Search

In sorting and packaging lines, fruits are submitted to impacts that can involve alterations to the flesh. For this study, impact measurements were taken at critical points on Italian machines at a domestic packing house. These impacts were then reproduced in the laboratory to analyse the damage and the mechanical behaviour of apples of four cultivars (Golden Delicious, Stark Delicious, Granny Smith and Rome Beauty). Using multiple linear regressions, correlations were determined between the characteristics of the apples, impact levels, subsequent damage and parameters describing the mechanical behaviour of the fruits. The deterioration of the flesh observed on the impacted apples does not represent serious commercial damage to the product, excluding the deterioration due to an accessory feeding line that employs a dry bin dumper. In this last case, damage can consist of darkening of the flesh and fractures having a depth of 4–5 mm and a diameter of 12–15 mm. The research emphasized the need to consider characteristics such as the impact radius, the flesh firmness and the sugary content of the flesh when studying the effects of dynamic stresses on apples. The sample of Stark Delicious showed the highest susceptibility to impacts.

Small cultivators can represent the main or the sole mechanical resource for agriculture in many countries. For such constant use, their ergonomic characteristics can assume a great importance. In this paper, the vibration and noise of some of these implements—one of which is made in China—were examined. The acceleration transmitted from the handle and the noise level at the user's ear were measured during soil tillage, according to International standards. The results indicate that in 10% of the exposed population, vascular disorders of the hand (Vibration White Finger) can appear after three years of continuous use of these machines, under usual working conditions. The level of noise at the worker's ear should not involve an appreciable risk for hearing after 10 yr of use. For the noise levels experienced on the majority of the implements examined, the domestic and European directives require that the worker need only receive appropriate information about the problems due to the noise. In view of the introduction and promotion of these implements in China and in the developing countries, it is necessary at least to reduce the vibration transmitted to the user's hands, by providing adequate insulating systems for the handle.

The vibration and noise of a modular rubber tracked forestry vehicle were examined. The acceleration experienced at the driver's seat and the steering-wheel and the noise level at the driver's ear were measured under repeatable test conditions, on a bituminous conglomerate track, with different forward speeds and with the engine at maximum speed. Measurements of vibration and noise were also carried out on a very uneven natural terrain to examine a condition of high risk from vibration transmitted to the driver. The results of the study indicate that the level of vibration on the track test was low and should not compromise the health of the driver. However, during transport on uneven ground and at high average speed (12 km/h), vibration at the seat (1·7 m/s 2 ) was such that a driver's exposure, prudently, should not exceed 2 h per day, if the most stringent criterion of the International Standard is followed. Noise levels were high, in all the test conditions [from 86 to 91 dB(A)], as a result of the position of the engine in the cab and the lack of adequate soundproofing measures.