閉じる
7月
15
15
ガンマ線照射に比べると、電子線滅菌は概してコストが低いのが特徴ですが、これは線量率がガンマ線照射よりも高く、同じ目標線量率での曝露時間が短くなることによるものです。曝露時間が短いと、ポリマー表面で酸化反応が起こる可能性が非常に低くなるため、ガンマ線照射と比較して樹脂の特性に対する影響が少なく抑えられます。
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.)
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.
Read the complete details of these studies here.
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6月
17
17
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:
For more information about using Tritan in secondary operations, download our Secondary Operations Guide.
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.
For more information about using Tritan in secondary operations, download our Secondary Operations Guide.
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5月
13
13
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?
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
- 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
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Apr
15
15
イーストマンTritan™コポリエステルの効果的な成形を可能にする要素とは、一体どのようなものでしょうか。最終的な成功をもたらす鍵は、デザインプロセスの初期の段階において、コンセプトから二次加工にいたるまで、デザインのあらゆる側面を見直すことです。
金型デザインの見直しは、デザインプロセスの重要なステップの一つです。これを行うことにより、機器に合ったゲートシステムのタイプを見極めるのが容易になります。ここでは、Tritanの射出成形をする際の金型デザインのポイントを4つご紹介します。
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!
金型デザインの見直しは、デザインプロセスの重要なステップの一つです。これを行うことにより、機器に合ったゲートシステムのタイプを見極めるのが容易になります。ここでは、Tritanの射出成形をする際の金型デザインのポイントを4つご紹介します。
- 適切なゲーティングを選ぶ
選択した樹脂に対応するゲートスタイルを決定します。Tritanコポリエステルでは、サブゲート、ピンゲート、ファンゲート、エッジゲート、スプルーゲート、ダイアフラムゲートなど、従来のコールドゲートのほとんどがうまく機能します。
- 冷却/温度制御機能の優れた金型をデザインする
コポリエステルで加工工程を最適化するためには、キャビティ全体の温度制御を効果的に行う必要があります。
- ベントを考慮した金型をデザインする
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
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!
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Mar
4
4
感染リスクを下げながら患者の安全性と快適性を向上させることが求められる中、耐薬品性が強化された、より性能の優れたプラスチックに対するニーズが大いに高まっています。薬物送達装置で一般的に使用される多くのポリマーは、最新のがん化学療法にまったく対応できていません。このようなポリマーを使用した装置が医療の現場で化学物質に曝露されると、印加応力や残留応力がある状態では、環境応力亀裂や早期故障が発生する可能性があります。
機器の故障は患者にとってリスクとなります。それだけでなく、機器の性能やライフサイクルに問題が生じると、規制機関がメーカーに特定の材料の使用を中止するよう指示することもあります。
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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