US2988453A - Core binder additive - Google Patents
Core binder additive Download PDFInfo
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- US2988453A US2988453A US743485A US74348558A US2988453A US 2988453 A US2988453 A US 2988453A US 743485 A US743485 A US 743485A US 74348558 A US74348558 A US 74348558A US 2988453 A US2988453 A US 2988453A
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- Prior art keywords
- core
- glutamic acid
- cores
- foundry
- sand
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- Expired - Lifetime
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- 239000011230 binding agent Substances 0.000 title claims description 25
- 239000000654 additive Substances 0.000 title description 5
- 230000000996 additive effect Effects 0.000 title description 5
- WHUUTDBJXJRKMK-UHFFFAOYSA-N Glutamic acid Natural products OC(=O)C(N)CCC(O)=O WHUUTDBJXJRKMK-UHFFFAOYSA-N 0.000 claims description 26
- 235000013922 glutamic acid Nutrition 0.000 claims description 26
- 239000004220 glutamic acid Substances 0.000 claims description 26
- 229920002472 Starch Polymers 0.000 claims description 17
- 239000000203 mixture Substances 0.000 claims description 17
- 235000019698 starch Nutrition 0.000 claims description 17
- 239000008107 starch Substances 0.000 claims description 13
- 229920000881 Modified starch Polymers 0.000 claims description 11
- 239000004368 Modified starch Substances 0.000 claims description 10
- 229920000856 Amylose Polymers 0.000 claims description 9
- 241000219310 Beta vulgaris subsp. vulgaris Species 0.000 claims description 9
- 235000021536 Sugar beet Nutrition 0.000 claims description 9
- 239000002699 waste material Substances 0.000 claims description 9
- 239000003607 modifier Substances 0.000 claims description 8
- 229920000945 Amylopectin Polymers 0.000 claims description 4
- 239000004576 sand Substances 0.000 description 20
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 229910052783 alkali metal Inorganic materials 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- -1 alkali-metal orthophosphate salt Chemical class 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 230000003301 hydrolyzing effect Effects 0.000 description 4
- 239000004615 ingredient Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 150000001340 alkali metals Chemical class 0.000 description 3
- 239000003906 humectant Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- FBPFZTCFMRRESA-FSIIMWSLSA-N D-Glucitol Natural products OC[C@H](O)[C@H](O)[C@@H](O)[C@H](O)CO FBPFZTCFMRRESA-FSIIMWSLSA-N 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- RQPZNWPYLFFXCP-UHFFFAOYSA-L barium dihydroxide Chemical compound [OH-].[OH-].[Ba+2] RQPZNWPYLFFXCP-UHFFFAOYSA-L 0.000 description 1
- 229910001863 barium hydroxide Inorganic materials 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 235000013339 cereals Nutrition 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 235000013312 flour Nutrition 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 235000011868 grain product Nutrition 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 235000019426 modified starch Nutrition 0.000 description 1
- 235000013379 molasses Nutrition 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- PWZUUYSISTUNDW-VAFBSOEGSA-N quinestrol Chemical compound C([C@@H]1[C@@H](C2=CC=3)CC[C@]4([C@H]1CC[C@@]4(O)C#C)C)CC2=CC=3OC1CCCC1 PWZUUYSISTUNDW-VAFBSOEGSA-N 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000600 sorbitol Substances 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- 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
- B22C1/26—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 carbohydrates; of distillation residues therefrom
Definitions
- the present invention relates to foundry cores. More particularly, it relates to an additive for foundry cores which improves their tensile strength and baking properties.
- cores are aggregates of inert matter such as sand, of somewhat porous structure, having controlled mechanical strength .sufficient to permit the core to be assembled without breakage as a part of a mold and to form molten metal into a desired shape.
- foundry cores various materials are incorporated into the sand and baked therewith to bind the sand together and to give it the desired structure and mechanical properties.
