Coated sand and preparation method thereof

Abstract

The present invention discloses coated sand and a preparation method thereof. The coated sand is prepared from the following raw materials: raw sand, a binder, a curing agent, an additive and a lubricant, wherein the raw sand is prepared by mixing quartz sand and pearl sand according to a weight ratio of 3:1, the binder is a mixture of a furan resin, isocyanate and paraffin wax, the curing agent is a mixture of fatty amine, acetic acid and sodium silicate, the additive is a mixture of expanded graphite, silicon carbide and sodium methyl silanolate, and the lubricant is a mixture of silicone oil, phosphate ester and calcium stearate. The preparation method comprises: (1) preparing a binder; (2) preparing a curing agent; (3) preparing an additive; and (5) mixing, wherein phosphate ester is added to raw sand, the additive is added, complete mixing is performed, silicone oil is added after mixing, the binder is added to mix, calcium stearate and the curing agent are sequentially added after uniformly mixing, and mixing is performed to obtain the coated sand.

Description

technical field

[0001] The invention relates to coated sand and a preparation method thereof, belonging to the technical field of foundry industry. Background technique

[0002] Coated sand refers to the molding sand or core sand that is covered with a solid resin film on the surface of the sand grains before molding. There are two coating processes: cold method and hot method: the cold method dissolves the resin with ethanol, and adds urotropine during the sand mixing process, so that the two are coated on the surface of the sand grains, and the ethanol volatilizes to obtain coated sand; Preheat the sand to a certain temperature, add resin to melt, stir to coat the resin on the surface of the sand, add urotropine aqueous solution and lubricant, cool, crush, and sieve to obtain coated sand. For steel castings and iron castings. Due to the advantages of high strength, low gas generation, high dimensional accuracy of production castings, smooth surface and easy storage, coat...

Examples

Embodiment 1

[0022] A coated sand, made of the following raw materials in parts by weight: 100 parts of raw sand, 18 parts of binder, 4 parts of curing agent, 0.5 parts of additive and 2.5 parts of lubricant; the raw sand is quartz sand and pearl The sand is mixed according to the weight ratio of 3:1; the binder is a mixture of furan resin, isocyanate and paraffin, the curing agent is a mixture of fatty amine, acetic acid and sodium silicate, and the additive is A mixture of expanded graphite, silicon carbide and sodium methyl siliconate, and the lubricant is a mixture of silicone oil, phosphate ester and calcium stearate.

[0023] The binder is composed of 18 parts of furan resin, 4 parts of isocyanate and 12 parts of paraffin wax in parts by weight.

[0024] The curing agent is composed of 15 parts of fatty amine, 7 parts of acetic acid and 8 parts of sodium silicate in parts by weight.

[0025] The additive is composed of 18 parts of expanded graphite, 12 parts of silicon carbide and 6...

Embodiment 2

[0033] A coated sand, made of the following raw materials in parts by weight: 120 parts of raw sand, 15 parts of binder, 2 parts of curing agent, 1.5 parts of additive and 1.5 parts of lubricant; the raw sand is quartz sand and pearl The sand is mixed according to the weight ratio of 3:1; the binder is a mixture of furan resin, isocyanate and paraffin, the curing agent is a mixture of fatty amine, acetic acid and sodium silicate, and the additive is A mixture of expanded graphite, silicon carbide and sodium methyl siliconate, and the lubricant is a mixture of silicone oil, phosphate ester and calcium stearate.

[0034] The binder is composed of 15 parts of furan resin, 7 parts of isocyanate and 14 parts of paraffin wax in parts by weight.

[0035] The curing agent is composed of 25 parts of fatty amine, 12 parts of acetic acid and 13 parts of sodium silicate in parts by weight.

[0036] The additive is composed of 12 parts of expanded graphite, 18 parts of silicon carbide and...

Embodiment 3

[0044] A coated sand, made of the following raw materials in parts by weight: 110 parts of raw sand, 16 parts of binder, 3 parts of curing agent, 1.2 parts of additive and 1.7 parts of lubricant; the raw sand is quartz sand and pearl The sand is mixed according to the weight ratio of 3:1; the binder is a mixture of furan resin, isocyanate and paraffin, the curing agent is a mixture of fatty amine, acetic acid and sodium silicate, and the additive is A mixture of expanded graphite, silicon carbide and sodium methyl siliconate, and the lubricant is a mixture of silicone oil, phosphate ester and calcium stearate.

