How do multihead weighers work?
Multihead weighers have been an essential part of factory production lines for decades, with their ability to weigh a wide range of different product types. Whether you are food manufacturers that are new to weighing within your sector or are wanting to invest in the best solution for your operational needs, it’s important to understand how a multihead weigher works and the different characteristics it has that can make it compatible with your products.
In this guide, we’ll be looking at how a multihead weigher machine works technically, why they’re used in industry, and what you need to think about when finding the right one to fit with your requirements.
How does a multihead weigher work?
A multihead weigher divides a large amount of product into smaller volumes, based on pre-defined limits. It has multiple features, including weigh buckets, an infeed funnel, feed buckets, feeder pans, top cone, collating chute, and collating funnel.
The beginning of the multihead weighing process involves materials being fed into the infeed funnel, usually via a conveyor belt or bucket elevator. Then through vibration or rotation, the tope cone and feed pans will move the product into the weigh buckets. Each bucket has a load cell to consistently monitor how much product is in it. Weighers are designed to make sure there is always an even distribution of product.
The software will decide on the best combination of weights to achieve the right total amount, depending on the desired weight and other programmed specifications. It will then spread out the product in accordance with the target parameters, with hoppers being used to refill a bucket once it becomes empty, forming a continuous cycle.
Why should you use a multihead weigher?
The main benefits of a multihead weigher in food processing are its speed and accuracy. Using load cells in the system means you can process bulk products whilst still adhering to your weight targets with accurate precision. Also, the heads of the weigher are regularly refilling, so you can tap into faster speeds than you would with a manual weigher and make the process automated.
Thanks to the various features that have the potential to be implemented in a multihead weigher machine, getting a customised solution that meets your product type is easily achievable. This means it can be utilised across different sectors and solve a number of production issues.
Another advantage is the majority of multihead weighers will work in conjunction with other pieces of equipment like checkweighers and product inspection systems. The conveyor system will transport product from one area to another without lots of manual intervention being needed. This results in better quality and accuracy throughout your production line and creates an output that meets specifications and expectations every time.
What to consider when choosing a multihead weigher
There are several factors to consider when choosing a multihead weigher to add to your operations. Each system includes unique features that make them better suited to specific types of products or objectives. The most significant of these are listed below.
The number of heads
Normally, a multihead weigher has multiple weigh buckets (or heads), ranging anywhere between 10 and 32+. The more heads your weigher has, the quicker the system determines the right combination to hit the total weight target. In addition, the accuracy of the weighed portions in one go is increased too. If you need to process large amounts of bulk product fast, having more heads will boost speed without compromising accuracy.
Depending on the consistency of the product you are processing, you might need extra features to allow it to be efficiently weighed. Textured surfaces could be required in weigh buckets to make it easier for sticky items (like confectionary or fruit) to move smoothly through the production line. Smoother surfaces work best for dry products.
As well as the type of surface, the amplitude and length of vibration you’re using to divide the product will need to be altered to fit with the materials being used. For example, sticky products will need more vibration to push the product to travel.
Given that dry products are often more free flowing, only minimal vibration is needed to move them. This also allows for the gentle handling of delicate materials. Think about the products you will be using in your weigher, and you can make sure you have the correct features to maximise compatibility and results.
Bucket shape and size
If you’re processing larger products, you will need a weigher that has bigger buckets so you can weigh more at any one time. This is also relevant if you need to filler bigger containers. Along with the size of your buckets, you should also think about the shape, which will mostly be based on your requirements.
Polygon-shaped buckets or rounded corners will be less awkward to clean, meaning they’re useful for sticky substances that demand cleaning between batches. Additionally, this will play a part in helping you to achieve high hygiene targets in your plant. For drier, smaller items, standard buckets should be suitable.
Maximum weight range
The maximum capacity of a multihead weigher is an important point of comparison when finding the right one for you. Some will be specifically designed to hold bigger volumes, and things like the size and number of heads can have an impact on this.
If you use larger produce or need to process substantial amounts in a single use, you will need a higher weight range. To determine how quickly you can process your output to meet targets, consider the maximum volume that can be weighed, the weight per load cell, and the available range in a single discharge.
Speed is another feature to look out for when deciding on the right weigher for you. The quicker a weigher can process product, the quicker your turnaround times will be reduced. This will be especially beneficial when working with large volumes. The speed of a machine can be determined by its weight per minute. The higher the weight per minute, the faster the machine will run.
It’s important to remember that when working with delicate products, you might need to compromise on speed to allow more careful handling. The main thing here is understanding your materials and making sure any weigher you implement will fully cater to their individual needs.
Depending on how big your plant is and how much space you have available in your production line, you might need a weigher that will take up as little room as possible. This will make sure you get the solution you need whilst adhering to your existing environment. If you are wanting a smaller multihead, you should choose one that offers great results, in speed, accuracy, and compatibility. So, you can maximise performance despite limitations with space.
On top of what we’ve already mentioned above, there are a number of optional extras that can be added to a multihead weigher. Not all of them will be necessary for your operations, but depending on the goals of your production line, they could give you invaluable support. Some examples of these extras include:
- Weighers with less waste to help reduce costs and achieve sustainability goals
- Usability features like touch screens and pre-set programming
- Data collection, so you’re able to analyse performance and deal with issues in real-time
- Automatic feeding control
Certain features might come as standard in systems, but the most important thing is making sure you choose a machine that works with your products and helps to achieve your goals.
If you need help finding the right multihead weigher for your production lines, our expert food engineering consultants can help. They’re on hand to make your processes as efficient as possible, so you can save money and run your operations as smoothly and stress-free as possible. Contact FESS Group today to discuss your needs.