- materials are cereal products, water glass, drying oils, resins, sulfate liquor, proteinaceous materials, molasses, clays, wood flour, gelatinized starches, dextrinized starches, and a variety of other substances and combinations thereof. All of the materials heretofore employed have a tendency, when baked, to develop peak tensile strengths over a narrow range of baking time, which necessitates rigid control of the baking operation.
- the present invention involves a novel additive for core binders of the prior-art type, whereby the baking time during which peak strength is maintained is greatly extended, and whereby the peak strength itself is substantially improved.
- One object of the present invention is to improve the baking of foundry cores.
- Another object is to render the baking time of foundry cores less critical.
- Another object is to extend the range of baking times within which the peak strength of foundry co'res is at a maximum.
- Another object is to increase the baked strength of foundry cores.
- a novel modifier is incorporated into a foundry core, prior to baking, the said foundry core containing a core binder or core binders of the prior art types, and the said modifier being an end liquor produced by hydrolyzing a sugar beet Waste liquor and removing a portion of the resulting glutamic acid therefrom.
- the modifier or additive of the present invention is commonly referred to in the art as a glutamic acid end liquor.
- Such end liquors are a final by-product obtained in the recovery of glutamic acid from sugar beet waste liquors, such as Steffens filtrate, barium filtrate, and the like.
- the sugar beet Waste liquor is subjected to hydrolysis by heating in the presence of a strong acid such as sulfuric acid or hydrochloric acid, or more commonly in the presence of a strong alkali such as sodium hydroxide, potassium hydroxide, barium hydroxide, or the like.
- the glutamic acid precursor substances contained therein are converted thereby into glutamic acid.
- the resulting hydrolyzate is acidified to around pH 3 to 7, preferably around 5 to 6, concentrated to around 80% dry solids by weight, and filtered or centrifuged to remove the resulting crop of inorganic salts.
- the partially desalted liquor is then further acidified as necessary to aroundpH 3.2, at which point glutamic acid crystallizes in good yield therefrom at ordinary or somewhat reduced temperatures. When the glutamic acid crystals are removed Patented June 13., 1961.
- the remaining liquid is the glutamic acid end liquor employed in the present invention.
- Glutamic acid end liquor in its natural state has a pH around 3.2. In this condition, it has been found to be most effective in foundry cores for extending the range of baking time for maximum tensile strength. For improving the tensile strength of the baked cores, however, the end liquor is somewhat more effective at higher pH ranges up to and around neutrality, and when used for these purposes the end liquor should be adjusted in pH, preferably to the range of about 6 to about 8, by adding thereto a suitable base such as sodium hydroxide, potassium hydroxide, or the like.
- a suitable base such as sodium hydroxide, potassium hydroxide, or the like.
- the glutamic acid end liquor is ordinarily incorporated into the foundry core in a proportion between about 0.1 and about 1% by weight, preferably between about 0.25 and 0.5% by weight, of the total core, dry basis.
- a sand of suitable grade is mulled with water, a glutamic acid end liquor, and a core binder of a conventional type and in a conventional proportion. It is preferred to first blend the sand with any other dry ingredients, then add a mixture of water, end liquor, and any other non-dry ingredients, and complete the blending.
- the total proportion of water in the mixture is suitably between about 2 and about 6%, based on the dry Weight of sand, preferably between about 3 and about 5%.
- Conventional co're binders including all of the examples set forth hereinabove, are employed in a proportion between about 0.1 and about 3%, optimally between about 0.5 and about 1.5%, dry sand basis.
- the order of mixing can be altered if desired without materially impairing the desirable results obtained by the present invention.
- the completed mixture is formed into cores in a conventional manner, and the cores are thereafter baked under conventional conditions prior to use.
- the temperature and time required vary widely according to the size of the core, the surfaceto-volume ratio, the water content, the type of sand, and the nature of the primary core binder.
- Laboratory cores are ordinarily baked at temperatures between about 300 and about 600 F., and the maximum tensile strength is ordinarily reached after a baking time in the range of 10 to minutes.
- the baking temperature is preferably between about 350 and about 450 F., and for smaller cores a baking time of around 10 to 30 minutes is ordinarily suflicient.
