Narrow belt sorters (NBS) are finding their way into more and more direct to consumer applications, but how do the new eSort shipping sorters compare? eSort is an off-the-shelf modular design capable of virtually endless configurations for sorting parcels, heavy cases and polybags. The eSort equipped with the G4 transfer appears most similar to a typical NBS belt sorter with multiple belts in the direction of flow and pop up rollers between. In reality, appearances are deceiving as the new patented eSort offers many benefits over the ubiquitous NBS.
The narrow belt sorter or strip belt sorter is typically configured as a bidirectional divert with pop up rollers providing motion 90 degrees to the main direction of travel. The belt length along with the number of sort points and spacing is usually engineered and manufactured for each particular application and assembled on site. Manufacturers claim length and sort points can be changed requiring tear down and parts to be replaced and or added.
Speed of NBS is good falling into the medium rate sorter category with effective rates for diverse packaging typically falling between 50 and 70 sorts per minute. Actual rate is a function of package type, package length, package width and package weight.
Sorter rates and accuracy are a function of physics. Like most sorter designs, the sort must occur within a window of opportunity when the package is in the zone of transfer to effectively divert from the main flow stream into the receiving container, chute or conveyor. Time to move the package from the main flow to the divert point is a function of the size of the package and how quickly it can be decelerated, accelerated in a direction 90 degrees to flow.
With changes brought about by eCommerce, Omni-Channel and new forms of Direct to Consumer packaging, present day packages on shipping sorters can be very diverse. NBS systems run at constant speeds and therefore rates can be limited to handling worst case packages. The alternative is to sacrifice accuracy and increase miss sorts to avoid slowing the system for worst case. Handling worst case packages manually is often practiced but becoming less effective as package variation is growing.
In contrast eSort sorting accuracy is always maintained by varying rate on-the-fly slowing briefly only for the most difficult packages in the split seconds when sorting issues are detected.
NBS and eSort uses friction to control motion of packages for sortation. Recent increase in the use of polybag packaging has evolved extreme diversity in items packaged challenging all friction based sorters. eSort patented and patent pending designs are the most effective in the industry for handling polybags further insuring accurate sorts and dependable rates.
eSort can successfully sort polybag packages weighing less than one ounce packed with non-flat items. Packages falling into this category are deemed “unconveyable” by many NBS manufactures.
Added capability does not equate to higher cost. eSort are modular units that fully enable mass production and economies of scale. Manufacturing cost are reduced with programming and engineering cost eliminated.
NBS continuous belts over many sort locations could be considered an advantage over eSort modular design with transitions between belts zones. eSort engineered seamless transitions between modules giving continuous flow across zones or modules while enabling the flexibly of full modularity that can be added to, changed out or modified in minutes.
Narrow belt sorter systems are typically optimized for handling cases or parcels. eSort is designed to handle both effectively AND simultaneously. eSort handles 4” x 4” polybags to 20” x 28” polybags to 50 lb cases 30 inches long (longer sizes available).
Narrow belt sorter will optimize throughput with proper induction equipment. An optimal gap will be maintained for each item inducted tracked via encoder. The benefit is superior rate but at the expense of sortation accuracy.
In contrast eSort uses a closed loop approach combining pulse rate tracking for each individual zone updated by sensors that see leading and trailing edge of each and every package. This way each package is completely tracked as it enters and leaves each sort location. Items to be sorted can be tracked leaving the sorter. Packages can be removed from the eSort system without affecting sorting of other packages in the system.
NBS strip belts require much power to move multiple heavy packages at 300ft per minute over long spans. Larger three phase motors are used requiring 230 VAC or 440 VAC three phase wiring, conduit and motor control center (MCC). eSort uses low voltage 24 VDC motors and motor driven rollers to achieve the same 300ft per minute but without conduit or MCCs. All eSort wiring is through the covered wire ways incorporated into every module and conveyor section.
Strip Belt Sorters use air to power the roller actuation for transferring packages. Each sort position has pneumatic cylinders, valves, plumbing and control wiring. Air systems also require connections with provisions for drying and lubricating the air. eSort shipping sorters use no air and have only two simple plug in connections 24VDC and Ethernet.
eSort eliminates the requirement for 3 phase wiring, motor controls, air plumbing, and air controls making for very fast installations and modifications. eSort modules can literally roll into position, plug in and run.
eSort uses less power, no air, has better sorting accuracy with more difficult to handle packages while narrow belt sorters provide a little higher rate. The eSort also installs faster with very fast deliveries being for the most part, off-the-shelf. eSort also has a stacking option to provide higher rates than NBS for about the same cost. Narrow belt sorters have been around for a while, but as of now, they will take back seat to the new eSort modular solution.