CA1093276A - Mass for production of cores and casting moulds - Google Patents
Mass for production of cores and casting mouldsInfo
- Publication number
- CA1093276A CA1093276A CA264,229A CA264229A CA1093276A CA 1093276 A CA1093276 A CA 1093276A CA 264229 A CA264229 A CA 264229A CA 1093276 A CA1093276 A CA 1093276A
- Authority
- CA
- Canada
- Prior art keywords
- masses
- moulding composition
- parts
- alkaline metal
- dextrin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Mold Materials And Core Materials (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Moulding composition or masses for production of cores and casting moulds comprising 100 parts by weight of grain base, particularly quartz sand, 0.5-30 parts of alkaline metal hydroxides, 1-40 parts of alkaline metal carbonates, 1-15 parts of water as well as 0.2-10 of known hydrophilic binders. The moulding composition or masses according to the invention is removed from the cast or mould by subjecting the core in the cast or mould to the action of solvent, particularly water, preferably by dipping.
Moulding composition or masses for production of cores and casting moulds comprising 100 parts by weight of grain base, particularly quartz sand, 0.5-30 parts of alkaline metal hydroxides, 1-40 parts of alkaline metal carbonates, 1-15 parts of water as well as 0.2-10 of known hydrophilic binders. The moulding composition or masses according to the invention is removed from the cast or mould by subjecting the core in the cast or mould to the action of solvent, particularly water, preferably by dipping.
Description
The invention relates to a novel moulding composition or masses for production of cores and casting moulds.
Moulding compositions or masses according to the invention finds its application in production of casting cores and moulds by methods known to the foundry industry.
Core sands and moulding sands, generally applied in the industry, are most often produced from quartz sand as well as binding agents. Binding agents can be of various types, e.g.
traditional oils, starches, clay and different combinations, such as urea-formaldehyde resin possibly stabilized with amines or phenol-formaldehyde-furfuryl resin. As a binder there have been known coal slime as well as mixture of water glass with urea resin and kaolin. From among binders having the character of oils there have been known e.g. pine oil with addition of paste starch or dextrin, vegetable oils or organic solvents possibly turpentine oil with resin-fatty acids as well as combinations of solid products of oxidation of drying oils and elemental sulphur.
There has also been known a binding agent for cores and casting moulds comprising per 100 parts by weight 50-30 parts by weight of bentonite, 50-80 parts of Portland cement, 3-12 parts of sodium carbonate, 1.5-6.5 parts of hydrated lime and 0.5-2 parts of aluminium hydroxide. The considerable variety of binders added to the grain base indicates how extremely important their proper selection is, since both further treatment of the masses e.g. hardening of cores and moulds made of it, as well as mechanical and technological properties depend on the type of binder used. Some of the hitherto applied binding agents are ~" ,~ -- 1 --l~g3276 expensive, low efficient or require a long time to harden in the core and moulding sand. Cores and moulds produced from the known masses are characterized either by a small abrasion resistance or are very difficult to remove, particularly cores.
The hitherto applied methods of removing cores from castings consist of a mechanical shaking-out by means of e.g. grating shake-out, pneumatic jumpers and other devices. These methods produce noise and dusting in the air of the foundry. Moreover all core sands and some moulding sands presently used cannot be recycled and are discarded, since their regeneration by existing methods is unprofitable.
The present invention is aimed at elimination of the disadvantages of known core and moulding sands by providing novel compositions, so that cores and moulds made from them reveal high abrasion resistance and can be easily removed by non-mechanical means at minimum cost without creating a noise problem or putting dust in the air.
Moulding compositions or masses for production of cores and casting moulds according to the invention comprises per 100 parts by weight of grain base, quartz sand, 0.5-30 parts of alkaline metal hydroxides, preferably sodium hydroxide and/or potassium hydroxide, 1-40 parts of alkaline metal carbon-ates, preferably sodium carbonate and/or potassium carbonate, 1-15 parts of water as well as 0.2-10 parts of known hydrophilic binders, preferably dextrin. Cores and moulds produced from the masses according to the invention, as the conducted tests prove, reveal high abrasion resistance and are durable for a
Moulding compositions or masses according to the invention finds its application in production of casting cores and moulds by methods known to the foundry industry.