- the baking time may range up to 24 hours or longer, and temperatures up to 600 F. are sometimes used to speed up the process.
- the maximum tensile strength is reached rapidly (around 10 minutes for laboratory cores), and is maintained essentially constant for an extended period of time (approaching an hour for laboratory cores). At the same time, the maximum tensile strength is materially increased.
- the present invention is especially useful in conjunction with the core binders of Neukom, comprising essentially alkalimetal phosphate-modified starches, .described in copending Neukom application Serial No. 706,- 155, filed December 30, 1957.
- the Neukom core binders are prepared by impregnating ungelatinized starch with an aqueous solution of an alkali-metal orthophosphate salt having a pH between about 4 and about 7, drying to a moisture content below about 15% by weight at a temperature below the level at which the starch gelatinizes, then heating at a temperature between about and about C. for a period of about 1 to about 15 hours, whereby the starch is converted into a form which disperses readily in cold water to yield viscous, stable dispersions.
- the preferred starches obtained thereby I l V 3 l are the sodium, potassium, and lithium orthophosphatemodified starches.
- the invention is also useful in conjunction with the improvedcore binder of John W. Frieders, comprising essentially an alkali-metal orthophosphate derivative of gelatinized amylose, prepared in the Neukom manner and described in application Serial No. 705,794, filed December 30, 1957; and in conjunction with the improved core binder of Sietsema, comprising gelatinized amylopectin substantially free from amylose, described in application Serial No. 705,793, filed December 30, 1957.
- glutamic acid end liquors exhibit the remarkable property of extending the range of baking time in which the maximum tensile strength of the core is maintained, and in addition increase the magnitude of the said tensile strength.
- This is in contrast to the prior art, in which a wide variety of materials, principally humectants, have been tested for the purpose, but with greatly inferior results, as the examples given below will demonstrate.
- Example 1 A series of tests were carried out to compare glutamic acid end liquor with a variety of prior-art humectants in a core formulation containing a Neukom-type sodium orthophosphate-modified starch as the primary core binder.
- the phosphate-modified starch contained 4.04% phosphorus and had a viscosity of 6310 cp. at 25 C. in 5% aqueous dispersion.
- the sand employed was Ottawa 50, having an AFS grain finess of 70.
- the core mixtures were prepared from 1.25% of the phosphatemodified starch, 0.25% of the end liquor or conventional humectant, and water to a total moisture content of 4%, based in each case on the dry weight of sand.
- the dry ingredients were first mulled together for 1 minute. The Wet ingredients were then added, and mulling was resumed for 6 minutes. The completed mixtures were discharged from the muller and stored in sealed cans until used to make cores. The retained water content was about 3.5%.
- the various mixtures were formed into standard test cores, then baked over a series of baking periods at 425 F., except the cores containing sorbitol, which were baked at 450 -F.
- the baked cores were tested according to the standard method defined in the Foundry Sand Handbook, 6th edition, @1952, published by the American Foundrymens Society, Chicago. In each case the cores were prepared and tested in triplicate, and the reported results are the average of three tests. The results show that end liquor maintains the cores at a high and uniform level of tensile strength over an extended range of baking time, while the controls exhibit a sharp decline after about 25 minutes:
- a fountry core comprising sand and a core binder
- said core binder consisting essentially of a starch composition selected from the group consisting of gelatinized starch, gelatinized amylopectin, phosphate-modified starch, phosphate-modified amylose, and mixtures thereof, a modifier consisting essentially of a glutamic acid end liquor obtained from hydrolyzed sugar beet waste liquor.
- a foundry core consisting essentially of sand, a core binder, and between about 0.1 and about 1%, based on the dry weight of sand, of a glutamic acid end liquor obtained from hydrolyzed sugar beet waste liquor, said core binder consisting essentially of a starch composition selected from the group consisting of gelatinized starch, gelatinized amylopectin, phosphate-modified starch, phosphate-modified amylose, and mixtures thereof.
