Yes, the presence of moisture in the material can cause various defects in the injection molding process of the injection molding. The following are specific impacts and reasons:
1. Bubbles and voids
Moisture will evaporate during the heating process, forming gas. When molten plastic is injected into the mold, these bubbles may be trapped inside the molded parts, causing surface bubbles or internal voids to form, thereby affecting the appearance and structural strength of the product.
2. Surface defects
When moisture evaporates rapidly at high temperatures, it may form uneven patterns or small holes on the surface of the molded parts, which can lead to surface roughness, uneven gloss, and in severe cases, defects or substandard appearance quality.
3. Material degradation
Moisture has a strong impact on certain plastic materials, such as polyester and nylon, and may cause material degradation. During the melting process, the presence of moisture can cause the molecular chains of plastic to break, reducing the mechanical strength and durability of the material, and even producing odors or discoloration.
4. Unstable injection process
Materials containing moisture can cause unstable flowability of molten plastics, affecting their filling speed and pressure in molds. This may lead to incomplete injection, uneven filling, and even mold sticking, affecting production efficiency and part accuracy.
5. Excessive pressure and temperature requirements
To eliminate moisture and ensure complete melting of the plastic, it may be necessary to increase the temperature or pressure of the injection machine. This will increase energy consumption, and excessive temperature and pressure may impose additional burdens on injection moldings and molds, increasing the risk of equipment wear and failure.
6. Uneven shrinkage
Moisture can cause uneven shrinkage of materials during the cooling process, resulting in dimensional deviations or warping of parts. Especially in thin-walled or complex structural components, this uneven shrinkage may result in molded parts failing to meet design requirements.
7. Increase material loss
When processing plastics in high humidity environments, a longer drying process may be required, increasing production time and costs. Meanwhile, damp materials may also decompose or produce impurities during processing, resulting in more material waste.