Sand casting is a versatile manufacturing process used to create metal parts by pouring molten metal into a sand mould.

The process begins with the creation of a pattern, representing the final shape and dimensions of the part, which is then placed in a two-part sand mould. Once the mould is prepared, the pattern is removed, leaving behind a precise impression of the desired part. Molten metal is poured into the mould cavity, where it solidifies and takes on the shape of the part. After cooling, the sand mould is broken apart to reveal the metal casting inside.

At Taiyuan Simis Investment Casting Co., Ltd. Our associated sand casting foundries are capable of producing a wide range of metal parts, from small components to large machinery parts, and can be used with both ferrous and non-ferrous metals. Examples of parts produced using this technique include engine blocks, cylinder heads, gears, pulleys, and ornamental metalwork.

Sand casting is one of the oldest and most widely used casting processes, primarily because it offers numerous benefits that make it an attractive choice for a broad range of applications. This method involves compacting sand around a pattern, removing the pattern to leave a cavity, and then pouring molten metal into this cavity. Once the metal solidifies, the sand mold is broken away, revealing the cast object. The advantages of this technique are manifold and contribute significantly to its enduring popularity in the manufacturing sector.

One of the primary benefits of sand casting is its versatility. It can be used to cast almost any alloy, including ferrous and non-ferrous metals, making it extremely flexible for industrial applications. This flexibility extends to the size and weight of the components it can produce, from very small to extremely large parts that might be difficult to cast through other methods.

Another significant advantage is the low cost of the tooling compared to other casting processes. The sand used in the mold is relatively inexpensive and can often be reused, which helps to keep material costs low. Furthermore, the equipment required for sand casting is generally less costly than that required for other casting methods, making it a cost-effective option for both small-scale and large-scale production.

The process also excels in its ability to produce complex shapes with a relatively rough surface finish. While the surface finish may not be as smooth as what can be achieved through die casting or investment casting, sand casting is still capable of creating complex geometries that are challenging to achieve with other techniques. This capability is particularly useful for creating large, intricate parts.

Sand casting is also beneficial for short-run productions or for producing parts that require a heavy section thickness that other casting methods cannot handle without defects. The setup time for creating molds is shorter compared to permanent molds or dies, which means it can be more efficient for producing small batches of parts.

Additionally, the method allows for easy changes in the design of the casting without significant additional cost. Adjustments to the sand mold are generally straightforward and do not require extensive modifications to tooling, which provides manufacturers with greater flexibility in iterating design throughout the production process.

However, sand casting is not without its drawbacks, such as the relatively lower dimensional accuracy and the rougher surface finish compared to other casting methods. But even with these considerations, the benefits often outweigh the disadvantages, particularly when flexibility, cost, and the ability to cast large or complex parts are critical requirements.

1. Pattern Making
The first step is creating a pattern that represents the shape of the desired casting. Patterns are typically made from materials like wood, metal, or plastic and are designed to be slightly oversized to compensate for metal shrinkage during cooling. The pattern includes allowances for machining and draft, facilitating its removal from the mould.

2. Mould Making
The mould is made by packing special moulding sand around the pattern in a moulding box, known as a flask. The moulding sand is mixed with clay and water or other bonding agents to help it retain its shape. The process involves two halves of the mould: the cope (top half) and the drag (bottom half). The pattern is placed in the drag, and sand is packed around it. Then, the cope is placed on top, and sand is packed into it as well. Once the sand has been compacted, the pattern is carefully removed, leaving a cavity that mirrors the shape of the pattern.

3. Core Making
If the casting requires internal cavities or undercuts, cores made of sand are used. These cores are formed in separate core boxes and are positioned in the mould cavity before the molten metal is poured. They remain in place during casting to form the internal features of the part.

4. Melting and Pouring
The metal, which can vary from iron, steel, aluminium, bronze, and more, is melted in a furnace to a specific temperature. Once the metal reaches the desired temperature and is thoroughly molten, it’s carefully poured into the mould cavity. Pouring must be done at a controlled rate to avoid turbulence and splashing, which can create defects in the casting.

5. Cooling
After the molten metal has been poured, it begins to cool and solidify within the mould. The cooling time can vary based on the metal used and the size of the casting. It’s crucial to allow the metal to cool completely to ensure the integrity and strength of the casting.

6. Mould Breakaway
Once the metal has solidified, the sand mould is broken apart to release the casting. This step is irreversible; moulds made from sand are destroyed during the casting removal, meaning a new mould is needed for each casting.

7. Cleaning and Finishing
The casting is then cleaned of any sand, scale, and excess metal from the gates, runners, and risers used to channel the molten metal into the mould. Cleaning can involve processes like shot blasting, grinding, and cutting. Further finishing processes, such as machining, painting, or coating, may be applied to achieve the desired surface finish and dimensional accuracy.

8. Inspection
Finally, the casting undergoes various inspections for quality assurance, including dimensional accuracy, surface finish, and structural integrity. Non-destructive testing methods such as X-ray, ultrasonic, or magnetic particle inspection may be used to detect internal defects.

Taiyuan Simis Investment Casting Co., Ltd boasts extensive capabilities in utilising green sand casting technique, a versatile and widely employed method in the manufacturing industry. With our state-of-the-art facilities and advanced equipment, we specialize in producing high-quality castings using green sand casting, catering to a diverse range of industries and applications.

Our advanced sand casting equipment for green sand casting includes modern molding machines, sand mixers, and molding lines, ensuring precision, efficiency, and consistency throughout the casting process. These cutting-edge tools enable us to create intricate molds with excellent dimensional accuracy and surface finish, meeting the most stringent quality standards.

One of the key advantages of our green sand casting capabilities is our ability to manufacture components of various sizes, complexities, and quantities. Whether it's small, intricate parts or large, heavy-duty components, we have the expertise and resources to handle diverse casting requirements with ease and precision.

Furthermore, our green sand casting process offers exceptional flexibility, allowing for rapid prototyping and efficient production runs. We can quickly adjust mold designs and casting parameters to accommodate design changes or new product iterations, ensuring timely delivery and cost-effective manufacturing solutions for our customers.

At Simis, we prioritise quality and reliability in every aspect of our operations. Our skilled workforce, coupled with stringent quality control measures, ensures that each casting meets the highest standards of excellence and consistency. From material selection to final inspection, we maintain strict quality checks to deliver superior products that exceed customer expectations.

In addition to our technical expertise and advanced equipment, our commitment to innovation and continuous improvement sets us apart in the industry. We invest in research and development initiatives to enhance our processes, optimise efficiencies, and stay at the forefront of technological advancements in green sand casting.

Taiyuan Simis offers comprehensive green sand casting capabilities backed by advanced equipment, skilled craftsmanship, and a commitment to quality and innovation. Whether you require prototypes, small-batch production, or large-scale manufacturing, we have the expertise and resources to deliver superior castings tailored to your specific requirements.