- a modifier in a proportion between about 0.1 and about 1%, based on the dry weight of sand, consisting essentially of an end liquor produced .by hydrolyzing a sugar beet waste liquor and removing a portion of the glutamic acid therefrom.
- a foundry core which consists essentially of sand and an alkali-metal orthophosphate-modified starch prepared by soaking ungelatinized starch in an aqueous alkalimetal orthophosphate solution having a pH between about 4 and about 7, drying the soaked starch to a moisture content less than about 15% by weight at a temperature below the gelatinization point thereof, and baking the dried starch at a temperature between about and about C. for a period of about 1 to about 15 hours, and in combination therewith a glutamic acid end liquor obtained by hydrolyzing a sugar beet waste liquor and sepa rating a portion of the glutamic acid therefrom.
- a foundry core which consists essentially of sand and an alkali-metal orthophosphate-modified amylose prepared by soaking gelatinized amylose in an aqueous alkali-metal orthophosphate solution having a pH between about 4 and about 7, drying the soaked amylose to a moisture content less than about 15% by weight, and baking the dried amylose at a temperature between about 120 and about 175 C. for a period of about 1 to about 15 hours, and in combination therewith a glutamic acid end liquor obtained by hydrolyzing a sugar beet waste liquor and separating a portion of the glutamic acid therefrom.
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- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Molecular Biology (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Mold Materials And Core Materials (AREA)
Description
United States Patent 2,988,453 CORE BINDER ADDITIVE Forest A. Hoglan, Glenview, and Jacob W. Sietsema, Northbrook, 111., assignors to International Minerals 8: Chemical Corporation, a corporation of New York No Drawing. Filed June 20, 1958, Ser. No. 743,485 8 Claims. (Cl. 106--38.5)
The present invention relates to foundry cores. More particularly, it relates to an additive for foundry cores which improves their tensile strength and baking properties.
In foundry practice, cores are aggregates of inert matter such as sand, of somewhat porous structure, having controlled mechanical strength .sufficient to permit the core to be assembled without breakage as a part of a mold and to form molten metal into a desired shape. In
the production of foundry cores, various materials are incorporated into the sand and baked therewith to bind the sand together and to give it the desired structure and mechanical properties. Among such materials are cereal products, water glass, drying oils, resins, sulfate liquor, proteinaceous materials, molasses, clays, wood flour, gelatinized starches, dextrinized starches, and a variety of other substances and combinations thereof. All of the materials heretofore employed have a tendency, when baked, to develop peak tensile strengths over a narrow range of baking time, which necessitates rigid control of the baking operation. The present invention involves a novel additive for core binders of the prior-art type, whereby the baking time during which peak strength is maintained is greatly extended, and whereby the peak strength itself is substantially improved.
One object of the present invention is to improve the baking of foundry cores.
Another object is to render the baking time of foundry cores less critical.
Another object is to extend the range of baking times within which the peak strength of foundry co'res is at a maximum.
Another object is to increase the baked strength of foundry cores.
Other objects of the invention will be apparent from the present description and claims.
In accordance with the present invention, a novel modifier is incorporated into a foundry core, prior to baking, the said foundry core containing a core binder or core binders of the prior art types, and the said modifier being an end liquor produced by hydrolyzing a sugar beet Waste liquor and removing a portion of the resulting glutamic acid therefrom.
The modifier or additive of the present invention is commonly referred to in the art as a glutamic acid end liquor. Such end liquors are a final by-product obtained in the recovery of glutamic acid from sugar beet waste liquors, such as Steffens filtrate, barium filtrate, and the like. The sugar beet Waste liquor is subjected to hydrolysis by heating in the presence of a strong acid such as sulfuric acid or hydrochloric acid, or more commonly in the presence of a strong alkali such as sodium hydroxide, potassium hydroxide, barium hydroxide, or the like. The glutamic acid precursor substances contained therein are converted thereby into glutamic acid. The resulting hydrolyzate is acidified to around pH 3 to 7, preferably around 5 to 6, concentrated to around 80% dry solids by weight, and filtered or centrifuged to remove the resulting crop of inorganic salts. The partially desalted liquor is then further acidified as necessary to aroundpH 3.2, at which point glutamic acid crystallizes in good yield therefrom at ordinary or somewhat reduced temperatures. When the glutamic acid crystals are removed Patented June 13., 1961.
from the crystallization mixture, the remaining liquid is the glutamic acid end liquor employed in the present invention.
