RU2459743C1 - Heat insulation pack and method of its fabrication - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to multilayer articles used in aircraft and space engineering, particularly, to heat insulation packs. Proposed pack is operated at cryogenic temperatures, aerodynamic heating and high operating pressures, and comprises isolated surface with heat-insulation foam plastic layer fitted on damping layer, heatproof layer and antistatic coating applied on the latter. Isolated surface is made from polymer composite material. Foam plastic is furnished with waterproof and tight coating from epoxy resin-based shockproof glue and tape made of glass complex threads wound with 50%-overlap of coils glued together. Said tape has adhesive layer coated by heatproof layer made of rubber-like elastic coat. Method of making said pack consists in spraying foam plastic on premade isolating surface and applying heatproof layer and antistatic layer thereon. Isolated surface represents polymer composite material with damping layer applied thereon before spraying of foam plastic thereon. Waterproof and tight coating from aforesaid shockproof glue is applied over foam plastic and tape made of glass complex threads wound with 50%-overlap of coils glued together. Said tape has adhesive layer coated by heatproof layer made of rubber-like elastic coat._<.

EFFECT: reduced strains in proposed pack, higher reliability and strength.

3 cl, 1 dwg

Description

The proposed solution relates to multilayer products and the technology for their production, used in various fields of technology, in particular in rocket and aviation, in which products operate at cryogenic temperatures and under conditions of aerodynamic heating and high working pressures.

From the patent literature, multilayer products are known that work both at cryogenic temperatures and under conditions of aerodynamic heating, containing a metal shell with a layer of thermal insulation in the form of foam (RU No. 2238225, B64D 37/00).

Due to the complexity and duration of the technological cycle of gluing thermal protection layers, the proposed multilayer products are not reliable enough.

This disadvantage is partially eliminated in the technical solution according to patent RU No. 2298480, B32B 7/02, "Multilayer product and method of its manufacture."

According to this patent, in a multilayer product operating at cryogenic temperatures and under conditions of aerodynamic heating and pressure, containing a metal shell with a thermal insulation layer in the form of foam and a thermal protection layer, anticorrosive and shock-absorbing layers are placed between the metal shell and the foam plastic layer, the thermal insulation layer is made of TPSh- ES and sealant glue, and an antistatic coating is placed on top of it.

In the method of manufacturing such a multilayer product, which consists in spraying a foam onto a previously prepared metal surface and then applying protective coatings on it, before spraying the foam onto the metal surface, an anti-corrosion layer and a cushioning layer are successively applied, after which the foam is additionally fixed with a network installed using glue, and thermal protection and an antistatic coating are placed on top of it.

The disadvantage of this technical solution is the length of the manufacturing cycle and the low operational reliability of the thermal insulation package, including cryogenic thermal insulation in the form of Izolan-123 foam and thermal protection based on the molded spatula texture TPSh-ES, due to their cracking at high operating pressures of 1.0 ÷ 1.2 MPa and, accordingly, depressurization on the shell of a polymer composite material.

The problem to which the invention is directed, is to ensure the operational reliability of the thermal insulation package on the shell of a polymer composite material under conditions of cryogenic temperatures, aerodynamic heating and high operating pressures.

The problem is solved in that in a package of thermal insulation operating under conditions of cryogenic temperatures, aerodynamic heating and high working pressures, containing an insulated surface with a layer of thermal insulation in the form of foam, installed on the cushioning layer, a layer of thermal insulation and fixed to the last antistatic coating, an insulated surface made of polymer composite material, the foam is equipped with a moisture-proof and sealing coating of vibration-proof adhesive based on epoxy discharge resins ribbon of glass filaments wound with a 50% overlap of coils, fastened with adhesive, and having an adhesive layer covered with a layer of thermal protection in the form of a rubber-elastic coating.

To solve the problem in a thermal insulation package, the insulated surface is made of a polymer composite material based on a polymer film with a double-sided fluoroplastic coating.

In addition, the solution of the problem in a method of manufacturing a package of thermal insulation operating under conditions of cryogenic temperatures, aerodynamic heating and high working pressures, which consists in spraying foam onto a previously prepared insulated surface with subsequent application of thermal protection and an antistatic layer on it, is achieved by as the insulated surface, choose a polymer composite material, before spraying the foam, an amortization layer is applied to it, and on top of the foam hundred applied layer and a moisture sealant coating, to which a 50% overlap of tape is wound glass filament yarn, which windings are interconnected adhesive tape coated with an adhesive layer to which is applied a thermal protection rubber-elastic coating and an antistatic layer.

The foregoing is explained in more detail by the layout of the layers in the thermal insulation package.

The thermal insulation package on the shell 1 of the polymer composite material consists of the following layers:

- layer 2 - depreciation (adhesive);

- layer 3 - thermal insulation in the form of foam;

- layer 4, which performs the functions of a moisture protective and sealing coating;

- tapes 5 - from glass multifilament yarn wound with 50% overlap of turns, strengthening the heat-insulating layer 3;

- layer 6 - glue, for fastening together the turns of tape 5;

- layer 7 - adhesive deposited on the tape 5;

- layer 8 - thermal protection in the form of a rubber-like elastic coating;

- layer 9 - antistatic enamel.

