An automatic vacuum hot press (often called a vacuum laminator or vacuum compression molding machine) is a high-precision piece of industrial equipment used to bond, laminate, or mold materials under three simultaneous conditions: vacuum, heat, and high pressure. By removing air from the chamber before applying heat and pressure, it prevents oxidation, eliminates air bubbles (voids), and ensures a flawless, uniform bond.

An automatic vacuum hot press operates through a carefully synchronized PLC (Programmable Logic Controller) system: (1) Vacuum Phase: The chamber is sealed and a powerful vacuum pump evacuates the air. This is crucial because it prevents air bubbles from being trapped in the material and stops materials from oxidizing at high temperatures. (2) Heating Phase: Precision heating elements (usually electric, oil, or steam) warm up the platens. Temperatures can range from 150°C to over 400°C, depending on the material. (3) Pressing Phase: Hydraulic cylinders apply immense, controlled pressure (ranging from a few tons to hundreds of tons) to compress the materials together while the vacuum and heat are maintained.

References:

J. Zhang, et al., Investigation on mechanical and microstructural evolution of lithium-ion battery electrode during the calendering process, Powder Technology, 2022, 409, 117828

M. Abdollahifar, et al., Insights into Influencing Electrode Calendering on the Battery Performance, Adv Energy Mater., 2023, 13, 2300973.