Technically Speaking | 21 JULY 2026
Nylon Conditioning Guide: Moisture Absorption, Dimensional Stability & Performance
Tech Tips from Our Engineers at Bamberger Amco Polymers
Nylon Conditioning Guide: Moisture Absorption, Dimensional Stability & Performance
Nylon is one of the most widely used engineering thermoplastics thanks to its great balance of strength, toughness, wear resistance, and cost-effectiveness. Unlike many other engineering polymers, however, polyamides are hygroscopic plastics, meaning they naturally absorb moisture from their environment.
Nylon conditioning helps manufacturers achieve the mechanical properties, dimensional stability, and long-term performance they need for applications ranging from medical devices to automotive connectors and EV battery system components. Moisture conditioning is also a key factor when comparing molded part performance to material datasheet values.
How to Condition Nylon Parts: Methods and Terms
Achieving the desired toughness, elongation, and other properties critical to your Nylon part will require a process known as “conditioning”.
The rate at which conditioning occurs depends on factors like temperature, storage medium, a part's wall thickness, and resin crystallinity of a specific grade. This can take hours, days, or even months.
- Dry as Molded (DAM): the lowest moisture content a part will contain, immediately after ejection from its mold.
- Conditioning: moisture absorbed by a part, either “naturally” or through accelerated methods.
- Passive Conditioning: letting a part to absorb moisture from its environment without interference.
- Active Conditioning: specialized techniques applied to accelerate moisture absorption.
The methods used to condition Nylon parts vary in cost and required equipment, with each offering unique challenges and benefits. Let’s explore the most common approaches:
Why Doesn't My Nylon Part Match the Datasheet?
One of the most common questions engineers encounter is why a newly molded nylon component doesn’t demonstrate the same toughness or elongation values shown in a technical datasheet right away.
It all comes down to the moisture content. Material suppliers typically publish both "dry as molded" and "conditioned" data for nylon materials. As moisture is absorbed into the amorphous regions of the polymer, it acts as a plasticizer, adding impact resistance and toughness while reducing stiffness and tensile strength. Make sure you check the data for the right stage of conditioning!
Nylon 6 vs. Nylon 66 Conditioning Behavior
Moisture absorption rates can vary significantly based on the polyamide grade in question. Nylon 6 generally absorbs moisture more readily than Nylon 66, which means greater changes in toughness, dimensional stability, and mechanical performance over time. Wall thickness, crystallinity, and environmental exposure conditions also affect how quickly moisture content equilibrium is reached.
Frequently Asked Questions
Your Partner in Nylon Conditioning
Let Bamberger Amco Polymers’ technical knowledge of engineering polymers and hygroscopic plastics support you as you choose – and condition – polyamides for your cutting-edge, medical, electrical, or industrial applications.
Featured Expert: David Katz
David is a renowned Technical Service Engineer with over 30 years of industry experience.
As a customer advocate, he supports our sales & marketing efforts through his expertise in material selection, conceptual design, design review, injection molding, extrusion processing, blow molding, troubleshooting, tooling review, and scientific molding education.
Technically Speaking: Tips & Material Insights
Technically Speaking is a content series empowering product designers, molders, and processors with practical knowledge and real-world insights. These tips are drawn from decades of experience in materials science and application development to help you solve problems faster and smarter. With a diverse portfolio and one of the most knowledgeable tech teams in the industry, we help our customers overcome challenges and bring better products to market.
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Disclaimer: The information provided in this post is intended solely for general guidance. Outcomes vary based on individual circumstances, and Bamberger Amco Polymers “BAP", "BA Polymers” does not ensure a specific result. Clients shall use their own independent skills and expertise when testing any application of technical support. Bamberger Amco Polymers is not responsible and will not be liable for any discrepancies between expected and actual outcomes. Bamberger Amco Polymers DISCLAIMS ALL WARRANTIES, WHETHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTIES OF MERCHANTABILITY OR FITNESS OF A PRODUCT FOR A PARTICULAR PURPOSE.
