DigiFill range of auger fillers use well proven clutch / brake drive systems, and come with a choice of either a compact digital counter control, or a fully featured and enhanced microprocessor control system.
Pillar mount models for mounting above other automatic packaging equipment, such as form, fill & seal machines are finished to a very high standard in polished stainless steel. Floorstanding models are offered in either painted or stainless steel finish. All contact parts are produced in 316 stainless.
DigiFill auger fillers are high quality machines for applications where the ultimate speed and sophistication is not required, whilst still maintaining high reliability and precision filling.
DigiFill pillar mounted auger fillers are readily integrated with other forms of automatic packaging equipment, such as container handling systems, sachet machines, and form fill & seal machines.
All pillar machines have included height adjustment facility offering 150mm of adjustment. This can be of particular value in installations requiring different discharge datum’s, or where the head has to be raised clear & rotated in order to extract the tooling when used in conjunction with form fill & seal machines.
All interface signals for normal operation are included with the basic digital control, check-weigher feed back is also included on machines fitted with enhanced microprocessor control option.
- Simple to set-up
- Control box sealedto IP66
- Ease of maintenance
- *1024 Product code memory
- *Printer option for machine set-up
- *PC connection with flash memory upgrade facility
- Ease of clean down
- Will readily interface to other equipment
- Exceptional quality
- *Tooling list display on product change
- *Check-Weigher feed back as standard
- *Weight control link option
- Fully compatible with EasiFill & ServoFill tooling
- High reliability
- Enhanced Control Options
- *Full control of product level probe
- *Comprehensive diagnostic reporting
- *Statistical reporting on weight controlled machines
DigiFill floor standing auger fillers may be used either in stand-alone hand presentation applications, or integrated with other container handling equipment to form a semi-automatic / fully automatic packaging system.
Machines configurations available include:
- Weigh platforms for manual presentation of rigid containers
- Weigh platforms for manual presentation of bags / sacks
- Adjustable height manual presentation container support tables
- Remote mounted weigh platform within automatic system
As with all G Webb Automation auger fillers, interface signals allowing connection to other packaging equipment is included as standard. In the case of DigiFill machines fitted with enhanced microprocessor controls & weigh platform, a printer output is included for providing full, comprehensive statistical reporting of filling data. Facility is also included on all machines with enhanced control to print hard copy reports of product & machine parameters.
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GWA “DigiFill” range of auger fillers come standard with a simple to use digital control pod, incorporating LED display for pre-set & actual dose length. This is the control of choice for most DigiFill installations, featuring ease of use and is an extremely cost effective solution.
An optional ‘State of the Art’ touch screen is also available for installations where the enhanced features & functionality such as check-weigher feed-back are required. These screens provide graphic representation of machine status and provide full statistics & diagnostic monitoring. These screens are also multi-lingual, allowing instant switching between languages. Extensive recipe handling is included, with a capacity for 1024 of recipes stored on a compact flash card.
All panels include serial port for printer option and an Ethernet port for network connection. Software is available for monitoring operator screens in real time via network connection (VNC Viewer), and optional PC based statistics software such as GWA “FillerNet” or a bespoke software solution can be provided.
The lower parallel flights of the auger within the funnel are produced to a constant pitch so that, when filled, each pitch has a precise and consistent volume. The auger drive rotates the auger at a preset speed to produce a continuous flow of product. The actual filling head comprises of the primary elements illustrated below. By moving the mouse pointer over the names below the illustration, elements within the illustration will change colour to identify each particular part.
1. Hopper containing the product to be dosed
2. Auger rotating vertically through the hopper and funnel to discharge product.
3. Funnel from hopper through which the lower section of the auger doses.
4. Scraper blade to assist powder feed by bringing product into the flights of the auger.
5. Auger drive mechanism.
The scraper blade rotates in the opposite direction to the auger and with the exception of the DigiFill range, is independently driven. Its purpose is to prevent any build-up that generally will form when running non-free flowing powders. The scraper blade extends right down to the neck of the funnel, ensuring that the auger flights are fully filled with product, and preventing cavitation (cavities that can other wise form within the product resulting in poor filling accuracy).
Non-free flowing powders
The auger illustrated is fitted with ‘over-flight’, this can be either a separate detachable component to provide ultimate flexibility, or can be part of the actual auger for dedicated applications.
An over-flight assists the flow of non free flowing products by providing compression into the auger flights, down to the neck of the funnel where the scraper blade feeds the flights of the parallel section of the auger.
With intermediate products, an auger with parallel flights would be normally be selected and no over-flight fitted, as compression could well cause unacceptable damage to the product. These types of product often have the tendency to dribble from the auger once it has stopped and therefore require back pressure to be applied by use of a lip or grid attachment to the bottom of the funnel.
