Method for manufacturing foundry cores

• US 4,089,691 A
• Filed: 11/12/1976
• Issued: 05/16/1978
• Est. Priority Date: 02/21/1975
• Status: Expired due to Term

• Current Assignee: Krause Milling Co.
• Original Assignee: Krause Milling Co.
• Inventors: Cummisford, Robert G., Krueger, Robert K., Wasielewski, Richard J.
• Primary Examiner(s): Hayes, Lorenzo B.
• Assistant Examiner(s): Yarbrough, A. B.
• Application Number:
  US05/741,177
• Time in Patent Office: 550 Days
• Field of Search: 106/38.4, 106/38.5 R, 106/210, 106/213, 106/214, 106/126, 106/38.8, 106/160, 106/161, 106/162, 106/212, 106/69, 127/32, 127/38, 536/104, 536/106, 260/DIG. 40, 427/134
• US Class Current: 106/38.4
• CPC Class Codes: B22C 1/2246 Condensation polymers of aldehydes and ketones B22C1/224, B22C1/2273 take precedence
• CPC Class Codes: B22C 1/26 of carbohydrates; of distillation residues therefrom
• CPC Class Codes: C08B 31/00 Preparation of derivatives of starch derivatives of amylose C08B33/00; derivatives of amylopectin C08B35/00
• CPC Class Codes: C08B 37/00 Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof cellulose D21; microbiological processes C12P
• CPC Class Codes: C08G 4/00 Condensation polymers of aldehydes or ketones with polyalcohols; Addition polymers of heterocyclic oxygen compounds containing in the ring at least once the grouping —O—C—O— of cyclic oligomers of aldehydes C08G2/00
• CPC Class Codes: C08K 3/16 Halogen-containing compounds
• CPC Class Codes: C08K 3/34 Silicon-containing compounds
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 3/02 Starch; Degradation products thereof, e.g. dextrin
• CPC Class Codes: C08L 5/00 Compositions of polysaccharides or of their derivatives not provided for in groups C08L1/00 or C08L3/00
• CPC Class Codes: C08L 97/02 Lignocellulosic material, e.g. wood, straw or bagasse manufacture of articles made from lignocellulosic material by dry processes B27N

Abstract

A method for manufacturing a foundry core comprising mixing sand and a binder system containing a saccharide-containing material, glyoxal and an alkali halide.

Claims

1. A method of manufacturing a foundry core comprising mixing sand and heat-accelerated curable binder system wherein the binder system is produced by the following steps, the percentages being a percent of sand:

(a) crosslinking 1-3% of saccharide-containing matter with 0.15-3% of 40% glyoxal aqueous solution;

(b) controlling, by accelerating or retarding, the rate of reaction by the use of 0.3-1.0% alkali halide as a catalyst using 0.4% water, 0-10% betonite, 0-10% silica flour, 0-10% iron oxide, and 0-1% of a material selected from the group comprising wax, wax emulsion, asphalt emulsion, and wax-asphalt emulsion, the reaction being at such a temperature and pressure relationship as to maintain a liquid condition during the reaction.

(c) forming the mixture to desired shape and causing it to cure to a hardened state.

2. A method as claimed in claim 1 including the step of curing the core for 5-120 seconds in a hot box.

3. A method as claimed in claim 2 wherein the hot box is between 250°

-550°

F.

4. A method as claimed in claim 1 wherein the saccharide-containing matter is selected from the group comprising sucrose, maltose, corn syrup, corn syrup solids, glyco proteins, hydrolyzed pregelled starches, and hydrolyzed pregelled flours.

5. A method as claimed in claim 1 wherein the saccharide-containing material is a hydrolyzed-gelatinized amylaceous material having alkaline viscosities of less than 20 seconds using a 1.3 g sample and less than 100 seconds using a 5.2 g sample.

6. A method as claimed in claim 1 where the alkali halide is selected from the group comprising KCl, KBr, KI, NaCl, NaBr, NaI or NaF.

7. A method as claimed in claim 1 where the glyoxal solution and alkali halide are admixed with water sufficient to dissolve the alkali halide prior to admixture with the rest of the ingredients.

8. A method as claimed in claim 7 wherein the alkali halide is selected from the group comprising KCl, NaCl, KBr or NaBr.

9. A method as claimed in claim 8 wherein the solution of glyoxal and alkali halide with water is in the following range of composition:

glyoxal 2-35%, alkali halide 6-25% and water 45-92%.

10. A method as claimed in claim 1 which includes the step of removing the core from the form and drying the core.

11. A method as claimed in claim 1 which includes the step of surface coating the core with a material selected from the group comprising water and water-containing core wash prior to drying.

12. A method as claimed in claim 11 wherein the drying is performed in an oven.

13. A method as claimed in claim 10 wherein the alkali halide is KCl, KBr, NaCl or NaBr.

14. A method as claimed in claim 13 wherein the saccharide-containing material is selected from the group comprising sucrose, maltose, corn syrup and corn syrup solids.

15. A method as claimed in claim 13 wherein the saccharide material is a hydrolyzed gelatinized amylaceous material having alkaline viscosities of less than 20 seconds for a 1.3 g sample and less than 100 seconds for a 5.2 g sample.

16. A method as claimed in claim 13 wherein the saccharide material is a glyco protein.

17. A method as claimed in claim 1 wherein the saccharide is water soluble amylaceous hydrolysate.

18. A method as claimed in claim 13 wherein the glyoxal and alkali halide are mixed prior to admixture with the rest of the ingredients.

19. A method as claimed in claim 19 wherein the glyoxal and alkali halide are mixed with water in the following range:

glyoxal 2-35%, salt 6-25%, water 45-92% prior to adding the rest of the ingredients.

20. A method as claimed in claim 19 wherein additional water is added at the time of mixing the glyoxal and alkali halide mixture with the rest of the ingredients.