When a die-casting plant encounters scrap die-castings, most teams immediately suspect the die-casting release agent—and then verify parameters with the supplier. In reality, unless the supplier changed raw materials (a potential cause of scrap), release agents—if they were truly a universal fix—would not be classified as auxiliary materials. This mindset and approach are fundamentally flawed.
The correct practice lies in analyzing two core factors: the rationality of release agent selection and the correctness of spraying processes. Many die-casting defects stem from improper use of release agents. When adopting a new release agent—whether during testing or bulk supply—do not dismiss it outright if it conflicts with traditional habits. This often creates a paradox: one plant may master a release agent for a specific casting, while another complains about its performance. Worse, domestic brands of the same release agent frequently receive poorer trial feedback than foreign ones. The root cause? Insufficient understanding of the release agent’s properties and neglect of critical precautions. Below are five key considerations:
This is a common pitfall. For high-temperature die-casting applications, select heat-stable release agents; for alloys with poor fluidity, choose release agents that enhance alloy flow.
Always dilute release agents per the manufacturer’s recommendations—avoid over-concentration or under-dilution. Over-concentration leads to dull (or even yellowed) part surfaces, impairing subsequent cleaning, coating, or electroplating. Under-dilution causes die sticking, galling, and product deformation.
Spraying aims to form a uniform, fast-setting film on the mold, requiring precise control of angle, distance, direction, pressure, flow rate, time, and atomization. A common misconception: “more spraying = better adhesion.” This is false—film formation takes time, and re-spraying too soon washes away the nascent layer. Many issues (die sticking, carbon deposition, deformation) can be resolved by optimizing spraying parameters.
For plants using recycled water, improper treatment of the recycling tank causes odor and die-casting defects (e.g., die sticking, black spots). Some use well/groundwater, which contains calcium/magnesium ions that promote carbon deposition. Even tap water demands attention to quality metrics like electrical conductivity and bacterial count—neglect can lead to nozzle blockages.
Release agents are auxiliary materials: their only role is to assist demolding without disrupting subsequent cleaning/coating. Die-casting machines, molds, and processes are far more critical. Die casting is a precision technology—any parameter shift (even minor) can affect part quality. Continuous mold opening/closing during production inevitably disrupts sensor readings for spraying parameters. Thus, using the correct dilution ratio, optimizing spraying, and aligning with process parameters will drastically improve part quality.
For more information about 100 Questions (22): Is the Release Agent Always the Culprit When Scrap Die-Castings Occur or die-casting auxiliary materials, and if you need customized die-casting release agent, please contact 15021483232 (same as Wechat)
