Sep 16, 2026APG Knowledge
What is APG technology
APG (Automatic Pressure Gelation) is an advanced epoxy casting technology for transformers, insulators and other electrical parts.
APG stands for "Automatic Pressure Gelation," and the associated equipment is referred to as an APG machine or APG clamping machine. APG technology is an advanced process used to cast products such as epoxy resin instrument transformers (CT/PT), insulators, bushings, and embedded poles. Due to its high efficiency, superior product quality, and excellent surface finish, an increasing number of epoxy resin manufacturers are adopting APG equipment for the production of these items.
The basic principles of APG technology are as follows:
- Mix the epoxy resin compound under high-vacuum conditions;
- Inject the mixed resin into a preheated mold;
- Maintain the process for a specific period to allow the material to cure within the mold;
- Open the APG clamping machine platens and remove the product;
- Transfer the product to an oven for post-curing.
Taking the casting of an 11kV current transformer (CT) as an example, the process steps from step 2 to step 4 require only 20 minutes, whereas the traditional vacuum casting process takes several hours.
