- Virgin pellets and powdered material present different challenges
- Handling of PVC and other plastics powders down to 1 micron
- Powder loaders available in integral-motor and central-vacuum configurations
Conair Group has launched two new powder-conveying units for handling PVC and other powders down to 1 micron in size, and dusty regrind as well. Available in a PR (powder receiver) model, for use in central vacuum systems, and a self-contained PM model with integral vacuum motor, they both offer very good conveying and filtration rates.
Integral-motor version for conveying material from bins directly to the molding machine
The integral-motor version is very suitable for conveying material from gaylords or bins directly to a molding machine or extruder. The PM motor loaders come in three sizes, with conventional DC brush or brushless motors. They can transport up to 1000 lb/hr (454 kg/hr) over distances up to 50 ft (15.25 m).
The PR powder receivers come in five different sizes ranging in volume from 0.14 to 3.0 cu ft (4 to 85 l) and accommodate line sizes up 4 inch (101 mm) OD.
Virgin pellets and powdered material present different challenges
“Conventional loaders, which rely on screens to separate material from conveying air, work very well with virgin pellets,” explains Doug Brewster, Conair Conveying Product Manager, “but when powdered material is being transported, screens can become laden with accumulated dust, decreasing the performance of the conveying system. The same thing can happen with dusty regrind and, as plastics processors attempt to use more reclaimed material, either for environmental or economic reasons, the issue becomes more acute. The new powder receivers and motor loaders were developed for these applications.”
The working principle
Both units operate the same way. Air and material are drawn into the receiver by the central vacuum pump or the integral motor. The powder remains in bottom of the receiver while conveying air and any suspended particles are drawn upward past as many as three pleated polyester cartridge filters that separate air from particulate. At the end of every load cycle (when an integrated fill sensor registers that the receiver is full), a blowback system directs high-power blasts of compressed air down through the filters, blowing off accumulated material, dust and fines. In this way, each new loading cycle starts with a clean filter. A 3:1 air-to-cloth ratio ensures maximum filtration efficiency.
The largest PR receiver has 168 sq ft (15.5 sq m) of filter area, and the PM units have up to 56 sq ft (5.2 sq m), and yet they are compact enough to be used even in low-headroom areas.
The control options
The PM motor loader can be controlled and monitored by the Conair control unit ELC-M (Easy Loader Control) or the ControlMate wich offers further functions. It comes complete with a 10-ft. (3-m) power/communications cable so operators can safely adjust settings from ground level (no need to climb on the machine to reach the receiver-mounted ELC). PR model receivers can also be controlled by the ELC, or a Universal Terminal Box (UTB) that connects to any Conair central material-handling controls systems.