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

Green Sand Metalcasting Foundry News

"L" - Glossary of Foundry Additives (including Lignin "Goulac" core binder)

Posted by Hill and Griffith Company on Apr 24, 2018 11:41:09 PM

L - Foundry Additives Glossary

LAC (See: RESIN-SHELLAC)

LAKE SAND (See: SAND, LAKE)
Sand occurring in, or near, lake areas which may contain some impurities is called "Lake Sand." It is used in many Midwestern foun­dry core and molding compositions. It is an economical foundry base sand.

LAMPBLACK (See: CARBON -CARBON BLACK
Lampblack is actually soot formed by the smudge process of burning oils, resins, tars, or other carbonaceous material where there is an insufficient supply of air. The soot is allowed to settle on the metallic, cooler walls or areas before it is collected. Lampblack is practically pure carbon. It is used in the foundry as a coloring agent and in a few commercial facing mixtures. Chemically it resembles carbon black which is made by burning gas. Lampblack is very fine and colloidal in form. One pound may occupy over 200 cubic inches in volume.

LARD Oil (See: LIQUID PARTINGS-OILS-PARTINGS)
Lard oil is a fluid oil which contains oleic, stearic and palmatic acids. It is widely used in foundry lubricating oils, but it is also used in many liquid partings of the foundry. It is usually blended with kerosene and other compatible liquids. It has a specific gravity of 0.92. Lard has been used in the past as an additive for certain core oils, as a pattern or core box release.

Read More

Tags: Metal Casting, Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Metal Casting Supplies, Foundry Supplies, Green Sand Metal Casting, Green Sand System, Green Sand Metalcasting, Foundry Additives Glossary, Core And Mold Coatings, Green Sand Additive Products, Green Sand Foundry Supplies

"K" - Glossary of Foundry Additives (Green Sand Foundry Supplies) 

Posted by Hill and Griffith Company on Apr 10, 2018 12:18:02 PM

K - Foundry Additives Glossary

KAOLIN (See: BONDING CLAY-CLAYS-FIRECLAY)
Kaolin is commonly called "kaolinite" as well as "China clay" in the ceramic industry. It is a hydrous aluminum silicate. It is a clay that has the composition of (2SiO2 • Al203 • 2H20). It is used through­out the foundry industry from refractories to bonding purposes, as well as in many foundry compounds and commercial foundry mixtures.
The fireclays used in the foundry are commonly called "kaolinites" but the fireclays contain impurities such as feldspar, fine quartz sand, mica and iron oxide. A true kaolinite clay generally has a specific gravity of 2.6 to 2.63 and a Moh's hardness of 2.0 to 2.5. When wetted, kaolin can be made into shapes and will retain these shapes after they are baked or fired. Most commercial "Kaolin" grades of clay are used by the ceramic industry and the whiter burning "Kaolins" are washed and shipped from the South for use as Green Sand Foundry Supplies. 

KAOLINITE (See: CLAYS -KAOLIN)

KELP (See: SODIUM ALGINATE)

KEROSENE (See: CORE OILS-FUEL OIL-OILS-PETROLEUM)
Kerosene is known in some localities as "Coal Oil." It is a light, oily, liquid prepared from the distillation of petroleum oils. It distills­ off after the gasoline. It is a hydrocarbon having the composition (C10H22 to C16H31). Its specific gravity is between 0.75 and 0.78. It burns freely but it is not so volatile as to be explosive, therefore, it is used in the foundry to prevent molding sands from drying-out. It is, and has been, used to replace some percentage of seacoal. Many liquid partings contain kerosene. Core oils contain kerosene, as a low tem­perature and faster baking ingredient, or a similar light oil.

Read More

Tags: Metal Casting, Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Metal Casting Supplies, Foundry Supplies, Green Sand Metal Casting, Green Sand System, Green Sand Metalcasting, Foundry Additives Glossary, Core And Mold Coatings, Green Sand Additive Products, Green Sand Foundry Supplies

Nobake: The Basics (Including Mold Coatings)

Posted by Hill and Griffith Company on Apr 4, 2018 3:37:11 PM

This article focuses on the nobake process and when it would be appropriate for use.

An MCDP Staff Report
Click here to see this story as it appears in the January/February 2018 edition of Metal Casting Design & Purchasing

Dozens of chemically bonded sand molding methods exist, but they can be divided into three main categories: coldbox, heat-activated and nobake. The basic principle is that a binder and catalyst are mixed with the sand to help form the mold into a “brick-like” product when cured. The differences in the process focus on the sand resin binder and catalyst used and how the mold or core is cured.

Coldbox—with this method, sand is coated with one of several binders, such as liquid sodium silicate or phenolic urethane, and catalyzed by a gas (such as carbon dioxide or sulfur dioxide) passing through the sand. This causes the resin binder to harden (cure) and lock the sand grains in place to maintain a solid mold wall.

Heat-Activated/Shell (also called hotbox and warmbox)—heat is used as the curing means in shell molding. Plastic resin-coated sand is compacted around a pattern and allowed to rest until a “shell” forms. The mold then is heated to temperatures higher than 500F (260C) to cure the mold.    

Nobake (also called airset, dry sand and precision sand)—like coldbox, several binders are optional. However, a liquid catalyst is used. The sand is processed in a continuous mixer and then formed around the pattern until it is fully cured.

Mold coatings are applied to more than 75% of noble molds. The coatings help prevent defects and improve surface finish.

Read More

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Metal Casting Supplies, Foundry Supplies, Green Sand Metal Casting, Green Sand Metalcasting, Core And Mold Coatings, mold coatings

"I" - Glossary of Foundry Additives (Green Sand Additive Products)

Posted by Hill and Griffith Company on Mar 27, 2018 2:56:47 PM

I - Foundry Additives Glossary

ILLITE (See: CLAYS-SHALE)

INDUSTRIAL ALCOHOL (See: ETHYL ALCOHOL)

INHIBITORS
Are agents which prevent decomposition, or retard decomposition rates to acceptable levels. They are widely used in magnesium molding sands to diminish oxidation rates which can cause severe fire conditions or explosions. Materials such as boric acid, sulphur or a fluoride are used to prevent the burning of molten magnesium alloys when poured in foundry molds, and are called inhibitors. These inhibitors restrain an undesirable mold-metal chemical reaction generally due to the oxygen reaction in the mold cavity when the hot metal enters the mold.

INORGANIC BINDERS
Binders such as clay, bentonite, cement, sodium silicate, silicon esters, and others are classified as inorganic binders. Some metallic salts are so classified in the foundry. Usually, foundry binders of this type are more refractory than the organic type. They do not decom­pose as fast and have more durability.

Read More

Tags: Metal Casting, Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Metal Casting Supplies, Foundry Supplies, Green Sand Metal Casting, Green Sand System, Green Sand Metalcasting, Foundry Additives Glossary, Core And Mold Coatings, Green Sand Additive Products

"H" - Glossary of Foundry Additives (including Core And Mold Coatings)

Posted by Hill and Griffith Company on Mar 13, 2018 1:25:00 PM

H - Foundry Additives Glossary

HALITE (See: SALT)

HEMATITE (See: FERRIC OXIDE-IRON ORE OXIDE-IRON OXIDE-KLEAN SURF IRON OXIDE)

HEVI-SAND (See: CHROMITE OR CHROMITE-SPINEL)

HEXA (See: NOVALAK)
Is a compound of formaldehyde and ammonia. It is used as a catalyst for the two step novalak resin binder in amounts of 10% to 17 % of the resin weight. Hexa is used with a lubricant (usually cal­cium stearate) in amounts of 4% to 6% of the resin incorporated into its weight. Hexa may also be added separately to the sand mixture during the coating process.

HEXAMETHYLENE-TETRAMINE (See: HEXA-RESINS)
Also known as Metheneamine [C6H12N4] and Hexamine or Hexa. Its molecular weight is 140.2. It is a compound from reactions of formaldehyde and ammonia. It occurs as a crystal or powder. Hexamine sublimes at 263°C. (506°F.) without melting. It is highly soluble in water, while sparingly soluble in alcohol. It is used in the manufacture of resin and also used as a white powder catalyst with phenolic resins for precoating the sand grains. In water, it is used as a quench during the hot sand coating operation for shell molds or cores. 

HEXAMINE (See: CATALYST-HEXA-HEXAMETHYLENE­-TETRAMINE-RESINS)
It is called a powder catalyst in the foundry for use with phenolic resins for precoating sand grains. Several commercial grades are available.

HI-EARLY PORTLAND CEMENT (See: CEMENT)
A special blend of Portland Cement designed to reach ultimate strength in 3 to 7 days, as contrasted to regular Portland Cement that requires 28 days for complete curing. Such a rapid curing cement depends upon its composition, fineness and environment to create this more rapid curing.

HOT BOX BINDER (See: HOT BOX RESIN-RESINS)
Any resin binder designed to cure from the heat generated in a metal core box. They consist of copolymers of (urfuryl alcohol, urea and formaldehyde or phenol, urea and for­maldehyde.

HOT BOX RESIN (See: HOT BOX BINDERS-PHENOLIC MODI­FIED FORMALDEHYDE-FURFURYL ALCOHOL-RESINS-UREA-FORMALDEHYDE-FURFURYL RESIN -UFFA)
Urea-formaldehyde-furfuryl alcohol resin (UFFA) is a liquid type used in the Hot Box process. A phenolic modified formaldehyde furfuryl. alcohol (PFFA) is also a liquid type used for the Hot Box process. There is still a resin manufactured by polymerizing phenol - urea -furfuryl alcohol with formaldehyde which can be used for the Hot Box process. A typical sand binder composition may be 30-80 parts of a urea compound to methaldehyde (HCHO). 5 to 50 parts may be furfuryl alcohol. Sugars, or other such additives may be added for specific reasons. Foundries having a high volume core production are more interested in the Hot Box process than smaller production foundries. There are various combinations of urea, phenol, and fur­furyl alcohol used in certain systems. Acid salts such as ammonium chloride are used as catalysts, or activators.

HOT COATING BINDER (See: RESINS-SHELL MOLDING)
One binder used is a flaked, phenolic, novalac resin. The resin melts and coats the sand surface. Hill and Griffith offers a full line of Core And Mold Coatings - Refractory coatings provide molds and cores with an impervious barrier between the sand surface and the molten metal. This ensures excellent sand peel from casting with improved casting finish.

Read More

Tags: Metal Casting, Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Metal Casting Supplies, Foundry Supplies, Green Sand Metal Casting, Green Sand System, Green Sand Metalcasting, Foundry Additives Glossary, Core And Mold Coatings

Subscribe to the Green Sand Metal Casting News

Recent Metalcasting News

Follow us

Metalcasting News Categories

see all