Plastics and Water Absorption
2025/11/6
If you’ve noticed plastic parts changing dimensions depending on the environment, or components losing strength in humid conditions, the cause may be water absorption in the material.
High Water Absorption Plastics
Most plastics absorb some moisture, though the amount varies by material. Nylon-based resins are particularly prone to water absorption, while others take in very little.
Nylon resins absorb more moisture due to their molecular structure. They contain amide groups (–CONH₂), which are hydrophilic, meaning they readily attract and interact with water.
Effects of Water Absorption
When plastics absorb moisture, they swell, leading to dimensional changes. Materials with higher water absorption have lower dimensional stability.
In addition, moisture uptake lowers the glass transition temperature (Tg), which can affect the material’s thermal and mechanical performance.
Step Up Your Project with Yumoto Electric
Yumoto Electric delivers high-quality components fast, worldwide. We provide precision machining for a wide range of engineering plastics, including PEEK, PPS, MC Nylon, and POM.
If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.
