Susceptor integration into reinforced thermoplastic composites

• US 5,916,469 A
• Filed: 07/29/1996
• Issued: 06/29/1999
• Est. Priority Date: 06/06/1996
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Woolley, William E., Scoles, Roger W.
• Primary Examiner(s): Hoang, Tu Ba
• Application Number:
  US08/688,071
• Time in Patent Office: 1,065 Days
• Field of Search: 219/633-645, 219/603, 219/612, 219/615, 219/617, 219/618, 219/646, 428/119, 428/120, 428/204.4, 428/247, 428/223, 156/92
• US Class Current: 219/633
• CPC Class Codes: B29C 2035/0811 using induction
• CPC Class Codes: B29C 2071/022 Annealing
• CPC Class Codes: B29C 65/3616 comprising discontinuous fibre-reinforcements
• CPC Class Codes: B29C 65/364 being a woven or non-woven fabric or being a mesh
• CPC Class Codes: B29C 65/3644 being a ribbon, band or strip
• CPC Class Codes: B29C 65/3648 said strip being perforated
• CPC Class Codes: B29C 65/3668 characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special induction coils
• CPC Class Codes: B29C 65/3676 being metallic
• CPC Class Codes: B29C 65/368 with a polymer coating
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/5057 positioned between the surfaces to be joined B29C65/5035 takes precedence
• CPC Class Codes: B29C 65/564 hidden in the joint, e.g. dowels or Z-pins B29C65/603 takes precedence
• CPC Class Codes: B29C 65/76 Making non-permanent or releasable joints
• CPC Class Codes: B29C 66/0242 Heating, or preheating, e.g. drying B29C66/3464 takes precedence
• CPC Class Codes: B29C 66/0342 Cooling, e.g. transporting through welding and cooling zone
• CPC Class Codes: B29C 66/0344 Annealing
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/43 Joining a relatively small portion of the surface of said articles B29C66/45 takes precedence
• CPC Class Codes: B29C 66/4344 Joining substantially flat articles for forming fork connections, e.g. for making Y-shaped pieces
• CPC Class Codes: B29C 66/43441 : with two right angles, e.g. for making T-shaped pieces, H-shaped pieces
• CPC Class Codes: B29C 66/472 : said single elements being substantially flat
• CPC Class Codes: B29C 66/474 : said single elements being substantially non-flat
• CPC Class Codes: B29C 66/524 : Joining profiled elements
• CPC Class Codes: B29C 66/5326 : said single elements being substantially flat
• CPC Class Codes: B29C 66/543 : joining more than two hollow-preforms to form said hollow articles
• CPC Class Codes: B29C 66/71 : characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/721 : Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29C 66/7212 : characterised by the composition of the fibres
• CPC Class Codes: B29C 66/72141 : Fibres of continuous length
• CPC Class Codes: B29C 66/72525 : comprising honeycomb cores
• CPC Class Codes: B29C 66/7311 : Thermal properties
• CPC Class Codes: B29C 66/73117 : Tg, i.e. glass transition temperature
• CPC Class Codes: B29C 66/7392 : characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/73921 : characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/7394 : characterised by the material of at least one of the parts being a thermoset
• CPC Class Codes: B29C 66/742 : to metals or their alloys
• CPC Class Codes: B29C 66/8122 : characterised by the composition of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps
• CPC Class Codes: B29C 66/81261 : Thermal properties, e.g. thermal conductivity, thermal expansion coefficient
• CPC Class Codes: B29C 66/81455 : being a fluid inflatable bag or bladder, a diaphragm or a vacuum bag for applying isostatic pressure inflatable element positioned between the joining tool and a backing-up part B29C66/82421
• CPC Class Codes: B29C 66/81457 : comprising a block or layer of deformable material, e.g. sponge, foam, rubber pressing elements supported or backed-up by resilient material B29C66/8161
• CPC Class Codes: B29C 66/8181 : characterised by the cooling constructional aspects
• CPC Class Codes: B29C 66/81811 : of the welding jaws
• CPC Class Codes: B29C 66/81821 : of the welding jaws
• CPC Class Codes: B29C 66/8223 : Worm or spindle mechanisms
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/83221 : cooperating reciprocating tools, each tool reciprocating along one axis
• CPC Class Codes: B29C 66/836 : Moving relative to and tangentially to the parts to be joined, e.g. transversely to the displacement of the parts to be joined, e.g. using a X-Y table B29C66/65 takes precedence
• CPC Class Codes: B29C 66/8362 : Rollers, cylinders or drums moving relative to and tangentially to the parts to be joined
• CPC Class Codes: B29C 66/8432 : Machines for making separate joints at the same time mounted in parallel or in series
• CPC Class Codes: B29C 66/929 : characterized by specific pressure, force, mechanical power or displacement values or ranges
• CPC Class Codes: B29C 66/949 : characterised by specific time values or ranges
• CPC Class Codes: B29C 70/24 : oriented in at least three directions forming a three dimensional structure
• CPC Class Codes: B29C 70/885 : with incorporated metallic wires, nets, films or plates as lost heating elements B29C35/0272, B29C61/0625
• CPC Class Codes: B29C 71/02 : Thermal after-treatment B29C71/0063 and B29C71/0072 take precedence
• CPC Class Codes: B29K 2063/00 : Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2071/00 : Use of polyethers , e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2079/085 : Thermoplastic polyimides, e.g. polyesterimides, PEI, i.e. polyetherimides, or polyamideimides; Derivatives thereof
• CPC Class Codes: B29K 2081/04 : Polysulfides, e.g. PPS, i.e. polyphenylene sulfide or derivatives thereof
• CPC Class Codes: B29K 2081/06 : PSU, i.e. polysulfones; PES, i.e. polyethersulfones or derivatives thereof
• CPC Class Codes: B29K 2307/04 : Carbon
• CPC Class Codes: B29K 2309/08 : Glass
• CPC Class Codes: B29K 2883/00 : Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as mould material
• CPC Class Codes: B29K 2909/02 : Ceramics
• CPC Class Codes: Y10T 428/23979 : Particular backing structure or composition