[0045] The binder is composed of 15-18 parts of furan resin, 4-7 parts of isocyanate and 12-14 parts of paraffin wax in parts by weight.

[0046] The curing agent is composed of 20 parts of fatty amine, 9 parts of acetic acid and 11 parts of sodium silicate in parts by weight.

[0047] The additive is composed of 14 parts of expanded graphite, 14 parts of silicon carb...

technical field

[0001] The invention relates to coated sand and a preparation method thereof, belonging to the technical field of foundry industry. Background technique

[0002] Coated sand refers to the molding sand or core sand that is covered with a solid resin film on the surface of the sand grains before molding. There are two coating processes: cold method and hot method: the cold method dissolves the resin with ethanol, and adds urotropine during the sand mixing process, so that the two are coated on the surface of the sand grains, and the ethanol volatilizes to obtain coated sand; Preheat the sand to a certain temperature, add resin to melt, stir to coat the resin on the surface of the sand, add urotropine aqueous solution and lubricant, cool, crush, and sieve to obtain coated sand. For steel castings and iron castings. Due to the advantages of high strength, low gas generation, high dimensional accuracy of production castings, smooth surface and easy storage, coat...

Examples

Embodiment 1

[0022] A coated sand, made of the following raw materials in parts by weight: 100 parts of raw sand, 18 parts of binder, 4 parts of curing agent, 0.5 parts of additive and 2.5 parts of lubricant; the raw sand is quartz sand and pearl The sand is mixed according to the weight ratio of 3:1; the binder is a mixture of furan resin, isocyanate and paraffin, the curing agent is a mixture of fatty amine, acetic acid and sodium silicate, and the additive is A mixture of expanded graphite, silicon carbide and sodium methyl siliconate, and the lubricant is a mixture of silicone oil, phosphate ester and calcium stearate.

[0023] The binder is composed of 18 parts of furan resin, 4 parts of isocyanate and 12 parts of paraffin wax in parts by weight.

[0024] The curing agent is composed of 15 parts of fatty amine, 7 parts of acetic acid and 8 parts of sodium silicate in parts by weight.

[0025] The additive is composed of 18 parts of expanded graphite, 12 parts of silicon carbide and 6...

Embodiment 2

[0033] A coated sand, made of the following raw materials in parts by weight: 120 parts of raw sand, 15 parts of binder, 2 parts of curing agent, 1.5 parts of additive and 1.5 parts of lubricant; the raw sand is quartz sand and pearl The sand is mixed according to the weight ratio of 3:1; the binder is a mixture of furan resin, isocyanate and paraffin, the curing agent is a mixture of fatty amine, acetic acid and sodium silicate, and the additive is A mixture of expanded graphite, silicon carbide and sodium methyl siliconate, and the lubricant is a mixture of silicone oil, phosphate ester and calcium stearate.

[0034] The binder is composed of 15 parts of furan resin, 7 parts of isocyanate and 14 parts of paraffin wax in parts by weight.

[0035] The curing agent is composed of 25 parts of fatty amine, 12 parts of acetic acid and 13 parts of sodium silicate in parts by weight.

[0036] The additive is composed of 12 parts of expanded graphite, 18 parts of silicon carbide and...

Embodiment 3

[0044] A coated sand, made of the following raw materials in parts by weight: 110 parts of raw sand, 16 parts of binder, 3 parts of curing agent, 1.2 parts of additive and 1.7 parts of lubricant; the raw sand is quartz sand and pearl The sand is mixed according to the weight ratio of 3:1; the binder is a mixture of furan resin, isocyanate and paraffin, the curing agent is a mixture of fatty amine, acetic acid and sodium silicate, and the additive is A mixture of expanded graphite, silicon carbide and sodium methyl siliconate, and the lubricant is a mixture of silicone oil, phosphate ester and calcium stearate.

[0045] The binder is composed of 15-18 parts of furan resin, 4-7 parts of isocyanate and 12-14 parts of paraffin wax in parts by weight.

[0046] The curing agent is composed of 20 parts of fatty amine, 9 parts of acetic acid and 11 parts of sodium silicate in parts by weight.

[0047] The additive is composed of 14 parts of expanded graphite, 14 parts of silicon carb...