Mechanical properties of wood carton used for long distance transport of tomatoes

Abstract

Tomatoes are produced and consumed year round. Wood carton is the dominant mode of packaging for produce coming to APMC Market, Ahmedabad from out-of-state. It has been known for long however that wood carton suffers from many shortcomings. It is unable to protect the produce sufficiently against mechanical hazards encountered in transit and handling. Produce gets bruised, dented and generally battered due to vibrations in transport, drops and shocks received in loading and unloading. Out own earlier study indicated that mechanical damages could be as high as 17 per cent in locally grown tomatoes and higher in those brought to APMC Ahmedabad from out-of-state. Growers are aware of this and have begun to use CFB cartons. However, these cartons are not designed for perishable produce, but for consumer durable like TV, compressor, etc. Our work aims at designing and introducing better cartons for tomatoes. First part of this work, reported in this paper, deals with the mechanical properties of presently used wood carton. The results will be used to develop design concept and specifications of the new carton being designed. Wood carton was found to have high stacking strength. It deforms 1 to 1.5 mm per 100 kg load. Drop tests indicate however that nail joints begin to loosen after about 6 drops. It cannot endure more than about 12 straight drops of 20 cm. Angular drops are equally severe on the carton. Cracks also develop and lengthen with longer sequence of drops and exposure to vibration.