Glutamic acid end liquor in its natural state has a pH around 3.2. In this condition, it has been found to be most effective in foundry cores for extending the range of baking time for maximum tensile strength. For improving the tensile strength of the baked cores, however, the end liquor is somewhat more effective at higher pH ranges up to and around neutrality, and when used for these purposes the end liquor should be adjusted in pH, preferably to the range of about 6 to about 8, by adding thereto a suitable base such as sodium hydroxide, potassium hydroxide, or the like.
The glutamic acid end liquor is ordinarily incorporated into the foundry core in a proportion between about 0.1 and about 1% by weight, preferably between about 0.25 and 0.5% by weight, of the total core, dry basis.
In preparing a core according to the present invention, a sand of suitable grade is mulled with water, a glutamic acid end liquor, and a core binder of a conventional type and in a conventional proportion. It is preferred to first blend the sand with any other dry ingredients, then add a mixture of water, end liquor, and any other non-dry ingredients, and complete the blending. The total proportion of water in the mixture is suitably between about 2 and about 6%, based on the dry Weight of sand, preferably between about 3 and about 5%. Conventional co're binders, including all of the examples set forth hereinabove, are employed in a proportion between about 0.1 and about 3%, optimally between about 0.5 and about 1.5%, dry sand basis. The order of mixing can be altered if desired without materially impairing the desirable results obtained by the present invention. The completed mixture is formed into cores in a conventional manner, and the cores are thereafter baked under conventional conditions prior to use.
In baking cores, the temperature and time required vary widely according to the size of the core, the surfaceto-volume ratio, the water content, the type of sand, and the nature of the primary core binder. Laboratory cores are ordinarily baked at temperatures between about 300 and about 600 F., and the maximum tensile strength is ordinarily reached after a baking time in the range of 10 to minutes. The baking temperature is preferably between about 350 and about 450 F., and for smaller cores a baking time of around 10 to 30 minutes is ordinarily suflicient. For commercial cores, the baking time may range up to 24 hours or longer, and temperatures up to 600 F. are sometimes used to speed up the process. In the present invention, it is found that the maximum tensile strength is reached rapidly (around 10 minutes for laboratory cores), and is maintained essentially constant for an extended period of time (approaching an hour for laboratory cores). At the same time, the maximum tensile strength is materially increased.
The present invention is especially useful in conjunction with the core binders of Neukom, comprising essentially alkalimetal phosphate-modified starches, .described in copending Neukom application Serial No. 706,- 155, filed December 30, 1957. The Neukom core binders are prepared by impregnating ungelatinized starch with an aqueous solution of an alkali-metal orthophosphate salt having a pH between about 4 and about 7, drying to a moisture content below about 15% by weight at a temperature below the level at which the starch gelatinizes, then heating at a temperature between about and about C. for a period of about 1 to about 15 hours, whereby the starch is converted into a form which disperses readily in cold water to yield viscous, stable dispersions. The preferred starches obtained thereby I l V 3 l are the sodium, potassium, and lithium orthophosphatemodified starches.
The invention is also useful in conjunction with the improvedcore binder of John W. Frieders, comprising essentially an alkali-metal orthophosphate derivative of gelatinized amylose, prepared in the Neukom manner and described in application Serial No. 705,794, filed December 30, 1957; and in conjunction with the improved core binder of Sietsema, comprising gelatinized amylopectin substantially free from amylose, described in application Serial No. 705,793, filed December 30, 1957. In these cases, as well as in conjunction with the other core binders of the prior art, glutamic acid end liquors exhibit the remarkable property of extending the range of baking time in which the maximum tensile strength of the core is maintained, and in addition increase the magnitude of the said tensile strength. This is in contrast to the prior art, in which a wide variety of materials, principally humectants, have been tested for the purpose, but with greatly inferior results, as the examples given below will demonstrate.
