What is a Multihead Weigher?
When packaging granulated (piece-based) products such as nuts, chips, frozen foods, or candies, the biggest challenge is hitting the "correct weight." Traditional volumetric filling systems cause significant weight errors (giveaway) because product shapes and sizes vary (for example, in a mix of walnuts and hazelnuts).
A Multihead Weigher is a high-tech weighing system typically consisting of 10, 14, or 20 small buckets, where each bucket measures the weight of its contents in microseconds thanks to a Load Cell.
How Does the System Work Perfectly? (Combination Logic)
Let's assume our goal is to fill a 200-gram bag of chips. The operating principle of the machine is as follows:
- The product is poured into the center dispenser and distributed to the feed buckets via vibration.
- Product falls from the feed buckets into the weighing buckets. In a 14-head machine, approximately 20-30 grams of product accumulate in each bucket.
- The Microprocessor (CPU) Kicks In: The computer calculates the different weights within the 14 buckets. Its goal is to find the "best bucket combination" that totals exactly 200 grams (or 201 grams).
- For example, if the sum of buckets 2, 5, 8, and 11 equals 200.3 grams, the machine opens only these four buckets simultaneously, and the product drops into the packaging machine (VFFS).
This process occurs 120 times per minute (or up to 240 in dual systems) with zero error!
Applications of Multihead Weighers
- Snacks: Chips, crackers, biscuits
- Nuts and Dried Fruits: Mixed nuts, sunflower seeds
- Frozen Foods (IQF): French fries, peas, seafood
- Fresh Produce: Cut salad leaves, cherry tomatoes
- Metal and Plastic Parts: Screws, nails, lego pieces
Frequently Asked Questions (FAQ)
Q: Why should I prefer 14 or 20 buckets over 10? A: As the number of buckets increases, the number of possible combinations for the computer increases. This allows the machine to operate faster and reach the target weight (e.g., 200g) with a much lower tolerance (e.g., ±0.1g). For high-capacity lines, 14 buckets are standard.
Q: Does the weigher freeze when handling frozen (IQF) products? A: No. For frozen foods, special "Dimpled" stainless steel buckets are used to prevent moisture from sticking to the surface. Additionally, electronic components are washable according to IP65/IP67 standards and protected by anti-condensation heated cabinets.
At Dr Mach, we offer Multihead Weighing systems featuring Japanese Load-Cell technology, managed via touchscreens, and working in 100% synchronization with our VFFS (Vertical Form Fill Seal) machines. We maximize your profitability by saving your company from overfilling (Giveaway).
Additional info: The importance of industrial systems cannot be overstated in modern lines.