In precision injection molding and metal die casting, demolding stability directly impacts product quality and productivity. Industry data shows that improper demolding agents can cause defect rates exceeding 15%, with standard dimethyl silicone oils performing especially poorly under high temperatures. Experts agree that only modified silicone oils—such as amino- or epoxy-modified types—can meet the demands of advanced manufacturing.
High-end molds typically operate at 200–350°C, and sometimes above 400°C. Under such conditions, conventional dimethyl silicone oils often lead to sticking, carbon buildup, and surface defects.
In practice, some manufacturers report carbonized residues after just a few molding cycles, resulting in reduced output and significant scrap losses.
The root cause is structural: ordinary silicone oils lack reactive functional groups. Above 200°C, their molecular chains degrade and carbonize, breaking the release film. Poor adhesion to mold surfaces further accelerates failure under pressure.
Modified silicone oils deliver superior thermal stability and durable film formation. In aerospace and tire manufacturing applications, epoxy-modified silicone oils have maintained clean molds after dozens of cycles, reducing porosity by up to 70% and raising product pass rates to nearly 99.8%, while extending maintenance intervals multiple times.
By introducing active functional groups, modified silicone oils achieve three key advantages:
high-temperature resistance, strong film adhesion, and excellent material compatibility.
Different chemistries serve different needs:
Amino-modified oils improve release and surface smoothness for polar polymers like nylon
Epoxy-modified oils perform reliably in high-temperature curing and casting
Polyether-modified oils offer better environmental compatibility for medical and clean applications
Experts recommend selecting demolding agents based on process temperature and material type: epoxy-modified for die casting, amino-modified for precision injection molding, and polyether-modified for environmentally sensitive applications.
Case studies show that switching to modified silicone oils can cut defect rates significantly and reduce total production costs by over 15%. As manufacturing standards continue to rise, modified and customized silicone oils are set to replace conventional products as the industry norm.
