RU2544827C1 - Honeycomb panel from polymer composite material and method of its production - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: honeycomb panel contains a medium layer of a honeycomb filler and external sheathings. The layer of the honeycomb filler is made from a thermoreactive polymer composite. The external sheathings are made from a duplex prepreg based on a thermoplastic matrix from the polymer composite material. In the layer of each sheathing, adjoining the honeycomb filler, contained is thermoreactive glue, introduced into the structure of a fibrous material of the sheathing from the side, adjoining the honeycomb filler. The composition of the thermoreactive glue contains a thermoplast of the origin identical to the polymer matrix of the sheathing. In the production of the honeycomb panel applied is the duplex prepreg, which is obtained by doubling the fibrous polymer composite material from one side with a film from a thermoplastic polymer in hot calendar at a temperature of the said film softening and melting.

EFFECT: increased quality of the honeycomb panel, simplification of the technology of its production, unification of the production process due to the application of the duplex prepreg.

3 cl, 1 tbl

Description

Technical field

The group of inventions relates to the field of production of aircraft, in particular honeycomb structures of a glider and passenger salons from polymer composite materials (PCM), and may find application in the manufacture of honeycomb structures with thermoplastic lining and for other vehicles. The objects of the group of inventions are a honeycomb panel and a method for its manufacture.

State of the art

The leading place in the production of cellular laminated (sandwich) structures in aviation technology is occupied by panels with plating of polymer composite materials based on woven and non-woven fibrous materials based on a thermosetting polymer matrix containing an adhesive component. The panels are manufactured using prepregs (fibrous materials previously impregnated with a binder) by hot molding / gluing in presses, autoclaves, etc. So, for example, from EP 0927737 known honeycomb panel containing the middle layer of honeycomb core of the aramid honeycomb layer and the outer upper and lower skin of a polymer composite material based on a thermosetting polymer matrix. Such a panel has a low weight and a sufficiently high strength, which is its advantage, but at the same time it has low impact strength, moisture resistance and maintainability.

In construction, multilayer panels are widely used, including cellular, made of thermoplastic materials, having manufacturability and low cost, but they are usually quite heavy and low strength, which excludes their use in aircraft.

Recently, some foreign companies have developed honeycomb panels made of composite materials based on a thermoplastic polymer matrix (TPKM). Sheaths made entirely from TPKM and honeycomb containing a homogeneous polymer thermoplastic matrix are firmly glued (welded) to each other. Such a honeycomb panel is known from published application US 2001042593. The panel contains made of a composite material based on a thermoplastic matrix: the middle layer of honeycomb core and the outer skin. In addition, from the application US 2001042593 there is known a method of manufacturing a honeycomb panel, in which preliminary heating is carried out to predetermined temperatures forming the structural panel of the core and casing, subsequent joint molding of the core and casing at a given temperature in the mold. The honeycomb panel and the method of its manufacture from the application US 2001042593 adopted as the closest analogue to the proposed group of inventions. Known panel has a high impact strength, moisture resistance and maintainability. However, the production of cellular aggregates based on a thermoplastic matrix is an extremely difficult technical task, because when welding the thermoplastic material of the honeycomb cells to fasten them together, there is a high probability of structural disruption in the finished honeycomb layer and, as a result, a poor quality panel.

Disclosure of invention

The objective of the invention is to develop the composition of the honeycomb panel and method of its manufacture, providing reliable bonding of the sheathing of the fibrous composite material based on a thermoplastic binder (TPM) with a honeycomb core of a thermosetting polymer composite.

The technical result achieved by using the present invention is to improve the quality of the honeycomb panel, to simplify the technology of its manufacture, to unify the manufacturing process through the use of duplex prepreg.

To achieve the technical result, a three-layer honeycomb panel is proposed comprising a middle layer of honeycomb core and an outer upper and lower skin. The honeycomb layer is made of a thermosetting polymer composite. The outer skin is made of prepreg based on a thermoplastic matrix of a polymer composite material. The layer of each skin adjacent to the honeycomb core contains a thermosetting adhesive embedded in the structure of the fibrous skin material from the side adjacent to the honeycomb core. The thermosetting adhesive contains a thermoplastic of an identical nature with a polymer matrix of the skin.

As a sheath prepreg, a duplex prepreg was used, formed on one side by a fibrous polymer composite material combined with a thermoplastic film and, on the other hand, impregnated with thermosetting adhesive.

As a second object of the invention, a method for manufacturing a three-layer honeycomb panel in the form of a package of the middle layer of honeycomb core and the outer skin of a prepreg impregnated with a binder. The panel skin is formed on the basis of a duplex prepreg, which is obtained by duplicating a fibrous polymer composite material on one side with a thermoplastic polymer film in a hot calender at the softening and melting temperature of the specified film and then duplicating the fibrous material on the other side with a thermosetting adhesive film in the hot calender at a temperature transition of glue to a state of softening and melting. The resulting prepreg is molded to the honeycomb layer at the adhesive curing temperature. When duplicating fibrous material with adhesive film, separation silicone paper is used.

The implementation of the invention

The honeycomb panel comprises a middle layer of honeycomb core of a thermosetting polymer composite and an outer upper and lower skin. A honeycomb layer is sandwiched between two outer composite skins, which are made of a prepreg based on a thermoplastic matrix of a polymer composite material.

As the fibrous filler of the prepreg can be used fabrics, woven tapes, strand materials based on glass or aramid fibers, or combinations thereof.

A thermoset adhesive is introduced into the structure of the fibrous sheathing material from the side adjacent to the honeycomb core. An adhesive containing a thermosetting curable composition contains a thermoplastic whose nature is identical to the nature of the polymer skin matrix. This ensures reliable bonding of the casing with honeycomb.

