Neoprene rubber sheet, commonly known as CR, is made from the polymerization of butadiene emulsion. Its density is influenced by various factors, including the density of the raw materials used, the materials used in the formulation design, and the addition of flame-retardant materials with a high specific weight. For example, after the addition of flame-retardant materials, the density may increase, generally ranging from 1.3 to 1.4. In addition, the density of neoprene rubber sheet may also vary due to differences in the type of foaming agent used (such as closed-cell, open-cell, semi-closed), as well as differences in the amount of vulcanizing agent used. Normally, it should be between 0.4 and 0.8. However, the density of neoprene rubber sheet may vary depending on the source and specific application scenario. For example, some sources show that the density of neoprene rubber is about 1.65, which may be related to a specific production process or product form. Therefore, in actual applications, the accurate density of neoprene rubber sheet needs to be determined based on the specific product specifications and uses.