3D printing nozzle structure for supercooled forming of continuous fiber self-reinforced composites

Abstract

A 3D printing nozzle structure that realizes the supercooled forming of continuous fiber self-reinforced composite materials, including a liquefier. During the process from the nozzle to the nozzle, the temperature is lowered to below the melting point of the matrix phase without crystallization, forming a supercooled melt; there are fiber holes on the side of the nozzle, and the reinforcement phase enters the supercooled melt of the matrix phase through the fiber holes, and the reinforcement phase wraps the matrix phase It is extruded from the nozzle and solidified after being cooled; the invention utilizes the supercooling degree of the polymer, and introduces the reinforcement phase through the fiber hole during the 3D printing cooling process. The processing temperature window of the self-reinforced composite material is wide, and the reinforcement fiber is not damaged by heat, and has a product size Large and complex shapes, short molding cycle, low cost, high production efficiency and other advantages.

Description

technical field [0001] The invention relates to the technical field of 3D printing of continuous fiber-reinforced composite materials, in particular to a 3D printing nozzle structure for realizing supercooling of continuous fiber self-reinforced composite materials. Background technique [0002] Continuous fiber self-reinforced composite material (single polymer composite material) is a composite material in which the matrix and the reinforcing phase are the same or the same family of polymers, because the matrix and the reinforcement have good interface adhesion and are easy to recycle. Compared with traditional fiber-reinforced composite materials, the advantage of fiber self-reinforced composite materials is that two materials with the same chemical composition and different physical properties can be combined together without adding modified fibers, and excellent interface bonding strength can be obtained. The product has low density and high recycling rate. [0003] Co...

AI Technical Summary

Problems solved by technology

For the fiber hot pressing method and the fiber winding hot pressing method, during the molding process, the hot pressing temperature is raised above the melting point of the fiber so that the surface layer of the fiber melts and the interior maintains orientation, and the melted part is subsequently solidified into a matrix phase. The disadvantage of this method lies in the processing The window is too narrow, and the temperature control is extremely strict in the process of processing. Choose a suitable hot-pressing temperature. If the hot-pressing temperature is too low, the surface fibers will not be fully melted, and a relatively complete matrix phase cannot be formed; if the hot-pressing temperature is too high, The fiber is more melted and the fiber content is reduced, which eventually leads to the ineffective enhancement of mechanical properties; and the processing temperature range is often controlled at 1 to 2 degrees

Another type of interlayer hot pressing method and film embedding hot pressing method require a sufficiently large melting point difference between the matrix phase and the reinforcing phase to achieve the effect that the matrix phase melts but the reinforcing phase does not melt. The body belongs to the same polymer material, the difference in melting temperature is small, and the difference in melting point is usually within 5 degrees. Under the conditions of conventional polymer processing melting temperature, the reinforcement in the matrix often also produces thermal damage, thereby reducing the reinforcement phase. The mechanical properties of the reinforced phase make it impossible to play a reinforcing role

[0004] The above forming methods all have the disadvantages of narrow processing temperature window and thermal damage of the reinforcement phase, and the hot pressing method has defects such as small size and simple shape, long molding cycle, high cost, and low production efficiency. Therefore, increasing the fiber self-reinforcement The processing temperature window of composite materials is the core issue in the development of self-reinforced composite materials, and it is also a difficult point in the research of self-reinforced composite materials

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