The process of forming raw materials into useful shapes is critical to the smooth functioning of many types of equipment in just about every industry imaginable, including automotive, aerospace and agricultural equipment. Metal shaping is used to create everything from small components to large pieces of equipment. Various technologies can be used to achieve the final effect, from press braking and stamping, to forging and casting.

Casting is the process of creating pieces by pouring liquid metal into a mold. As the metal solidifies, it takes on the shape of the mold. After cooling, the shape is extracted from the mold, and may move on for additional machining. This article looks at the types of sand casting equipment that are employed to achieve the end casting products.

What is Sand Casting?

In sand casting, the mold is formed from a three-dimensional pattern of sand. Cores may be used in the mold to create internal structures or walls. The liquefied metal is poured into the void created by the sand. After the molten material solidifies and cools, the sand mold is removed. A secondary machining process may be required after casting to improve product accuracy.

Sand casting can process a wide range of metals and alloys, including iron, special alloy steel, and others. This is a cost-effective and efficient technology, which is generally flexible with regards to size and the shape of the finished piece.

What Equipment is Used in Sand Casting?

A variety of equipment is employed in the sand casting process, depending on the material and desired product outcome. Processes and equipment include:

• Core Making: A core is a preformed insert which is placed into the outside mold to shape the interior of the casting. It keeps the material from filling the entire mold, to achieve the desired shape. Two processes can be utilized to create the core:
  • Hot-box core making: In this method, heat is used to activate a resin binder within the sand mixture to create the core shape. Machines such as the KC800, KC600, and KC400 can achieve a sand injection pressure of 0.4–0.6 MPa and a maximum sand core weight of 40 kg. Other options include the High Production 40L Hot Box Machine and the PHB-22 Core Machine.
  • Cold-box core making: In this process, the sand is chemically bonded using a catalyst instead of heat. Machines such as the 80L Cold-Box Core Making Machine and 450L Cold-Box Core Making Machine can achieve a maximum sand injection pressure of 0.6 MPa, a sand core weight of 500 kg, and sizes up to 1,600 × 1,600 mm. Another option is the Premium CB Series Cold Box Core Machine, which can produce cores horizontally and vertically. It is available in 10, 30, and 60-liter sizes.
• Molding: Equipment to complete the molding is based on the type of sand process:
  • Resin-sand process: Resin sand is a type of quartz sand that is mixed with a resin material. A chemical reaction created by the resin serves to bind and stiffen the quartz sand, resulting in quite solid, hard and strong molds. This can involve manual molding machines or IMF Automatic Molding Lines for small, medium or large volumes. Equipment might include a sand shakeout system, crushing system, cooling process, regeneration system, sand conditioning system, air delivery system, and particulant removal system.
  • Green sand process: In this casting method, the sand is recyclable. There are no chemical additives in the sand. Only clay and water are added. Applicable equipment includes FBO Automatic Production lines and the Z149 production line. Mold handling equipment might include indexing lines, looping lines and mold car lines. The metal can be poured from a furnace or transported in ladles of various sizes. A shakeout system separates the sand from the castings. A runner system gets metal back to the melt department for reuse, while the actual castings are sent to the finishing process. Finishing might include grinding, trimming, and cutting.
• Pouring: This is the process where the material flows from the melting furnaces, to be delivered to the mold. Metal flows through a carefully controlled gating system.
• Heat Treatment: The casting is put through thermal cycles to alter the grain properties. Relief annealing uses heat to make the metal softer when it hardens too much from casting, rolling, or other processes. The treatment helps soften the metal so it can be machined, but retains the original shape without cracking.

Key Benefits of Sand Casting

The main advantages of the sand casting process are:

• Its ability to manufacture parts in nearly all metal materials, including those with a high melting point.
• Ease of scalability.
• Ability to accommodate complex geometries with thin-wall sections.
• Output capacity for castings of all sizes and weights.
• Low production cost.

 Learn More About Sand Casting Equipment

Impro is a global, integrated manufacturer of high-precision, high-complexity and mission-critical components for diversified markets. We use state-of-the-art process technologies and equipment. If you are interested in finding more information about the sand casting equipment we use, and our process capabilities, please don’t hesitate to contact our team of experts today.