<img alt="" src="https://secure.hims1nice.com/150891.png" style="display:none;">

Green Sand Metalcasting Foundry News

Hill and Griffith Company

Recent Posts

Sand Casting

Posted by Hill and Griffith Company on Jul 7, 2020 5:34:52 PM

Excerpt from the September 2019 TheLibraryofManufacturing.com article.

Metalcasting Sand

Sand casting is the most widely used metal casting process in manufacturing. Almost all casting metals can be sand cast. Sand castings can range in size from very small to extremely large. Some examples of items manufactured in modern industry by sand casting processes are engine blocks, machine tool bases, cylinder heads, pump housings, and valves, just to name a few.

Sand

Most sand casting operations use silica sand (SiO2). A great advantage of sand in manufacturing applications is that sand is inexpensive. Another advantage of sand to manufacture products by metal casting processes, is that sand is very resistant to elevated temperatures. In fact, sand casting is one of the few processes that can be used for metals with high melting temperatures such as steels, nickel, and titanium. Usually sand used to manufacture a mold for the casting process is held together by a mixture of water and clay. A typical mixture by volume could be 89% sand, 4% water, 7% clay. Control of all aspects of the properties of sand is crucial when manufacturing parts by sand casting, therefore a sand laboratory is usually attached to the foundry.

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Coatings, Green Sand Release Agents, Green Sand Metalcasting, Core Binders, Green Sand Additive Products

Castings of the Year 2020 Part 3

Posted by Hill and Griffith Company on Jun 30, 2020 8:19:23 PM

Excerpt from the May 2020 Issue of Modern Casting

This year’s annual AFS Casting Competition continues with 2 more casting category winners:

  • Best Casting Conversion for Waupaca Foundry Inc.'s rear suspension trailing arm
  • Outstanding Achievement from O'Fallon Casting for their aluminum pump housing
Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Release Agents, Green Sand Metalcasting, Modern Casting Magazine

More Flexibility for Green-Sand Molding Operations

Posted by Hill and Griffith Company on Jun 23, 2020 5:31:12 PM

Excerpt from the September 2019 Foundry Management & Technology article.

Top and bottom sand-blowing system extends the Hunter expertise with a new option for foundries' mold-filling needs.

The science of sand molding has not changed for centuries, but the process technologies involved in mold production are another matter. In that case, the changes are demand-driven. Molding machinery is developed to suit the production requirements of foundries, and foundries know where to turn for molding technology expertise.

Hunter Foundry Machinery Corp. has been innovating and refining molding machinery for more than half a century, famously with the Hunter HMP machine that introduced the "matchplate" concept that made green-sand molding faster, more reliable, and more cost-effective, and allowed foundries of all types to be competitive in terms of volume and product quality. It is a rugged, gravity-driven system that’s easy to operate and easy to understand; it is scalable to foundries’ available space; and it adapts easily to different foundries’ molding operations.

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Coatings, Green Sand Release Agents, Green Sand Metalcasting, Core Binders, Green Sand Additive Products, Foundry Management & Technology magazine

A Revolutionary Inorganic Core and Mold Making Process

Posted by Hill and Griffith Company on Jun 16, 2020 4:18:54 PM

Excerpt from February 2009 Foundry Management & Technology article by Nobuyoshi Sasaki.

A novel concept uses sodium and silica to increase the heat resistance of organically bonded molds and cores, which increases hot strength and allows the production of thin-wall castings.

Historically, foundries worldwide have been forced to rely on organic-based core and mold binders, and the use of refractory coatings, along with sand additives, when the hot strengths of the binders are insufficient to produce salable castings.

In 1995, Cadic Corp., and its subsidiary CTI Inc., introduced the Cadic Convert Process, which uses a liquid mixture of silicon oxide and sodium in alcohol to treat resin-bonded molds and cores. In practice, cores and molds produced using organic heat- and amine-cured resins were dipped or immersed in the ethanol solution, dried, and subsequently fired in a kiln to convert the organic-bonded article to an inorganic bonded mold or core.

This post-production treatment of organic-bonded aggregates resulted in the formation of organo-silicates that were converted to ceramics when fired at elevated temperatures, and poured hot to produce thin-wall (2 mm or less) stainless steel castings.

Laboratory evidence, supported by foundry trials, confirmed that the silica compound formed a crystal lacuna surrounding the sodium (Na) at room temperatures and allowed the Na ion to retain its high degree of reactivity.

The subsequent high-temperature treatment resulted in the conversion of quartz to tridymite, thereby increasing the high-temperature properties of the core or mold.

Because of the high degree of reactivity, the Na ion is utilized in this process as the alkali oxide Na2O. In this new process, the nano silica composition allows the Na ion to maintain its reactivity from room temperature to the boiling point of the compound.

With the elimination of a post-production treatment for the core or mold using ethanol as a carrier, the resulting new development makes the Cadic Convert Process considerably simpler, because the nano silica compounds can be added to the sand mix prior to the production of the core or mold in any organic resin-bonded processes, such as phenolic urethanes and shell sand mixtures.

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Coatings, Green Sand Release Agents, Green Sand Metalcasting, Core Binders, Green Sand Additive Products, Foundry Management & Technology magazine

Green Sand Emissions and the Concentration of Carbonaceous Additives

Posted by Hill and Griffith Company on Jun 9, 2020 1:22:54 PM

Excerpt from December 2019 Modern Casting article by Liam Miller, Ray Vakili, Jason St. Onge, and Zhen Wang.

A replacement of seacoal with causticized lignite has the potential to reduce foundry emissions.

