Powder fillers come in three main types: Net Weight Fillers, Auger Fillers and Cup Fillers. This powder-filling and dispensing equipment has particular characteristics with advantages and disadvantages for various products including powders, granules, and parts counting. The fact that we call these machines powder fillers is something generic to the packaging industry and not a limitation to the many applications that can be run. When deciding on the type of powder-filling and dispensing equipment that is best suited to your application, we have a number of factors to consider including: speed requirements, compressibility of the product, flow characteristics, stickiness, cost of the product, irregularity of the size and shape of the product, and the range of filling needs from smallest to largest. While there is a large area of overlap between these three types of powder fillers, there are also certain products that can only be run on one type of machine. Please read on and we will refine these differences for you.
Net weight powder fillers are distinct from auger fillers and cup fillers (both are volumetric filling machines) in that it is the only type of machine that actually weighs the product before dispensing into your container. This fact alone may help mitigate the need for a checkweigher down the line. A net-weight powder filler moves product from a hopper via vibratory trays or belts depending on the type of product. The product streams directly into a bucket mounted onto a load cell. As the weight in the bucket nears the target weight the feed system slows to a "dribble" feed rate. Oftentimes a second tray or belt is added that is dedicated for the dribble feed when great accuracy is required. When the final weight is reached the dribble feed is also turned off. Now the powder-filling and dispensing equipment is on standby to dump its contents via a trap door, down a funnel and into the container or bag.
Auger fillers are the machine of choice for all fine powders or any product that has consistent size particulates such as talcum powders, flour, cake mixes and more. Auger powder-filling and dispensing equipment consists of a main hopper, stirring bar to keep the auger fed (even on powders that are not free flowing), and an auger that fits in a closeley fit cylinder. So long as the auger flights can be consistently fed, these machines can be extremely accurate. Since auger powder fillers are volumetric they do not actually weigh the product, except in cases where mated directly to a scale, but depend on accurate revolution counts of the auger. In some applications auger fillers can be used as depositors for fillings such as for eggrolls or other light extrudable types of products.
Cup fillers are also volumetric powder-filling and dispensing equipment that work in a different way than an auger filler. If you imagine a measuring cup where you level off the cup with a straight blade, you have an understanding of how a cup filler works. Cup fillers work well with any free flowing product such as nuts, granules, and course powders and can be found in reciprocating and rotary styles. Cup fillers are also the machine of choice for canning operations of peas, corn, beans and many other similar products. A hopper sits above the top of the cup and gravity feeds product in. Wipers remove excess product so that the cup is leveled. When the cup reaches the discharge chute it falls out of the bottom of the cup and into the container or bag. Cup fillers can be made for very high production rates compared to auger and net weight fillers.
Call Busch Machinery today and let our sales engineers help find the right powder-filling and dispensing equipment for your application.