A method for measuring the content of gaseous formaldehyde in polyoxymethylene and a collection device

Abstract

The invention provides a content determination method and a collection device of gas-state formaldehyde in polyformaldehyde. The content determination method comprises the following steps: (1) collecting gas-state formaldehyde in polyformaldehyde and dissolving gas-state formaldehyde into water to obtain a formaldehyde solution with unknown concentration; (2) determining the concentration of the formaldehyde solution with unknown concentration; and (3) calculating the content of gas-state formaldehyde in polyformaldehyde, wherein in the step (1), polyformaldehyde particles are hot melted and then gas-state formaldehyde, which is released after hot melting, is dissolved into water to obtain the formaldehyde solution with unknown concentration. The collection device comprises a hot melting device, a gas-state formaldehyde collection bottle, a gas absorption bottle and a mixed gas conveying pipeline. According to the content determination method and the collection device, provided by the invention, polyformaldehyde is hot melted, obtained gas-state formaldehyde is dissolved into water, and thus gas-state formaldehyde on the surface of and in polyformaldehyde is completely collected, so that a content determination result of gas-state formaldehyde in polyformaldehyde is accurate, and polyformaldehyde with the gas-state formaldehyde content exceeding the standard is prevented from being available to the markets; and the feasibility and the operability are very high.

Description

technical field [0001] The invention belongs to the field of energy and chemical industry, in particular to a method for measuring the content of gaseous formaldehyde in polyoxymethylene and a collecting device. Background technique [0002] Gaseous formaldehyde in polyoxymethylene is a toxic substance with a pungent odor. If the content of free formaldehyde in polyoxymethylene products exceeds the standard, it will affect the working environment and personal safety during the production process and downstream processing. Therefore, it is very important to determine the content of gaseous formaldehyde in POM. And because the determination result of gaseous formaldehyde content will directly affect the qualification rate of the same batch of polyoxymethylene finished products, therefore, the determination of gaseous formaldehyde content is also a very important decisive factor in terms of production cost and operation control. At present, for the determination of the content...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: 1. When soaking the polyoxymethylene pellets with an aqueous solution, the aqueous solution can only dissolve the gaseous formaldehyde on the surface of the polyoxymethylene pellets, but cannot dissolve the gaseous formaldehyde inside the polyoxymethylene pellets, and then make the measurement result smaller; 2. Since the gaseous formaldehyde is volatile, when the polyoxymethylene pellets are soaked in an aqueous solution, the aqueous solution cannot completely dissolve the gaseous formaldehyde on the surface of the polyoxymethylene pellets, thereby making the measurement results smaller; 3. When this method is operated, the sample Direct contact with the operator will cause harm to the health of the operator; 4. The small measurement result will cause the POM with excessive gaseous formaldehyde content to flow into the market. Harm to the body and pollute the space environment in which it is located

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