The level of moisture in polymers significantly influences compounding outcomes — if stored improperly, hygroscopic resins including PA, PC, and PET — retain moisture at the molecular level. The water isn’t superficial — it becomes embedded in the polymer backbone, resulting in processing anomalies under high heat.

During compounding, polymers are heated to high temperatures to enable melt flow and uniform blending with additives}. Even trace amounts of humidity in the feedstock — it transforms into gaseous water under process conditions. Gas formation leads to cavities within the molten polymer, resulting in visible surface flaws such as splay marks, dull finishes, or streaking. These imperfections compromise aesthetics, and significantly weaken structural integrity, lowering fracture toughness and durability.

Beyond physical defects, moisture can induce chemical degradation. In polyesters and polyamides, hydrolysis occurs, a degradation pathway that fragments long-chain molecules. This chain scission reduces the average molecular weight, and critically affects processability and extrusion stability. Lower molecular weight means the polymer becomes more brittle, increasing susceptibility to fracture under stress, especially detrimental in automotive, تولید کننده گرانول بازیافتی medical, or aerospace components.

Eliminating moisture before processing is a mandatory industry practice. Resins like nylon and PET require thermal treatment within this range, for durations of 2 to 8 hours depending on material type and humidity levels. State-of-the-art facilities use precision drying technologies, maintaining residual moisture under 200 ppm.

Dried material is vulnerable to rehydration during handling. Proper material management is critical after thermal treatment. Operators must utilize airtight storage, dry-air purged feed systems, or vacuum-sealed bins. The surrounding environment’s dew point must be tracked in real time, Material must be fed into the extruder within 30–60 minutes of drying.

Moisture management is a core pillar of successful compounding operations. Neglecting moisture control leads to expensive scrap, rework, and downtime. It can also trigger customer complaints, warranty claims, and brand damage. With comprehensive moisture management systems, trained personnel, and process controls, they achieve optimal compounding efficiency and product reliability.