Effects Of Vibration On Pears’ Damage Characteristics And The Study Of Protective Packaging Methods

The purpose of this study was to explore the influence of vibration on the damage characteristics and physicochemical property of pears, and the development and application of new anti-vibration packaging technology. The shaking table simulate transported conditions of Pears by the way of frequency sweep and fixed frequency vibration. Signals were collected and analyzed by DASP. In the way of establishing the relationship between the vibration frequency, vibration acceleration and the damage characteristics and physicochemical property of pears. Using PBAT as biodegradable cushioning materials to carry out cushioning packaging experiments to verify the effect of the new cushioning materials. In combination with cushioning material and stacking way to explore new type of vibration packaging technology. The results showed that, in single layer sweep frequency test, the resonance frequency of pear gradually declined with the increase of vibration acceleration. Vibration acceleration was 0.25g, resonance frequency was at around 82Hz, and vibration acceleration increased to lg resonance frequency decreased to around 53Hz, the damping was 35.37%. In the multilayer sweep test, resonance frequency increased with increasing vibration acceleration when the pear in low layer.When the pear in high layer, resonance frequency decreased with increasing vibration acceleration. In the single layer fixed frequency test, the damage volume and the soluble solids contented of pear alonged with the increase of vibration acceleration which has a tendency to incline and with the increase of resonance frequency which has a tendency to decline.The hardness of pears with increase of vibration frequency and vibration acceleration declined. In the Multi layer fixed frequency test, the first and third layers of pears were the most seriously damage, the second and the fourth inferior. The optimum foaming process of PBAT was obtained as followings:the foaming agent was 20%, the foaming temperature was 140℃ and foaming time was 25min. Under this condition, the apparent density was 0.18 g/cm3,and buffer effect was superior to the net and inferior to sponge. In the simulation of transportation, the EBI of pears in the way of overlapping stacking was lower than crisscross stacking.In the actual transportion, under the condition of high frequency, low vibration acceleration, and overlapping stacking,those may appropriately reduce the mechanical damage of fruits and vegetables by vibration, collision in the transportation process.