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The present invention is a method and apparatus for controlling a mold flow process using inner (impinge) and/or edge temperature sensors, wherein articles processed in a constraining mold cavity, having a constant melt "shrink" quality, can be obtained even with fluctuations in resin "melt" propert

The present invention is a method and apparatus for controlling a mold flow process using inner (impinge) and/or edge temperature sensors, wherein articles processed in a constraining mold cavity, having a constant melt "shrink" quality, can be obtained even with fluctuations in resin "melt" properties (flowability). At least one temperature-dependent output or "trigger" signal is sampled, and the level of the signal (e.g., temperature) initiates at least one step in the molding cycle. Using a sampling circuit, thermal waveforms are obtained from thermal sensor array data such that if a sequence of melt temperature set-point trigger times fluctuates outside control limits, then the process melt-flow is judged as a hotter/faster melt-flow or cooler/slower melt-flow injection process.

대표청구항 ▼

The present invention is a method and apparatus for controlling a mold flow process using inner (impinge) and/or edge temperature sensors, wherein articles processed in a constraining mold cavity, having a constant melt "shrink" quality, can be obtained even with fluctuations in resin "melt" propert

The present invention is a method and apparatus for controlling a mold flow process using inner (impinge) and/or edge temperature sensors, wherein articles processed in a constraining mold cavity, having a constant melt "shrink" quality, can be obtained even with fluctuations in resin "melt" properties (flowability). At least one temperature-dependent output or "trigger" signal is sampled, and the level of the signal (e.g., temperature) initiates at least one step in the molding cycle. Using a sampling circuit, thermal waveforms are obtained from thermal sensor array data such that if a sequence of melt temperature set-point trigger times fluctuates outside control limits, then the process melt-flow is judged as a hotter/faster melt-flow or cooler/slower melt-flow injection process. ses a tubular shaped portion and wherein said introducing includes positioning the graft relative to the source so that an opening faces the source. 5. The method as described in claim 1, wherein said introducing the graft into the chamber in contact with the conductive base plate comprises slipping the graft over the conductive base plate. 6. The method as described in claim 1: wherein the graft comprises a tubular shaped portion; wherein the conductive base plate has a cylindrical shaped portion that generally conforms to the tubular shaped portion of the graft; and wherein introducing the graft into the chamber in contact with the conductive base plate comprises slipping the tubular shaped portion of the graft over the cylindrically shaped portion of the base plate. 7. The method as described in claim 1: wherein the graft has a bifurcation and the conductive base plate has a conforming bifurcation; and wherein introducing the graft into the chamber in contact with the conductive base plate comprises slipping the bifurcation of the graft over the conforming bifurcation of the conductive base plate. 8. The method as described in claim 1, wherein depositing the vaporized metal onto the graft to form the radiopaque marking comprises depositing a metal that is selected from the group consisting of platinum, iridium, tungsten, gold, and any combination thereof onto the graft at a deposition rate that is in a range of about 0.1 nm to about 5 nm per second to form a radiopaque marking having a thickness in a range of about 0.5 μm to about 1 mm. 9. The method as described in claim 1, wherein depositing the vaporized metal onto the graft to form the radiopaque marking comprises depositing platinum onto the graft to form a radiopaque marking having a thickness in a range of about 1 μm to about 10 μm. 10. The method as described in claim 1, further comprising moving the graft through the vaporized metal while depositing the vaporized metal onto the graft. 11. The method as described in claim 1: further comprising placing a template having a design formed therethrough in a position relative to the graft prior to evacuating the chamber; and wherein depositing comprises depositing the vaporized metal through the design in the template onto the graft. 12. The method as described in claim 1: wherein the graft comprises a bifurcated graft having a main body and a bifurcation that defines a first leg and a second leg; further comprising placing a template having a design formed therethrough in a position relative to the graft prior to evacuating the chamber; and wherein depositing comprises depositing the vaporized metal through the design in the template onto the graft to deposit a differentiating marking on the first leg of the graft to allow the first leg to be differentiated from the second leg of the graft. 