Equipment manufacturers say paraformaldehyde is a peculiar polymer.

Polyformaldehyde (CH2O) n, also called solid formaldehyde, formaldehyde polymer, the polymerization degree n of low molecular weight formaldehyde is about 8-12, the solubility is 80, there is a strong odor of formaldehyde, the degree of polymerization degree n is more than 12 of solubility is 120-170, insoluble in ethanol, propanol and ether, soluble in dilute acid and dilute alkali solution. Some mechanical properties of the plastic can not be made into thin films, which can be used as disinfectants, bactericides, and resin and artificial ivory, and can be obtained by polymerization of pure formaldehyde under the alkaline condition (such as HaOH).

In 1950s, the formaldehyde industry in China started the formaldehyde industry in the Shanghai solvent plant. At the same time, the use of the skill came from the Soviet Union, using the pumice silver as a catalyst, the system pressure was lower than the normal pressure, the oxidation temperature was between 650 and 750 centigrade, and then formaldehyde was diluted through water to transpiration in the transpiration. With the production technology, formaldehyde is produced. With the continuous development of science and technology, in the mid 1960s, the concentration of formaldehyde water has a higher request, and at this time the production process of formaldehyde has begun to use iron molybdenum oxide catalyst. By 1997, China developed a new generation of formaldehyde catalyst, electrolytic silver, the development of the catalyst made China's solid polyformaldehyde equipment manufacturers have a new development space. By twenty-first Century, the major solid formaldehyde producers also gradually improved the production capacity of the oxidation reactor, and continued to innovate, and put forward higher requirements for various functions of the catalyst.