the mold, is greater than the first rate at which the liquid color is supplied, namely during rotation of rotatable reciprocable screw 18 within screw barrel 12.

[0081] A processor 42 controls the rate of furnishing liquid color and may do so based on rotation of screw 18, based on position of screw 18, based on cycle time of injection molding press 10 and screw 18 or based on a combination of these parameters. A transducer 38 senses position of rotatable screw 18 within barrel 12 and provides a signal indicative thereof to processor 42 for controlling pump speed according to either sensed position of the screw, or sensed rotation of the screw, or based on cycle time. Accordingly, transducer 38 may be of several different types, so long as transducer 38 is suitable for sensing the desired parameter(s) to be used for controlling supply of liquid color to the interior of screw barrel 12.

[0082] Once again referring to the drawings, in FIG. 3 an injection molding machine is denoted generally 110 and is similar to injection molding machine 10 illustrated in FIGS. 1 and 2. Injection molding machine 110 in FIG. 3 includes a barrel 112 of generally cylindrical configuration with a heater 114 wrapped around barrel 112. Heater 114 is optional. Still referring to FIG. 3, mold 116 is located at one end of barrel 112 and receives molten thermoplastic material provided by the action of rotatable, longitudinally reciprocable screw 118. Mounted at the end of screw 118 close to mold 116 is a check valve 120.

[0083] A hopper 122 is provided to hold and to supply resin material to be molded by molding machine 110 with the resin material being supplied to the interior of barrel 112 via throat 172. Rotatable, reciprocable screw 118 has a shaft 134 extending out of barrel 112, at the end of barrel 112 opposite from mold 116. Shaft 134 has a driven gear 130 mounted therein, in much the same manner as illustrated in FIGS. 1 and 2.

[0084] Similarly to the injection molding machine illustrated in FIGS. 1 and 2, a drive gear 128 meshes with a driven gear 130. Drive gear 128 is rotatably driven by motor 126, as illustrated in FIG. 3. The end of shaft 134 remote from mold 116 is connected to ram 124, which reciprocates within a housing 150 in a manner essentially identical to that described above and illustrated in FIGS. 1 and 2.

[0085] Ram 124 is hydraulically driven from right to left in FIG. 3, thereby moving rotatable, reciprocal screw 118 longitudinally from a position remote where the end of screw 118 (the left end of screw 118 in FIG. 3) is remote from mold 116. The reciprocable driving of screw 118 moves screw 118 to the position where the end of screw 118 more proximate mold 116 is essentially at the position illustrated at FIG. 3.

[0086] Similarly to FIG. 1, screw 118 is rotatably driven by a motor 126 via a drive gear 128 meshing with a driven gear 130. Driven gear 130 is desirably fixably mounted on shaft portion 134 of rotatable, reciprocable screw 118.

[0087] Still referring to FIG. 3, a single “shot” of viscous molten resin material filling the cavities in mold 116 may be considered to commence with rotatable, reciprocable screw 118 at a position similar to that illustrated in FIG. 2 where ram 124 fixed to an end of screw shaft 134 remote from screw flight 154 is in a position similar to that illustrated in FIG. 2. Much like the sequence of events illustrated in FIGS. 1 and 2, rotation of rotatable, reciprocable screw 118 in molding machine 110 illustrated in FIG. 3 positions rotatable screw 118 at a position at which rotatable screw 118 has rotated and “worked” the mixture of polymeric resin material and additive(s) supplied from hopper 122 and feeder 170 so that the interior volume of barrel 112 is filled with the mixture of resin and additive(s), with the mixture having become molten due to the “working” of the mixture by screw thread 154. Ram 124 is then moved by application of hydraulic fluid pressure thereto by pumping hydraulic fluid through a passageway 152 formed in housing 150 with the hydraulic fluid being under high pressure. The high pressure fluid moves ram 124 and rotatable reciprocal screw 118 to the left in FIG. 3.

[0088] Still referring to FIG. 3, feeder 170 receives additive to be combined with resin stored in hopper 122 with the act of combining the additive with the resin preferably taking place in throat 172 leading immediately to the interior of barrel 112.

[0089] The rapid advancement of screw 118 required to force the molten mixture of resin and additive into the cavities of mold 116 is facilitated by rapid application of high pressure hydraulic fluid through passageway 152 to contact ram 124 and push ram 124 to the left in FIG. 3 through space 162 to a position at which ram 124 has longitudinally traversed space 162 illustrated in FIG. 3. The combination of ram 124 and chamber 162 are analogous to and operate much the same way as a piston within the cylinder of an internal combustion engine. However, of course, there is no combustion associated with operation of ram 124 within chamber 162 of injection molding machine 110 illustrated in FIG. 3.

[0090] Still referring to FIG. 3, a first sensor 138, preferably positioned on or within barrel 112 provides a signal indicating rotation of screw 118. A second sensor 140, also preferably positioned in or on barrel 112, provides a signal indicative of longitudinal advancing screw 118 injecting the molten resin-additive mix into mold 116. The signal indicative of screw rotation provided by first sensor 138 and the signal indicative of screw longitudinal advancement injecting molten material into mold 116 provided by second sensor 140 are both desirably provided to a microprocessor 200. Transmission of the signals is desirably wirelessly accomplished using any one of the available wireless protocols for such signal transfer, including Bluetooth, the Internet, and the like. Microprocessor 200, while illustrated as a stand-alone component in FIG. 3, may equally well be provided as a part of feeder 170, or may be part of injection molding machine 110 or may be an entirely standalone component.

[0091] One desirable arrangement is to have microprocessor incorporated into as a part of feeder 170. Whether microprocessor 200 is built into feeder 170 or controls feeder 170 from afar, feeder 170 apportions additive added to the resin material in response to the sensor signals received from first and second sensors 138, 140. Microprocessor 200, no matter where it is located and no matter the supplier/vendor of microprocessor 200, receives the first sensor signal from sensor 138, and records time duration of screw rotation. Microprocessor 200 thereafter computes time, based on the duration of screw rotation, for screw injection of the molten resin-additive mix into the mold and controls feeder 170 to regulate the rate of additive addition to the resin during screw rotation and during injection. In this way, microprocessor 200 and feeder 170 coordinate during machine operation, with screw 118 rotating while feeder 170 works together with microprocessor 200 and hopper 122 to feed resin and additive into barrel 112 of screw 118 at a first selected rate. Rotation of screw 118 converts the resin-additive mixture into molten material; screw 118 then drives the molten material forward into space in front of screw 118 filling the space with molten material; pressure from the molten material in the space in front of screw 118 then causes screw 118 to retract longitudinally as it rotates. Screw rotation stops upon screw 118 retracting to a pre-selected position whereupon ram 124 drives screw 118 forward, to the left in FIG. 3, thereby injecting molten material into mold 116 while concurrently feeding resin and additive at a second selected rate. Feeder 170 is preferably concurrently feeding additive and combining it with the resin at the second selected rate and supplying the resin-additive mixture into barrel 112 through throat 172.

[0092] It is desirable that the second rate of supply of the additive together with resin into barrel 112 through throat 172 during injection be at a second selected rate, which is desirably a continuously calculated percentage of the first rate, with such calculations being performed by microprocessor 200.

[0093] In another operational aspect of the invention, the invention provides a method for operating an injection molding machine for molding granular resin into solid parts where the machine includes barrel 112 having a throat 172 formed therein for resin feed into barrel 112 with a longitudinally movable, rotatable screw 118 resident within the barrel and a feeder 170 at the throat 172 providing additive to the resin coming from hopper 122. The method in this aspect of the invention proceeds by feeding the resin-additive mix into barrel 112 through throat 172, rotating screw 118 thereby converting granular resin and additive into molten material collecting at a mold end of barrel 112, while screw 118 retreats longitudinally due to force exerted on the screw by molten material collecting in barrel 112 at the mold end of barrel 112. The method proceeds by longitudinally advancing screw 118 thereby injecting molten material collected at the screw end into mold 116 where the longitudinal advancement is effectuated by application of high pressure hydraulic fluid to ram 124, thereby pushing ram 124 and screw 118 to the left in FIG. 3, thereby injecting molten material collected at the opposite end of screw 118 into mold 116. The method then proceeds by optionally maintaining screw 118 at this longitudinally advanced position for sufficient time to allow at least some cooling of molten material in mold 116. In this practice of the invention, the invention proceeds with recording the time for performance of the step of rotating the screw 118 to convert granular resin material and additive into molten material while screw 118 retreats, determining the time for performance of the steps of longitudinally advancing screw 118 and optionally maintaining screw 118 at the longitudinally advanced position to allow some cooling of molten material in mold 116 and thereafter apportioning the amount of additive provided to the resin at the throat 172 according to the times determined for the screw rotation step, the screw longitudinal injection step and the screw maintenance at the injection position to allow cooling.

[0094] In still another aspect of the method of the invention, feeder 170 is regulated to apportion the amounts of additive added to the resin during screw rotation and during screw advancement and optionally during the optional time for maintaining screw 118 at the longitudinally advanced post-injection position, to allow some cooling of the molten material in mold 116 where feeder 170 is regulated to apportion amounts of additive according to the times determined by measuring the steps of screw rotation, screw advancement, and optional screw position maintenance. In such performance of the method, microprocessor 200 has capability for measuring times for performance of these various steps of operation by screw 118, recording those measured times, and thereafter performing calculations using those times found in the course of operating screw 118.

[0095] While wireless communication between sensors 138 and 140 and microprocessor 200 is desirable, whether microprocessor 200 stands alone or is a part of feeder 170, hard wire communication is also within the scope of the invention and may be used. However, such hard wire communication has not been illustrated in FIG. 3 to ensure drawing clarity.

[0096] In addition to Internet and Bluetooth communication, GPRS, EDGE, ZIGBEE, PICONET, or Zwave are all suitable communication protocols for effectuating communication wirelessly between sensors 138, 140, and microprocessor 200, no matter where microprocessor 200 is located.

[0097] While the Maguire MGF feeder is the preferred feeder to be used as feeder 170, which is a gravimetric feeder, the invention is applicable to any feeder mounted at the throat of an injection molding machine.

[0098] When the Maguire MGF feeder is used as feeder 170, the feeder can accept both “screw” and “injection” signals, and can apportion the additive, whether it be color or some other additive, over both time periods, namely over the injection time period and over the screw rotation time period.

[0099] It is within the scope of the invention to use an independent signal supplied by after-market supplier to tell microprocessor 200 or to control feeder 170 exactly when the screw is advancing during injection and when the screw stops, at full injection. That signal can be used in lieu of a signal generated by sensor 138 as illustrated in FIG. 3. The invention may be practiced with any signal relating to injection time. The injection molding press circuitry itself, which provides an injection signal, or an injection timer, can be used to generate a suitable injection signal for use in practice of the invention. Similarly, a third-party, after-market device mounted on the injection molding press to provide the information as to injection time and to produce a signal regarding the same to be supplied to microprocessor 200, whether microprocessor 200 is mounted independently or part of feeder 170, provides adequate information for practice of the invention.

[0100] The invention does not depend on the type of signal. The invention can operate with any signal indicating injection and facilitating the provision of coordinated additive feeding over both injection and screw times, with resin and additive flowing together into the screw barrel.

[0101] As discussed above and from the foregoing description of the exemplary embodiments of the invention, it will be readily apparent to those skilled in the art to which the invention pertains that the principles and particularly the structures disclosed herein and the methods of use thereof can be used for applications other than those specifically mentioned. All such applications of the invention are intended to be covered by the appended claims unless expressly excluded therefrom.

[0102] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. The disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive with the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0103] As used in the claims herein, the term “comprising” means “including” while the term “consisting of” means “including so much and no more” and the term “consisting essentially of” means including the recited elements and those minor accessories; exchanges and variations required as known in the art as being used to facilitate the invention as claimed. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description and all changes which come within the range of equivalency of the claims are to be considered to be embraced within the scope of the claims.