13. The method as described in claim 1, wherein the graft comprises a polyethylene terephthalate and the chamber is kept at a temperature that is not greater than about 150° C. 14. The method as described in claim 1, wherein the conductive base plate comprises a material that is selected from the group consisting of stainless steel and aluminum. 15. The method as described in claim 1, wherein the graft is maintained at the temperature that is not greater than the damage threshold. 16. The method as described in claim 1, wherein the chamber is maintained at the temperature that is not greater than the damage threshold. 17. The method as described in claim 1, wherein depositing comprises depositing a portion of the vaporized metal at an initial rate of deposition and then depositing another portion at an increased rate of deposition. 18. The method as described in claim 1, wherein introducing comprises positioning the graft off-axis from the source. 19. The method as described in claim 1, wherein depositing comprises depositing vaporized platinum onto the graft to form the radiopaque marking having a thickn ess that is greater than 1 μm. 20. The method as described in claim 1, further comprising placing a template having a design therethrough in a position relative to the graft. 21. The method as described in claim 20, wherein the template comprises a conductive metal template, wherein said placing the template comprises placing the conductive metal template into contact with the graft, and wherein the method further comprises conducting heat from the graft into the template. 22. The method as described in claim 20, wherein placing the template in a position relative to the graft comprises fitting a tubular portion of the template over a tubular portion of the graft. 23. The method as described in claim 1, wherein depositing comprises forming a leg identification marking. 24. The method as described in claim 1, wherein depositing comprises forming an opening identification marking. 25. The method as described in claim 12, wherein the differentiating marking comprises a letter that is selected from the group consisting of a letter R and a letter L. 26. A method comprising: providing a deposition chamber containing a source of a radiopaque metal and a conductive cylindrically shaped base plate; placing a tubular shaped graft comprising a polymeric textile having a damage threshold into the chamber in contact with the cylindrically shaped base plate by slipping the tubular graft over the cylindrically shaped base plate; placing a template having a design therethrough in a position relative to the graft; evacuating the chamber; vaporizing the radiopaque metal from the source to form a vaporized metal within the evacuated chamber; depositing the vaporized metal through the design in the template onto the graft to form a radiopaque marking which is visible under a fluoroscope, wherein depositing includes depositing at an average deposition rate in a range of about 0.1 nm per second to about 5 nm per second, to form a radiopaque marking having a thickness in a range of about 0.5 μm to about 1 mm, while maintaining a temperature that is not greater than the damage threshold; and conducting heat from the graft into the conductive base plate. 27. The method as described in claim 26, wherein depositing comprises depositing an initial layer of the vaporized metal having a thickness that is at least 0.1 μm at an average initial rate in a range of about 0.1 nm to about 0.3 nm per second and then increasing the rate of deposition of the vaporized metal onto the graft. 28. The method as described in claim 26: wherein introducing the graft into the chamber comprises introducing the graft into the chamber such that a first portion of the graft that is facing the source is shielded in order to reduce exposure to ultraviolet radiaiation generated at the source; wherein depositing comprises depositing sputtered metal on a second portion of the graft that is not facing the source; the method further comprising, after depositing the sputtered metal on the second portion, rotating the graft so that the first portion of the graft is not facing the source; and wherein depositing further comprises depositing sputtered metal on the first portion of the graft after it has been rotated so that it is not facing the source. 29. The method as described in claim 26, wherein the graft comprises a tubular shaped portion that is positioned relative to the source so that an opening faces the source. 30. The method as described in claim 26: wherein placing the template in the position relative to the graft comprises placing a conductive template into contact with the graft; and further comprising conducting heat from the graft into the conductive template. 31. The method as described in claim 26: wherein the polymeric material comprises a polyethylene terephthalate and the damage threshold is about 150° C.; and wherein the radiopaque metal comprises platinum deposited while maintaining the temperature not greater than about 150° C. as