电子束灭菌对Eastman Tritan™的影响
医疗器械灭菌有助于将生物负载降低到安全水平,同时对其聚合物的物理和光学特性的影响最小。当今医疗行业使用最广泛的一些灭菌方法包括伽马辐射、环氧乙烷(EtO)、高压灭菌器和低温过氧化氢气体等离子体。另一种越来越流行的方法是电子束(e-beam)辐射。由于运行效率的最新进展,它是一种安全、可靠的能源。
 
与伽马辐射相比,电子束辐射的成本通常更低,因为更高的剂量率可减少在相同目标剂量下的暴露时间。较短的曝光时间也最大限度地减少了聚合物表面可能发生的氧化反应,与伽马辐射相比,对树脂性能的影响较小。

To determine the effects of e-beam radiation on Tritan and other transparent medical polymers, Eastman conducted a series of studies that measured color shifting and physical property retention. Specific products tested are shown here:
Optical properties
Samples were exposed to e-beam radiation (25 and 50 kGy) and then stored in darkness. Their color was measured at days 3, 7, 14, and 42 using HunterLab UltraScan Sphere 8000 and the CIE L*, a*, b* color scale. (Samples were stored in darkness and only exposed to light for color measurement.)
 
 
Figure 2 shows the difference in b* color values between unexposed samples and sterilized samples at day 42—after e-beam radiation at both 25 and 50 kGy. 
 
Figure 2. Change in b* color 42 days after e-beam radiation—25 and 50 kGy  

Physical properties were measured before and after e-beam sterilization at 25 and 50 kGy. No physical property degradation was noted for Tritan MX711 or the other resins tested. The polyesters and copolyesters in the study showed no statistical change in molecular weight, although Tenite propionate 360 did show a loss of molecular weight, as expected from an aliphatic polymer.


Read the complete details of these studies here
 
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Overmolding with Tritan
Using overmolded soft-touch materials can provide many functional and decorative benefits to items made from rigid thermoplastics. Eastman Tritan copolyester demonstrates exceptional adhesion with commercial grades of TPE. When selecting the TPE you want to use, make sure it is formulated for use with a copolyester substrate.
Consider these factors for part design:                 
  • Optimize part and TPE thickness for adhesion and dimensional stability. If the TPE thickness is in excess of the Tritan part thickness, you could see warpage when you remove it from the mold. Use a substrate thickness twice that of the TPE.
  • Incorporate mechanical interlocks to improve TPE adhesion and promote part durability. Mechanical interlocks are important for thin TPE layers and very demanding fitness-for-use requirements.
  • Use flow-through designs to improve adhesion and durability. This is especially beneficial for designs incorporating soft-touch features on multiple surfaces.
  • Ensure the edge of the TPE is flush with or below the level of the non-overmolded section of the rigid substrate. This will minimize the potential for peeling or delamination. 
Work with your TPE supplier or Eastman to ensure your part is designed for successful results. Remember to think about the specific end-use environment of the overmolded part when selecting the appropriate TPE grade to confirm that it is compatible with your specific fitness-for-use criteria.
   
For more information about using Tritan in secondary operations, download our Secondary Operations Guide
 
 
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Which medical grade polymer is right for you?

We know that material choice is a crucial component of any medical device or device housing. When you're deciding what medical grade polymer you need for your next project, consider these criteria:
  • Does it make the grade?
  • Will it match the application?
Selecting the right medical grade polymers helps ensure your device complies with quality and biocompatibility standards-and that you have reliable support for regulatory approvals. Different polymers offer different combinations of strengths that help ensure performance in specific medical applications.
 
When matching a medical grade of Eastman Tritan copolyester to your needs, keep in mind that each medical application has different performance priorities. For example, while opaque medical housings demand a greater level of durability, chemical resistance, color stability, and heat resistance, clear applications—such as fluid management and IV components—also place a high value on clarity.
 
Eastman provides a range of medical grades of Tritan. Here are some outstanding properties of our clear and opaque formulations of the polymer:
 
Clear formulations of Tritan:
  • Offer greater toughness, heat resistance, processability, and design freedom compared with other copolyesters
  • Retain clarity, color stability, and functional integrity after sterilization
  • Provide outstanding chemical resistance to lipids, IPA, disinfecting agents, and bonding solvents and adhesives
Opaque formulations of Tritan:
  • Provide excellent functionality and reliability to device housings
  • Ensure compatibility with the new reality of aggressive disinfection and the daily impact stresses that come with greater portability
  • Retain color and functionality following sterilization with gamma and e-beam irradiation
  • Offer reliable color matching—drawing on the expertise of the Eastman Color Technology Center
  • Provide flame-retardant properties
Find out more about our different products here. We also have the technical expertise and support you need to make the right material choice. Our team will work with you every step of the way to help bring your product to market as seamlessly as possible.
 
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使用Tritan进行模具设计的技巧

 
Eastman Tritan™共聚聚酯的有效成型有哪些特征?在流程的早期审视设计的所有方面——从概念到二次加工——对于最终的成功至关重要。
 
模具设计审查是该过程中的一个重要步骤,它将有助于确定哪种类型的浇口系统适合您的设备。以下是使用Tritan进行注塑的四个快速模具设计技巧:
 
  • 适当的浇口选择
    为所选树脂选择兼容的浇口样式。大多数传统的冷浇口样式都适用于Tritan共聚聚酯,包括潜伏式浇口、针点浇口、扇形浇口、边缘浇口、射料浇口和隔膜浇口。
 
  • 设计具有良好冷却/热控制的模具
    共聚聚酯需要在整个腔体中进行良好的热控制,以实现最佳加工。
 
  • 在设计模具时考虑排气计划
    Poor venting can result in burn marks and incomplete fill. Suggested vent depths for Tritan copolyesters are typically 0.0005-0.0015 in.
 
  • Design tooling with a plan for ejection 
Parts should be adequately supported during ejection to avoid part deformation/breakage.
 
By collaborating with our team from the get-go, you’ll be sure to see greater return on investment for your project in the end. Contact us for processing tips and more!

探索肿瘤药物相容性的复杂难题

降低感染风险和提高患者安全性和舒适度的需求显着增加了对具有更高耐化学性的高性能塑料的需求。许多通常用于给药装置的聚合物根本无法适应现代肿瘤化学疗法。在医疗环境中接触化学品后,由这些聚合物制成的设备可能会在施加或残余应力的情况下出现环境应力开裂或过早出现故障。
 
损坏的设备使患者处于危险之中。此外,当设备性能或生命周期受到影响时,监管机构可能会告诉制造商停止使用某些材料。
 
For these reasons, when you are choosing materials for your medical device, evaluating polymers for chemical resistance is key. Eastman Tritan copolyesters have excellent overall chemical resistance and other advantages that make them superior alternatives to polycarbonate (PC) or acrylonitrile-butadiene-styrene (ABS) for oncology drug delivery devices.
 
Tritan also offers compatibility with many popular sterilization methods and has outstanding hydrolytic stability. This balance of properties makes Tritan a great choice for IV system components, blood therapy devices, and any parts that face frequent disinfection. Read more about the benefits Tritan offers devices that encounter hospital disinfectants and oncology drugs here.

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