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Title: Effect of stringer repair methods and repair frequency on GMA performance

Author: Clarke, John W.; White, Marshall S.; Araman, Philip A.;

Date: 2005

Source: Pallet Enterprise. 25(2): 68-73

Publication Series: Miscellaneous Publication

Description: Over 135 million wooden pallets were repaired for reuse in 1995. Notched stringers are one of the most commonly damaged components. Metal plates, half companion stringers, and full companion stringers are repair methods described in the U.S. industry standard published by the American Society of Mechanical Engineers. This study evaluated the effect of these three stringer repair methods on the bending strength and stiffness of 48x40 GMA-style pallets spanning the pallet stringers. Pallets with up to two stringers repaired with full-companion stringers were stronger and stiffer than new, undamaged pallets. In general, pallets with one or two repaired stringers using up to two metal plates or half-companion stringer repairs were as strong or stronger, but less stiff, than the original pallets without stringer repairs.

On the other hand, on average pallets with two stringers repaired with metal plates or half-companions were less strong and less stiff than pallets with only one such repair. These results indicate that all three repair practices (metal plates, half-companions, and full companions), when properly applied, will restore pallet strength when used to repair one notch on one or two stringers of a 48x40 partial 4-way, three stringer pallet.

There may be an additional species effect on repair performance that warrants further evaluation. Current repaired pallet grades group metal plate repairs in upper grades, while companion member repairs are placed in lower grades. Based on functionality with material handling equipment, these grades do not reflect the racking performance of these repair methods.

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Clarke, John W.; White, Marshall S.; Araman, Philip A. 2005. Effect of stringer repair methods and repair frequency on GMA performance. Pallet Enterprise. 25(2): 68-73


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