Technology allowing much easier, low cost fabrication of
complex shaped composite structures. It is based on a
discontinuous tow reinforcement directions permitting
the forming of complex shapes from simple preform
starting shapes. Presently available fabrics can conform
to simple shapes but will wrinkle and/or distort if made
to conform to a complex shape. Using the Pepin
technology, complex shaped parts with good mechanical
properties can be fabricated at low cost.
The concept is based on cutting currently available
reinforcing yarns or tows into discrete lengths and
aligning these to form a discontinuous tow. This
DiscoTex® tow is composed of long, discontinuous and
overlapped reinforcing tow segments combined with
aligned continuous fiber and an overwrap. The aligned
continuous fiber and overwrap fiber are required to
handle the DiscoTex® tow during textile operations but
they can also be used as the matrix precursor material.
In cases where the continuous fiber is not needed in
later processing steps it is removed to yield an all
discontinuous textile material.
Since this textile material is discontinuous it can be
stretched in its reinforcement direction allowing complex
shapes to be formed easily. A DiscoTex® Fabric for
example, can be prepregged or used in an infusion
process. A multiple, flat prepreg layup can be formed
into a bead stiffened panel in one forming step.
DiscoTex™ Preforms which are not impregnated can
also be formed. Simple starting shapes such as flat
plates, tubes, channels and the like can be formed into
more complex shapes such as beaded stiffened panels,
tubes with flanges, and curved channels. The
DiscoTex® fabric stretching permits the rapid fabrication
of complex contours while preserving fiber orientation
and fiber volume fraction. Labor intensive cutting and
darting of the fabric is eliminated.
The DiscoTex® technology is applicable to any type of
reinforcing yarns that are of current interest in the
composites industry including glass, carbon, and
ceramic. This results in a wide range of product options
including carbon aircraft structure, glass fiber piping for
the chemical industry and ceramic matrix composites for
turbine engine hot sections.