SBIR-STTR Award

The objective of this project is to demonstrate an innovative approach to mold preparation materials and/or processes for vacuum-bag-only composite processing. We will identify the mechanism that causes surface pitting and then develop a novel mold release for overcoming this issue in the preparation of Out-of-Autoclave composites. Preliminary experiments will be performed to demonstrate the potential of the new nonstick materials on a mold release Al tool. An OoA carbon/epoxy fabric prepreg, such as T650-35/5320-1 8HS fabric, will be laid up and cured in the Al tool, yielding initial results that show promise for eliminating surface pitting on the finished composite.

Benefit:
Commercialization of an effective mold release technology for producing Out-of-Autoclave (OoA) composites with smooth surface finishes will be a major advancement in aerospace manufacturing technology. It will produce aircraft structures that are lighter weight and with higher performance aerodynamics. This will solve a major problem with OoA manufacturing technology, and will accelerate its widespread use by the aerospace industry. The anticipate benefit will be much lower cost and higher performance aircraft for both commercial and military applications.

Keywords:
Out-Of-Autoclave Composites; Surface Finish; Mold Release Process

We have investigated different strategies for removing the surface porosity from out-of-autoclave (OOA) composites. It was found that a release layer on the aluminum tool with a microstructure similar to that of woven Teflon release plies was effective at reducing the porosity. These structures allow trapped gases to escape during curing, so that they do not generate bubbles/pores in the laminate. Initial work yielded a decrease in porosity from 3% to 1%. A new technology has been demonstrated for rapidly coating the Al tooling with a microstructured release layer. During phase II, the topography, adhesion, durability, and surface energy of the coating will be optimized such that smooth, porosity-free OOA composites may be produced reliably and at low cost. This project will solve a long standing problem with out-of-autoclave composites that will lead to their rapid adoption throughout the aerospace industry.

Benefit:
An exciting new technology will be developed for producing out-of-autoclave structural composites with smooth surface finishes. This method will enable the adoption of OOA composites for a wide range of commercial and military applications. The new process greatly reduces the time and cost to manufacture OOA materials. In addition to aerospace applications, this technology can be adapted to other industries, including renewable energy, automotive, and consumer electronics. The phase II project proposed herein aligns well with the government's Open Manufacturing initiative, since it will dramatically reduce the expense of acquiring future warfighter systems.

Keywords:
Composites, Out-Of-Autoclave, Porosity-Free Surfaces, Structured Release Layer