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At least 235 records · Page 13

Evaluation of Additive Manufacturing for Composite Part Molds

The ORNL Manufacturing Demonstration Facility (MDF) collaborated with Tru-Design to test the quality and durability of molds used for making fiber reinforced composites using additive manufacturing. The partners developed surface treatment techniques including epoxy coatings and machining to improve the quality of the surface finish. Test samples made using the printed and surface finished molds demonstrated life spans suitable for one-of-a-kind and low-volume applications, meeting the project objective.

36 MATERIALS SCIENCE↗

Evaluation of Additive Manufacturing for High Volume Composite Part Molds

ORNL worked with TruDesign, LLC to develop viable coating solutions to enable the use of large scale 3D printing for both low-temperature and high-temperature composite molds. This project resulted in two commercial products and successfully demonstrated the use of printed molds for autoclave processing for the first time.

42 ENGINEERING↗

Feasibility of Using BAAM for Mold Inserts for the Precast Concrete Industry (CRADA NFE-17-06874 Final Report)

Oak Ridge National Laboratory worked with Gate Precast to demonstrate the viability of using carbon fiber reinforced acrylonitrile butadiene styrene (ABS) plastic and the Big Area Additive Manufacturing (BAAM) technology to rapidly manufacture molds for the precast concrete industry. This Phase 2 project focused on developing more complex molds that will be used in production.

42 ENGINEERING↗

Printed Metal Molds for Mainstream Automotive Production

The main focus of this work was to evaluate additive manufacturing of metal molds, with significantly reduced cost and/or procurement lead time, for production of large composite components for mainstream (> 100k units/yr) automobiles. A two-component large tool with conformal heating channels was designed, optimized, printed, machined, and tested in production. The resulting analysis indicates that large scale AM is suitable for manufacturing complex geometry large scale metal molds.

36 MATERIALS SCIENCE↗

Enabling Next Generation Reaction Injection Molding (RIM) for Lightweight Structures

Replacing metal components in trucks, trailers, and buses with lightweight polymer composites is challenging due to high temperatures and complex manufacturing. The Reaction Injection Molding (RIM) process using Dicyclopentadiene (DCPD) resin offers a solution by producing robust parts with excellent stiffness, impact strength, and resistance properties. Simulations are essential for optimizing this process, predicting defects, and improving quality. However, most commercial software is tailored for thermoplastics, requiring thermoset users to generate their own datasets. In this project, a material data card for DCPD was developed to perform RIM simulations. Design of Experiments (DOE) was used to identify key factors affecting filling, curing, and warpage, aiming to minimize cycle time and defects. The simulations explored varying injection gate parameters (size, location, number) and process conditions (mold/resin temperature, injection/curing pressure). Results showed that gate design significantly impacts filling behavior and defects. A single central gate provided balanced flow with fewer defects, while two corner gates led to more defects. Additionally, lower injection pressure increased filling time, while higher mold temperature accelerated curing but led to more warpage. This optimization framework aims to enhance DCPD part performance and promote sustainable manufacturing by reducing waste and energy consumption. This research has been performed in collaborations with McClarin Composites. The research outcome has been submitted to the Journal of Manufacturing Processes.

36 MATERIALS SCIENCE↗

Molding a high-density laminate

Molding press is used to form phenolic resin impregnated glass fiber cloth into a high-density, cylindrical-ring laminate. The press applies clamping pressure and heat to a mold containing the glass fiber cloth laminate, which has hydrostatic pressure applied to it by means of a specially designed pressure plug.

Haraway, W. M.↗

Improved molding process ensures plastic parts of higher tensile strength

Single molding process ensures that plastic parts /of a given mechanical design/ produced from a conventional thermosetting molding compound will have a maximum tensile strength. The process can also be used for other thermosetting compounds to produce parts with improved physical properties.

Heier, W. C.↗

Strong, easy-to-mold, spiral buttress thread

Buttress thread with steep taper connects two molded plastic cylinders without changing wall thickness or sacrificing longitudinal strength at the juncture. Technique lends itself to conventional molding methods.

Heier, W. C.↗

Folding tool for preparing FCC molded-plug terminations

Assemblies consist of window piece, conductor spacer, insulator, outer seal, and molded portion that integrates all components. Preparation of FCC for molded plug termination requires that terminated ends of conductors in each cable be accurately folded simultaneously into spacer end and groove.

