Moisture Measurement in Polymers Using Enhanced Loss-On-Drying Technology

摘要

Knowing the correct dryness level of many of the engineered thermoplastic resins is crucial to proper injection molding. Some resins are affected by under-drying and exhibit cosmetic defects such as splay marks. Improper drying of resins such as PET, however, can grossly affect the structural integrity of the finished part, while appearing optically correct. Overdrying can also be a problem with materials such as nylon which incorporate water as a natural plasticizer and can cause brittleness in the finished part.Although "Loss-on-Drying" technology has been used quite extensively in the plastics industry, many questions still arise concerning the influence of other volatiles when measuring moisture using "Loss-on-Drying" technology.A quick, accurate, moisture determination method is now available using digital force-balance technology and product-specific parameters to control volatile influence. Results correlate well with known standards such as Karl Fischer analysis, while still providing the ease of use typically associated with loss-on-drying instrumentation.