CN108971418A - A kind of overlay film sand additive for preventing sand core from shelling, anti-shelling precoated sand and preparation method thereof - Google Patents
A kind of overlay film sand additive for preventing sand core from shelling, anti-shelling precoated sand and preparation method thereof Download PDFInfo
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- CN108971418A CN108971418A CN201810724301.7A CN201810724301A CN108971418A CN 108971418 A CN108971418 A CN 108971418A CN 201810724301 A CN201810724301 A CN 201810724301A CN 108971418 A CN108971418 A CN 108971418A
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- China
- Prior art keywords
- sand
- hulling
- precoated
- additive
- overlay film
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
- B22C1/22—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins
- B22C1/2233—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- B22C1/2246—Condensation polymers of aldehydes and ketones
- B22C1/2253—Condensation polymers of aldehydes and ketones with phenols
Abstract
The present invention provides a kind of overlay film sand additive for preventing sand core from shelling, including silane coupling agent 5-8%, benzoic acid 2-5%, ethylene glycol 20-35%, ammonium chloride 3-6%, water surplus；A kind of anti-hulling precoated sand, phenolic resin 2-4%, methenamine 1-2%, anti-hulling additive 0.5-1.5%, calcium stearate 0.5%, roughing sand surplus；And the preparation method of the anti-hulling precoated sand.The beneficial effects of the present invention are: by adding the overlay film sand additive for preventing sand core from shelling in precoated sand manufactures, significantly improve the curing rate of precoated sand, pass through optimization precoated sand each group distribution ratio and fabrication process parameters simultaneously, improve the integral strength of precoated sand, the shell uniformity is improved, the drop phenomenon of sand core inner cavity when coremaking is turned to sky in the process is effectively improved, reduces coremaking rejection rate, to reduce production cost, the manufacturing suitable for sand core.
Description
Technical field
The invention belongs to founder's industrial technical fields, add more particularly, to a kind of precoated sand for preventing sand core from shelling
Agent, anti-shelling precoated sand and preparation method thereof.
Background technique
Precoated sand is invented during World War II by German Crow doctor Ning, and technical process is by the thermosetting of powdery
Property phenolic resin and roughing sand mechanical mixture, when heating solidifies.After develop into thermoplastic phenolic resin add latent curing agent (crow
Lip river tropine) and lubricant precoated sand is configured to by certain coating technique, sand grain surface is coated on when precoated sand is heated
Resin melting, under the action of the methylene that methenamine decomposites, the resin of melting is rapidly transformed by linear structure not to be melted
Three-dimensional-structure, to make precoated sand curing molding.
For Foundry Coated Sand during coremaking, sand core inner cavity has drop phenomenon when being turned to sky at present, has sand core scarce
It falls into, the later period needs a large amount of manual repairs, causes sand core to be scrapped when serious, and increasing coremaking rejection rate, (rejection rate is reachable when serious
15%-25%), raw material are wasted, increased costs are led to problems such as.
Summary of the invention
The problem to be solved in the present invention is to provide a kind of raising precoated sand curing rate, the precoated sands for preventing sand core from shelling to add
Add agent, anti-shelling precoated sand and preparation method thereof.
In order to solve the above technical problems, the technical solution adopted by the present invention is that: it is a kind of prevent sand core shell precoated sand add
Add agent, be made of following weight ratio component: including silane coupling agent 5-8%, benzoic acid 2-5%, ethylene glycol 20-35%, chlorination
Ammonium 3-6%, water surplus.
In technical solution, it is preferred that the silane coupling agent is gamma-aminopropyl-triethoxy-silane.
A kind of anti-hulling precoated sand comprising anti-hulling overlay film sand additive, is made: phenolic aldehyde tree of following weight ratio component
Rouge 2-4%, methenamine 1-2%, anti-hulling additive 0.5-1.5%, calcium stearate 0.5%, roughing sand surplus.
In technical solution, it is preferred that dioxide-containing silica is 90% or more in the roughing sand.
In technical solution, it is preferred that the roughing sand includes that 70% partial size is that 70/140 mesh cleans sand and 30% partial size is 50/
100 mesh clean sand.
In technical solution, it is preferred that the poly- speed of the phenolic resin is 20-22 seconds.
A kind of preparation method of anti-hulling precoated sand, specific preparation step are as follows:
(1) each component is weighed by the parts by weight, roughing sand temperature is heated to 130-134 DEG C, is put into sand mixer, puts
The sand time controlled in 20 seconds；
(2) phenolic resin is added when putting the sand time by 10-15 seconds, is kneaded stirring 50-60 seconds；
(3) anti-hulling overlay film sand additive is added, is kneaded stirring；
(4) curing agent methenamine solution is added when sand temperature drop is to 110-112 DEG C, is kneaded stirring 25-35 second, is added admittedly
Agent opens simultaneously sand mixer pucking wind and sand mixer top dehumidifying valve is dried；
(5) lubricant stearic acid calcium is put into, stirring is kneaded；
(6) it shakes out when sand temperature drop is to 67-73 DEG C, is crushed, is cooled to 40 degree or less and packs, obtain precoated sand.
In technical solution, it is preferred that controlled 150-160 seconds from sand control to the time of shaking out.
In technical solution, it is preferred that prepare anti-hulling overlay film sand additive before step (1): according to dosage weighing each group
Point, benzoic acid and ammonium chloride are sequentially added into stirring and dissolving in water, stand 4-6 hours；Silane coupling agent and ethylene glycol are mixed,
It is added in benzoic acid and aqueous ammonium chloride solution, it is stand-by to stir evenly standing barrelling in 2 hours.
In technical solution, it is preferred that sand mixer revolving speed is 65-95r/min in preparation process.
The advantages and positive effects of the present invention are: by adding the overlay film for preventing sand core from shelling in precoated sand manufactures
Sand additive significantly improves the curing rate of precoated sand, while passing through optimization precoated sand each group distribution ratio and manufacturing process ginseng
Number improves the integral strength of precoated sand, improves the shell uniformity, is effectively improved sand core inner cavity when coremaking is turned to sky in the process
Drop phenomenon reduces coremaking rejection rate, so that production cost is reduced, the manufacturing suitable for sand core.
Specific embodiment
Below in conjunction with specific embodiment, clear, complete description is carried out to technical solution of the present invention, it is clear that retouched
The embodiment stated is only a part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, originally
Field those skilled in the art all other embodiment obtained without making creative work belongs to this
The protection scope of invention.
Embodiment 1
It prepares anti-hulling precoated sand: taking 96 parts of roughing sand temperature to be heated to 130 DEG C with parts by weight, be put into sand mixer, mix
Sand machine revolving speed 65r/min put the control of sand time in 20 seconds；2 parts of phenolic resin are added when putting the sand time by 10 seconds, mixing is stirred
It mixes 55 seconds；0.5 part of anti-hulling overlay film sand additive is added, is kneaded stirring；1 part of curing agent crow is added when sand temperature drop is to 112 DEG C
Lip river tropine solution is kneaded stirring 30 seconds, be added curing agent open simultaneously sand mixer pucking wind and sand mixer top dehumidify valve into
Row drying；0.5 part of lubricant stearic acid calcium is put into, stirring is kneaded；It shakes out when sand temperature drop is to 69 DEG C, is crushed, is cooled to 40 degree
It packs below, obtains precoated sand.
Prepare anti-hulling overlay film sand additive: weighing each component in parts by weight, by 3 parts of benzoic acid and 5 parts of ammonium chlorides according to
Stirring and dissolving in 57 parts of water of secondary addition stands 4 hours；5 parts of silane coupling agents and 30 parts of ethylene glycol are mixed, be added benzoic acid and
In aqueous ammonium chloride solution, it is stand-by to stir evenly standing barrelling in 2 hours.
Embodiment 2
It prepares anti-hulling precoated sand: taking 94 parts of roughing sand temperature to be heated to 134 DEG C with parts by weight, be put into sand mixer, mix
Sand machine revolving speed 95r/min put the control of sand time in 20 seconds；3 parts of phenolic resin are added when putting the sand time by 12 seconds, mixing is stirred
It mixes 50 seconds；1 part of anti-hulling overlay film sand additive is added, is kneaded stirring；1.5 parts of curing agent crows are added when sand temperature drop is to 110 DEG C
Lip river tropine solution is kneaded stirring 25 seconds, be added curing agent open simultaneously sand mixer pucking wind and sand mixer top dehumidify valve into
Row drying；0.5 part of lubricant stearic acid calcium is put into, stirring is kneaded；It shakes out when sand temperature drop is to 67 DEG C, is crushed, is cooled to 40 degree
It packs below, obtains precoated sand.
Prepare anti-hulling overlay film sand additive: weighing each component in parts by weight, by 2 parts of benzoic acid and 3 parts of ammonium chlorides according to
Stirring and dissolving in 70 parts of water of secondary addition stands 4 hours；5 parts of silane coupling agents and 20 parts of ethylene glycol are mixed, be added benzoic acid and
In aqueous ammonium chloride solution, it is stand-by to stir evenly standing barrelling in 2 hours.
Embodiment 3
It prepares anti-hulling precoated sand: taking 95 parts of roughing sand temperature to be heated to 130 DEG C with parts by weight, be put into sand mixer, mix
Sand machine revolving speed 70r/min put the control of sand time in 20 seconds；2.3 parts of phenolic resin are added when putting the sand time by 14 seconds, are kneaded
Stirring 55 seconds；1.2 parts of anti-hulling overlay film sand additives are added, are kneaded stirring；1 part of curing agent is added when sand temperature drop is to 112 DEG C
Methenamine solution is kneaded stirring 25 seconds, and curing agent is added and opens simultaneously sand mixer pucking wind and sand mixer top dehumidifying valve
It is dried；0.5 part of lubricant stearic acid calcium is put into, stirring is kneaded；It shakes out when sand temperature drop is to 67 DEG C, is crushed, is cooled to 40
It is packed below degree, obtains precoated sand.
Prepare anti-hulling overlay film sand additive: weighing each component in parts by weight, by 5 parts of benzoic acid and 6 parts of ammonium chlorides according to
Stirring and dissolving in 46 parts of water of secondary addition stands 6 hours；8 parts of silane coupling agents and 35 parts of ethylene glycol are mixed, be added benzoic acid and
In aqueous ammonium chloride solution, it is stand-by to stir evenly standing barrelling in 2 hours.
Embodiment 4
It prepares anti-hulling precoated sand: taking 92 parts of roughing sand temperature to be heated to 132 DEG C with parts by weight, be put into sand mixer, mix
Sand machine revolving speed 80r/min put the control of sand time in 20 seconds；4 parts of phenolic resin are added when putting the sand time by 15 seconds, mixing is stirred
It mixes 60 seconds；1.5 parts of anti-hulling overlay film sand additives are added, are kneaded stirring；2 parts of curing agent crows are added when sand temperature drop is to 111 DEG C
Lip river tropine solution is kneaded stirring 35 seconds, be added curing agent open simultaneously sand mixer pucking wind and sand mixer top dehumidify valve into
Row drying；0.5 part of lubricant stearic acid calcium is put into, stirring is kneaded；It shakes out when sand temperature drop is to 73 DEG C, is crushed, is cooled to 40 degree
It packs below, obtains precoated sand.
Prepare anti-hulling overlay film sand additive: weighing each component in parts by weight, by 4 parts of benzoic acid and 4 parts of ammonium chlorides according to
Stirring and dissolving in 60 parts of water of secondary addition stands 5 hours；7 parts of silane coupling agents and 25 parts of ethylene glycol are mixed, be added benzoic acid and
In aqueous ammonium chloride solution, it is stand-by to stir evenly standing barrelling in 2 hours.
Reference examples
It prepares precoated sand: taking 92 parts of roughing sand temperature to be heated to 132 DEG C with parts by weight, be put into sand mixer, sand mixer turns
Fast 80r/min put the control of sand time in 20 seconds；4 parts of phenolic resin are added when putting the sand time by 15 seconds, are kneaded stirring 60
Second；2 parts of curing agent methenamine solution are added when sand temperature drop is to 111 DEG C, are kneaded stirring 35 seconds, curing agent is added and opens simultaneously
Sand mixer pucking wind and sand mixer top dehumidifying valve are dried；0.5 part of lubricant stearic acid calcium is put into, stirring is kneaded；When
It shakes out when sand temperature drop is to 73 DEG C, is crushed, is cooled to 40 degree or less and packs, obtain precoated sand.
The test data of embodiment 1-4 and reference examples are as follows:
As seen from the above table, compared with reference examples, hardening ratio and crust thickness are all significantly increased embodiment 1-4.
The embodiments of the present invention have been described in detail above, but content is only the preferred embodiment of the present invention,
It should not be considered as limiting the scope of the invention.Any changes and modifications in accordance with the scope of the present application,
It should still be within the scope of the patent of the present invention.
Claims (10)
1. a kind of overlay film sand additive for preventing sand core from shelling, which is characterized in that be made of following weight ratio component: including silane
Coupling agent 5-8%, benzoic acid 2-5%, ethylene glycol 20-35%, ammonium chloride 3-6%, water surplus.
2. the overlay film sand additive according to claim 1 for preventing sand core from shelling, it is characterised in that: the silane coupling agent
For gamma-aminopropyl-triethoxy-silane.
3. a kind of anti-hulling precoated sand comprising anti-hulling overlay film sand additive as claimed in claim 1 or 2, which is characterized in that by
Following weight ratio component is made: phenolic resin 2-4%, methenamine 1-2%, anti-hulling additive 0.5-1.5%, calcium stearate
0.5%, roughing sand surplus.
4. anti-hulling precoated sand according to claim 3, it is characterised in that: dioxide-containing silica is 90% in the roughing sand
More than.
5. anti-hulling precoated sand according to claim 3 or 4, it is characterised in that: the roughing sand includes that 70% partial size is 70/
140 mesh clean sand and 30% partial size is that 50/100 mesh cleans sand.
6. anti-hulling precoated sand according to claim 3, it is characterised in that: the poly- speed of the phenolic resin is 20-22 seconds.
7. a kind of method for preparing the overlay film sand additive for preventing sand core from shelling as claimed in claim 1 or 2, feature exist
In: it prepares anti-hulling overlay film sand additive before the step (1): according to dosage weighing each component, successively by benzoic acid and ammonium chloride
It is added to the water stirring and dissolving, stands 4-6 hours；Silane coupling agent and ethylene glycol are mixed, benzoic acid and ammonium chloride solution is added
In liquid, it is stand-by to stir evenly standing barrelling in 2 hours.
8. a kind of method for preparing anti-hulling precoated sand as claimed in any one of claims 1 to 6, which is characterized in that specific preparation
Step are as follows:
(1) each component is weighed by the parts by weight, roughing sand temperature is heated to 130-134 DEG C, is put into sand mixer, when putting sand
Between control in 20 seconds；
(2) phenolic resin is added when putting the sand time by 10-15 seconds, is kneaded stirring 50-60 seconds；
(3) the anti-hulling overlay film sand additive of method preparation as claimed in claim 7 is added, is kneaded stirring；
(4) curing agent methenamine solution is added when sand temperature drop is to 110-112 DEG C, is kneaded stirring 25-35 second, addition curing agent
It opens simultaneously sand mixer pucking wind and sand mixer top dehumidifying valve is dried；
(5) lubricant stearic acid calcium is put into, stirring is kneaded；
(6) it shakes out when sand temperature drop is to 67-73 DEG C, is crushed, is cooled to 40 degree or less and packs, obtain precoated sand.
9. the preparation method of anti-hulling precoated sand according to claim 8, it is characterised in that: from sand control to time control of shaking out
System is between 150-160 seconds.
10. the preparation method of anti-hulling precoated sand according to claim 8, it is characterised in that: sand mixer in preparation process
Revolving speed is 65-95r/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810724301.7A CN108971418B (en) | 2018-07-04 | 2018-07-04 | Preparation method of anti-shelling precoated sand |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810724301.7A CN108971418B (en) | 2018-07-04 | 2018-07-04 | Preparation method of anti-shelling precoated sand |
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| Publication Number | Publication Date |
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| CN108971418A true CN108971418A (en) | 2018-12-11 |
| CN108971418B CN108971418B (en) | 2020-10-27 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201810724301.7A Active CN108971418B (en) | 2018-07-04 | 2018-07-04 | Preparation method of anti-shelling precoated sand |
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Cited By (1)
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| CN110421114A (en) * | 2019-08-08 | 2019-11-08 | 柳晶（溧阳）环保科技有限公司 | A kind of heat resisting film-coating sand |
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| CN108971418B (en) | 2020-10-27 |
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