At Omega Sinto, we understand the intricate and essential processes that result in successful metal and
sand casting. One of these critical processes is core making. This technique is used to create hollow sections and complex internal structures in metal parts, crucial for industries ranging from automotive to aerospace.
Understanding Foundry Core Making
Foundry core making is integral to the casting process, allowing for the creation of intricate internal features or hollow sections in metal parts. Here’s a simplified overview:
- Casting Basics: Metal casting involves pouring molten metal into a mould to form specific shapes. However, creating parts with hollow sections or intricate internal details requires a different approach – core making.
- Cores: Cores are special sand structures placed inside the mould to shape these complex features. They occupy the space that molten metal would otherwise fill.
The Sand Core Making Process
Sand core making is a process within foundry core making, utilising sand to create the cores needed for casting, not metal. Here’s a detailed look at the steps involved:
1. Preparing the Sand Mixture
- High-Quality Silica Sand: The foundation of sand core making is high-quality silica sand, chosen for its uniform, fine grains.
- Binders: Binders, such as organic resins or inorganic compounds like sodium silicate, are mixed with the sand to help it hold its shape.
- Additives: Additional materials, including catalysts and hardening agents, are incorporated to effect curing and hardeining of the samnd mixture.
2. Core Formation
- Core Box: The sand mixture is packed into a core box, a mould that shapes the core. Core boxes can be made from wood, plastic, or metal.
- Compaction: The sand is compacted inside the core box, either manually or by ‘blowing’ the sand using a core shooter ensuring it fills all details and forms a solid structure.
3, Hardening the Core
- Chemical Hardening: For chemical binders, a catalyst is used to harden the core. The cold box process, for instance, involves passing a gas (like amine vapor) through the core to cure the binder.
- Heating: Heat-activated binders require the core to be baked, as seen in the hot box process, where the core is oven-baked to achieve hardness.
4. Core Removal
Once hardened, the core is carefully extracted from the core box, maintaining its shape and integrity.
5. Placing the Core in the Mould
The finished core is positioned within the mould cavity. It defines the internal spaces or complex features of the final cast part.
6. Casting the Metal
Molten metal is poured into the mould, flowing around the core and solidifying into the desired shape.
7. Core Removal After Casting
After the metal cools and solidifies, the mould is opened, and the cast part is removed. The sand core is then broken apart and extracted, revealing the hollow sections or intricate features created by the core.
Why Choose Omega Sinto?
At Omega Sinto, we specialise in providing advanced machinery and solutions for sand core making -ensuring precision, efficiency, and high-quality results. Our expertise and innovative technologies help industries achieve their casting goals with unparalleled accuracy.