Static eliminating precoated sand and preparation method thereof

Abstract

The invention relates to static eliminating precoated sand. A stratification phenomenon of the precoated sand is reduced and the size distribution is more uniform. The flowability of the precoated sand is improved, so that a mold-filling capacity of the precoated sand is increased in a core preparation process, the generating probability of detects such as loose sand cores and defective blocks isreduced, and therefore, the rate of finished products of castings is increased, the production cost is lowered, and damage of static electricity in the using process of the precoated sand on human body is also eliminated. According to a preparation method of the static eliminating precoated sand provided by the invention, the preparation process is adjusted properly according to compositions of raw materials. The preparation method comprises the following steps: firstly, blending phenolic resin and an antistatic agent; and then adding the mixture into heated raw sand, wherein the coating effect of the phenolic resin is excellent, static electricity generated in the blending process of the phenolic resin and the original sand is eliminated, and the size distribution and flowing property ofthe produced precoated sand are good. A conducting device is additionally arranged to export static electricity in a precoated sand product, so that the antistatic agent does not act yet, and the produced static electricity is eliminated immediately.

Description

technical field [0001] The invention belongs to the technical field of casting, and in particular relates to static-eliminating coated sand and a preparation method thereof. Background technique [0002] The existing production of coated sand is mainly through heating and blending of raw sand and thermoplastic phenolic resin. Under the action of curing agent, the resin is wrapped on the surface of sand grains, and after crushing and cooling, it becomes coated sand for foundry. [0003] However, in the process of producing coated sand, due to the friction between sand grains and the waste heat generated in the production process, electrons are generated on the surface of coated sand. These electrons cannot be discharged in time and will remain in the coated sand. Static electricity builds up on the surface. The existence of static electricity will make the fluidity of the coated sand worse and the particle size distribution uneven, causing many adverse effects on the detecti...

AI Technical Summary

Problems solved by technology

[0003] However, in the process of producing coated sand, due to the friction between sand grains and the waste heat generated in the production process, electrons are generated on the surface of coated sand. These electrons cannot be discharged in time and will remain in the coated sand. Static electricity is formed on the surface

The existence of static electricity will make the fluidity of the coated sand worse and the particle size distribution uneven, causing many adverse effects on the detection and production of coated sand products.