Core sands and moulding sands, generally applied in the industry, are most often produced from quartz sand as well as binding agents. Binding agents can be of various types, e.g.
traditional oils, starches, clay and different combinations, such as urea-formaldehyde resin possibly stabilized with amines or phenol-formaldehyde-furfuryl resin. As a binder there have been known coal slime as well as mixture of water glass with urea resin and kaolin. From among binders having the character of oils there have been known e.g. pine oil with addition of paste starch or dextrin, vegetable oils or organic solvents possibly turpentine oil with resin-fatty acids as well as combinations of solid products of oxidation of drying oils and elemental sulphur.
There has also been known a binding agent for cores and casting moulds comprising per 100 parts by weight 50-30 parts by weight of bentonite, 50-80 parts of Portland cement, 3-12 parts of sodium carbonate, 1.5-6.5 parts of hydrated lime and 0.5-2 parts of aluminium hydroxide. The considerable variety of binders added to the grain base indicates how extremely important their proper selection is, since both further treatment of the masses e.g. hardening of cores and moulds made of it, as well as mechanical and technological properties depend on the type of binder used. Some of the hitherto applied binding agents are ~" ,~ -- 1 --l~g3276 expensive, low efficient or require a long time to harden in the core and moulding sand. Cores and moulds produced from the known masses are characterized either by a small abrasion resistance or are very difficult to remove, particularly cores.
The hitherto applied methods of removing cores from castings consist of a mechanical shaking-out by means of e.g. grating shake-out, pneumatic jumpers and other devices. These methods produce noise and dusting in the air of the foundry. Moreover all core sands and some moulding sands presently used cannot be recycled and are discarded, since their regeneration by existing methods is unprofitable.
The present invention is aimed at elimination of the disadvantages of known core and moulding sands by providing novel compositions, so that cores and moulds made from them reveal high abrasion resistance and can be easily removed by non-mechanical means at minimum cost without creating a noise problem or putting dust in the air.
Moulding compositions or masses for production of cores and casting moulds according to the invention comprises per 100 parts by weight of grain base, quartz sand, 0.5-30 parts of alkaline metal hydroxides, preferably sodium hydroxide and/or potassium hydroxide, 1-40 parts of alkaline metal carbon-ates, preferably sodium carbonate and/or potassium carbonate, 1-15 parts of water as well as 0.2-10 parts of known hydrophilic binders, preferably dextrin. Cores and moulds produced from the masses according to the invention, as the conducted tests prove, reveal high abrasion resistance and are durable for a
2 -period of about 4 weeks without decreasing their properties.
After production of cores or moulds from moulding and core sand according to the invention, the core in the casting or mould are subjected to the action of a solvent, particularly water. The preferred method is by dipping e.g. in a tank. The core or mould undergoes spontaneous crumbling within 2-6 minutes.
Cores or moulds, produced from masses according to the invention, under the action of temperature in a mould develop a capacity to absorb solvents. The absorbed solvent destroys bonds within the masses in the core or mould. The removal of cores from castings by this solvent method is extremely simple, inexpensive and safe operation. It does not cause noise or emit dust into the air. The surfaces of castings made by this method are characterized by exceptional cleanliness, free of residual core sand grains. The core and moulding sand when kept in the water or solvent undergo regeneration and can be reused.
The following examples are preferred embodiments of the invention but are not intended to limit the scope of the invention.
Example I. Composition of the masses:
100 kg of quartz sand 1 kg of pale dextrin 6 kg of sodium carbonate 1.5 kg of sodium hydroxide 4.5 kg of water The moulding composition or masses is prepared in a roll mixer. The said mixer is loaded with 100 kg of quartz sand, 'C
1 kg of pale dextrin and 6 kg of sodium carbonate. This com-bination is mixed for 2 minutes. Separately there is prepared a solution comprising 1.5 kg of sodium hydroxide and 4.5 kg of water. This solution is added into the mixer without stopping the mixing. The operation of mixing is continued for a further
After production of cores or moulds from moulding and core sand according to the invention, the core in the casting or mould are subjected to the action of a solvent, particularly water. The preferred method is by dipping e.g. in a tank. The core or mould undergoes spontaneous crumbling within 2-6 minutes.