Example 1 A series of tests were carried out to compare glutamic acid end liquor with a variety of prior-art humectants in a core formulation containing a Neukom-type sodium orthophosphate-modified starch as the primary core binder. The phosphate-modified starch contained 4.04% phosphorus and had a viscosity of 6310 cp. at 25 C. in 5% aqueous dispersion. The sand employed was Ottawa 50, having an AFS grain finess of 70. The core mixtures were prepared from 1.25% of the phosphatemodified starch, 0.25% of the end liquor or conventional humectant, and water to a total moisture content of 4%, based in each case on the dry weight of sand. The dry ingredients were first mulled together for 1 minute. The Wet ingredients were then added, and mulling was resumed for 6 minutes. The completed mixtures were discharged from the muller and stored in sealed cans until used to make cores. The retained water content was about 3.5%.
The various mixtures were formed into standard test cores, then baked over a series of baking periods at 425 F., except the cores containing sorbitol, which were baked at 450 -F. The baked cores were tested according to the standard method defined in the Foundry Sand Handbook, 6th edition, @1952, published by the American Foundrymens Society, Chicago. In each case the cores were prepared and tested in triplicate, and the reported results are the average of three tests. The results show that end liquor maintains the cores at a high and uniform level of tensile strength over an extended range of baking time, while the controls exhibit a sharp decline after about 25 minutes:
A further series of tests were carried out using a glutamic acid end liquor which had been adjusted to a pH near neutrality by addition of sodium hydroxide thereto. The cores were prepared generally in accordance with the procedure and under the conditions given in the previous example, except as noted in the table of data given below. The glutamic acid end liquor, prior to use, was adjusted 4 to pH 6.8 or 6.9, this being the approximate pH level of an aqueous solution of the phosphate-modified starch employed as the primary core binder. The results show a marked increase in tensile strength arising from the addition of end liquor to the core mixture:
- pH of Phosphate- Baking I Tensile Prop'n of End Liquor, End Modified Time, Strength,
percent Liquor Starch, min. p.s.l.
percent While the invention has been described with reference to certain specific prior-art core binders, certain specific glutamic acid end liquors, and other details of process and composition, such matters are to be understood as being illustrative only, and not as limitations upon the scope of the invention. Numerous modifications and equivalents of the invention will be apparent from the foregoing description to those skilled in the art.
In accordance with the foregoing description, the following claims particularly specify and distinctly claim the subject matter of the invention:
What is claimed is:
1. In a fountry core comprising sand and a core binder, said core binder consisting essentially of a starch composition selected from the group consisting of gelatinized starch, gelatinized amylopectin, phosphate-modified starch, phosphate-modified amylose, and mixtures thereof, a modifier consisting essentially of a glutamic acid end liquor obtained from hydrolyzed sugar beet waste liquor.
2. A modifier in a foundary core as in claim 1 wherein said glutamic acid end liquor has a pH of about 3.2.
3. A modifier in a foundry core as in claim 1 wherein said glutamic acid end liquor has been adjusted to a pH between about 6 and about 8.
4. A foundry core consisting essentially of sand, a core binder, and between about 0.1 and about 1%, based on the dry weight of sand, of a glutamic acid end liquor obtained from hydrolyzed sugar beet waste liquor, said core binder consisting essentially of a starch composition selected from the group consisting of gelatinized starch, gelatinized amylopectin, phosphate-modified starch, phosphate-modified amylose, and mixtures thereof.
5. In a foundry phosphate-modified starch core consisting essentially of sand and a core binder, a modifier, in a proportion between about 0.1 and about 1%, based on the dry weight of sand, consisting essentially of an end liquor produced .by hydrolyzing a sugar beet waste liquor and removing a portion of the glutamic acid therefrom.
