Low-density underwater sound absorbing plate and preparation method thereof

Abstract

The invention relates to a low-density underwater sound absorbing plate mainly used for an underwater sandwich structure core and a preparation method thereof. The sound absorbing plate effectively absorbs sound and has relatively low density. The sound absorbing plate is molded by separately pouring and curing an upper layer and a lower layer, wherein the upper layer comprises the following raw materials in percentage by weight: 55-75 percent of matrix resin, 10-20 percent of filler, 10-30 percent of curing agent and 1-5 percent of auxiliary agent; the lower layer comprises the following raw materials in percentage by weight: 40-65 percent of matrix resin, 15-30 percent of filler, 15-40 percent of cutting agent and 1-5 percent of auxiliary agent; the fillers contain hollow glass beads with grain sizes of 10-800 micrometers; and the thickness ratio of the upper layer to the lower layer is 1:(3-5). The preparation method comprises the following steps of: dewatering the raw materials of the upper layer and the lower layer; respectively proportioning and weighing the raw materials according to a range of 0.75-0.8 of the relative density of the whole plate and the content of the components of the upper layer and the lower layer; preheating the matrix resin of the upper layer and the lower layer; adding the fillers and then adding the auxiliary agents and the curing agents so as to ensure that the fillers are sufficiently dispersed in the matrix resin; initiating crosslinking and carrying out vacuum-pumping treatment on the raw materials; and then pouring the raw materials into a mold by adopting a layered pouring and curing method that the upper layer is firstly poured and then the lower layer is poured.

Description

technical field [0001] The invention relates to an underwater sound-absorbing material, in particular to a low-density underwater sound-absorbing plate mainly used as a core material of an underwater sandwich structure and a preparation method thereof. Background technique [0002] Using high-strength fiber-reinforced composite materials with good sound transmission performance as the surface layer and polymer sound-absorbing materials as the core material, sandwich sandwich structure composite materials can be prepared. This composite material integrates load-bearing and sound-absorbing functions, and has vibration The advantages of good damping performance, non-magnetic characteristics, and easy molding will become an important direction for future research on sound absorption of underwater structures. It has been more than 30 years abroad that sandwich sandwich composite materials have been used in the research of underwater sound-absorbing structures. With the further m...

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Problems solved by technology

However, the above-mentioned sandwich structure sound-absorbing core materials studied in the past, such as sound-absorbing rubber, must have a good underwater sound-absorbing effect without opening a cavity or foaming, and its relative density (relative to water) is very low. It is difficult to achieve less than 1, and the thickness is generally more than 50mm, which makes the overall weight of the sandwich structure larger and limits the scope of use of this structure

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