The Evolution of the Combination Scale: High-Speed Precision Weighing for Modern Packaging Solutions

The combination scale, also known as a multihead weigher, has revolutionized the way materials are weighed and packaged. This advanced automatic weighing solution is now essential in many industries—from food to pharmaceuticals—due to its speed, precision, and efficiency.

Why Was the Combination Scale Invented?

In the late 1970s, a Japanese agricultural organization raised a challenge: how to accurately weigh green peppers for retail packaging. The goal was to pack exactly 120g per bag. However, due to the variation in the size and weight of green peppers, traditional manual weighing methods were inefficient. Workers would need to combine multiple peppers to get close to the target weight, often removing and adding peppers repeatedly to hit 120g exactly. This time-consuming process highlighted the need for a more intelligent and efficient weighing method.

The solution came with the invention of the combination scale—a smart system that automatically selects the best combination of items from multiple hoppers to match the target weight with high precision. This innovation marked the beginning of a new era in automatic weighing technology.

What Is a Combination Scale?

A combination scale, or multihead weigher, consists of multiple independent weighing hoppers (typically 8 to 32 units). A built-in computer calculates all possible weight combinations from the available hoppers and selects the one that most closely matches the preset target weight. For example, a 10-head weigher has 1,023 possible combinations, allowing the system to choose the most accurate and efficient grouping automatically.

Key Technical Features and Advantages

1. High Accuracy Weighing

• The system confirms weight accuracy through multiple verification steps.

• After the initial combination is selected, the computer rechecks the weight to ensure consistency. If discrepancies are found, an alternative combination is chosen.

• To maintain accuracy, the system also compensates for dust or residual material that may accumulate on the hoppers.

• An additional vibration load cell is included to cancel out the effect of environmental vibrations caused by nearby machinery.

2. High-Speed Performance

• Advanced data processing and signal interpretation via computer chips enable rapid weighing operations.

• Stepper motors control the opening and closing of hoppers with high precision, even adjusting discharge based on material weight and flow behavior.

Why the Market is Booming

China's domestic combination scale industry has rapidly developed. Large-scale manufacturers have achieved world-class quality, while smaller, less-equipped companies often face challenges in product reliability and after-sales support. Selecting an unreliable supplier can lead to frequent breakdowns, poor performance, and long downtimes due to inadequate programming or subpar vibration suppression technologies.

Kenwei: A Trusted Leader in Multihead Weigher Technology

Guangdong Kenwei Intellectualized Machinery Co., Ltd. is a pioneer and industry leader in China’s multihead weigher sector. Kenwei has received the Guangdong Province Science and Technology Project Combination Award, a testament to its innovation and quality. By 2017, the company had exported to 87 countries and served over 800 customers globally, selling more than 5,000 sets of weighing and packaging equipment.

In 2018, Kenwei adopted a semi-automated production model with a refined parts specialization strategy, boosting production capacity to over 7,000 units annually. This transformation has positioned Kenwei as a benchmark for manufacturing excellence in the packaging machinery industry.

With its professional focus, reliable performance, and international recognition, Kenwei has become the go-to brand for fully automated combination scale systems, helping replace outdated manual packaging practices across food, metal, plastic, and other industries.