SBIR Phase II: Ultrasonic Inspection of Internal Bond Strength in Paper Products

Sonisys, Llc, Smyrna GA

Investigators

Abstract

This Small Business Innovation Research (SBIR) Phase II project focuses on the development of an ultrasound technology that measures internal bond strength (IBS) in paper and paperboard materials. IBS is a very important quality control parameter because it provides an assessment of bond strength between wood pulp fibers and between plies in multi-ply grades. Two standardized test methods are widely used throughout the paper industry to evaluate IBS: Z-direction tensile (ZDT) and Scott Plybond. However, these methods are problematic in many ways: they require destructive testing, are technically deficient, are labor and time intensive, and cannot be integrated into automated paper testing equipment in quality control laboratories. Since the propagation of ultrasonic waves in paper is sensitive to bonding between fibers, an ultrasonic IBS method has the potential to address all shortcomings of existing methods. Preliminary results gathered during Phase I confirmed correlations between ultrasonic IBS, ZDT and Scott Plybond. Phase II involves additional work on the ultrasound technology to improve its accuracy, reliability, and universality. Also, it includes the development of an engineering prototype instrument for paper mill quality control testing, a comprehensive statistical study comparing ultrasonic IBS, ZDT, and Scott Plybond, and the drafting of a standardized test method. The worldwide market of ZDT and Scotty Plybond Instruments is estimated at 400 units, largely in QC labs. Expected sales are $11M. Commercialization of a few hundred units would be considered as a tremendous success in the paper industry. The successful deployment of ultrasonic IBS in the QC lab could support the future development of real-time IBS monitoring during production.