The characteristics of film coated sand production line

Qingdao Bestech machyinery co.,ltd 

1. High yield: The casting yield is generally ≥92%, up to 96~98%.

2. Smooth surface: 2~3 grades higher than ordinary clay sand modeling, and the surface roughness can reach Ra12.5.
 Bestech company.
3. High dimensional accuracy: Due to the high strength of the molding sand, the dimensional accuracy of the casting is 2 levels higher than that of the general green sand, reaching IT8-10 level, the subsequent machining allowance is reduced, and the tool wear is small.

4. The process is simple and easy to control: the coated sand production line is hard-shaped, and the key points of the process are guaranteed by the equipment. As long as the process parameters are mastered, the quality of the castings can be completely guaranteed, so the operating quality requirements for operators are low. In addition, labor is saved and labor intensity is reduced. The output of castings per unit area of the workshop is doubled compared with clay sand, and the sand cleaning efficiency is also greatly improved. At the same time, there are fewer dust spots and scattered sand, so the working environment is relatively clean.

5. High work efficiency: It can improve work efficiency, increase unit area and save workshop area.

6. Reduce labor intensity: The coated sand production line greatly reduces the labor intensity of workers in core making, molding, sand falling, and cleaning, which is conducive to the realization of mechanized operations.

Coated sand mainly uses natural quartz sand as raw sand, thermoplastic phenolic coating, urotropine and reinforcing agent as raw materials. According to the needs of users, the processing of the coated sand equipment can be properly adjusted in terms of hardening speed, film release, fluidity, collapse, casting surface roughness, storage, etc. It is an excellent molding material for automobiles, tractors, hydraulic parts, etc.

The quality of material strength in the production of coated sand equipment directly affects the quality of castings. In order to obtain good castings, it is necessary to strictly control from the formulation of raw materials, auxiliary materials to specific inspection techniques. The strength is related to the original sand and coated sand, but under the premise that the quality of the original sand is the same as that of the resin, the amount of phenolic resin added is an important factor affecting the strength.

Due to the large amount of phenolic resin added, the strength is higher, but the amount of gas generation also increases, and the increase in the amount of gas generation will lead to a decrease in collapsibility. Therefore, in the production of coated sand equipment, the strength of the material should be controlled to reduce the amount of gas generated and enhance the collapsibility. A balance point must be found when formulating the strength standard. This balance point is to ensure the surface quality of the sand core, and the strength of the core without deformation during pouring. Thereby, the quality and dimensional accuracy of the casting can meet the requirements, the sand production performance of the sand core can be improved, and the loss of the sand core can be reduced.

There are certain differences between the procurement and regeneration of coated sand equipment. The so-called used sand procurement and treatment generally refers to crushing the lumps in the used sand, cleaning up dust and metal inclusions, and achieving the purpose of recycling. This requires the old sand to be processed by crushing, magnetic separation, screening and dust removal. Occasionally, hot sand cooling is also included. Due to the presence of the particles, the adhesive film attached to the surface of the particles was not removed. Although this kind of purchased sand can achieve cleanliness, it can be reused for clay sand, but it cannot replace new sand. The recycling rate of other organic and inorganic self-hardening sand is not high, and it is mostly used as back sand. and it is easy to produce casting defects, so the proportion of new sand should be increased.

The difference between the so-called used sand regeneration and the meaning of procurement. It is mainly to carry out physical, chemical and heat treatment on the old sand to remove the film or shell of the residues such as dehydrated clay or resin accumulated on the sand grains, as well as harmful particles and dust, so as to re-establish the original particle size distribution and make the regenerated sand. The particle size distribution is similar to that of the original sand: the shared physical, chemical and refractory properties are not greatly reduced. A true regeneration system should be able to handle all the grit so that it behaves like virgin sand and can replace new sand as molding and core ground sand. Of course, whether the reclaimed sand is used for molding sand or core sand, or what kind of sand is used for, the proportion of the application depends on the degree of regeneration.