Free flowing powders
Free-flowing powders require a positive means of cut-off to be fitted to the end of the funnel. This can be in the form of a scissor cut-off unit where two horizontal scissor blades close at the end of the funnel immediately a discharge has completed, or a single / double flap attachment (also fitted to outlet of funnel). Either method ensures a clean cut-off at the end of each discharge and prevents product dribble / seepage when the machine is not it a filling cycle. In general, the flap type cut-off is used when the filling machine is mounted above a bag making machine (form, fill & seal machine), allowing the auger and funnel to be extended down through the bag forming tube, and the scissor cut-off is used in applications where the auger filler is dosing into ready made bags / containers.
Spinner plate & Cowl
An alternative tooling option that usually would be fitted for handling particle type products is the Spinner plate & Cowl illustrated below.
Attached to the end of the auger is a spinner plate (disc), this is a saucer shaped disc designed to retain the product flow. All powders have an angle of repose, the angle at which a collapsing heap of powder will come to rest rather than continue to spread outwards. The angle for small smooth beads would be much greater than, for example, vermicelli. The distance between the bottom of the funnel and the spinner plate (the gap needed to allow unrestricted product flow) is defined by the product dose rate. The spinner plate is sized to prevent the powder dribbling over the rim of the disc once the auger has stopped, taking into account this gap and the powder’s angle of repose. As the spinner plate throws the powder outwards, a simple collection cowl funnels it to a size suitable for the aperture of the container to be filled. The use of a spinner plate results in a perfectly clean fill without the requirement for any additional cut-off devices.
The size of the auger and funnel is determined by a number of factors: fill weight, discharge rate, accuracy and container neck opening. The smaller the auger/funnel, the slower the discharge rate but greater the accuracy. Conversely, a larger auger delivers more quickly but less accurately. Where a wide range of fill weights are required, more than one auger/funnel set may be supplied to achieve the required combination of speed and accuracy.
Clutch/brake drives offer a combination of high accuracy and torque at a budget price. The down side is that clutch/brake drives require periodic maintenance and have less features relating to epitomized control that is on offer from direct drive alternatives. Direct drive closed loop a.c. motor and servo systems offer the best in terms of technical performance and flexibility, with completely maintenance free heads and a high level of control in terms of acceleration / deceleration and auger speed.
In volumetric filling mode, the auger will rotate a consistent amount each time a discharge takes place and providing that the product being dispensed has a stable bulk density, i.e. a measured volume of product always weighs the same, then accuracy will also remain consistent from discharge to discharge. Volumetric filling machines are often linked up to automatic check-weighers placed down stream of the filler, these can provide a feedback signal that increases / decreases the discharge should the dose weights start deviating due to density fluctuation.
The discharge amount is determined by the number of auger revolutions for a given set of tooling, and can be set / displayed to 1000th of a revolution of EasiFill machines. On ServoFill machines this increases to a control accuracy to 4096th of a revolution. The auger drive motor is fitted with a precision encoder to measure rotation.
Setting up product discharge parameters is a breeze with DigiFill/E, EasiFill and ServoFill machines where an operator simply selects the setup screen, enters the number discharge turns and conducts a sample discharge. The sample discharge is then weighed with the result along with the required weight entered into the system by the operator. The control then calculates and stores the required auger rotation to achieve the required weight.
In applications requiring high speed filling into rigid containers intermittent dosing can be too slow, therefore all G Webb Automation auger fillers can also be operated in a continuos dosing mode. In this instance the auger filling machine would generally be fitted above a rotary container handling machine (RP125/RP760/RP1400 Rotoplant). Here containers are transferred via scroll into an infeed star-wheel and subsequently into a continuously rotating turret. The turret is effectively a carousel with a number of pockets, each of which are fitted with an overflow chute with a precision machined splitter ring above. The turret speed is set to the required line speed and the auger rotation speed adjusted to achieve the correct amount of product per container, the auger will continue to discharge all of the time that the turret is rotating with containers present. The precision splitter ring divides the actual dose into equal portions as the turret rotates, and a vibratory track fitted beneath the containers applies vibration through the container and overflow chute above to settle the product within the container prior to it exiting the turret. A Check-weigher can be integrated down stream to provide density correction, and in this case increase / decrease the auger speed. Filling speed in excess of 300 containers per minute can be achieved on continuos dosing systems.
Weigh Filling (Gravimetric)
Weigh filling machines operate by dynamically weighing the product as it enters the bag / container during actual discharge. These machines are suitable for discharge weights ranging from a few grams up to as much as 50Kg and are used for the following reasons;
1. Product has inconsistent density and therefore is not suitable for volumetric filling.
2. Requirement for filling machine to provide printed reports / statistics on fill performance.
3. Expensive product where product giveaway must be minimized.
Manual Presentation Systems.
