Study On The Preparetion Of Foam Cushioning Material By Micronized Fiber And Starch

The plant fiber foam cushioning materials with the advantages of complete degradation and abundant resources of raw materials has been attracted extensive attention at home and abroad, so optimizing the preparation process and improving the materials properties have became particularly important.In this study, bleached bagasse pulp and bleached eucalyptus pulp were micronized by the PFI mill,and foam cushioning materials were prepared by pulp with different Schopper-Riegler slowness,in order to study on dimensional stability, moisture absorption, static compression and dynamic compression characteristics of foam cushioning materials;it has also analyzed that the affect on the performance of foam cushioning material of the content of bagasse pulp fiber, cationic starch and polyvinyl alcohol.A new image processing and analysis method was developed to determine the porosity of materials.On the basis of experiments,static compression model of different porosity of the buffer materials were established.The results show as followed:With the rise of revolutions of PFI mill,SR slowness of bleached bagasse pulp and bleached eucalyptus pulp were significantly increased,fiber length and coarseness were decreased and the content of fine fiber was increased, the effect of fiber micronized by the PFI mill was obvious.With the rise of SR slowness, the dimensional stability of the samples was declined during the drying process; the moisture absorption of the samples were increased.In static compression and dynamic compression tests, the cushioning properties of samples prepared by bleached bagasse pulp and bleached eucalyptus pulp increased with the increase of SR slowness,cushioning materials were prepared by the pulp with high SR slowness has better strength.The relative content of the bagasse fibers and cationic starch of the foam cushioning materials have greater impact on material properties,such as the density, dimensional stability, static compression and dynamic compression characteristics. The buffer materials contained70%-75%Bagasse fiber and20%-25%cationic starch have good applicability and mechanical strength. Polyvinyl alcohol as an adhesive and moisture additives can significantly improve the applicability of the cushioning material,the addition of5%-10%was effective in reducing the rate of volume change and moisture absorption, and ensured that the buffer strength of the material was not significantly reduced.Observed the cross-section of foam cushioning materials by a digital microscope,there are a large number of pore structures in the materials.Using Matlab software analyzed information of images, then calculated the porosity of the sample.On the basis of experiment, the static compression model of plant fiber foam cushioning materials was established, the equation is: σ=a1th(a2ε)+a3tan(a4ε).Using experimental data of different porosity of materials to identify the model parameters, and the final validation of the model.