Additive Manufacturing

Electroimpact has integrated an in-situ out-of-autoclave thermoplastic AFP process and an advanced FFF 3D printing process into a unified Scalable Composite Robotic Additive Manufacturing (SCRAM) system. SCRAM is an industrial true 6-axis continuous fiber-reinforced 3D printer, which enables the tool-less rapid fabrication of aerospace-grade integrated composite structures. High-performance thermoplastics combined with a high percentage of continuous fiber reinforcement are used to produce parts with exceptional material properties previously unheard of in the world of additive manufacturing. This technology has no equal in the industry and is a unique offering available only from Electroimpact.

"True 3D" Printing

Most 3D printing processes are accurately described as “2.5D” printing, as material is always deposited successively in flat slices, which when stacked together form a 3D object. The SCRAM process, on the other hand, can be considered “true 3D” printing. Layers of continuous fiber-reinforced thermoplastic can take the shape of complex contours, such as aerodynamic surfaces and ducts for fluid flow. Furthermore, as it is a 6-axis process, fiber orientation within each layer can be tailored to the specific application to provide optimal strength and stiffness distribution throughout the part, much like a conventional AFP system.

Tooling Printed On Demand

Each SCRAM cell is equipped with not only a continuous fiber-reinforced printing system, but also a rapid tool fabrication system based on an advanced FFF printing process. Conventional automated fiber layup always requires a substantial investment in hard tooling that is inflexible, expensive, and long-lead. Operators of a SCRAM cell, in contrast, can simply print their support tool on demand, starting from just a flat plate. Later, after the part has finished printing, the tool material is dissolved away. This enables rapid design iteration and allows any given SCRAM cell to be only limited by its size and the imagination of the designer. It also allows creation of part geometries such as internal channels that are difficult or impossible to produce otherwise.

A Multi-Material System

In addition to the continuous fiber-reinforced thermoplastic printing process and the FFF support tool printing process, SCRAM cells are also fitted with an FFF nozzle optimized for deposition of thermoplastic material reinforced with short or “chopped” fiber. A proprietary laser heating system is incorporated, producing exceptionally strong bonds between layers. This process is ideal for situations where laying up continuous fiber is geometrically impossible or otherwise doesn’t make sense.

Like the continuous fiber process, this is a “true 3D” printing process where the layers are not constrained to a stack of planes. Complex geometries such as variable density core and other internal structures can be printed directly onto continuous fiber-reinforced layers with widely varying curvature. If desired, continuous fiber-reinforced layers can then be deposited on top of the chopped fiber-reinforced core structure, forming an upper skin.

Example Material Systems

  • PAEK family thermoplastics (PEEK, PEKK, etc.)
  • Nylons and other low-temp thermoplastics (PA12, ABS, etc.)
  • Water-soluble thermoplastics
  • Carbon fiber
  • Glass fiber
  • Boron fiber

SCRAM Cell Typical Bill of Materials

  • Siemens 840D CNC
  • 6-axis robot with Electroimpact’s patented Accurate Robot package
  • Continuous 6th robot axis for utilities pass-through with unlimited rotation
  • Tool change interface allowing end effectors to be picked up and dropped off seamlessly
  • Multi-material deposition end effector
  • Heated build platform with rotating hot plate
  • Heated build chamber
  • Coupon and calibration stand
  • CAM part programming software suite
  • Training for operators, mechanics, and programmers

Optional Features

  • High-throughput plastic pellet extrusion end effector, for depositing large support tools quickly from inexpensive feedstock
  • Subtractive machining end effector, for trimming parts and conditioning support tool surfaces for optimal finish and accuracy
  • Partially-reusable support tool system incorporating a water-soluble sacrificial layer for short production runs

Contact Electroimpact for more information: