Small Business Resources, Business Advice and Forms from AllBusiness.com
 

Expanding opportunities for precision sand casting: recent advances in coldbox tool design have...

By Archibald, James J.
Publication: Modern Casting
Date: Wednesday, February 1 2006

Precision sand casting (PSC) is a molding technique used to produce dimensionally accurate castings with thin sections through the use of chemical binders and dimensionally accurate and durable pattern equipment.

PSC mainly has been applied to

the casting of light alloy automotive components. The chemically-bonded sand molds and cores used in PSC usually incorporate phenolic urethane nobake (PUNB) binders due to the excellent mold rigidity and dimensional stability imparted by this binder system. More recently, such molding has advanced in volume output by utilizing vapor curing techniques and mainly phenolic urethane coldbox (PUCB) binders cured with vaporized tertiary amines. The use of these vapor-cured binders gives even better rigidity and precision and allows more rapid mold production.

In high-volume green sand casting facilities, amine-cured PUCB bonded sands have largely remained a means of core production, whereas in light alloy casting facilities, the application of these binders, using PSC techniques, has been adopted as an alternative to the more traditional molding techniques of green sand and semi-permanent molding (SPM).

The application of PSC holds opportunities for both light alloy and ferrous casting facilities for the production of medium- to high-volume components.

Capital Costs

There are three basic incarnations of PSC (Fig. 1):

* the core assembly where individual mold and core components are made on a number of core machines and then assembled into complete mold-core packages;

* conventional molds blown on larger core machines, cored and assembled with complete or partial automation;

* stack molding where vertical or horizontal stacks are made using PSC molds blown with form on both sides.

[FIGURE 1 OMITTED]

No metalcasting facility is likely to use PSC unless it offers good cost or technical advantages over conventional molding methods. The global casting industry has invested heavily in green sand molding (ferrous) and SPM (nonferrous) as the dominant techniques for high-volume cored castings. However, in an increasing number of cases, PSC has been used for:

* reduced capital costs in the case of a new installation or product;

* lower operational costs for either a new or existing process or product;

In addition, make sure to read these articles:

  • aPriori v5.5 Enterprise Cost Management...
  • Added Support for Sand Casting Manufacturing Processes Expands Capabilities for Real-time Product Costing December 12 Webinar to Demonstrate How Manufacturing Organizations Can Drive Costs ......
  • TMB Industries Acquires Richland Center Foundry.
  • Acquisition will Leverage Private Equity Firm's Foundry Management Experience CHICAGO -- TMB Industries ("TMB") announces the acquisition of Richland Center Foundry ("RCF"), a manufacturer of ......
  • 20-Year Foundry Veteran Joins the GMBOND Sand...
  • Business Editors AUSTIN, Minn.--(BUSINESS WIRE)--Oct. 7, 2003 Hormel Foods Corporation announced that Greg Sanders has joined the company as a GMBOND(R) sales agent. Mr. Sanders ......
  • Correction.
  • It was recently pointed out that an error occurred in the literature review shared in "How Green Sand Systems are Impacted by Core Sand Dilution" ......
  • Dimensionally accurate, lightweight castings...
  • The driving force for dimensional accuracy in the automotive manufacturing industry is the marketplace's demand for higher performance, efficient, reliable, compact and lighter car engines....
  • Casting answers & advice.
  • Q: We are a small foundry making aerospace and precision castings in aluminum. We are using oil-based green sand and find there is little information ......
  • Controlling sand and additives.
  • While the practice of pouring molten metal into molds composed of sand with clay binder and various additives has been common for several centuries, today ......
  • Molding Methods & Materials Silver...
  • In his Silver Anniversary Presentation titled, "Influence of Chemical Binder Core Sand Contamination on Green Sand Molding Properties--25 Years of Controversy" (04-001), Rodney L. Naro, ......
  • Additives improve sand molding.
  • A change in the method of making green sand molds occurred when foundries began producing harder molds, a process that continues to evolve. Harder molds ......
  • Bahr Bros. Manufacturing buys green sand...
  • Bahr Bros. Mfg. Inc., Marion, Ind., purchased Specialty Castings, Springport, Mich., on April 30. Specialty Castings is a low to medium mn green sand metalcaster ......
  • New Vertical Green Sand Molding Machines...
  • Foundries are constantly facing demands for complex and thin-walled castings with great accuracy and at competitive prices. To meet these demands, Georg Fischer Disa A/S ......
  • Fata Aluminum Inc.
  • Fata Aluminum supplies automated casting plants for aluminum castings produced in semi-permanent mold, automatic carousels, casting machines, pouring robots, manipulators, and engineering of the 7 ......
  • Clean, Profitable One-Step Process
  • The Mark 5 Series rotary media drum by Didion performs shakeout; sand conditioning; double sand screening; casting cleaning; and casting cooling in a single efficient ......
  • Sand reclamation issues under study.
  • Victor LaFay, participant in several molding methods and materials technical presentations at the 1991 Casting Congress, said many steps are involved in the metalcasting process, ......
  • Richland Center Foundry.
  • Richland Center Foundry, a green sand and nobake iron foundry in Richland Center, Wisconsin, has selected Summit Foundry Systems, Inc., Fort Wayne, Indiana, to install ......