The benefits of adding finely divided bituminous coal, commonly known as seacoal, or other carbon rich additives to clay-bonded molding sands have been well established by the foundry industry to generate air emissions. Hazardous air pollutants (HAPs) and volatile organic compounds (VOCs) are generated and released during the metalcasting process because of the pyrolysis of the carbonaceous additives in the molding sand.

In general, organic substances produce volatile gases and deposit a solid residue enriched in carbon after pyrolysis. This pyrolysis of carbon containing materials has generally been accepted as serving several essential functions in green sand castings as summarized in publications as far back as 1980. The generation of volatile gases from the carbonaceous material promotes a reducing environment in the mold cavity helping to inhibit the oxidation of the liquid metal. The pressure generated by the volatile gases, in addition to the carbon rich residue deposited during pyrolysis, helps resist metal penetration and promote good casting finish while aiding in the peel of the solidified casting from the sand mold. The gases that are evolved from the carbonaceous material exposed to high temperatures in the sand mold contain VOCs and HAPs and have been shown to be major contributors to overall foundry air emissions.

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Release Agents, Green Sand Metalcasting, Green Sand Additive Products, Modern Casting Magazine

Castings of the Year 2020 Part 2

Posted by Hill and Griffith Company on Jun 2, 2020 5:26:01 PM

Excerpt from the May 2020 Issue of Modern Casting

This year’s annual AFS Casting Competition continues with 2 of the casting category winners: Achievement by a Small Foundry and Outstanding Achievement. Congratulations go to LA Aluminum Casting Co. for their lift wrench and to Dotson Iron Casting for their trip arm. 

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Release Agents, Green Sand Metalcasting, Modern Casting Magazine

Castings of the Year 2020

Posted by Hill and Griffith Company on May 26, 2020 8:48:48 AM

Excerpt from the May 2020 Issue of Modern Casting

This year’s annual AFS Casting Competition is a rare one. Two submitted castings tied for the top honor, and for very different reasons. The opener main body casting by Lethbridge Iron Works Co. (Lethbridge, Alberta, Canada) showcases the opportunities in converting from fabrication to casting, while the V6 engine block by BRP-US (Spruce Pine, North Carolina) exemplifies the ultra-complexity achievable with the lost foam casting process. Eight additional castings also have been honored for their exemplary work in achieving customer benefits and advancing the metalcasting industry.

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Release Agents, Green Sand Metalcasting, Modern Casting Magazine

Casting: Pattern, Mold and Core Design

Posted by Hill and Griffith Company on May 19, 2020 2:49:02 PM

Excerpt from TheMetalCasting.com article.

Pattern, mold and core design involves orientation and parting. The parting line is influenced by designs of patterns and cores, number of voids in the mold, location of feeders, orientation of the part and locations of channels of gating, cooling and venting.

Orientation and parting line
A parting line is usually defined as the part of the mold that divides the segments to create cavities with the mold section and remove the final product from its mold as in die casting.

Factors which determine the number of parting lines required are:

  • Geometry of the component to be molded
  • Number of cavities required within the mold sections
  • The nature of the runner system
  • The kind of gating required and
  • The method of ejecting the final product from its mold
Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Release Agents, Green Sand Metalcasting, TheMetalCasting.com

Additive Manufacturing Comes to Metal Foam

Posted by Hill and Griffith Company on May 12, 2020 12:07:51 PM

Sand casting is a method used to make ordered-cell metal foams. Aluminum ordered-cell foam is lightweight, moves heat, and absorbs impact. Binder-jet 3D-printed sand castings could create a hybrid method to manufacture metal foam.

Excerpt from the April 2013 Machine Design article by Lindsey Frick.

Metal foams, also called cellular materials, are metallic bodies with interspersed voids called cells. They have a reputation for high strength, low density, and absorbing impact. This combination works well for military vehicles where lighter parts can save money and the degree of impact cushioning can be the difference between life or death.

Traditionally made metal foam is stochastic, meaning the foam has irregular cells that are spaced unevenly. If the cell structure in metal foam is arranged and regular it is called ordered-cell foam. Stochastic materials reduce weight as do ordered-cell metal foams. However, ordered-cell foam has superior strength, stiffness, energy absorption, and it moves heat.

Goodfellow’s aluminum foam is made by sand casting. The foam has regular, evenly spaced, 10-mm open pore cells.

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Release Agents, Green Sand Metalcasting, Machine Design Magazine

New Look at Recycling Green Sand Wastes

Posted by Hill and Griffith Company on May 5, 2020 4:51:47 PM

A new water-based reclamation process offers foundries a method for recovering bentonite and carbon from foundry dust.

Excerpt from the March 2020 Foundry Management & Technology article.

Despite numerous challenges to its long-term viability — some serious and credible, others just imagined or mistaken — green sand casting is thriving, both in practical terms and in its technological progress. But one constant dilemma for producers of green sand castings is what to do with the byproducts.

For background, green-sand casting involves molds formed with silica (or chromite, or zircon) sand mixed with water and bonding compounds, notably bentonite (clay) and carbon. Finished castings ultimately leave their molds but the bonded sand remains, and what to do with that sand is one of those challenges that green-sand casters routinely discuss. Reportedly, the U.S. foundry industry consumed approximately 700,000 tons of bentonite and carbon during 2018.

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Release Agents, Green Sand Metalcasting, Foundry Management & Technology magazine

Subscribe to the Green Sand Metal Casting News

Recent Metalcasting News

Follow us

Metalcasting News Categories

see all