Heating of thermoplastic interlayers in a preform tool for producing a preform of a composite member

Patent metadata

Field	Value
Publication number	US-2022105659-A1
Application number	US-202117554542-A
Country	US
Kind code	A1
Filing date	Dec 17, 2021
Priority date	Oct 26, 2015
Publication date	Apr 7, 2022
Grant date	—

Abstract

Systems and methods for producing a preform for a composite member. An exemplary method includes preparing a lay-up of reinforcement layers and thermoplastic interlayers, and transferring the lay-up to a preform tool. The method further includes inducing heat in the preform tool to a transition-temperature range that causes the thermoplastic interlayers to become tacky or viscous, and applying pressure to the lay-up with the preform tool to shape the lay-up into the preform.

First claim

1 . A method of forming a composite member, the method comprising:
shaping a non-conductive lay-up of dry reinforcement layers and thermoplastic interlayers into a preform for the composite member by:
inducing heat in a preform tool to a transition temperature range that causes the thermoplastic interlayers of the lay-up to become tacky without liquefying; and
applying pressure to the lay-up between complimentary dies of the preform tool, with the lay-up heated to the transition temperature range where the thermoplastic interlayers are tacky, to shape the lay-up into the preform.

2 . The method of claim 1 further comprising:
removing the pressure applied by the preform tool; and
cooling the preform below the transition temperature range to solidify the thermoplastic interlayers.

3 . The method of claim 2 further comprising:
determining whether a shape of the preform matches a near-net shape for the composite member;
when the shape of the preform does not match the near-net shape, the method further comprises:
inducing heat in the preform tool again to the transition temperature range; and
applying pressure between the dies of the preform tool to further shape the lay-up into the preform.

4 . The method of claim 2 further comprising:
when a shape of the preform matches a near-net shape for the composite member:
infusing the preform with a thermosetting matrix material; and
curing the thermosetting matrix material to produce the composite member.

5 . The method of claim 1 wherein inducing heat in the preform tool comprises:
applying a current to an induction coil that encompasses the preform tool to generate a magnetic field that induces heat in a susceptor in the preform tool to the transition temperature range.

6 . The method of claim 5 wherein:
a surface area of the susceptor corresponds with a surface area of the lay-up.

7 . The method of claim 5 further comprising:
selecting a material for the susceptor that reaches a maximum temperature within the transition temperature range in the presence of the magnetic field from the induction coil.

8 . The method of claim 1 wherein:
the lay-up comprises a thermoplastic interlayer disposed between each of the reinforcement layers.

9 . The method of claim 1 wherein the composite member is formed for an aircraft.

10 . An apparatus configured to form a composite member, the apparatus comprising:
a preform tool to shape a non-conductive lay-up of dry reinforcement layers and thermoplastic interlayers into a preform for the composite member; and a controller to induce heat in the preform tool to a transition temperature range that causes the thermoplastic interlayers of the lay-up to become tacky without liquefying; wherein the preform tool applies pressure to the lay-up between complementary dies, with the lay-up heated to the transition temperature range where the thermoplastic interlayers are tacky, to shape the lay-up into the preform.

11 . The apparatus of claim 10 wherein:
the preform tool removes the pressure applied; and
the controller controls a cooling device to cool the preform below the transition temperature range to solidify the thermoplastic interlayers.

12 . The apparatus of claim 10 further comprising:
a molding tool that infuses the preform having a near-net shape for the composite member with a thermosetting matrix material, and cures the thermosetting matrix material to produce the composite member.

13 . The apparatus of claim 10 further comprising:
an induction coil that encompasses the preform tool;
wherein the controller instructs a power supply to apply a current to the induction coil to generate a magnetic field that induces heat in a susceptor in the preform tool to the transition temperature range.

14 . The apparatus of claim 13 wherein:
a surface area of the susceptor corresponds with a surface area of the lay-up.

15 . The apparatus of claim 13 wherein:
a material selected for the susceptor reaches a maximum temperature within the transition temperature range in the presence of the magnetic field from the induction coil.

16 . The apparatus of claim 10 wherein:
the lay-up comprises a thermoplastic interlayer disposed between each of the reinforcement layers.

17 . The apparatus of claim 10 wherein the composite member is formed for an aircraft.

18 . A system configured to form a composite member, the system comprising:
a preform tool to shape a non-conductive lay-up of dry reinforcement layers and thermoplastic interlayers into a preform for the composite member, wherein the preform tool includes:
complementary dies; and
a susceptor embedded in at least one of the dies;
an induction coil that encompasses the preform tool; and a controller that instructs a power supply to apply a current to the induction coil to generate a magnetic field that induces heat in the susceptor to a transition temperature range that causes the thermoplastic interlayers of the lay-up to become tacky without liquefying; wherein the preform tool applies pressure to the lay-up between the dies, with the lay-up heated to the transition temperature range where the thermoplastic interlayers are tacky, to shape the lay-up into the preform.

19 . The system of claim 18 further comprising:
a molding tool that infuses the preform having a near-net shape of the composite member with a thermosetting matrix material, and cures the thermosetting matrix material to produce the composite member.

20 . The system of claim 18 wherein:
a material selected for the susceptor reaches a maximum temperature within the transition temperature range in the presence of the magnetic field from the induction coil.

Assignees

• Boeing Co

Inventors

• Tsotsis Thomas Karl

Classifications

• B29B11/16 Primary

  comprising fillers or reinforcement {(non-woven fabrics per se D04H1/00, D04H3/00)} · CPC title

• B29C33/06

  using radiation {, e.g. electro-magnetic waves, induction heating} · CPC title

• B29C70/443

  and impregnating by vacuum or injection · CPC title

• B29C2035/0811

  using induction · CPC title

• B29C35/0805

  using electromagnetic radiation · CPC title