Auxiliary equipment supplier Conair (Cranberry Township, PA) has announced upgrades to its TrueBlend gravimetric blenders that include the introduction of next-generation SmartBlend SB-3 control and mechanical design changes that eliminate material loss, optimize critical blends and simplify clean-out and maintenance.
The SmartBlend SB-3 control from Conair is designed to facilitate operation and improve precision in blender control for injection molding and extrusion. Accessed through an enlarged and more vivid, 256-color, 7-inch touchscreen display, the SB-3 control simplifies blending control with more intuitive graphics, easier programming and more comprehensive monitoring and control features. It also sustains a best-in-industry dosing accuracy of 0.025% for the total batch dispensed, thanks to the “feed forward” dosing algorithm, said Conair.
Fewer steps are required to create and store material blending recipes, and the control’s expanded memory can now store 3,000 recipes and 4,000 resin names. An improved home screen display provides realistic graphics, showing current material levels and target-vs-actual dosing for each attached TrueBlend feed hopper. It also displays information about the mixing-chamber material level and blender blade rotation.
Automatic data collection has been simplified, enabling users to produce companywide reports using Microsoft SQL Server over standard Ethernet networks. A virtual network client offers user access to the control touchscreen from in-plant computers and Internet-connected devices or by Conair personnel for remote troubleshooting.
The control display supports 16 languages, which can be easily changed at any time, even from minute-to-minute, as different employees interact with the system.
The control also includes a self-loading option and can be used to set parameters and control up to 12 loaders and one pump for conveying to or from the blender.
TrueBlend blenders equipped with the Trueblend EXT option combine gravimetric batch blending with extrusion yield control. Components are dispensed, weighed and mixed according to recipe percentages, dropped into the TrueWeigh hopper on demand and fed continuously to the extruder. The SB-3 control reads the rate of weight loss in the hopper to control extruder output to within 0.5%. With the addition of an optional line-speed encoder at the extruder haul-off, extrusion weight can be precisely controlled in relation to length, adjusting the extruder screw and haul-off speeds to optimize dimensional stability.
The latest TrueBlend blenders also feature a series of mechanical improvements, including redesigned standard mixing chambers with:
- Taller, steeper sides plus new, all-around chassis seals to eliminate pellet leakage;
- improved mixing impellers with blades designed to ensure uniform mixing;
- removable impeller assemblies for foolproof cleaning and preventive maintenance; and
- improved, bottom-mounted flow control valves in manual or automatic configurations.
Available as an option on the larger TrueBlend TB-250 through TB-900 model blenders is a tapered mixing chamber suited for mixing and dispensing critical blends that include material percentages less than 1%. Tapered chambers include all the features of standard chambers, but have both tapered sides and ends that form a conical shape. This shape eliminates corners and dead spots, making it almost impossible for any ingredients to get hung up and escape the mixing action inside the chamber. The result is more-consistent product quality and reduced scrap and waste, even for difficult-to-control materials.