Trickle feed avoids over-filling
15 Jan 2000
Hodgson Chemicals needed a weighing system capable of handling polymer resin powder directly from the process finishing dryer and elevating it from a receiver hopper to the weigh filler.
Flexicon has been involved with Hodgson Chemicals since 1996, when the first series of flexible spiral conveyors were installed to transfer product between the stages of drying. So, Flexicon were invited to engineer the new weighing system.
The enclosed design of the polyethylene conveyor tube has helped to ensure dust emmission is within the Environmental Protection Act guidelines governing the handling of powders.
Polymer resin powder used in the manufacture of textile coatings and adhesives have a critical bead size, therefore it was vital to the integrity of the product that no damage occurred during conveyance.
The new system also had to provide a higher level of weighing accuracy than with manually controlled filling.
Pre-determined weights are selected by the operator, depending on the type of packaging requirement per batch.
The weigh/filling frame is mounted on four Toledo load cells, which can work in combination with a single PLC control package. All weigh data is then communicated to a printer or central control system.
The signal from the load cell controls the conveyor to reduce speed at a pre-determined weight, then the valve is activated to reduce flow product gradually, before closing at the end of each weigh cycle. This final, accurate trickle feed technique avoids over-filling and precise measurement of the product.
Even with bag change overs, the operator needs no assistance. Resetting the height when switching from one bag to another is a simple matter of turning a handle.
