You can speak with a Tritan expert in person at MD&M West.
Eastman will be exhibiting in Booth 2407, February 9 to 11. Stop by to see how Eastman Tritan™ copolyester and other medical-grade polymers are helping device makers meet regulatory requirements, improve patient safety, and ensure confidence in end-product performance.
While at our booth, you can pick up two white papers with great information about important roles chemical resistance plays in preventing health care-acquired infections and complying with best practices for oncology drug delivery devices.
MD&M West will be the center of the medtech world in early February. It’s a great place to discuss possibilities our whole portfolio of medical-grade polymers. You’re invited to talk with Tritan experts about specific advantages for medical devices, including:
• Crystal clear or opaque
• Chemical resistance
• Sterilization stability
• Made without bisphenol A (BPA)
• UL V2 flame rating
• Successful secondary operations
|TMI TIP: To schedule a private appointment during your booth visit, go to www.Eastman.com/MDMW2016.|
Some traditional polymers used in drug delivery devices are not compatible with modern oncology chemotherapies—including the cancer drugs and the carrier solvents that help make them effective.
Device manufacturers have more reasons than ever to understand the chemical resistance of the materials they use in devices, including:
• The widespread use and growing economic importance of oncology drugs
• A recent FDA Safety Alert* concerning infusion devices made with polycarbonate (PC) or acrylonitrile-butadiene-styrene (ABS)
All stakeholders are working together to reduce product failure and improve safety through:
• Vigilance by regulatory agencies
• Chemical resistance research by polymer manufacturers
• Informed polymer selection for oncology drug delivery devices
For its part, Eastman has conducted a series of chemical resistance tests on Eastman Tritan™ copolyester and competitive polymers. The test results are presented and discussed in a recently posted webcast titled “Why Devices are Failing in Oncology Drug Delivery Applications”.
Eastman also offers a free white paper that will give you more details of the testing.
TMI TIP: You can learn more about the chemical resistance characteristics of Tritan in the TritanMoldIt blogs posted Sept. 8 and Sept. 14, 2015.
With any polymer, poor and uneven cooling can result in:
• Increased cycle time
• High levels of residual stress
• Increased warpage
• Sticking and difficulty in ejection
Considering the unique properties of Eastman Tritan™ copolyester, a few important guidelines will improve efficiency and part performance.
Because of the relatively low flex modulus of Tritan, uniform and efficient mold cooling—especially in the cores— is critical for the successful molding and ejection of parts.
When working with Tritan, you need to make sure you are cooling the resin enough to set up the outer skin of the part in order to get good release from the mold. This initial skin formation can take 10 to 20% longer than normal engineering resins, but cooling time throughout the rest of the part will be approximately the same.
Here are a few tips to improve cooling efficiency:
• Design ample mold-cooling channels with proper spacing and sizing.
• Use properly sized pumps and supply lines to deliver a good turbulent flow of water around the cavity. (The flow rate should be high enough to reach a minimum Reynolds number (Nr) of 6,000 in those areas where cooling is desired.)
• Use chillers, if practical, to ensure a proper supply of cool water to molds.
• Remove heat uniformly to avoid hot spots that can cause sticking and local deformation.
• Provide ample cooling near potential hot spots such as sprues and hot runners.
• Pay special attention to cooling heat sinks in pins and thin areas, and around slides.
• The mold should be cooled to 60°C (140°F) before ejection.
For more information, see May 29, 2014 Blog “Tooling design — keys to success”
For best results, involve an Eastman tech services engineer or design services engineer early in your planning. We’re prepared to discuss mold design, including line spacing and core cooling techniques such as baffles and bubblers, and much more.
|TMI TIP: For more information download the Eastman polymers Processing and mold design guidelines.|
The Tritan experts at Eastman are hosting a live webinar on December 10, 2015, from 11:00 to 12:00 EST. This webinar will cover these important considerations to help you design for manufacturability:
• Material selection criteria
• Part design for injection molding
• Tool design for injection molding
• Molding workcell design
• Processing tips for Tritan
Join us live! Register now to participate in “Designing for Injection Molding Manufacturability,” offered by Eastman from 11:00 to 12:00 pm EST on Thursday, December 10, 2015.
To help ensure continued molding success, this blog focuses on three different types of flashing problems, their possible causes, and corrective actions you can take for each.
|Possible cause||Corrective action|
|1. Poor mold spot||Spot mold to ensure fit and vent depths at ~0.025mm (0.001in).|
|2. Injection Pressure too high||Reduce pressure. This may require higher melt temperature or lower injection speed.|
|3. Coost time too long||Shorten boost time, lower boost pressure, or move transfer to an earlier position.|
|4. Insufficient clamp tonnage||Increase clamp pressure or move to a machine with more tonnage.|
Flash and Short Shot in Different Shots:
|Check ring inconsistent; worn barrel||Check and replace assembly ring. Replace/reline barrel as needed.|
Flash and Short Shot in Same Shot:
|Possible Cause||Corrective action|
|1. Core shift||Check wall thickness for core shift. Investigate for source of core shift and repair mold.|
|2. Inadequate clamp tonnage||Increase clamp pressure or move to a machine with more tonnage.|
|3. Fill speed or pressure too high||Reduce speed or fill pressure.|
|4. Melt temperature too low||Check and raise melt temperature if needed.|
|5. Sprue too long too small, "O" dimension||Install correct-size sprue.|
TMI TIP: Tritan can be successfully ultrasonic welded using energy director and shear-joint designs. The resulting device can exhibit outstanding impact strength, clarity, and durability—without weld joint flashing.
For more information about flashing, talk with your Eastman technical service representative. You can also download an Injection Molding Troubleshooting Guide (specify medical or durables).