When Everbuild Building Products required a discharging system that could handle a range of bulk components and additives, it had to be sure the chosen system could cope with difficult powders. Tests proved that Spiroflow equipment was capable of meeting the requirements

Everbuild Building Products is the UK and Ireland’s largest independent manufacturer of building sealants, adhesives, fillers and chemicals for both the professional and DIY trades. To meet growing demand, earlier this year, Everbuild installed a new twin shaft mixer alongside an existing machine. Operations manager, Lisa Broadhead, then set about identifying the means to load bulk materials and minor additives into both mixers, whilst taking the opportunity to improve working conditions by reducing manual handling and dust emissions.

Difficult powder handling

The materials charged into the mixer during the production of Everbuild’s acrylic sealants, fillers and mastics, range from chalk based compounds to glass beads and includes Titanium Dioxide which, as anyone involved in powder handling knows, is notoriously difficult to handle.

Tests carried out on a range of materials, including the Titanium Oxide, at Spiroflow’s Test Centre, convinced Broadhead that Spiroflow equipment could do the job. The tests also confirmed that the performance of the company’s Bulk Bag Discharger and Conveyors was more than adequate to meet the speed at which the mixers needed to be loaded. As Broadhead confirmed: “We can’t have one mixer standing idle whilst we wait for the other to be filled.”

The equipment supplied to Everbuild is a model T3 Bulk Bag Discharger working in conjunction with a Sack Tip Station, Flexible Screw Conveyor, Aero-Mechanical Conveyor and a feed chute system. The bulk materials are delivered to Everbuild in 1000kg bags. The Discharger has a load cell arrangement designed to discharge accurate quantities. The optional pinch bars fitted to the Discharger supplied to Everbuild enable the neck of partially discharged bags to be tied-off and removed once the required amount has been unloaded from them. Discharged materials are conveyed by a short Flexible Screw Conveyor into the collection hopper below the adjacent Sack Tip Station. An agitator is installed above the inlet to the Flexible Screw Conveyor to ensure that difficult materials are prevented from bridging across the inlet. In a similar vein, the Bulk Bag Discharger has paddle massagers ready to encourage the flow of materials from Bulk Bags that have become compacted or which contain otherwise difficult to discharge materials. All Spiroflow Bulk Bag Dischargers have spring-loaded bag support arms that rise as material is discharged to ensure minimum residue.

Dust management

Minor additives, supplied to Everbuild in 25Kg bags, are loaded manually via the Sack Tip Station. This is furnished with a dust hood and plastic strip curtain. The cabinet is connected to Everbuild’s central filter system which ensures dust emitted from bags, as they are opened, is drawn away from the operator.

Material emptied from the 25kg bags and from the Bulk Bag Discharger is conveyed by an Aero-Mechanical Conveyor from the hopper below the Sack Tip Station some 5m vertically so that it can be dropped into either of the two mixers. A gravity diverter valve controls the flow of material into either of two feed tubes below the outlet of the Conveyor. According to Spiroflow, its Aero-Mechanical Conveyors are proven to convey materials such as Titanium Dioxide successfully. The high speed rope and disc assembly carries materials in an airstream which prevents any compacting or sticking during conveying. In addition, they offer ‘total transfer’, an essential attribute when handling pre-weighed batches of materials.

Controls for the system were designed and manufactured in-house by Spiroflow. Such controls can be designed to include touch-screen driven recipe systems and can interface with other PLC control systems in a production environment.

Broadhead concluded: “I am really happy with the Spiroflow equipment. So are the operatives. It handles all of our materials. The controls are great. Now we can weigh batches of material very accurately.”

Visit www.connectingindustry.com/ spiroflow where you will find a technical article describing the benefits of Tubular Chain/Cable Drag Conveyors.