When forming the skin, a duplex prepreg is used - this is a prepreg containing a layer of fibrous polymer composite material, combined on one side with a thermoplastic film, and impregnated with thermoset adhesive on the other.

As a material of a thermoplastic film (thermoplastic binders), polysulfones, polyamides, and others with a film thickness of 0.08-0.15 mm can be used. As the adhesive composition, film adhesives can be used: VK-36, VK-41, VK-51, VK-24, PKS-171 and others with a thickness of 0.15-0.20 mm. Sotoplasts are based on phenylonic, aramid, glass and carbon fibers with phenolic, polyamide, bismaleimide and other binders.

EXAMPLE 1

As the fibrous material of the casing, fiberglass T-10-14 (GOST 19170-2001) is used, which is duplicated on one side with PSN film on a hot calender at a temperature of 190 ° C and a roll gap of 0.25-0.30 mm (TU 6 -19-151-285-88) from polysulfone and wound into a roll. Then, in the same calender at a temperature of 60-70 ° C and a roll gap of 0.35-0.45 mm, the glass fabric on the other hand is duplicated with an VK-36 brand epoxy adhesive film (TU 6-41-1499-89), containing up to 30 % powdered polysulfone brand PSK-1 (TU 6-06-46-90). Film thickness 0.18 mm. When duplicating fiberglass with adhesive film, separation silicone paper is used, which, together with the obtained duplex prepreg, is wound into a roll.

The obtained duplex prepreg from the side of the adhesive film is molded to a honeycomb of the grade ПСП-1-2,0-96 (ТУ 1-596-231-01) at a temperature of 175 ± 5 ° C and a pressure of 2-4 kgf / cm ² with exposure to within 3 ± 0.5 hours. After molding or during molding, the lining is further reinforced with layers of a polysulfone-based thermoplastic prepreg.

EXAMPLE 2

As the fibrous lining material, fiberglass T 45 (P) -76 (TU 6-48-107-94) is used, which is duplicated on one side in a hot calender at a temperature of 190 ° C and a roll gap of 0.25-0.30 mm film grade PA-6 (TU 6-19-255-84) from polyamide and wound into a roll. Then, on the other hand, in the same calender at a temperature of 60-70 ° C and a roll gap of 0.30-0.40 mm, the glass fabric is duplicated with an adhesive film based on PKS-171 polyamide (TU 6-06-20-88). Film thickness 0.075 mm. When duplicating with adhesive film, separation silicone paper is used, which, together with the obtained duplex prepreg, is wound into a roll.

The obtained duplex prepreg from the side of the adhesive film is molded to a honeycomb of the grade ПСП-1-2,0-64 (ТУ 1-596-231-01) at a temperature of 170 ± 5 ° C and a pressure of 3-4 kgf / cm ² with exposure to within 1 ± 0.1 hours. After molding or during molding, the lining is further reinforced with layers of a thermoplastic polyamide-based prepreg.

From the panels obtained by examples, the following were cut out:

- disks with a diameter of 60 mm for tests for uniform separation according to OST 1 90069-72,

- plates with a width of 75 mm for testing for peeling on a drum according to OST 190196-75

- and for testing for breakdown by a striker, square samples of 100 × 100 mm according to ASTM D3029-84.

Similar samples were made from Type II floor panels (TU 1-596-416-01) using the same cells and T-10-14 fiberglass claddings impregnated with EP-2MK epoxy binder. A similar panel was made of T-10-14 fabric casing and polysulfone binder preformed in the press, then the casing was glued to the honeycomb core PSP-1-2,0-96 with VK-36 film glue.

Table 1 shows the test results.

A panel with sheathing made of fiberglass based on a thermosetting binder (EP-2MK), with good bonding strength, has a relatively low breakdown strength.

The panel glued with preformed thermoplastic fiberglass plating has a high breakdown strength, but poor bonding strength.

The panel made according to the invention has high performance in all three parameters shown in table 1.

Table 1 Bonding strength of skin with honeycombs Panel, TU from fiberglass Panel glued with TPKM skin In example 1, with a polysulfone-based duplex prepreg According to example 2 with a duplex prepreg based on polyamide Uniform separation, MPa 4.4 1.8 4.2 3.8 Peeling on the drum, N / 75 mm 260 140 320 290 Breakdown by a drummer, N * m 3.95 5.74 5.57 5.35

Claims (3)

1. A honeycomb panel containing a middle layer of honeycomb core and outer skin, characterized in that the honeycomb layer is made of a thermosetting polymer composite, the outer skin is made of prepreg based on a thermoplastic matrix of a polymer composite material, while in the layer of each skin adjacent to honeycomb core, contains thermosetting adhesive embedded in the structure of the fibrous sheathing material from the side adjacent to the honeycomb core, and as part of the thermosetting adhesive with erzhitsya identical nature thermoplastic matrix resin plating. 2. The panel according to claim 1, characterized in that a duplex prepreg is used as a lining prepreg, formed on the one hand by a fibrous polymer composite material combined with a thermoplastic film, and on the other hand, impregnated with thermoset adhesive. 3. A method of manufacturing a three-layer honeycomb panel in the form of a package of the middle layer of honeycomb core and the outer skin of a prepreg impregnated with a binder, characterized in that the skin of the panel is formed on the basis of a duplex prepreg, which is obtained by duplicating a fibrous polymer composite material on one side with a thermoplastic film polymer in a hot calender at the softening and melting temperature of the specified film, and followed by duplication of the fibrous material on the other hand with an adhesive term reactive film in a hot calender at the transition temperature of adhesive to a state of softening and melting the resulting prepreg priformovyvayut to a layer of honeycomb core with the adhesive curing temperature.