Campbell, E. C.↗

Twistable mold for helicopter blades

Design is described of mold for fabrication of blades composed of sets of aerodynamic shells having same airfoil section characteristics but different distributions. Mold consists of opposing stacks of thin templates held together by long bolts. When bolts are loosened, templates can be set at different positions with respect to each other and then locked in place.

Carter, E. S.↗

Evacuated displacement compression molding

A process for molding long, thin-wall tubular bodies from thermosetting plastic molding compounds is described. The tubular bodies produced may have body lengths several times the diameters. The application of the process for manufacturing rocket engine cases and nozzles is discussed. The advantages of the system over other methods of circular tube manufacture are analyzed.

W C Heier↗

Molding apparatus

Apparatus for compression molding of thermosetting plastics compositions including interfitting hollow male and female components is reported. The components are adapted to be compressed to form a rocket nozzle in a cavity. A thermal jacket is provided exteriorly adjacent to the female component for circulating a thermal transfer fluid to effect curing of a thermosetting plastics material being molded. Each of the male and female components is provided with suitable inlets and outlets for circulating a thermal transfer fluid.

Heier, W. C.↗

Thermal stresses in chemically hardening elastic media with application to the molding process

A method has been formulated for the determination of thermal stresses in materials which harden in the presence of an exothermic chemical reaction. Hardening is described by the transformation of the material from an inviscid liquid-like state into an elastic solid, where intermediate states consist of a mixture of the two, in a ratio which is determined by the degree of chemical reaction. The method is illustrated in terms of an infinite slab cast between two rigid mold surfaces. It is found that the stress component normal to the slab surfaces vanishes in the residual state, so that removal of the slab from the mold leaves the remaining residual stress unchanged. On the other hand, the residual stress component parallel to the slab surfaces does not vanish. Its distribution is described as a function of the parameters of the hardening process.

Levitsky, M.↗

Some load limits and self-lubricating properties of plain spherical bearings with molded graphite fiber reinforced polyimide liners to 320 C

Plain spherical bearings with molded liners of self-lubricating graphite fiber-polyimide composite were developed and their dynamic load capacities were determined. Liners were prepared by transfer molding a prepolymer resin-fiber mix into the space between the ball and outer race, the completing polymerization under heat and pressure. Bearing dynamic load capacities were in excess of 140 MPa (20,000 psi) from room temperature to 260 C and about 70 MPa (10,000 psi) at 320 C. Friction coefficients were about 0.20 at room temperatures and light loads and tended to decrease with increasing temperatures and loads to about 0.15. Thermal expansion of the liner at uniform bearing temperatures of 200 C or higher produced a bearing preload which could be alleviated by providing an initial internal diametral clearance of 0.05 to 0.10 mm.

Sliney, H. E.↗

Volume-change indicator for molding plastic

Monitor consisting of two concentric disks measures change in volume of charge during compression/displacement molding. Device enables operator to decide whether process pressure and temperature are set properly or whether sufficient material has been placed in mold.

Heler, W. C.↗

Development of molded, coated fabric joints: Fabric construction criteria for a spacesuit elbow joint

The design and fabrication of a molded, coated fabric elbow joint capable of operating reliably at 8 psi internal pressure for extended periods of flexure is considered. The overall design of the joint includes: (1) selection of heatsettable fiber of sufficient strengths; (2) choosing an optimum fabric construction; (3) a fatigue resistant; flexible coating; and (4) a molding technique. A polyester yarn of type 56 Dacron and a urethane coating system were selected. The relationships between yarn and weave parameters which lead to an optimum fabric construction for the 8 psi elbow joint are defined.

Olson, L. H.↗

New methods and materials for molding and casting ice formations

This study was designed to find improved materials and techniques for molding and casting natural or simulated ice shapes that could replace the wax and plaster method. By utilizing modern molding and casting materials and techniques, a new methodology was developed that provides excellent reproduction, low-temperature capability, and reasonable turnaround time. The resulting casts are accurate and tough.

Reehorst, Andrew L.↗

Contamination Barrier For Contour-Molding Material

Release agent prevents molding compound from adhering to or contaminating surface. Cleaning agent, Turco 4215 NCLT, forms barrier preventing silicone molding compound from sticking to surface and leaving contaminating residue. Also see MFS-29243.

Adams, James F.↗