Method for molding biomass composite product based on subcritical water micro-foaming

Abstract

The invention relates to a method for molding a biomass composite product based on subcritical water micro-foaming. The composite system is pre-mixed according to a formula and then added to an eccentric rotor extruder through a feed port. The composite system is plasticized into a melt after a solid delivery stage and a melting stage, wherein water in the biomass material is used as a foaming agent, and the biomass material is used as a carrier of the foaming agent to realize first mixed distribution of the foaming agent at a mixing stage I. The water in the melt is in a subcritical state byproviding pressure at a pressurization stage, the subcritical water is fully dispersed and mixed at a mixing stage II under the action of tensile rheology to form dense nucleuses, finally the subcritical water is triggered to foam at a depressurization stage, and the foam is cooled and molded by a mold. The water in the biomass material is used as a foaming agent, so that the biomass material doesnot need to be dried. The foaming agent is distributed more uniformly after two dispersions, so that the cell distribution is more uniform, and the performance of the molded product is more excellent. The method belongs to the field of polymer material molding.

Description

Technical field [0001] The invention relates to the field of polymer material molding, in particular to a method for molding biomass composite material products based on subcritical water micro-foaming. Background technique [0002] Biomass composite material has mechanical processability, water resistance, corrosion resistance, long service life, wide raw material sources, low cost, and excellent mechanical properties. It is an environmentally friendly recyclable material widely used in various fields. However, the mechanical properties of biomass composite materials are limited by the compatibility of the biomass filler material with the polymer matrix, especially the impact resistance. At the same time, its higher density also limits the application of biomass composite materials. [0003] The current molding method of continuous extrusion foamed biomass composite material usually requires drying the biomass material that has been pretreated, such as steam explosion, and mixing...

AI Technical Summary

Problems solved by technology

The distribution and size of the cells are greatly limited by the uniformity of the foaming agent in the melt, and the introduction of the foaming agent often increases the cost or is not friendly to the environment

At the same time, the drying treatment of biomass materials also increases the process links and cannot be continuously produced

[0004] Aiming at the discontinuous production of micro-foamed biomass composites and uneven distribution of cells, a molding method of biomass composite products based on subcritical water micro-foaming was proposed.

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