A global producer of specialty resins and chemical additives for use in consumer and industrial applications was facing a significant increase in demand for several of its dry resin products. The material characteristics of the resins included high combustibility, hygroscopicity and agglomeration. Material fill rate requirements were set to increase to 20,000 pounds/hour, far exceeding the capacity of the producer’s existing packaging line. In addition, new market requirements called for bulk bag packaging rather than the producer’s previous 50-pound sack packaging.
|An automated double-bag fill-and-stack sequence was programmed into the HMI menu.|
Such significant change to the producer’s material processing and packaging operation led to a thorough reassessment of the operation, including upstream material infeed through end-of-line package handling. Three critical factors were identified. Proper implementation of these factors would ensure the new processing and packaging system delivered total line optimization. The critical factors were:
- Equipment integration. The producer’s upstream material processing operation was fully capable of supplying the packaging operation at the required capacity. The new bulk bag filling system must be able to seamlessly integrate with the legacy upstream process equipment without an interruption in material flow.
- Process automation. The new bulk bag filling system’s automation architecture must include control of all process-associated legacy equipment automation, including upstream bulk material storage and conveyance systems, and downstream finished-package conveyance and accumulation. The integrated automation of the bulk bag filling system must sense upstream material supply; control variable-frequency drives for consistent material feed; control automatic pallet dispensing; automatic, operator-specific fillhead positioning; material recipe management; NTEP-certified weighing; high-speed finished package handling; and system-wide data reporting from the control layer.
- Equipment construction. The process requirements of high-volume material flow rates, extended duty cycles, reduced labor utilization and the handling of combustible materials demand application-specific equipment. The equipment manufacturer must exhibit expertise and experience in dry bulk chemical processing and packaging equipment design, systems engineering and performance-proven construction.
Single-Source Engineering, Manufacturing & Support
Accountable from concept to completion, National Bulk Equipment (NBE) used 3D modeling technology to render dynamic process flow and equipment engineering plans in reference to the actual facility layout. This, together with NBE factory acceptance testing protocols, and expertise in domestic and international standards, codes and regulatory matters, ensured a streamlined system startup and immediate line performance optimization.
Integration of the NBE bulk bag filling equipment with the legacy upstream material feed system was achieved using an application-specific, processing-to-packaging conveyor/diverter. To ensure sufficient material flow at startup and allow for the producer’s anticipated capacity growth, the conveyor/diverter was designed with a maximum material flow capacity of 48,000 pounds/hour. All upstream process controls and the new bulk bag filling system controls were centralized to a single HMI, enabling coordinated material feed, interlocking safety switches and reduced labor allocation for managing multiple machine operations.
Integrated automation controls manage the complete processing operation from a single menu-driven interface.
From custom programming to construction, NBE designed and built a single UL-listed HMI to direct all of the system-wide equipment control communications, sensing, weighing, monitoring and data reporting. In addition to the bulk bag filling operation, NBE automated the producer’s upstream and downstream processing to enable fully integrated automation.
Designed for use by a single operator, the menu-driven controls are presented using a color touch-screen HMI. High-speed Ethernet communications facilitate system-wide operations, including: creating material fill recipes, metering material feed rates, calling specific pallet types, customizing fill/densify cycles by material, weighing material to an NTEP-certified accuracy of ±0.5 percent, creating operator-specific fillhead settings and monitoring operator safety systems. The integrated automation not only optimized line throughput, but also increased material deliver accuracy and improved labor utilization.
Performance, Not Compromise
NBE’s application-specific equipment features include an 8-GPM hydraulic fillhead carriage lift that enables safe, fast fill cycles, exceeding the lift speed and capacity of ball screw designs. Thick-wall structural tubing, heavy-gauge carbon and stainless steel, high motor horsepower, and torque ratings on gear reducers and drives additionally provide performance advantages.
Moreover, the process automation and control systems, built by NBE, meet or exceed application-specific, domestic and international regulatory standards, including those relating to explosion protection. And NBE proactive risk assessment procedures ensure the entire bulk bag filling system work center is designed and built to help prevent hazards to those who operate and maintain the equipment.
The application-specific construction of this system also boasts:
- A 4,500-pound hang weight bag capacity. Cantilevered fillhead and bag hangers easily lift bag weights that manual or swing-style designs cannot.
- An NTEP-certified hang weigh scale system. As the only manufacturer of NTEP-certified, 4,500-pound capacity bulk bag weigh systems, NBE can provide batch accuracies to ±0.5 percent or better at a 20,000-pound/hour material flow rate.
- Operator-friendly bag hanging and spouting. Pneumatically-driven action brings the fillhead forward and moves the rear hooks to well within operator reach to eliminate the need to step into equipment, while providing the operator optimal ergonomic posture during interaction with the equipment.
- In-line package densification. A high-intensity, low-frequency vibration is isolated through the deck to the bulk bag only. This concentrated densification enables precise material fill volume, weigh accuracy and bag stability without transferring the vibration to other equipment or work areas.
- An automatic pallet dispenser. A continual delivery of pallets into the system was required to support the high-volume packaging. A fully automatic 20-pallet capacity pallet dispenser was integrated to ensure safe and optimal pallet feeding.
- A static dissipation system. The bag fill sequence cannot begin unless the insulated monitoring clamp is attached to the bag and the system senses the bag is properly grounded. An indicator light informs the operator of proper grounding.
For more information, please visit www.nbe-inc.com/chemical .