6. A foundry core which consists essentially of sand and an alkali-metal orthophosphate-modified starch prepared by soaking ungelatinized starch in an aqueous alkalimetal orthophosphate solution having a pH between about 4 and about 7, drying the soaked starch to a moisture content less than about 15% by weight at a temperature below the gelatinization point thereof, and baking the dried starch at a temperature between about and about C. for a period of about 1 to about 15 hours, and in combination therewith a glutamic acid end liquor obtained by hydrolyzing a sugar beet waste liquor and sepa rating a portion of the glutamic acid therefrom.
7. A foundry core which consists essentially of sand and an alkali-metal orthophosphate-modified amylose prepared by soaking gelatinized amylose in an aqueous alkali-metal orthophosphate solution having a pH between about 4 and about 7, drying the soaked amylose to a moisture content less than about 15% by weight, and baking the dried amylose at a temperature between about 120 and about 175 C. for a period of about 1 to about 15 hours, and in combination therewith a glutamic acid end liquor obtained by hydrolyzing a sugar beet waste liquor and separating a portion of the glutamic acid therefrom.
References Cited in the file of this patent UNITED STATES PATENTS Outerbridge Dec. 9, 1919 Hill Sept. 19, 1922 Durand Aug. 22, 1933 Giesecke Sept. 25, 1934 Barnett Feb. 26, 1935 6 Prangc May 25, Salzberg Jan. 31, Cahn Mar. 21, Baker May 23, Young Dec. '18, Pacsu et a1. Jan. 29, Novak Mar. 19, Klein May 21, Naukom Apr. 28,
FOREIGN PATENTS Great Britain Dec. 6,
OTHER REFERENCES 15 Feiser and Feiser: Organic Chemistry, pub. 1956 by Reinhold (page 430).
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2 988 453 June 13 1961 Forest A, Hoglan et al0 It is hereby certified that error appears in the above, numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 3, line 31, for "finess" read fineness =3 column 4 line 29, for fountry read foundry line 36 for "foundary" read foundry lines 49 and 50 for "In a foundry phosphate-modified starch core consisting essentially of sand and a core binder" read In a foundry core consisting essentially of sand and a phosphate modified starch core binder Signed and sealed this 27th day of November 1962,
isEAL) :Attest:
ESTON o. JOHNSON r mxmiom DAVID LADD Commissioner of Patents l Attesting Officer
Claims (1)
1. IN A FOUNDRY CORE COMPRISING SAND AND A CORE BINDER, SAID CORE BINDER CONSISTING ESSENTIALLY OF A STARCH COMPOSITION SELECTED FROM THE GROUP CONSISTING OF GELATINIZED STARCH, GELATINIZED AMYLOPECTIN, PHOSPHATE-MODIFIED STARCH, PHOSPHATE-MODIFIED AMYLOSE, AND MIXTURES THEREOF, A MODIFIER CONSISTING ESSENTIALLY OF A GLUTAMIC ACID END LIQUOR OBTAINED FROM HYDROLYZED SUGAR BEET WASTE LIQUOR.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US743485A US2988453A (en) | 1958-06-20 | 1958-06-20 | Core binder additive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US743485A US2988453A (en) | 1958-06-20 | 1958-06-20 | Core binder additive |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2988453A true US2988453A (en) | 1961-06-13 |
Family
ID=24988959
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US743485A Expired - Lifetime US2988453A (en) | 1958-06-20 | 1958-06-20 | Core binder additive |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2988453A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3046146A (en) * | 1958-06-12 | 1962-07-24 | Woodhead James Seward | Thermosetting material |
| US3341861A (en) * | 1966-12-12 | 1967-09-19 | Beulah M Robbins | Open weave anti-slip glove |