According to the proposed method of manufacturing a package of thermal insulation on the shell 1, each of the layers is applied sequentially using individual installations.

Consider a method of manufacturing a package of thermal insulation on a specific example of its implementation.

On a pre-prepared shell 1 made of a polymer composite material based on a polymer film with a double-sided fluoroplastic coating, a depreciation (adhesive layer) 2 is applied in the form, for example, of Cryosil-R epoxy adhesive based on SEDM-3P phenol-formaldehyde resin.

A layer 3 is sprayed onto layer 2, for example, made of Izolan-123 rigid polyurethane foam, which is insulated with a moisture-proof and sealing coating 4, consisting of vibration-resistant adhesive, for example, TsMK-5 based on ED-20 epoxy resin with oligoester epoxy resins having elongation in tension 5 ÷ 6% and tensile strength at shear 12.0 ÷ 13.0 MPa.

To strengthen thermal insulation 2, a tape 5 of glass complex filaments with a force of 2 ÷ 3 kgf is wound on layer 4, for example, LES having a breaking load of 441 ÷ 450N, with 50% overlap of coils fastened with 6 EPK-1 glue based on epoxy ED mixtures -20, E-181, PO-300 with glass microspheres having a tensile strength at separation of 1.0 ÷ 1.2 MPa.

An adhesive layer 7 of vibration-resistant adhesive, for example, CCM5, is applied to the tape 5.

Layer 8 of thermal protection in the form of a rubber-like elastic coating, for example, TTP-BS (L) based on styrene-butadiene latex with a tensile breaking stress of (1.3 ÷ 1.4) MPa and elongation at elongation of 123%, is sprayed over layer 7.

A layer of antistatic coating 9, for example, KhP-5237 enamel, which is a suspension of pigments and fillers in a solution of chlorosulfonated polyethylene, is located above layer 8 of thermal protection.

The proposed percentage overlap of the turns of the LES tape, the application of the proposed coatings (adhesives) and thermal protection with specified limits of physical and mechanical characteristics is confirmed by the following examples.

1. Winding of reinforcing tape LES, 2.2 × 35 GOST 5937-81 on Izolan-123 foam, impregnated with EPK-1 glue according to OST 92-0949-74, with overlapping turns of less than 50% and effort (2-3 kgf ) and the physico-mechanical characteristics of the coatings (adhesives) used, thermal protection less than the specified limits at maximum working pressures on the shell of 1.0-1.2 MPa, leads to cracking of the thermal insulation package and, consequently, to a decrease in its tightness, as a result of a decrease in the strength of the applied turns of tape LES.

2. Winding of reinforcing tape LES, 2.2 × 35 GOST 5937-81 on Izolan-123 foam, impregnated with EPK-1 glue according to OST 92-0949-74, with overlapping turns of more than 50% and effort (2-3 kgf ) and the physicomechanical characteristics of the coatings (adhesives) used, thermal protection above the specified limits at maximum working pressures on the shell of 1.0-1.2 MPa, cause the heterogeneity of the stress distribution in the thermal insulation package and the occurrence of high local stresses, leading to cracking and loss its tightness.

The technical solution proposed as an invention has the following advantages:

- reduction of the level of deformation in the thermal insulation package;

- increase in strength and tightness;

- improving operational reliability, which is ensured by the structural combination of the used layers of the thermal insulation package.

Claims (3)

1. The package of thermal insulation, operating under conditions of cryogenic temperatures, aerodynamic heating and high working pressures, containing an insulated surface with a thermal insulation layer in the form of foam, installed on the cushioning layer, a thermal insulation layer, and fixed to the last antistatic coating, characterized in that the insulated surface made of polymer composite material, the foam is equipped with a moisture-proof and sealing coating of vibration-proof adhesive based on epoxy resin, tapes minutes of glass filaments wound with a 50% overlap of coils, fastened with adhesive, and having an adhesive layer covered with a layer of thermal protection in the form of a rubber-elastic coating. 2. The thermal insulation package according to claim 1, characterized in that the insulated surface is made of a polymer composite material based on a polymer film with a double-sided fluoroplastic coating. 3. A method of manufacturing a package of thermal insulation operating under conditions of cryogenic temperatures, aerodynamic heating and high working pressures, which consists in spraying foam onto a previously prepared insulated surface, followed by applying thermal protection and an antistatic layer to it, characterized in that the polymer is selected as the insulated surface composite material, before the foam is sprayed, an amortization layer is applied to it, and a moisture-protective and germic layer is applied over the foam a tizing coating of vibration-proof adhesive based on epoxy resin, on which a tape of glass complex threads is wound with a 50% overlap, the turns of which are joined together by glue, the tape is coated with an adhesive layer on which heat protection is applied in the form of a rubber-like elastic coating and an antistatic layer.