Material Drying
2 views
PA6 Rapid Moisture Re-Absorption After Drying
Problem Phenomenon
Qualified dried pellets placed in the hopper for one or two hours show silver streaks again
Cause Analysis
PA6 absorbs moisture extremely fast; in the humid season at 75%RH, one hour of exposure can re-absorb 0.35% moisture; even in a dry 25%RH environment, 40 hours is enough for moisture absorption to exceed the standard, and leaving the hopper open is equivalent to drying in vain
Solution
①Insulated drying hopper at 80-100°C for continuous protection; ②pellets exposed to air for no more than 30 minutes; ③enclose the feeding system and replenish frequently in small batches; after adjustment, continuously sample to verify the effect, and resume mass production after confirming stability
Key Takeaway
PA6's moisture re-absorption speed far exceeds that of ordinary materials; drying is only a momentary state, and only an insulated hopper plus the 30-minute time limit can preserve the drying results until the moment of injection; after confirming effectiveness, fix the parameters and practices into the work instructions to prevent recurrence
Was this helpful?
0 people found this helpful
Thank you for your feedback!