| US4957558A (en) * | 1987-11-16 | 1990-09-18 | Hiroshi Ueda | Temporary solidifier for playing with sand |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1324208A (en) * | 1919-12-09 | Sand core for molds for casting metal and process of the manufacture of | ||
| US1429879A (en) * | 1919-09-15 | 1922-09-19 | American Hominy Company | Core binder |
| US1924028A (en) * | 1928-09-29 | 1933-08-22 | Durand Jean Baptiste | Manufacture of foundry molds |
| US1974915A (en) * | 1928-12-26 | 1934-09-25 | Int Patents Dev Co | Gelatinized starch |
| US1992462A (en) * | 1933-06-09 | 1935-02-26 | S M A Corp | Manufacture of flavoring materials |
| US2081558A (en) * | 1934-04-20 | 1937-05-25 | Austenal Lab Inc | Casting investment material and process |
| US2145317A (en) * | 1935-01-17 | 1939-01-31 | Borden Co | Foundry core binder |
| GB515470A (en) * | 1938-04-28 | 1939-12-06 | Alexander Mclaren Wilson | Improvements in and relating to the production of sand cores for foundry purposes |
| US2500919A (en) * | 1948-12-03 | 1950-03-21 | Louis Milani Foods Inc | Sodium-free flavoring compositions |
| US2508359A (en) * | 1947-02-21 | 1950-05-23 | Rose C Baker | Core binder |
| US2774673A (en) * | 1954-06-02 | 1956-12-18 | Robert H Young | Food additive |
| US2779693A (en) * | 1952-03-07 | 1957-01-29 | Textile Res Inst | Fractionation of starch |
| US2785977A (en) * | 1954-10-18 | 1957-03-19 | Ohio Commw Eng Co | Food flavor-enhancing material and method of making same |
| US2793129A (en) * | 1953-09-04 | 1957-05-21 | Klein Alexander | Hydraulic cementitious mixtures |
| US2884412A (en) * | 1953-09-04 | 1959-04-28 | Int Minerals & Chem Corp | Phosphate-modified starches and preparation |
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1958
- 1958-06-20 US US743485A patent/US2988453A/en not_active Expired - Lifetime
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1324208A (en) * | 1919-12-09 | Sand core for molds for casting metal and process of the manufacture of | ||
| US1429879A (en) * | 1919-09-15 | 1922-09-19 | American Hominy Company | Core binder |
| US1924028A (en) * | 1928-09-29 | 1933-08-22 | Durand Jean Baptiste | Manufacture of foundry molds |
| US1974915A (en) * | 1928-12-26 | 1934-09-25 | Int Patents Dev Co | Gelatinized starch |
| US1992462A (en) * | 1933-06-09 | 1935-02-26 | S M A Corp | Manufacture of flavoring materials |
| US2081558A (en) * | 1934-04-20 | 1937-05-25 | Austenal Lab Inc | Casting investment material and process |
| US2145317A (en) * | 1935-01-17 | 1939-01-31 | Borden Co | Foundry core binder |
| GB515470A (en) * | 1938-04-28 | 1939-12-06 | Alexander Mclaren Wilson | Improvements in and relating to the production of sand cores for foundry purposes |
| US2508359A (en) * | 1947-02-21 | 1950-05-23 | Rose C Baker | Core binder |
| US2500919A (en) * | 1948-12-03 | 1950-03-21 | Louis Milani Foods Inc | Sodium-free flavoring compositions |
| US2779693A (en) * | 1952-03-07 | 1957-01-29 | Textile Res Inst | Fractionation of starch |
| US2793129A (en) * | 1953-09-04 | 1957-05-21 | Klein Alexander | Hydraulic cementitious mixtures |
| US2884412A (en) * | 1953-09-04 | 1959-04-28 | Int Minerals & Chem Corp | Phosphate-modified starches and preparation |
| US2774673A (en) * | 1954-06-02 | 1956-12-18 | Robert H Young | Food additive |
| US2785977A (en) * | 1954-10-18 | 1957-03-19 | Ohio Commw Eng Co | Food flavor-enhancing material and method of making same |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3046146A (en) * | 1958-06-12 | 1962-07-24 | Woodhead James Seward | Thermosetting material |
| US3341861A (en) * | 1966-12-12 | 1967-09-19 | Beulah M Robbins | Open weave anti-slip glove |
| US4957558A (en) * | 1987-11-16 | 1990-09-18 | Hiroshi Ueda | Temporary solidifier for playing with sand |
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