Applications for linear weigher

Nowadays linear weighers are often used for grains/granulates and larger weights, which is easy to explain. The introduction of the multihead weigher enabled a faster and more accurate weighing of many easy products in smaller portions than the linear weighers used so far. Before the multihead weigher was introduced in 1986, linear weighers from different brands were available such as Atoma, Hastamat, SPK, Ward Bekker, Easyweigh, Euroweigh, etc.

Disadvantages of a linear weigher (also called line weigher) are both accuracy (whatever is in the weighing bucket will end up in the packaging; all additional features will reduce the speed) and speed (the machine can weigh accurately, but carefully = slowly). The multihead weigher offered speed and accuracy, which solved all problems - i.e. for easy products and small weights. Therefore, the first multihead customers were manufacturers of sweets, chocolates, crisps and nuts. Soon after, multihead weighers got popular and cheaper. At the time, a 3-head linear weigher used for weighing, for example, 200 grams of peanuts with 50 weighings per minute cost as much as a 10-head multihead weigher, so most customers decided to buy a multihead weigher. Therefore, the current linear weighers are often only available in a 1 or 2-head version for larger weights (and therefore lower speeds, with high accuracy).

The 1-head “long” linear weighers are often used for manual filling and the 2 and 3-head weighers are often placed above a deep-drawing machine where, contrary to multihead weighers, no expensive transfer system is required between linear weigher and deep-drawing machine.

Linear weighers are also used for fragile products such as cookies and hard sweets, since the product fall is limited in a linear weigher. In multihead weighers a product will fall at least 4 times harder, compared to linear weighers.

For weighing granulates, a simple “short” (1-feeder) linear weigher in a 1, 2 or 3-head version offers sufficient output and it is also easier (cheaper!) to make it leak proof than for instance a 10-head multihead weigher with the same output. A short Newweigh 3-head linear weigher can obtain a speed of 40/minute when weighing 5,000 grams of fertilizer in a perfect compact and dustproof covering, while most multihead weighers cannot achieve this speed when weighing an amount of 5 kg, are not dustproof and are difficult to clean. Since the control systems of linear weighers have been improved, the give-away of these products is often as small as in a multihead weigher.

All in all, there are a great deal of applications where linear weighers are unsurpassable!