For millennia, sand casting has offered an indispensable way to create large volumes of similar products around the world. Manufacturing and engineering companies value sand casting for its ability to produce highly complex casts that work with many different metal alloys for large and small projects; more than 60% of all metal castings rely on sand casting process technologies.
Sand casting employs nonreusable sand molds to create metal castings. Sand casting produces parts ranging from very small (less than a pound) to very large and complex parts. Because sand casting can create products across a wide range of shapes, sizes, and materials, sand-casted products are:
? Easily recyclable
? Inexpensive
? Able to withstand high temperatures
? Suitable for low- and high-volume production
? Able to work with almost any metal alloy
Selecting the Proper Sand
Different types of sand offer different casting possibilities. The ideal sand should hold up under mechanical stress but also be permeable enough to allow gasses and steam to escape during sand casting.
The chosen sand must also incorporate ideal flowability levels for your project, and its moisture content should be chosen with care—low moisture content breaks the mold apart, whereas too much could lead to trapped steam bubbles in the mold.
Sand grain shape and size also affect mold quality, as well as the sand’s ability to withstand extreme heat (also known as refractory strength), its ability to collapse under force, and its reuse capabilities (after sand conditioning).
Sand Casting Process
The sand casting process consists of six basic steps to create a metal cast:
1. Workers place the pattern into the sand mold
2. They then place the pattern and sand in a gating system
3. The gating system creates a cavity in the sand, after which the pattern is removed
4. Molten metal is poured into the cavity
5. The metal cools and sets
6. Workers break away the sand mold and remove the casting
Methods of Sand Casting
Sand casting typically employs one of three methods:
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Green sand — Sand casters often use green sand to create a mold because of its solid performance and low costs. Typical green sand mixtures contain 7% clay, 4% water, and 89% sand, thus providing the proper levels of strength, permeability, reusability, and collapsibility desired for sand casting projects.
? Cold setting processes — Cold setting uses nontraditional binders, resulting in a sand-casting process that does not rely on heat to perform well. Cold setting processes chemically bond at room temperature when mixed with sand. While relatively new, this process has grown in popularity because of its exceptional dimensional accuracy.
? Shell molding — Shell molding uses a mixture of dry, fine silica sand to create casts with smooth finishes. Workers mix this sand with 3–8% thermosetting resin and minimal clay content and then drop it onto a heated pattern plate, creating a thick (6 mm) shell that they then heat for several minutes to cure the shell.
ABOUT KEVA
Keva Casting is a professional casting company that focuses on Construction, Machinery, Automobile, Hardware, Pipeline and many other industries.
We provide top quality products with the best service based on our complete production chain including our own mold design, advanced production techniques, and full management of the supply chain. Keva Casting has two factories located in Zhucheng, China's Shandong province.
We use "shell molding", which is a new technique that has been developed in recent years.This new technique has simplified production procedures and reduced air pollution compared with traditional sand casting and investment casting. Shell making and core making are faster to ensure production in enormous quantities. The dimensions and surface finishing are satisfactory for all kinds of industrial requirements. Besides supplying our own formwork & scaffolding systems, our casting products also supply OEM services in various industries.