- Multihead weigher
A multihead weigher is a fast, accurate and reliable weighing machine, used in packing both food and non-food products.
The multihead weigher was first invented and brought to market by Ishida, back in the early 1970s as a solution to quickly distributing vegetables of varying weight to make up packs of near-equal weight. In 1962, Multipond as the first european manufacturer starts the production of automatic weighers. Today this kind of machine, thank to its high speed and accuracy, has widely spread in the packaging industry and is produced worldwide by a number of manufactures. Some manufacturers offer complete packaging lines, integrating the multihead weigher with other packaging machinery (often including Vertical FFS, due to their vertical workflow).
How multihead weighing works
A ‘typical target’ weight per pack might be 100 grams of a product. The product is fed to the top of the multihead weigher where it is dispersed to the pool hoppers. Each pool hopper drops the product into a weigh hopper beneath it as soon as the weigh hopper becomes empty.
The weigher’s computer determines the weight of product in each individual weigh hopper and identifies which combination contains the weight closest to the target weight of 100g. The multihead weigher opens all the hoppers of this combination and the product falls, via a discharge chute, into a bagmaker or, alternatively, into a distribution system which places the product, for example, into trays.
Dispersion is normally by gravity, vibration or centrifugal force, while feeding can be driven by vibration, gravity, belts, or screw systems.
An extra layer of hoppers (‘booster hoppers’) can be added to store product which has been weighed in the weigh hoppers but not used in a weighment, thus increasing the number of suitable combinations available to the computer and so increasing speed and accuracy.
How multihead weighing can help a business
Multihead weighing can help in the following ways:
The range of bags which can be filled using multihead weighers is immense. At one end of the scale are large catering packs of many kilogrammes. At the other are small bags of crisps which can be handled at high speed and efficiency.
Products containing up to eight components can be mixed on a multihead weigher, very accurately at high speeds. The weigher is divided into sections, each with its own infeed. For example, a breakfast cereal containing hazelnuts and dried fruit plus two relatively cheap ingredients, could be weighed on a multihead with say eight heads devoted to each of the more expensive components and four heads to each of the other two. This would ensure high weighing speed while ensuring that overfilling of the expensive ingredients was negligible.
Placing into trays
A well-engineered distribution system enables you to combine the speed and accuracy of multihead weighing with precise, splash-free delivery of product into trays.
Multihead weighers were used initially for weighing certain vegetables. Their use expanded exponentially in the 1970s and 1980s when they were applied to the rapid weighing of snacks and confectionery into bags. What cherry tomatoes and crisps had in common was that they flowed easily through the machine and into the pack, with no more encouragement than gravity and a moderate level of vibration of the feeders. Since then, the accuracy and relative speed have been extended to many products which would in the early days of the technology have been seen as difficult to handle.
Fresh meat and fish, whether in a sauce or not, poultry and cheese (including grated cheese) can be moved along by using belts or screw feeders rather than vibration.
Granules and powders
While free-flowing, fine-grained powders can be weighed more cheaply by other means (such as cut-gate or linear weighers, or volumetric feeders), granules such as coffee granules and products such as loose tea can be weighed on today’s multiheads.
Weighers with more shallow angles of descent and various cushioned inserts have made it possible to pack delicate and brittle items such as hand-made chocolates and gourmet biscuits.
Using mix-weighing combined with a distribution system tailored to deliver separate components into a tray, a ready meal can be assembled with just the right quantities of, say, rice, meat and vegetables in the appropriate compartments.
- ^ http://www.multipond.com/en/about-us/history-of-the-scale.html History of the Scale | MULTIPOND Multihead Weighers
- Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, ISBN 978-0-470-08704-6
Wikimedia Foundation. 2010.
Look at other dictionaries:
Check weigher — Example checkweigher. Product passes on the conveyor belt where it is weighed A checkweigher is an automatic machine for checking the weight of packaged commodities. It is normally found at the offgoing end of a production process and is used to… … Wikipedia
Мультиголовочный дозатор — компании Yamato Мультиголовочный дозатор (англ. Multihead weigher) это высокоскор … Википедия
Corrugated fiberboard — is a paper based material consisting of a fluted corrugated sheet and one or two flat linerboards. It is widely used in the manufacture of corrugated boxes and shipping containers. The corrugated medium and linerboard are made of containerboard,… … Wikipedia
Bottle — This article is about bottles in general. For baby bottles, see Baby bottle. Composite body, painted, and glazed bottle. Dated 16th century. From Iran. New York Metropolitan Museum of Art … Wikipedia
Screw cap — A screw cap or closure is a common type of closure for bottles, jars, and tubes. Common screw closures: Plastic bottle with plastic screw cap, Dispensing closure for salad dressing (with inner seal), Break away closure for syrup, Dispensing pump… … Wikipedia
Paperboard — Corrugated fiberboard made from paperboard Paperboard is a thick paper based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker (usually over 0.25 mm/0.010 in or 10 points)… … Wikipedia
Shelf life — This pack of diced pork says display until 7 May and use by 8 May … Wikipedia
Barrel — For other uses, see Barrel (disambiguation). For the use of oak aging barrels in wine, see Oak (wine). Traditional oak barrels in Chile … Wikipedia
Drum (container) — A standard, 55 US gallon / 44 Imperial gallon drum. A drum is a cylindrical container used for shipping bulk cargo. Drums can be made of steel, dense paperboard (commonly called a fiber drum), or plastics, and are generally used for the… … Wikipedia
Carton — Examples of several types of cartons for different products Carton is the name of certain types of containers typically made from paperboard which is also sometimes known as cardboard. Many types of cartons are used in packaging. Sometimes a… … Wikipedia