In recent years, various types of low-density carbon graphite materials have been actively studied, including carbon (graphite) foam made of mesophase pitch or polymer resin, and carbon nano foam formed when carbon materials are ablated by high repetition rate pulsed laser. Expanded graphite is also a low-density carbon graphite material. Due to the simple preparation process, low production cost, and convenience for large-scale industrial production of expanded graphite, research on expandable graphite has continued to deepen in recent years. The following editor from Jinhui Graphite Company introduced the method of making low-density expanded graphite blocks by soaking flexible graphite in concentrated acid:

The worm like shape and weak macroscopic structure of expanded graphite limit its application. If a stable and expandable graphite block can be made, it will be beneficial for expanded graphite to play its role as a functional material for adsorption, insulation, thermal conductivity, and other functions. Flame retardant seals made of expandable graphite can be used in building components, such as fire doors, fire windows, fire resistant glass walls, fire dampers, fire louvers, etc. The author found during the study of expanded graphite flame retardant seals that properly treated flexible graphite paper or flexible graphite plate has good expansion performance at high temperatures. By controlling appropriate expansion conditions, a fully shaped expanded graphite block can be obtained. This article mainly reports the research results of preparing expanded graphite blocks using flexible graphite. The thickness of flexible graphite is 0.40 millimeters and 0.02 millimeters, with an average bulk density of 1.43 grams per centimeter. Flexible graphite plate, thickness 1.20 mm 0.04 mm, average bulk density.