Method for Insertion of Carbon Fiber Through the Thickness of Dense Dry Fiber Preform

Heat shields for re-entry vehicles, and jet engine exhaust components are two potential applications.

Ames Research Center, Moffett Field, California

Creation of a structural joint for a heat shield for extreme entry environments requires structural fibers penetrating through the thickness of the shield at joint locations. The structural fibers must be made of carbon to withstand extremely high temperatures, i.e. 2000 ºC. Carbon fibers, due to their relatively high modulus (stiffness), are easily damaged and broken when handled by a conventional sewing machine. Special coatings such as nylon are required to increase the durability of the fiber to enable its use in a sewing or tufting process.

Posted in: Briefs, Manufacturing & Prototyping, Coatings, colorants, and finishes, Fibers, Materials properties

Edge-Bonded Shims

Edge-bonded shims reduce assembly time and require less inventory storage space.

SPIROL International Corp., Danielson, Connecticut

Precision shims are used as compensators to absorb tolerances between mating components. They significantly reduce manufacturing costs by eliminating the need for each component to be precision-machined in order to achieve the proper fit and function of the total assembly. During the assembly process, shims provide adjustment to compensate for accumulated tolerances that significantly reduces the need for re-machining and assembly time. Additionally, shims are commonly used to preserve the faces between mating components, cutting down the required machining time during rebuilds/retrofitting.

Posted in: Briefs, Manufacturing & Prototyping, Assembling, Machining processes, Parts

Precision Detector Conductance Definition via Ballistic Thermal Transport

This innovation could be applied in the development of bolometric detector array sensors.

Goddard Space Flight Center, Greenbelt, Maryland

The characteristics of a thermal detector, such as sensitivity, response time, and saturation power (or energy resolution), are functions of the thermal conductance of the detector to its cryogenic environment. The thermal conductance is specified to achieve a tradeoff among the highest sensitivity, allowed response time, and the desired saturation energy or power budget for the particular application. It is essential to achieve the design thermal conductance (within an acceptable variance) after a thermal detector has been fabricated. Otherwise, the detector will fail to achieve its desired functionality. In addition, the formation of a multi-pixel imaging array becomes difficult and costly when the design thermal conductance is not achieved with high post-fabrication yield.

Posted in: Briefs, TSP, Manufacturing & Prototyping, Sensors, Imaging and visualization, Conductivity, Thermal testing

Products of Tomorrow: February 2016

The technologies NASA develops don’t just blast off into space. They also improve our lives here on Earth. Life-saving search-and-rescue tools, implantable medical devices, advances in commercial aircraft safety, increased accuracy in weather forecasting, and the miniature cameras in our cellphones are just some of the examples of NASA-developed technology used in products today.

Posted in: Products, Aerospace, Manufacturing & Prototyping

Scientists Print in 4D

Scientists at the Wyss Institute for Biologically Inspired Engineering at Harvard University and the Harvard John A. Paulson School of Engineering and Applied Sciences have brought a fourth dimension to their microscale 3D printing technology.

Posted in: News, Manufacturing & Prototyping, Materials

Thermal Spraying of Coatings Using Resonant Pulsed Combustion

This is a high-volume, high-velocity surface deposition of protective metallic and other coatings on surfaces.

John H. Glenn Research Center, Cleveland, Ohio

Thermal spray coating is not a new process. There are different techniques utilized that depend on the objective function of the coating, the environment to which the coated piece will be subjected, and the coating material used. In any application, quality is ultimately measured by how well the coating material adheres to the sprayed surface. This, in turn, is controlled by the velocity at which the coating material impinges on the substrate, the size of the molten coating particles, and the degree to which the coating material is prevented from chemically reacting while in a molten state.

Posted in: Briefs, TSP, Manufacturing & Prototyping, Spraying, Coatings, colorants, and finishes

Plasma Treatments to Assist Fluid Manipulation in Microgravity

Altering the surface energy of container walls permits anchoring of fluids within the container.

Lyndon B. Johnson Space Center, Houston, Texas

A recent innovation has made manipulation of hazardous laboratory reagents in microgravity easier, thus enabling even more scientific research to be performed on the International Space Station (ISS). Prior to this innovation, moving fluids from container to container was performed only under conditions of redundant and physically separate layers of containment. This design paradigm restricts access to — and direct manipulation of — fluids in microgravity conditions.

Posted in: Briefs, Manufacturing & Prototyping, Waste management, Hazardous materials, Spacecraft

Stencil-less Jet Printing for PCB Assembly

Solder paste inkjet is an inline, solder-mask printing technology that enables 3D printing of different thicknesses of solder paste for prototype PCBs.

Imagineering Inc., Elk Grove Village, Illinois

For many years, stencil printing has been the standard method of depositing solder paste on surface mount assembly printed circuit boards (PCBs). It has provided a durable method of applying solder paste, but there were always difficulties that significantly slowed down a change from one product to another in the assembly operation, and added cost. A significant challenge in newer, smaller electronics assembly is the huge difference in size among components. Therefore, trying to apply the right amount of solder paste for each component with one stencil is difficult. The biggest problem is how to produce quick-turn prototypes without disrupting series production that is already running in the line. Product changeover requires time-consuming tweaks to the stencil printing process, while unnecessarily shutting down an expensive assembly line to change the product. The inability of the stencil’s technology to vary solder paste volume by part, on the run, remains the biggest impact on the soldering quality.

Posted in: Briefs, Manufacturing & Prototyping, Computer software and hardware, Production, Welding

In-Situ Mixing, Degassing, Decavitation, and Extrusion Modules for Fused Deposition Modeling 3D Printers

A resonant acoustics mixing mechanism equipped with high-vacuum pulling capacity will be employed.

John H. Glenn Research Center, Cleveland, Ohio

Additively manufactured 3D articles of certain high-temperature polymer composites such as ULTEM 1000 reinforced with chopped carbon fibers and printed by current state-of-the-art Fused Deposition Modeling (FDM) printers, suffer significantly with high porosity due to moisture-induced cavitation during the liquefying process under high printing temperatures because the pre-fabricated feedstock filaments contain excessive moisture trapped in polymer matrix or fiber interfaces that is extremely difficult to remove. During compounding (mixing of chopped fibers with resin) and the filament extrusion process, controlling moisture absorption is extremely difficult and very costly. Furthermore, compounding and filament fabrication are two separate processes normally performed at different plants, and thus add extra costs and technical challenge of keeping the material dry. In the case of the high-temperature polymer, it is even more difficult to control the residual moisture content and is more prone to blistering during FDM printing due to higher melting temperature.

Posted in: Briefs, TSP, Manufacturing & Prototyping, Additive manufacturing, Composite materials, Polymers

Products of Tomorrow: January 2016

The technologies NASA develops don’t just blast off into space. They also improve our lives here on Earth. Life-saving search-and-rescue tools, implantable medical devices, advances in commercial aircraft safety, increased accuracy in weather forecasting, and the miniature cameras in our cellphones are just some of the examples of NASA-developed technology used in products today.

Posted in: Articles, Products, Manufacturing & Prototyping

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