Claims
- 1. Method for forming molder plastic articles which comprises:
- feeding molten plastic from a feeding means to at least one mold cavity via a hot runner channel in a hot runner system and nozzles, wherein at least two nozzles communicate with each mold cavity;
- providing one shooting pot containing molten plastic communicating with two of said nozzles and with the mold cavity, wherein said feeding steps feeds molten plastic from a feeding means to the nozzles and to the shooting pot and to the mold cavity;
- blocking the flow of molten plastic from the feeding means to the mold cavity and to the said one shooting pot to form a closed system between the shooting pot and mold cavity, wherein the flow of molten plastic from the feeding means and hot runner channel to the mold cavity and to the nozzles and shooting pot is blocked by valve means located in the hot runner system upstream of the shooting pot;
- alternately feeding molten plastic from the said one shooting pot to the mold cavity by first feeding from the shooting pot to one of said nozzles followed by feeding from the shooting pot to a second of said nozzles, said feeding being while the flow of molten plastic to the mold cavity from the feeding means and hot runner system is blocked, whereby the molten plastic is oscillated in the mold cavity; and
- including the step of feeding molten plastic from the feeding means to a plurality of mold cavities, with two nozzles communicating with each mold cavity and separate shooting pots for each mold cavity, including the step of alternately feeding molten plastic from each shooting pot to its respective mold cavity.
- 2. Method according to claim 1 including the step of forming closed communication channels between said shooting pot and nozzles, wherein said alternate feeding step feeds molted plastic via said closed communication channels.
- 3. Method according to claim 1 including the step of providing entrances from said hot runner system to said closed communication channels and closing said entrances to form said closed communication channels.
- 4. Method according to claim 1 including the step of purging the air from the shooting pot.
- 5. Method according to claim 1 including the step of cycling the shooting pot while feeding molten plastic to the mold cavities to flush molten plastic from the shooting pot.
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 734,148 filed Jul. 22, 1991 now U.S. Pat. No. 5,192,555 which is a Continuation-In-Part of copending application Ser. No. 480,866, filed Feb. 16, 1990 now, U.S. Pat. No. 5,069,840.
US Referenced Citations (14)
Foreign Referenced Citations (3)
Number |
Date |
Country |
339184 |
Nov 1989 |
EPX |
1463687 |
Feb 1977 |
GBX |
2170142 |
Jul 1986 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Article entitled "Multiple Live-Feed Injection Moulding", by P. S. Allen et al., Plastics and Rubber Processing Applications, vol. 7, No. 1, pp. 3-10, 1987. |
Divisions (1)
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Number |
Date |
Country |
Parent |
734148 |
Jul 1991 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
480866 |
Feb 1990 |
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