SAMPE Journal - July/August 2017 - 18

Feature
Design Guide Development for Composite Tooling
Produced with Additive Manufacturing (FDM)
T. J. Schniepp
Stratasys, Inc., Eden Prairie MN
Abstract
The advanced composites industry has a continual need for innovative tooling solutions to enable new applications and
product improvements, as well as address the constant demand for reductions in response (lead) time and costs. Stratasys Fused
Deposition Modeling (FDM®) technologies allow rapid production of cost effective, highly capable composite tooling across
a broad range of tool sizes, complexity, and cure temperatures. This paper will outline the development efforts, testing, and
characterization performed to produce a comprehensive design guide for additive manufacturing (FDM) of high temperature
(>350°F) molds and mandrels for fabrication of composite structures.
Introduction
Fused
Deposition
Modeling
(FDM) is a Stratasys-patented
additive manufacturing technology
that builds parts layer-by-layer by
heating and extruding thermoplastic
filament. FDM builds in a wide range
of standard, engineering-grade, and
high-performance thermoplastics,
such as ABS, PC, and ULTEM™
resins.
FDM is becoming a technology of
choice for rapid production of high
temperature (>180 °C), low volume
composite lay-up and repair tools,
as well as for production sacrificial
(wash-out) tooling. Relative to
traditional tooling materials and
methods, FDM offers significant
advantages in terms of lead time,
tool cost, and simplification of tool
design, fabrication, and use while
enabling increased functionality and
geometric complexity.
To
enable
successful
implementation and use of FDM

composite molds and mandrels
(referred to as "composite tooling"
or "composite lay-up tooling"
herein), Stratasys has developed
a comprehensive Design Guide to
address best practices for printed
tooling, as well as to provide relevant
performance characterization data
and numerous examples of effective
tool designs. A summary of the
development and characterization
efforts are presented herein.
Background and Purpose
Traditional
manufacturing
methods for high performance
fiber-reinforced polymer matrix
(FRP) composite structures require
the use of hard tooling for the
mold or mandrel that dictates the
shape of the final part. The mold or
mandrel is most commonly made
of metallic materials (aluminum,
steel, or Invar alloys), although nonmetallic materials are also utilized
(specialized
composite
tooling

materials, high temperature tooling
board, etc.). Regardless of material,
tool fabrication typically requires
significant labor and machining,
leading to high costs, material waste,
and long lead times, consisting of
many weeks for even relatively
simple part shapes and many
months for more complex tools.
The use of additive manufacturing
(or "3D printing"), and specifically
FDM, for composite tooling has
demonstrated considerable cost and
lead time reductions while providing
numerous other advantages such as
immense design freedom and rapid
iteration, nearly regardless of part
complexity.
Stratasys FDM technology has
been successfully utilized for low
volume composite lay-up and repair
tooling applications for years, but
was limited by the lack of materials
capable of withstanding the 180°C
cure
temperature
frequently
required for aerospace and similar
high performance structures, as well
as a lack of design knowledge and
guidance. FDM materials ABS (and
ASA), PC, and ULTEM™ 9085 have
been demonstrated to be effective
to temperatures up to 85°C, 135°C,
and 150°C, respectively. With the
introduction of ULTEM™ 1010,
FDM technology has demonstrated
numerous advantages for fabrication
of composite structures cured at
temperatures in excess of 180°C and
pressures of 0.7 MPa.

Figure 1. Cure temperature capabilities for FDM materials.
18

SAMPE Journal, Volume 53, No. 4, July/August 2017

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