Study On The Preparation Of Porous Polyvinyl Alcohol/polypropylene Meltblown Nonwoven Composite Thermal Insulation Material

The development of wearable thermal insulation materials has attracted more and more attention in the market,and new thermal insulation materials have paid more attention to the characteristics of lightness and thinness.Meltblown nonwoven materials account for a large proportion in the application of industrial textiles.Because of its fluffy structure,low cost,and wide source,it is a commonly used material in the field of thermal insulation.However,single-structure and single-component nonwoven thermal insulation materials are often difficult to meet the requirements of thin and light thermal insulation materials,so the development of composite thermal insulation materials has received more attention.Porous materials have broad application prospects in the field of light and thin insulation due to their advantages such as high porosity,small relative density,and strong designability.In this paper,using polyvinyl alcohol as the raw material,a metastable solution system was prepared by using a poor solvent induced phase separation method,and then the nonwoven material was impregnated into the system,and the porous polyvinyl alcohol/polyester was prepared by the process of standing,replacement and drying.Propylene meltblown nonwoven composite thermal insulation material.This article mainly studies and analyzes the following parts(1)The process requirements for the preparation of metastable polyvinyl alcohol solution system by poor solvent induced phase separation method are:poor solvent and replacement solvent are both acetone,the concentration of polyvinyl alcohol solution is 50?80mg/mL,poor solvent and poly The volume ratio of the vinyl alcohol solution is 3:4(2)Immerse meltblown nonwoven materials with different areal densities into the prepared metastable polyvinyl alcohol solution system,and adjust the process parameters,such as the concentration of polyvinyl alcohol solution,the molecular weight of polyvinyl alcohol and the standing temperature to prepare Porous polyvinyl alcohol/polypropylene melt-blown nonwoven composite thermal insulation material with different pore size structures.The results show that when the concentration of the polyvinyl alcohol solution gradually increases,the thermal resistance of the porous polyvinyl alcohol/polypropylene melt-blown nonwoven composite insulation material increases first and then decreases.When the molecular weight of the polyvinyl alcohol gradually decreases,the insulation material The thermal resistance gradually increases;as the static temperature increases,the thermal resistance of the thermal insulation material increases first and then decreases(3)The process parameters of the preparation process of porous polyvinyl alcohol/polypropylene meltblown nonwoven composite thermal insulation material were optimized,and the molecular weight of polyvinyl alcohol,the standing temperature and the concentration of polyvinyl alcohol solution were selected as three factors,each factor Set three levels to carry out three-factor three-level orthogonal experiment.The results show that the static temperature is the factor that affects the thermal resistance of the thermal insulation material most,followed by the molecular weight of the polyvinyl alcohol,and the concentration of the polyvinyl alcohol solution has the smallest effect(4)Construct a model of the component structure of porous polyvinyl alcohol/polypropylene meltblown nonwoven composite insulation material and derive the expression of effective thermal conductivity.According to the numerical expressions established by the model and comparing with the actual experimental measurement values,it is found that the establishment of the model is more suitable for the calculation of the thermal conductivity of the thermal insulation material prepared with a melt density of 30g/m2 as the base fabric.