Abstract

Problems associated with accurately positioning a susceptor at the bond line between two or more prefabricated, fiber reinforced, resin composite detail parts to facilitate thermoplastic welding (i.e., fusion bonding) between the detail parts. The integrated susceptor detail part is compatible with Z-pinning along the bond line for the pulloff strength enhancement associated with Z-pin reinforcement. We make the parts by (1) preparing the faying overface of the prefabricated part or prepreg preform for the overlayment of the bond line materials, (2) placing a thermoplastic film on the part or preform, (3) placing the susceptor on the film, and (4) securing the film and susceptor to the part by applying suitable heat and pressure to produce a prefabricated, consolidated detail part having an integrated susceptor in a resin rich region intended as the bond line to other parts in the final assembly.

Claims

1. An unitary prefabricated resin composite structure for joining the structure to another composite detail part with a fusion bond, comprising:

(a) one or more plies of a fiber reinforced resin defining a faying surface;

(b) a thermoplastic film as a surface ply adhered on the faying surface to define a resin rich bond line; and

(c) an integrated metal mesh susceptor bonded to the film at the bond line, the susceptor being heatable under the influence of an oscillating magnetic field to a temperature sufficient to melt the resin and the film to form a fusion bond between the structure and another part adjacent the faying surface at the bond line.

6. The detail part of claim 1 wherein the susceptor is copper.

2. An unitary prefabricated resin composite structure for joining the structure to another composite detail part with a fusion bond, comprising;

(a) a resin composite detail part including at least one ply of a fiber reinforced resin, the part having a faying surface;

(b) a thermoplastic film adhered to the part on the faying surface to define a resin rich bond line;

(c) an integrated metal mesh susceptor bonded to the film at the bond line, the susceptor being heatable under the influence of an oscillating magnetic field to a temperature sufficient to melt the resin and the film to form a fusion bond between the structure and another part adjacent the faying surface at the bond line; and

(d) Z-pin reinforcement stubble along the bond line and interleaved with the susceptor.

3. The structure of claim 2 wherein the thermoplastic film and the resin are the same composition.

4. The structure of claim 2 wherein the film is less than about 10 mils thick and the susceptor is less than 10 mils thick.

5. The structure of claim 2 being an aerospace spar having a web and a cap connected to the web, the susceptor being adhered to the cap.

7. The detail part of claim 2 wherein the susceptor is a metal mesh.

8. The detail part of claim 7 wherein the metal is copper.

9. The detail part of claim 2 wherein the stubble is present at an areal density of about 0.375-1.50%.

10. The detail part of claim 9 wherein the stubble includes chopped carbon fibers.