A high impedance composite film

Abstract

The invention discloses a high-impedance composite film which is composed of nine layers, wherein the nine layers are symmetrically arranged from the central layer to the two sides; the material of the outermost layer is metallocene polyethylene; the materials of the layers inside the outermost layers are sequentially polyethylene bonding agents, adhesives and nylon; the material of the middle layer is an ethylene-vinyl alcohol copolymer; the high-impedance composite film is composed of the following film materials in percentage by thickness: 40-60% of metallocene polyethylene, 5-15% of polyethylene bonding agent, 5-15% of adhesive, 15-25% of nylon and 5-15% of ethylene-vinyl alcohol copolymer; and the total thickness of the film is 0.1-0.3mm. The composite film has the advantages of excellent heat sealability, excellent meltability, superhigh water and gas barrier property, excellent chemical stability and favorable compatibility (compatible with five solutions).

Description

Technical field [0001] The invention relates to a composite membrane, in particular to a high-impedance composite membrane, belonging to the field of space liquid medium storage. Background technique [0002] The space station is an excellent test platform for multi-system integration. There are various types of liquid media inside, such as drinking water, technical water, condensate water, wastewater, cooling circulating water, etc. Water storage tanks are used on the International Space Station to transport and store water. There are four commonly used water tanks: CWC, PWR, Rodnik, and EDV. The first two are portable, foldable soft water tanks or water bags, and the latter are hard-shell, soft-capped water tanks. In order to make the water storage container and the relevant medium meet the compatibility requirements, the soft inner capsule structure is adopted, and the compatibility of the inner capsule and the medium needs to be considered in the design. [0003] CWC uses a t...

AI Technical Summary

Problems solved by technology

[0003] CWC uses a thicker Combitherm film (VPCXX140) as the material of the inner bladder of the water tank, which is better compatible with the drinking water of astronauts containing silver ions, but the caprolactam released by this material will increase the concentration of TOC in drinking water, and long-term use The drinking water will have a certain impact on the health of astronauts, and this type of film cannot be used to hold highly corrosive liquids (urine containing treatment agents, treatment agents, etc.); PWR uses FEP film, and its disadvantage is that the film It cannot prevent carbon dioxide in the air from entering the storage water through the film, resulting in the PH value of the storage water tending to decrease under long-term storage conditions, and its airtightness is poor, it cannot prevent the leakage of the smell of the contained liquid, and the heat sealing performance is poor, especially for thin film

These film materials can only be used to store one or several types of water for space stations, and cannot be applied to the storage of all liquid media in space stations

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