The basic weight controlled auger filler usually is fitted with either a bag support or container platform, that is fitted with a precision loadcell. In the case of systems with a bag support platform, an automatic bag gripper can be included to secure the bag in place during the filling cycle.
On commencing a fill, the system will tare off the bag / container weight and then discharge until the required weight has been achieved. The auger runs for the first part of the fill cycle at a fast speed changing to a slower speed for the final part of the fill. Both fast and slow auger speeds are user configurable as is the speed change set-point.
‘Product-in-flight’, the amount of product between the end of the auger when stopping and the product already in the bag / container is automatically measured at the end of the filling cycle, and is then taken into account by the system adjusting it’s cut-off point to ensure that the correct amount of product is dispensed each time.
Semiautomatic / Fully automatic systems.
A weighcell can be placed within conveying systems directly under the filling head operating in exactly the same way as when filling manually. It is possible to tare weigh the empty containers prior to dosing to achieve true nett weight filling. For an increase in speed, moving the weighcell downstream and filling volumetrically with feedback can be considered, with upstream tare weigh cell as required. This system configuration is subject to product density fluctuations not being erratic.
Bulk Fill & Top-up Systems
Another alternative is the ‘Bulk fill & Top-up’ system configuration with two filling heads. In this instance the container is transferred beneath the first auger filler that discharges volumetrically approximately 80% of the required weight, optional container vibration can be used at this station to assist settling the product if required, the container is then transferred beneath the second filler where it is lifted clear of the conveyor belt by a grid mounted on a weighcell. The second filler then discharges the final 20% fill via a smaller auger under direct control of the weighcell, thus maintaining overall accuracy regardless of density variations. The system is optimized so that both filling operations take the same overall time, thus providing maximum line speed.
Program Forward Systems
For even greater speed and accuracy, the weighcell can be moved between the two filling heads turning it into a bulk fill, program forward & top-up system. This offers the speed of large auger bulk fill together with the accuracy of program forward and volumetrically filling the top-up with a smaller auger. In this case the weighcell between the filling heads feeds back to the bulk filling head to maintain the proportion of the bulk fill as well as feeding forward the individual discharges required once the container arrives at the top-up filler. A second weighcell is required downstream of the top-up head which provides density check & correction feedback to the top-up filler, can display and produce hard copy reports of filling statistics, and also police the line by rejecting any out of tolerance weights. A tare weigh station can be added prior to the bulk filling head if required when filling containers with an irregular tare weight, a good example of this would be glass jars which tend to vary in weight significantly.
A broad range of tooling is available for GWA auger fillers to enable clean and accurate dosing of a vast array of different products, from free flowing to difficult fatty products / products with varying particle sizes and densities. Auger filler tooling includes;
- Standard short length auger s & funnels
- Long length augers & funnels specifically for form, fill & seal applications
- Detachable over-flights for fitting to augers
- Detachable Grids & Lips attachments for fitting to bottoms of funnels
- Detachable Compression nozzles for fitting to bottom of funnels
- Single / double flap cut-off arrangements for bottom of funnels
- Detachable Scissor cut-off units for fitting to bottom of funnels
- Detachable Bomb-door cut-off units for fitting to bottom of funnels
- Stirrers / scrapers for product agitation within auger filler hoppers
Whatever your product/s & filling requirements, you can rest assured that GWA will be able to provide you with the optimum tooling to get the very best results possible from any auger filler supplied by ourselves.
We have a dedicated test facility with a huge array of tooling with which we will conduct comprehensive filling trials within your presence, and supply detailed reports of exactly what accuracies and discharge times can be achieved.
Frequently Asked Questions
My product is particularly free flowing; will I have a problem with product dribble between filling cycles?
I already have an existing G Webb Automation auger filler but it is either an older model than those currently listed, or a different model to the filler I would like to purchase. Can any of my existing tooling be used on the filler I now wish to purchase?
The DigiFill is suitable for all dosing applications where speed is less than eighty discharges per minute. However if your application is for a gravimetric filler, then we would recommend selecting the EasiFill model due to the much enhanced feature set for only a small cost increase. The appeal for the DigiFill is simplicity of operation & maintenance, and for applications on a tight budget.
The EasiFill is suitable for all filling applications where requirements are up to one hundred and twenty discharges per minute, and in the case of gravimetric filling will provide far greater flexibility over the DigiFill. The advantages of the EasiFill over the DigiFill are direct variable speed auger drive with independent stirrer drive, and total lack of maintenance.
The ServoFill is suitable for all filling operations, be it low speed manual presentation or high speed volumetric dosing at speeds in excess of two hundred fills per minute. The ServoFill range of fillers includes all of the benefits offered by EasiFill machines, but provides a far greater performance for higher speed applications and absolute accuracy.