A combination weigher, also known as a multihead weigher, is a type of weighing machine used primarily in the packaging industry to accurately measure and dispense products into packages. It’s widely used for bulk and precise weighing of products like snacks, candies, grains, powders, and other items. Here’s a detailed look at how it works and its key features:

1. Working Principle

• Multiple Heads: The machine features multiple weighing heads (often between 10 and 14, but can vary). Each head has its own set of load cells that weigh the product.
• Product Distribution: The product is fed into the machine’s hopper, which distributes it into each of the weighing heads. Each head independently weighs its portion of the product.
• Combination Selection: The machine’s control system calculates the optimal combination of weights from the different heads to achieve the target weight for each package. It uses complex algorithms to determine the best combination of head weights to meet the desired weight with minimal product waste.
• Dispensing: Once the optimal combination is selected, the machine directs the product from the selected heads into the final packaging. This is often done using a discharge chute or vibratory system.

2. Key Features

• High Accuracy: Combination weighers are known for their precision. By combining weights from multiple heads, they can achieve very accurate target weights, minimizing over- or under-filling.
• Speed: These machines are capable of high-speed operation, making them suitable for high-volume production environments.
• Flexibility: They can handle a wide variety of products, from free-flowing items like nuts and candies to non-free-flowing powders.
• Adjustability: The machine can be adjusted to weigh different product sizes and types by changing the settings or components.

3. Components

• Hoppers: The machine includes several hoppers, each of which feeds product into the weighing heads.
• Weighing Heads: These are the critical components where the product is weighed. Each head has its own load cell and weighing mechanism.
• Control System: The control system manages the weighing process, calculates combinations, and controls the dispensing of the product. It often includes a touchscreen interface for user control.
• Discharge Mechanism: This is where the weighed product is transferred into the packaging. It can be a chute, conveyor, or other mechanism designed to handle the product gently.

4. Advantages

• Precision and Accuracy: By using multiple weigh heads and sophisticated algorithms, combination weighers provide precise weight measurements, which is crucial for meeting regulatory and quality standards.
• Reduced Product Waste: The optimized combination of weights helps minimize product waste and ensures packages are filled to the desired weight.
• Increased Efficiency: High-speed operation and precise weighing contribute to efficient packaging processes, boosting overall production rates.
• Versatility: Capable of handling a variety of products, including irregularly shaped or difficult-to-handle items.

5. Applications

• Food Industry: Commonly used for packaging snacks, candies, nuts, and other food products.
• Pharmaceuticals: Used for packaging tablets, capsules, and powders.
• Non-Food Products: Also used in industries like chemicals and agriculture for packaging products like seeds and granular materials.

In summary, a combination weigher is a sophisticated piece of equipment designed for accurate, high-speed weighing and packaging of a variety of products. Its ability to efficiently manage and dispense product with minimal waste makes it a valuable tool in many production environments.