Device and method for preparing fiber-reinforced silica sol composite shell by air laying

Abstract

The invention discloses a device and a method for preparing a fiber reinforced silica sol composite shell through airflow laying. The device comprises a fiber laying chamber, a fiber storage chamber,an air supply unit and a support, wherein the fiber laying chamber is a hollow cube and is composed of four side vertical plates and an upper bottom surface exhaust hole plate and an upper bottom surface exhaust hole plate, and an exhaust hole is formed in the upper bottom surface exhaust hole plate; a rotating shaft used for bearing the shell sample is installed in the fiber laying chamber; the fiber storage chamber is of a hollow inverted quadrangular frustum shape formed by four side plates and a lower bottom surface air inlet plate, a fiber storage rack is arranged in the fiber storage chamber, and airflow guide holes are formed in the fiber storage rack; and the fiber spreading chamber is located right above the fiber storage chamber, the side length of the side vertical plate of thefiber spreading chamber is equal to the side length of the side plate of the fiber storage chamber, and the four side vertical plates and the four side plates are fixedly connected in a one-to-one correspondence manner. According to the device and the method, the fibers can be uniformly distributed in the shell, the fibers can be laid on the shell in a quantitative mode, so that the performance ofthe prepared shell is consistent, and the fiber with the large length-diameter ratio can also be added into the shell.

Description

technical field [0001] The present invention relates to an investment pattern apparatus for casting. More specifically, it relates to a device and method for preparing a fiber-reinforced silica sol composite shell by air laying. Background technique [0002] In the production of investment casting, it is generally required that the shell has a high enough wet strength to prevent the shell from cracking during handling or dewaxing; high temperature strength to prevent the shell from cracking during roasting and casting; low residual strength to make the casting Easy to clean up. [0003] Silica sol shells have the disadvantages of low wet strength, slow drying, and long shell-making cycle. People usually adopt methods such as improving the shell-making process, using multiple adhesives to harden alternately, and accelerating the drying rate of the shell to promote the silica sol shell. Builds wet strength quickly. However, these methods often have limited enhancement effec...

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Problems solved by technology

[0004] In the document CN 103962506 B, the adding method of fiber is to mix in the paint, and after making the paint, dip-coat it on the pattern to make the shell. There will be uneven fiber mixing, entanglement, etc.; second, the fibers are wetted and agglomerated in the coating, and it is impossible to achieve complete uniform distribution through stirring. When the agglomerated fibers are made into a shell, it will cause Uneven distribution of shell properties and reduced strength after firing; Third, due to the uneven distribution of fibers in the coating, the uneven distribution of fibers at different positions in the container will eventually cause the fibers of the same batch of shells to be produced The content is different, and there is a huge difference in performance; fourth, for fibers with a large aspect ratio, this kind of fiber is added to the shell by mixing the coating, and the fibers are prone to problems such as agglomeration and clustering, which seriously affects the quality of the fiber. The uniformity of fiber distribution will cause the instability of the shell performance; fifth, the addition of fibers to the coating will affect the rheological properties and viscosity of the coating, especially when the amount of fiber added is relatively large. The rheological properties and viscosity and other process properties have a very significant impact

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