Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
• • 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
  • B22C1/167—Mixtures of inorganic and organic binding agents
• • 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
  • B22C1/2293—Natural polymers
• • 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
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B33/00—Clay-wares
  • C04B33/02—Preparing or treating the raw materials individually or as batches
  • C04B33/13—Compounding ingredients
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B33/00—Clay-wares
  • C04B33/02—Preparing or treating the raw materials individually or as batches
  • C04B33/13—Compounding ingredients
  • C04B33/1315—Non-ceramic binders
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
  • E04B1/92—Protection against other undesired influences or dangers
  • E04B1/94—Protection against other undesired influences or dangers against fire

Definitions

• This invention relates to new core binders and to a new process for making cores suitable for use in fabrication of metal castings.
• sand is mulled with about 1 part by weight of cereal binder, 3 parts by weight of water is added and mulled into the mixture, followed by addition and mulling of 1 part by weight of core oil.
• other binders such as bentonite, may also be used.
• the mulling period depends on the type of machine used, and the proportion of binders depends on the design of the core, the properties of the binders and on the metal to be poured, all of which are recognized by those skilled in the art.
• the mulled mixture is rammed or blown into a corebox which is subsequently opened, the core is carefully removed and transferred to a hot oven where it is baked.
• the core After removal from the oven and cooling, the core is an accurately formed hard object which will withstand rough handling. In use, it must retain its shape as molten metal flows and solidifies around it, and should then collapse to an easily removable mass asthe binders slowly burn off.
• the cereal binder such as pregelatinized starch
• the cereal binder is added primarily so that the freshly formed damp core possesses sufiicient wet or green strength to retain its shape until it is placed in the oven.
• the baked core must have high dry or baked strength, most of which is provided by the core oil in the typical process described.
• a further object of this invention is to provide an easily prepared, dry, free-flowing binder which imparts both green and dry strengthto cores.
• a further object of this invention is to decrease volume of gases liberated by sand cores baked with organic binders, particularly cereal binders and sugars. Further, the invention is useful for decreasing volume of gases liberated by core pastes and core washes containing organic binders when the pasted or washed cores are baked. Further objects will appear hereinafter in the description which follows.
• the present invention comprises a mixture of suitable proportions of cereal binder, ucertain sugars which are specified hereinafter, and an adjunct selected from the Cereal binders are well known in the art and include pregelatinized starches and pregelatinized starchy flours, the latter usually containing small amounts of protein or fiber.
• cereal binder includes dextrins which may be employed for certain specific uses.
• sugar means those monoand disaccharides ofan aldose or ketose character, or such non-reducing saccha-rides which may be hydrolyzed under conditions of use herein described to give aldose or ketose saccharides.
• sucrose is elfective as a component of the described binder and is claimed in this invention, while sorbitol is not.
• the sugars which I prefer are dextrose, sucrose, and
• fructose or mixtures thereof but maltose and lactose are Sirupswhich may be made by hydrolysis of starch or from cane sugar by appropriate treatments are-also--effective in carrying out this invention.
• Dextrose greens or hydrol may be treated to prevent crystallization of the dextrose contained therein by boiling them with acid or alkali in accordance with known methods.
• These byproducts may be less efiective than dextrose or sucrose, as is apparent from the data in Table II, but are within the scope of this invention because of their economic advantages.
• the chemical adjuncts which are suitable for purposes of my invention are sulfuric acid; phosphoric acid; any chemical or mixture of chemicals which generates either or both of these acids under the conditions of use, such as ammonium sulfate, ammonium acid sulfate, aluminum sulfate, alums, e. g., ammonium aluminum sulfate, ammonium .rer t taaad th alkali permit-ates.
• n nil mig lq ra mixt of natetq ma h dr ch ri acid; .b i aci T e a r mentioned compounds may act as catalytic agents to promote condensation of sugars, or may decomposeunder the conditions used to produce .such catalytic agents. However, I do not wish to be limited by any tlzteory of the operation of the aforementioned compounds.
• Ammonium sulfate is the preferred adjunct, among the reasons being its effectiveness, cheapness, stability, noncorrosive character and theease with which itmay be blended with ,the other components of the core.
• anyq wfc em nt qn djun wh c are suitable forthe purposes of myjnvention should be used in proportions which yield optimum benefits from their use. These proportions maybe diiferent for each adjunct.
• adjuncts may vary widely.
• 0.25 to 2 parts of cereal binder 0.5 to parts of sugar and from,0.002 to O.l5 part by weight of adjunct p er part by weightof sugar may be used.
• the amount of water may vary from 1.5 to 6.0 percent of the sand. All ,partsabovespecified are parts by weight. In general, volume of gases liberated by baked cores as well as heating time required for cores to attain peak strengths are decreasedas the proportion of the preferred adjunct in thesand is-raised.
• This example ShOWSZ'hOW SIIQHEih of baked cores is increased when certain adjunctsare used with the binders.
• EXAMPLE 2 This example reveals the superiorgreen strength properties of cores preparedawith cerealtbinderin combina tion with a sugar and an adjunct .as compared to vthose prepared with cereal binder .used in.-combination.,with -a core oil.
• the core sandmixture containing cereal binder, sugar and adjunct was prepared, as described in Example l. Green strength and dry.- strength were determined in accordance with procedures described in the Foundry Sand Handbook mentioned above. sResultsare set forth in TableI, i-where percentages .of binder and adjunct are based on .sand.
• a process for producing a core for foundry use which comprises mixing parts of sand, 0.25 to 2 parts of cereal binder, 0.5 to 5 parts of sugar and from 0.002 to 0.15 part of adjunct per part of sugar, and sufiicient water to mull the resultant mixture, molding said mixture and baking it at a temperature of at least 350 K; said sugar-adjunct-binder containing from 1 to 20 parts of adjunct; all parts being on a weight basis; said adjunct being selected from the group consisting of hydrochloric acid; sodium chloride; a mixture consisting of 5 parts by weight of paraformaldehyde and 1 part by weight of ammonium chloride; boric acid; sulfuric acid, phosphoric acid, and salts which producesuch acids under said baking conditions.
• a process for producing a core for foundry use which comprises mixing 100 parts of sand, 0.25 to 2 parts of cereal binder, 0.5 to 5 parts of sugar and from 0.002 to 0.15 part of ammonium sulfate per part of sugar, and suflicient water to mull the resultant mixture, molding said mixture and baking it at a temperature of at least 350' F.; all parts being on a weight basis.
• a composition for bondingilOO parts of core sand consisting of 0.25 to 2 parts ofv cereal binder, 0.5 to 5 parts of sugar and from 0.002 to. 0.15 partof ammonium of parts by .Weightpof sulfate per partpf sugar, all parts on dry weight basis, and suificient water to mull the entire mixture.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Architecture (AREA)
• Inorganic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Molecular Biology (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electromagnetism (AREA)
• Civil Engineering (AREA)
• Mold Materials And Core Materials (AREA)
• Catalysts (AREA)

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Publications (1)

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Cited By (28)

Citations (6)

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• 1955
  • 1955-05-23 US US510583A patent/US2875073A/en not_active Expired - Lifetime
  • 1955-08-18 DE DEC11717A patent/DE1023389B/de active Pending
  • 1955-08-19 DE DEC11721A patent/DE1169085B/de active Pending

Patent Citations (6)

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