1.Water Absorbency
The water absorption of plastic pellets generally varies depending on the type of plastic and its composition. In general, most common plastic materials are not water-absorbent in dry conditions, such as polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). However, certain types of plastics may absorb water, especially under conditions of high temperature, high humidity, or prolonged exposure to water.
Here are some characteristics of water absorption for common plastic materials:
Polypropylene (PP): Polypropylene has relatively low water absorption and usually exhibits low water absorption at room temperature.
Polyethylene (PE): Polyethylene also has low water absorption at room temperature, with high-density polyethylene (HDPE) typically having lower water absorption than low-density polyethylene (LDPE).
Polyvinyl Chloride (PVC): Rigid PVC has low water absorption, but flexible PVC can absorb some water.
Nylon (PA): Nylon is known for its high water absorption, especially nylon 6 and nylon 66 types.
Polyethersulfone (PES): Polyethersulfone generally has low water absorption.
Polycarbonate (PC): Polycarbonate typically has low water absorption but can be influenced by humidity and temperature.
2.Vacuum Method
Isolation of Air: Vacuum sealing effectively removes the air inside the packaging, preventing oxygen and other gases from entering. This helps extend the shelf life of plastic pellets, especially those sensitive to oxygen.
Isolation of Water Vapor: Vacuum sealing prevents the penetration of water vapor, crucial for plastic pellets prone to moisture absorption or requiring a dry state to maintain quality and performance.
Convenient Transportation: Vacuum-sealed plastic pellet packaging is typically more compact, reducing volume and weight to lower transportation costs. Sealed packaging also shields pellets from external influences during transport, ensuring they remain in good condition.
Reduced Friction: Vacuum sealing decreases friction between plastic pellets, helping to maintain their shape and quality. This is particularly important for pellets that need to retain their integrity, reducing damage and wear to ensure product quality stability.