Powder fillers come in three main types: Net Weight Fillers, Auger Fillers and Cup Fillers. All three have particular characteristics with advantages and disadvantages for various products including powders, granules, and even for 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 equipment that is best suited to your application we have a
Powder Fillers - Powder Filling Equipment
Powder fillers come in three main types: Net Weight Fillers, Auger Fillers and Cup Fillers. All three have particular characteristics with advantages and disadvantages for various products including powders, granules, and even for 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 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 Fillers
Net weight filling machines 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 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 filler is on standby to dump its contents via a trap door, down a funnel and into the container or bag.
Advantages of Net Weight Fillers:
- Very Accurate Fill Weights
- Gentle Product Handling Capability - Little Compression
- Many combinations of vibratory trays and dribble feed gates are available
- Handles Irregular Shapes, Sizes and Weights
- Can be ganged together for more accurate weights on irregular product sizes and weights to compare between any 2 heads for better overage control.
- Can be adapted for counting consitent products such as hardware, tablets, and other piece count applications.
Disadvantages of Net Weight Fillers:
- Relatively Slow Compared to augers and cup fillers although that gap has been narrowed with the introduction of the IQ series
- Running very fine powders such as talcs, flour, and powdered milk can get a little messy.
Auger Filling Machines
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 filling 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 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.
Advantages of Auger Fillers
- Fast, oftentimes usually at least 2-3 times faster than a single head net weight filler
- Relatively dust free, even on very fine powders that tend to get airborne easily. This is because auger fillers can be made so they are virtually closed off from the atmosphere, even during the dispense cycle.
- Can run free flowing powders as well as many less than free flowing products, so long as the product is consistent.
- Easy to integrate into a wide variety of packaging applications such as form and fill machines or applications for cans, bottles or boxes.
- Large range of filling capacity without need for change parts
- Very cost effective solution
Disadvantages of Auger Fillers
- Not reliably accurate for products with irregular shapes or densities
- Can damage products that cannot withstand compression
- Not particularly soft handling of product.
Cup Fillers (Also known as Pocket Fillers)
Cup fillers are also volumetric fillers 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.
Advantages of Cup Fillers - Pocket Fillers
- Can run virtually any free flowing product (not recommended for fine powders)
- Fast - Capable of speeds into the hundreds of fills per minute
- Simple design - very little downtime for mechanical problems
- Relatively inexpensive to other filling systems.
Disadvantage of Cup Fillers
- Very limited fill range without change parts (less than 2:1)
- Cannot run products that are not very free flowing
- Does not run irregular shapes or densities