Cores or moulds, produced from masses according to the invention, under the action of temperature in a mould develop a capacity to absorb solvents. The absorbed solvent destroys bonds within the masses in the core or mould. The removal of cores from castings by this solvent method is extremely simple, inexpensive and safe operation. It does not cause noise or emit dust into the air. The surfaces of castings made by this method are characterized by exceptional cleanliness, free of residual core sand grains. The core and moulding sand when kept in the water or solvent undergo regeneration and can be reused.
The following examples are preferred embodiments of the invention but are not intended to limit the scope of the invention.
Example I. Composition of the masses:
100 kg of quartz sand 1 kg of pale dextrin 6 kg of sodium carbonate 1.5 kg of sodium hydroxide 4.5 kg of water The moulding composition or masses is prepared in a roll mixer. The said mixer is loaded with 100 kg of quartz sand, 'C
1 kg of pale dextrin and 6 kg of sodium carbonate. This com-bination is mixed for 2 minutes. Separately there is prepared a solution comprising 1.5 kg of sodium hydroxide and 4.5 kg of water. This solution is added into the mixer without stopping the mixing. The operation of mixing is continued for a further
3-4 minutes.
From the prepared moulding composition or masses there is produced by the known methods, a core consisting of inner shapes of the head. The core is hardened by blowing in a core box for 15-30 seconds with carbon dioxide. To the tank filled with water there is inserted a cast of the head, produced from the aluminium alloy together with a core reproducing the inner shape of the head. After 5 minutes of maintaining the head and core in the water there occurs a complete crumbling of the core and the cast is taken out of the tank. The core sand remaining in the tank will be separated from the binding agent.
Thus the cast does not require further any cleaning of the inner surfaces.
Example II. Composition of masses:
100 kg of quartz sand 1 kg of pale dextrin 10 kg of sodium carbonate 3 kg of sodium hydroxide 5 kg of water The masses is prepared as in the Example I.
' ~-o 10932~76 In the table below there are presented properties of the core and moulding sand according to the invention. The given properties relate to top and lower values for the quoted examples.
10932~76 A 3 J o ~ o ~1 ,D
~ ~ l l l O ~ C) U~ ~ ~ o a.) ~ ~ ~ ~
¢ ~ ~
o ~ o S~ o o ~ o ¢~
_~ O r- O O
a) ~ o ~ ~1 o ¢~
o-S~ oo I~ o ¢~ O t~3 ~D O
.
~ o ~ o ~ ~d cr. ~ o~ ~1 f~ o ~ U~ o ¢ ¢4~0 __ ~ o b4 ~ O ~
,~ ~ ~ oo U~
~ h t~) ~ ~`J o ¢~
a>
U~ ~ ~ ~ ~ ., .~ U~ ~ ~ .C
u~ ~ ~ ~0 ~ ~ a~ ~ ~ ,~
~ ~ 7 ~ ~ ~ ~ ~
a) s~ ~ ~ ~ ~ ~ ~ a~
~ ~ a) ~ a~ ~ a~ ~ t~
O ~ ~ ^ ~ S~ ^ i~ h ^ 5~
o ~ c~ ~ ~ ~4 ~ ~ ~ a~ ^
~ c~ ~n ~ p~ E~ ~ ~
_ _ .
h ~
O
The content of hydroxides and carbonates has a sub-stantial influence on the technical properties of the masses.
An increase in these components in the masses improves the technical properties, however, permeability of the masses decreases and the time for crumbling of the masses in solvent is slightly longer.
s 7
From the prepared moulding composition or masses there is produced by the known methods, a core consisting of inner shapes of the head. The core is hardened by blowing in a core box for 15-30 seconds with carbon dioxide. To the tank filled with water there is inserted a cast of the head, produced from the aluminium alloy together with a core reproducing the inner shape of the head. After 5 minutes of maintaining the head and core in the water there occurs a complete crumbling of the core and the cast is taken out of the tank. The core sand remaining in the tank will be separated from the binding agent.
Thus the cast does not require further any cleaning of the inner surfaces.
Example II. Composition of masses:
100 kg of quartz sand 1 kg of pale dextrin 10 kg of sodium carbonate 3 kg of sodium hydroxide 5 kg of water The masses is prepared as in the Example I.
