Vertical Green Sand MoldingEach of our 33 automated, vertically parted, high-pressure green sand molding machines is custom-designed, engineered, built and maintained in-house. These hybrid machines, named “Waupaca-Matics” earned a patent in 2010. Through the implementation of double-indexing and exclusive dual-pouring technology, our automating iron pouring machines feature unmatched speed and reliability—approximately 30 percent more productive than competitors’ molding lines.
It’s not really the color green, but that’s the term used for sand that has not been used for a mold. Why sand? It’s all in the chemistry.
Iron melts at about 2,800 degrees Fahrenheit. Sand won’t melt until the temp is roughly 3,000 degrees, making it a perfect holder for molten iron. But at Waupaca Foundry, sand alone won’t stand up to the pressure and heat of making quality castings. Our green sand is made of:
- Silica sand to act as an insulator
- Clay or Bentonite used to bind the sand grains together and form a mold that won’t break down
- Filler material such as cereal or wood flour that will fill the spaces between sand grains
- Seacoal, which is a fine dust, adds carbon between sand grains to prevent oxidization by reducing atmosphere in the mold
Green sand molding provides a variety of advantages for our customers:
- Lowers cost compared to other casting processes
- Provides a variety of molding processes to suit specific volume and quality requirements
- Ability to produce both prototype and production volumes with the same process
Waupaca Foundry specializes in vertical molding due to the speed, quality, versatility and safety of the process. With vertical molding, one side of the mold cake has the pattern for the front of the casting, the other side the pattern for the back of the casting. When two mold cakes come together on the molding line, they form the entire casting.
The process requires extremely high pressure and speed—while at the same time guaranteeing exacting precision.
One-half of the casting pattern and the core (if required) are set into the molding machine; the pattern for the other half is on what is called the swing plate. When the two are closed, green sand is poured into place and squeezed at very high pressure to form the mold. Very quickly, the swing arm lifts the swing plate. This choreographed process happens over and over, forming one mold after the other to complete the order.
Vertical Molding Vs. Horizontal Molding
Vertical molding, as compared to horizontal molding, is the most cost-efficient casting method for medium- to high-volume orders. Because flasks are not required in vertical molding, there is improved mold mass alignment and a streamlined process—eliminating the need for flask movement and storage.