Classification, Formula Selection, and Spray Process Control of Die Casting Release Agents
Release agents are not only "convenient for demolding", but also serve the functions of cooling, anti sticking aluminum, and lubricating the mold cavity. Many factories rely solely on experience for spraying, and parameter control can lead to batch defects. New Peak Machinery standardizes the sorting process.
1、 Three mainstream categories of release agents
Water based emulsion release agent is widely used, with good cooling effect and moderate cost, suitable for ADC12 conventional shell; Semi synthetic release agents have stronger resistance to high temperatures and anti stick aluminum, and A356 wheels and high wettability aluminum materials are preferred for use; Pure oil release agents have weak cooling and high smoke emissions, and are rarely used on a large scale in high-pressure die-casting nowadays. The mass production of alloy wheel molds mostly uses semi synthetic special release agents.
2、 Four major variables of spraying parameters: pressure, flow rate, atomization, and distance
Atomization pressure is 0.3-0.6MPa, with a distance of 150-250mm from the mold cavity; spraying is divided into pre spraying, main spraying, and blowing. Pre spray to establish a uniform isolation film; The main spray takes away heat; Blow away residual water and avoid air holes. Poor atomization results in large droplets concentrating locally, causing sudden cooling and hot cracking.
3、 Differences in formula between A356 and ADC12
A356 has strong wettability and requires a higher content of anti sticking aluminum additives, silane based and ceramic additive formulas; ADC12 ordinary water-based version is sufficient, with a focus on controlling the adhesion of silicon slag. The excessive thickness of the release agent film layer can decompose and produce gas, which is a cause of porosity and peeling in castings; The film layer is too thin, which increases the risk of aluminum adhesion and tearing.
4、 Spray timing and mold temperature linkage
When the mold temperature is high, the release agent droplets quickly vaporize, making film formation difficult; The mold temperature is too low, and the moisture cannot completely evaporate, resulting in residual water vapor being carried into the mold cavity and forming pores. The A356 mold is sprayed in the temperature range of 200-240 ℃ for optimal film stability. Continuous production, spraying time and rhythm cannot be arbitrarily extended or shortened.
5、 Characteristics of Low Pressure Casting Release Agent
Low pressure casting has a slow filling speed and low pressure, and the amount of mold release agent used is much less than that of high-pressure die casting. Many low-pressure wheel hubs use diluted mold release agents, and even local graphite coatings, to prevent aluminum from sticking to the gate. Google's "die casting release agent spraying process" is aimed at on-site technicians.
FAQ
Is it better to use more release agents for demolding?
Excessive production of gas can result in pores, carbon deposits, and dirty cavities, which are not worth the loss.
2. How to clean carbon deposits on release agents?
High temperature air burning+polishing, carbon deposition will adsorb aluminum liquid, inducing aluminum adhesion.
What is the reason for the high smoke of water-based release agents?
Poor atomization, high mold temperature, and inappropriate formula.
Can different brands of release agents be mixed?
Not recommended, emulsion systems conflict and are prone to layering and precipitation.
5. What is the difference between automatic spraying machines and manual spraying?
Strong consistency in automatic spraying and more stable batch defects; Manual spraying has significant fluctuations.
How to handle the release agent at the top needle position?
The ejector pin is prone to carbon deposition and aluminum adhesion, so the amount of local spraying should be controlled.
Where is the price of semi synthetic release agents expensive?
The cost of high temperature resistant and anti stick aluminum functional additives is higher.
8. Do release agent wastewater need to be treated?
Overseas factories have strict environmental control measures and require oil-water separation.
低圧ダイカスト金型(LPDC)
重力鋳造金型
対圧鋳造金型(CPC)
構造部品用鋳造金型
オートバイ用ホイールハブ鋳造金型
ホイールハブ用差圧鋳造金型
ホイールハブ用重力鋳造金型
ホイールハブ用低圧鋳造金型
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