' ~-o 10932~76 In the table below there are presented properties of the core and moulding sand according to the invention. The given properties relate to top and lower values for the quoted examples.
10932~76 A 3 J o ~ o ~1 ,D
~ ~ l l l O ~ C) U~ ~ ~ o a.) ~ ~ ~ ~
¢ ~ ~
o ~ o S~ o o ~ o ¢~
_~ O r- O O
a) ~ o ~ ~1 o ¢~
o-S~ oo I~ o ¢~ O t~3 ~D O
.
~ o ~ o ~ ~d cr. ~ o~ ~1 f~ o ~ U~ o ¢ ¢4~0 __ ~ o b4 ~ O ~
,~ ~ ~ oo U~
~ h t~) ~ ~`J o ¢~
a>
U~ ~ ~ ~ ~ ., .~ U~ ~ ~ .C
u~ ~ ~ ~0 ~ ~ a~ ~ ~ ,~
~ ~ 7 ~ ~ ~ ~ ~
a) s~ ~ ~ ~ ~ ~ ~ a~
~ ~ a) ~ a~ ~ a~ ~ t~
O ~ ~ ^ ~ S~ ^ i~ h ^ 5~
o ~ c~ ~ ~ ~4 ~ ~ ~ a~ ^
~ c~ ~n ~ p~ E~ ~ ~
_ _ .
h ~
O
The content of hydroxides and carbonates has a sub-stantial influence on the technical properties of the masses.
An increase in these components in the masses improves the technical properties, however, permeability of the masses decreases and the time for crumbling of the masses in solvent is slightly longer.
s 7
Claims (13)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A moulding composition or masses for the production of cores and casting moulds consisting of a grain base and binding agent, characterized in that per 100 parts by weight of grain base, it comprises 0.5-30 parts of alkaline metal hydroxides, 1-40 parts of alkaline metal carbonates, 1-15 parts of water and 0.2-10 parts of known hydrophilic binders.
2. A moulding composition or masses as claimed in claim 1 wherein the grain base is quartz sand.
3. A moulding composition or masses as claimed in claim 1 wherein the alkaline metal hydroxide is selected from sodium hydroxide and potassium hydroxide or a combination thereof.
4. A moulding composition or masses as claimed in claim 2 wherein the alkaline metal hydroxide is selected from sodium hydroxide and potassium hydroxide or a combination thereof.
5. A moulding composition or masses as claimed in claim 1 wherein the alkaline metal carbonate is selected from sodium carbonate and potassium carbonate or a combination thereof.
6. A moulding composition or masses as claimed in claim 2 wherein the alkaline metal carbonate is selected from sodium carbonate and potassium carbonate or a combination thereof.
7. A moulding composition or masses as claimed in claim 3 wherein the alkaline metal carbonate is selected from sodium carbonate and potassium carbonate or a combination thereof.
8. A moulding composition or masses as claimed in claim l wherein the hydrophillic binder is dextrin.
9. A moulding composition or masses as claimed in claim 2 wherein the hydrophillic binder is dextrin.
10. A moulding composition or masses as claimed in claim 3 wherein the hydrophillic binder is dextrin.
11. A moulding composition or masses as claimed in claim 5 wherein the hydrophillic binder is dextrin.
12. A moulding composition or masses comprised of 100 kg of quartz sand 1 kg of pale dextrin 6 kg of sodium carbonate 1.5 kg of sodium hydroxide 4.5 kg of water.
13. A moulding composition or masses comprised of 100 kg of quartz sand 1 kg of pale dextrin 10 kg of sodium carbonate 3 kg of sodium hydroxide 5 kg of water.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA264,229A CA1093276A (en) | 1976-10-26 | 1976-10-26 | Mass for production of cores and casting moulds |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA264,229A CA1093276A (en) | 1976-10-26 | 1976-10-26 | Mass for production of cores and casting moulds |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1093276A true CA1093276A (en) | 1981-01-13 |
Family
ID=4107133
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA264,229A Expired CA1093276A (en) | 1976-10-26 | 1976-10-26 | Mass for production of cores and casting moulds |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1093276A (en) |
-
1976
- 1976-10-26 CA CA264,229A patent/CA1093276A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |