How does metal foundry work?

Metal foundry working process

The metal foundry is the facility that works on creating the casting product by pouring the molten metal into the mold. It manufactures casting parts and servers almost industry.

If you spend time to notice you may happen to aware that so many of the items surrounding us are from a foundry somewhere. Have you wondered how they manufacture excellent aluminum lamppost standing charmingly on the roadside or by what manner super detail cast iron machine parts are created?

From marine, street furniture, transportation to agriculture machine, construction industry we all see the product of metal foundry. Its application presents popularly surrounds our daily life but most of us are next to know nothing about the metal foundry industry.

Today’s article, VIC brings to our beloved readers a summary of how the metal foundry work? Hopefully, you will find interesting facts through our post.

What is the metal foundry?

What is Metal Foundry
Metal foundry working

Well, a metal foundry, simply explained is a facility that works on melting metal material, pouring into the mold cavity, and creating the casting in different shapes and designs as required.

Foundry today serves in a range of industries. Its work closely corresponds to tremendous fields such as transportation, lighting, urban furniture, machine, marine, construction that related to numerous of the essential consumer products we depend on.

The casting industry is very wide, hence foundry is also various dividing on the focused working field, metal, etc. There are foundries that mainly work on cast iron or aluminum for example; a range of facilities specialize in machine parts; street furniture, home cookware, OEM, so on.

Which metal is used in the foundry?

Cast iron and aluminum are the two most popular materials often applied in the casting process at the foundry. Other counterparts such as bronze, steel, brass, zinc are also used regularly.

Cast iron in metal foundry
Cast iron in metal foundry

Each metal maintains not similar casting properties and the manufacturer often has to consider very carefully which material is suited to their need.

Aluminum is preferentially treated as a good cast-ability material. Its low melting point (approximately 660°C) allows saving time in comparison with other metals (bronze at 950°C, cast iron at 1100-1900°C of cast iron for example).

Furthermore, aluminum’s versatility also allows casting different shapes and styles therefore it is applied widely in many industries from outdoor street furniture to machine parts. The aluminum casting collected is high appreciated by its smooth, polished, and bright surface finish.

At the same time, cast iron is often seen in manufacturing lighting post base, agricultural counterweight, urn planter, manhole cover, bollard, etc. due to its high-density weight and long-lasting to external expose. Cast iron lighting pole can stand at least 50 years and face up with extreme weather but still performs good look, whereas, the ductile iron manhole cover is able to withstand a dozen tons of loading.

Oppositely, steel material is easy to get rust so it is limited to use for outdoor application or requires further expensive treatments if in need.

What is the casting process in the foundry?

By definition, you may think it is just a piece of cake but once you step into a certain foundry nearby you will know how skillful and ingenious this casting work is. Casting any product in a foundry all involves many steps and each step requires carefully and exactly working spirit.

Summarized speaking, the general metal casting process involves pattern making, molding, pouring, cooling, shaking-out, sand-blasting, fettling, and inspection. The further machining step applied CNC precise machine for milling, turning, lathe etc. is upon request and depends on foundry’s capacity.

In the first step, pattern making is very important in the casting process. The pattern is a replica of the project to be cast. It is commonly made from wooden or metal (aluminum is widely used). These patterns can be reused to create as much as mold cavity as needed.

Aluminum Lamppost manufacturer
Lamppost aluminum Pattern

The preferable mold material in the foundry is green sand which features wet-content and naturally high bonding ability. Basically, the worker presses the pattern into the sand flask and the mold cavity is created after the pattern withdrawing. This step can do either by automatic line or manual.

The cavity features the shapes as the pattern does and includes a few holes and lines for the pouring step. By pouring the molten metal into these cavities, the casting is formed.  Nowadays, melting metal mostly is processed by an electric furnace, whereas coal furnace can find in a few small foundries.

After pouring, it requires a few hours to allow the casting to be cool down. Roughcasting is collected by the shaking-out process and goes through cleaning remain sand.

Lamppost foundry process
Foundry process after pouring molten metal

Depending on requirements, the fettling can be simple, super complicated, and hard work. It could be applied treatments for surface defects such as pinhole, crack, rough skin, etc. The inspection will be carefully processed before shipping to the customer.

Which equipment included in the foundry?

Large-sized metal foundries are mechanized heavily. They equip all the machinery and equipment for almost processes such as pattern making, molding, pouring, cleaning, machining, etc. That modern metal foundry includes high advance machining machines, high capacity furnace, automatic line, forklift, crane, conveyor, assistant robot, etc.

Small to medium foundry works based on either semi-automatic or manual process, but the furnace and molding lines are essential.

The furnace used to melt the metal is various depending on capacity and fuel. The traditional furnace includes the coal furnace and the electric furnace. More advanced type names electric arc furnace (EAF), induction furnace, cupolas, and reverberatory. The furnace can range in size, from tabletop type to equipment that weighs several tons. The bigger furnace is, the higher the melting capacity it performs.

Furnace used in metal foundry

Molding line, another very significant to any metal foundry. Each molding technique requires a distinct manufacturing line equipped with supporting equipment. There is its own line for the green sand casting process, similar to furan resin sand casting, lost foam casting.

How to ensure safeness in the metal foundry?

Obviously, metalworking is such a heavy industry and maintains many unexpected hazards. The violent and unpredictable nature of the chemical reaction is always concerned. Hence, it is vitally important to take the safeness of workers into the account.

Ensuring labor safety in the casting process to minimize injuries and accidents to workers, to avoid loss and damage to people and property for foundry. Prior to run the operation, any foundries have to guarantee safety protocols regulated by the authority.

The foundry design and equipment used are required to ensure safety with the worker and nearby areas.

My Dong traditional casting village in Vietnam
Safety in metal foundry

Unsurprisingly, the foundry temperature is very hot. It daily works with melting metal that could heat up to 2000oC. In this working condition, the roof has to be high to allow air circulation. It better should be constructed of non-reactive, flame-retardant materials. It is also recommended to invest mechanical supports such as forklifts, mechanical ladles, or conveyors to minimize human exposure and reduce the hazard counter.

The worker in the foundry has to been equipped with protective clothing fully such as a hat, eyes cover, glove, and so on depending on each working position. To prevent unexpected accidents, fire and explosion tools have to be always ready.

Also regularly check the machine, automatic line, furnace, etc. to find out failure, electricity leakage, or incorrect operation if there are any is needed. The worker also is asked to compliance the standards and procedures for using the machine safely.

Additionally, the foundry also has to ensure other external conditions such as providing enough lighting, ventilator, or control noise, etc.

Which industry does the foundry serve?

Huge demand of metal foundry
Metal foundry serves many fields

Currently, the market demand for casting products is huge. From agricultural machinery, construction machinery, industrial equipment, transportation, marine, water supply and drainage, urban decoration, electricity, metallurgy, mechanics, and so on, all use casting parts from the metal foundry.

It is very common to catch outdoor lampposts in front of your yard or along the street to your office. This lighting fixture is mainly manufactured by casting technique and constructed of metal material (cast iron and aluminum are mostly preferable). Similarly to street furniture such as manhole covers, bench ends, litter bin, fence, railing, or kitchen equipment as gas stove accessories, cookware.

Machinery for agricultural, industrial, defense, aviation, marine…also no longer to skip from casting details.

VIC is proud to inherit the traditional casting profession from our great grandfather and deliveries the best casting product to the world market. We are the OEM and ODM foundry specialize in casting customized products upon different requirements. Kindly suggested checking our website to get to know more about us. Also, contact us if you are looking for a reliable and loyal metal foundry.

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