Educating product managers on how plastics affect your brand


The material you choose for your medical devices can have a big impact on your brand's image. In today's healthcare environment, not all plastics can withstand exposure to the aggressive disinfectants being used in hospitals. If your device is showing outward signs of suffering from exposure to effects of disinfection, including yellowing, cracking, crazing, or paint peeling, it's time to reconsider material selection.


Thank You for Asking

We often receive great questions about molding with Eastman medical grade polymers and are always glad to provide answers and more information. Here is a response to a recent query from our inbox:
“How environmentally friendly is Eastman MXF221 copolyester?”

Eastman strives to create solutions that offer more value with less environmental impact.
MXF221 copolyester is one of our many environmentally responsible offerings that meets
industry standards for safety and sustainability. Some of its innovative properties include:
  • It’s made without BPA, halogens, or ortho-phthalate plasticizers.
  • Its toughness and durability can potentially increase product life and reduce waste.
  • The flame-retardant additives used in do not contain antimony, bromine, or chlorine.
  • It’s suitable for transducer housing applications that require contact with the skin.
Read more about how Tritan is improving sustainability and design for devices and diagnostics.

Secondary Operations: Adhesive Bonding

蒸発してしまう溶剤とは違い、接着剤層は組立後のパーツの機能部分として残ります。 Therefore, the characteristics of the adhesive layer play a key role in the performance and appearance of the finished part.
Consider these characteristics when selecting an adhesive:
  • Chemical compatibility with parts being joined
  • 組立後の接合部の外観の美しさ
  • Expansion/contraction with temperature changes (NOTE: if expansion/contraction are a major concern, consider mechanical fasteners.)
  • 脆性、剛性、柔軟性
  • 耐久性 / 耐用性
  • 接着強度(プラスチックとの接着力)
  • 結合強度(引裂き強さ)
  • 最終用途の要件
Eastman Tritan copolyester offers outstanding chemical resistance and has been studied with many adhesives and different bonding procedures. 
Adhesive bonding procedures for Eastman Tritan copolyester     
When adhesive bonding parts made with Tritan, joining surfaces should:
  • Fit well without forcing
  • Have no visible gaps


硬質熱可塑性エラストマー製の製品に機能的要素や装飾的要素を付加するために、ソフトタッチの材料をオーバーモールドすることがよくあります。イーストマンTritanコポリエステルは、市販グレードの熱可塑性エラストマー(TPE) に対して優れた接着性を示します。使用するTPEグレードを選択に当たっては、TPE サプライヤーまたはイーストマンと協力し、コポリエステル基材との使用に適切なグレードを選び、成形品を正しくデザインすることが非常に重要です。


  • パーツの厚さと TPE の厚さを最適化し、接着および寸法の安定性を図ります。TPEの厚さがイーストマンTritanコポリエステルの成形品よりも厚いと、金型から外したときに反りが生じる場合があります。一般的に、基材の厚さをTPEの厚さの2倍にすることが推奨されます。
  • 機械的インターロックを組み込むと、TPE の接着力を向上させるとともに、パーツの耐久性を高めることができます。機械的インターロックは、TPE 層が薄 い場合や使用品質要件が非常に厳しい場合に特に重要となります。
  • 複数の表面にソフトタッチ特性を取り入れたデザインの場合、フロースルー (flow-through) デザインを用い、接着力と耐久性を向上させる必要があります。
  • 剥離の可能性を最小化するため、TPEエッジを硬質基材のオーバーモールドされていない部分の高さとぴったり合わせるか、それ以下となるようにする必要があります。

Troubleshooting Focus: Flashing

Proper mold design provides a giant step toward reducing problems like flashing when injection molding with Eastman Tritan copolyester and other Eastman copolyesters. Collaborating with an Eastman technical service representative early in your project can help ensure you’re off on the right foot.

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.