Multihead weighers
Weigh accurately and quickly with the multihead weigher. Use the carousel with different weighing bins and determine the exact weight. Vibrations transport the product to the storage bins. The storage bins are filled accurately to the desired weight.
What is an MHW machine?
An MHW machine (in full a Multi Head Weigher) is a computer-controlled combination weigher, mostly used in the food industry. The multi head weigher is an ideal machine for filling a very constant weight of bulk goods at high speeds. Think of weighing products such as washing powder, seeds, cookies and chips.What is a multihead weighing machine used for?
Multihead weighing machines are used to fill bulk goods. Due to the availability of different volumes of weighing buckets, a suitable solution can be offered for every volume, weight and product. Products for which a multihead weighing machine is used:- Candy, chips, popcorn;
- Nuts, grains and seeds;
- Vegetables such as cherry tomatoes, carrots, lettuce, radishes, onions;
- Coffee, tea;
- Sugar;
- Rice;
- Washing powders;
- Etc.
In addition, there are special versions of multi-head weighing machines for certain products or environmental situations:
- Seeds. For light/expensive products such as seeds, a weigher is used with 0.1 liter containers equipped with very high quality load cells. This is especially for products with weights from 0.5 grams with an accuracy down to 0.01 grams.
- Bean sprouts and noodle products;
- Fine/heavy granules
- Fragile products such as candy and cookies;
- Cold and wet areas. If the weighing machine is in a cold and/or wet room, the machine must be equipped with a heater and dehumidifier.
Benefits of a multihead weigher
There are some great advantages to working with a multihead weigher:- The multihead can be assembled based on desired speed, the weight to be dispensed and the product to be filled. This allows almost any product to be weighed;
- High reliability;
- High weighing speed;
- High accuracy;
- Low maintenance costs.
Different types of multihead weighing machine
Multi-head weighing machines, or MHW machines, can be divided into two groups. The difference of these two groups is in the method of drive.- Pneumatic actuator
MHW pneumatic-powered machines are generally the somewhat older machines. These machines operate on air pressure and electricity. The buckets are opened and closed pneumatically, with electric vibrating magnets providing vibration. - Servo controlled actuator
The MHW machines with servo-controlled drive are the machines of the new generation. This machine operates electronically and on electricity. The buckets are opened and closed electronically by actuator units. Again, electric vibrating magnets provide the vibration.
Operation of an MHW machine
The multihead weigher consists of 1 central cone, vibrating chutes, storage bins and weighing buckets.- The central cone, located on top of the multihead, is supplied with product via a feed conveyor.
- The amount of product on the cone is detected by sensors. Depending on the amount of product, the feed will automatically stop or start.
- Through the vibrating or rotary motion, the cone will distribute the product evenly across the vibrating chutes.
- The vibrating chutes move the product to the storage bins.
- The control system then ensures that the ideal amount of product reaches the hopper.
- The storage bin dumps the portion into the lower weighing bin if it is empty or requires more product.
- The load cells then determine the weight of the weigh bin. A weigh bin holds about a quarter of the set weight, and then the weigher itself calculates the best combination to come within the limits of the target weight.
- The selected bins are opened and these meet through the central outlet funnel.
- When they have come together, they are deposited in the packaging machine.
The multi-head machine is often used in combination with a vertical packaging machine. They can be supplied as a stand-alone solution or as a complete solution including packaging machine.