The process and principle of ULVAC vacuum pump oil epoxy resin casting vacuum system

ULVAC Vacuum Pump Oil Epoxy Resin Casting Vacuum System: Process and Principle

【Overview】 Epoxy resin casting is the process of pouring epoxy resin, curing agent, and other compounding materials into a designated mold, where the thermoplastic fluid cross-links and cures into a thermosetting product. Because epoxy resin cast products combine excellent electrical and mechanical properties, epoxy resin casting has been widely used and rapidly developed in the electrical industry.

【Epoxy Resin Casting Vacuum System Principle】
1. Vacuum Casting Process: Vacuum casting is currently the most widely used and mature process method in epoxy resin casting. For an epoxy resin cast electrical insulation product, it requires perfect appearance, dimensional stability, and qualified mechanical and electrical properties. These properties depend on various aspects such as the design of the part itself, the quality of the mold, the selection of casting materials, and the control of casting process conditions. The key technical point of epoxy resin vacuum casting is to minimize air gaps and bubbles in the cast product. To achieve this goal, the vacuum level, temperature, and process time must be carefully controlled in each step of the process, including raw material pretreatment, mixing, and casting.
[Basic Processes of Epoxy Resin Casting] The processes of epoxy resin casting can be categorized in different ways depending on the process conditions. Based on the way the material enters the mold, they can be divided into casting and pressure casting. Casting refers to the material flowing into the mold by gravity. It is further divided into atmospheric pressure casting and vacuum casting. Pressure casting refers to the material entering the mold under external pressure, and to force shrinkage, a certain external pressure is maintained during the material curing process. It has evolved from the simple pressure gel method of the past to the mature automatic pressure gel method of today.

Based on the material curing temperature, they can be divided into room temperature casting and high temperature casting. The choice between room temperature and high temperature casting is determined by the properties of the casting material itself. The fundamental difference lies in the temperature conditions necessary for the curing process. Based on the material curing speed, they can be divided into ordinary curing methods and rapid curing methods. The time required from the material entering the mold to demolding is the initial curing time. Ordinary curing methods require several or even tens of hours.
Rapid curing methods take only ten to several tens of minutes. According to experts from the China Epoxy Resin Industry Association, the most mature casting processes in modern casting technology are vacuum casting and automatic pressure gelation.

Epoxy resin casting vacuum systems can be equipped with up to eight vacuum joints, which can connect to vacuum lines in one or more molds. The mold obtains a vacuum through these joints. Each joint has an independent vacuum control valve, allowing individual control of the vacuum level at each point in the mold. The vacuum tank ensures a continuous, stable, and sufficient vacuum process, even for large molds. By using the vacuum tank, a relatively smaller vacuum pump can be selected. This ensures that the Busch vacuum system provides the most economical solution while achieving the highest pumping capacity. Furthermore, the Busch vacuum system is compact and portable, allowing for flexible use in any location.