Study On The Properties Of Luffa Sponge Column Mattress Filling Material And Mattress

Natural plant fiber materials has entered into many aspects of our lives due to its rich resource,renewability,non-toxic,free pollution and degradability.Among them,natural plant fiber mattresses are very popular in the current Chinese market.At present,plant fiber mattresses,such as palm and jute mattresses have high firmness,poor air permeability,heavy weight,so they cannot provide a comfort support and a dry surface of mattress and are not beneficial to transportation.However,luffa sponge has a natural three-dimensional network structure with light-weight,higher porosity,better air permeability,these indicate that luffa sponge has a potential to act as mattress filling materials.Furthermore,few studies on luffa sponge filling materials and mattress have been reported.Therefore,it is essential to furtherly study the properties of luffa sponge filling material and mattress,and their preparation.In this paper,using scanning electron microscope?SEM?,X-ray Diffraction?XRD?,fourier transform infrared?FTIR?,quasi-static uniaxial compression,repeated loading and other experiments,studied two kinds of luffa sponge column and the effects of three softening methods of luffa sponge column on the microstructure,chemical composition,mechanical properties and energy absorption.On this basis,the luffa sponge filling materials of mattress were prepared.The support performance,dimensional stability,energy absorption,moisture absorption and hygroscopicity of the filling materials of luffa sponge column mattresses were investigated by comparing with 3D jute,palm and jute mat.In addition,the support of the mattress of the luffa sponge mattress is studied by the index of the mattress firmness,the hysteresis loss rate and the suitability on the basis of comparison with latex mattresses,memory foam mattresses,palm mattresses,bamboo fiber mattresses and so on.That provides a scientific theoretical basis for the humanized design and customized production of luffa sponge mattresses.The main conclusions of this thesis are as follows:?1?The compressive strength,peak stress and energy absorption per unit volume of the high-density of luffa sponge column are about 10 times of those of the low-density,but the densification strain distribution range of the two type of luffa sponge column is similar,both concentrated in the range of 0.6-0.7.Therefore,luffa sponge column can batch processing by density classified to produce mattress filling materials.After compression treatment,the dimensional stability of high density luffa sponge column was better,while that of low-density of luffa sponge column was greatly affected by compressibility.Both high-density and low-density luffa sponge have good hygroscopicity and moisture permeability,and the water absorbability of 2.07 and3.45 times of their own weight,respectively,and water dissipation can reach 91.44%and 76.86%after 13 hours.?2?The firmness of mattress filling materials of high-density luffa sponge column was 3 times higher than that of low-density luffa sponge column.Among them,the surface firmness and core firmness of mattress filling materials column luffa sponge mattresses with 60%compression were significantly lower than those of three kinds of plant fiber mats?such as 3D jute mats,carvel jute mat and palm mat?.?3?The compressive strength,peak stress and other properties of luffa sponge column were obviously reduced after softening,and the lignin,hemicellulose,pectin and other non-fiber substances in the fibers were partially removed.Thereinto,which the 5%NaOH-5%H₂O₂ treatment was the most effective.After treatment,a large number of holes,grooves and cracks appeared on the surface of the fiber bundles,and the cell wall was destroyed,which resulted in the decrease of the mechanical properties of the columnar luffa sponge.In addition,the height recovery rate of luffa sponge column was increased after three kinds of softening treatments,but the height recovery was less than 6.6 mm.The hygroscopicity and moisture permeability of luffa sponge after softening was superior to that of untreated luffa sponge.?4?The firmness of luffa sponge filling material was obviously decreased after softening treatment,and the firmness of luffa sponge filling material of compressing to initial densification region was less than that of filling material of luffa sponge column at the stage of compression to smooth plateau region.?5?The firmness of the surface layer,core layer and bottom layer of the mattresses are lower than those of palm mattresses and bamboo fiber mattresses,and are slightly larger than those of latex mattresses,but are less than those of memory foam mattresses.The S-values of memory foam mattresses and latex mattresses are more than 5,less than 6,which belong to middle firmness mattresses.The suitability of luffa sponge mattresses was better than that of palm mattresses and bamboo mattresses,but less than that of memory foam mattresses and latex mattresses.There is a negative correlation between mattress suitability and mattress mechanical properties.?6?The use of bedstead can not only change the mechanical properties of the mattress,but also change the distribution of the firmness of the mattress.The firmness of the core layer and the bottom layer of the mattress decreases after the bottom layer of the mattress is added with the bedstead.?7?The pressure reduction property effect of luffa sponge mattresses is slightly worse than that of memory foam mattresses and latex mattresses,but better than that of palm mattresses.The average pressure,the maximum pressure,the contact area that greater than the 30mmHg pressure threshold,the pressure index at the human-bed interface?overall,shoulder,hip?showed a negative correlation with the mattress firmness index?the absolute value of correlation coefficient are more than 0.6?.And there was a significant positive correlation with the mattress suitability index?the absolute value of correlation coefficient are more than 0.5?.In addition,the mattress suitability index showed a negative correlation with the total contact area and the contact area that larger than the 5mmHg pressure threshold?the absolute value of correlation coefficient are more than 0.6?.