Erdem Özdemir - 030070307 - 7th Week Definitions Part 2

Elastic Reservoir Molding

Manufacturing
New Definition

Foamed reservoir molding is also known as elastic reservoir molding. It has had limited use. This process creates a sandwich of plastic-impregnated, open-celled, flexible plastic foam between the face layers such as fibrous reinforcements. When this plastic composite is placed in a heated mold and squeezed, the foam is compressed, forcing the plastic and air outward and into the reinforcement. The elastic foam exerts sufficient pressure to force the plastic-impregnated reinforcement into contact with the mold surface and simultaneously removing entrapped air.

(Plastic Product Material and Process Selection Handbook, 2004, Dominick V. Rosato, Donald V. Rosato, Matthew V. Rosato, P365)

Previous - Better Definition

The starting charge in elastic reservoir molding (ERM) is a sandwich consisting of a center of polymer foam between two dry fiber layers. The foam core is commonly open-cell polyurethane, impregnated with liquid resin such as epoxy or polyester, and the dry fiber layers can be cloth, woven roving, or other starting fibrous form. As depicted in figure, the sandwich is placed in the lower mold section and pressed at moderate pressure – around 0,7 MPa (100 lb/in2). As the core is compressedi it releases the resin to wet the dry surface layers. Curing produces a lightweight part consisting of a low-density core and thin FRP skins.

(Fundamentals of Modern Manufacturing: Materials, Processes, and Systems, Mikell P. Groover, p. 328)

Tube Rolling

Manufacturing
New - Better Definition

In the tube rolling technique, prccut lengths of a prepreg are rolled onto a removable mandrel by a number of techniques. Some of the various tube rolling methods arc illustrated in Figure 6.15. In this method, the uncurcd tube is wrapped with a heat-shrinkablc film or sleeve and is cured at high temperatures in an air-circulated oven. As the outer wrap shrinks tightly on the rolled prepreg, air is squeezed out at the ends. After the curing, the mandrel is removed and a hollow lube is formed. The tube rolling process is more suitable for simple lay-ups containing 0 and 90° layers. Its advantages arc low tooling costs, simple operation, goinJ control of resin content and resin distribution, and fast production rates.

(Handbook of Composite Fabrication, 2001, Güneri Akovali, P 155)

Previous

Tube rolling FRP tubes can be fabricated from prepreg sheets by rolling technique.Such tubes are used in bicycle frames and space trusses.In the process a precut prepreg sheet is wrapped around a cylindrical mandrel several times to obtain a tube wall of multiple sheets thicknesses.The rolled sheets are then encased in a heat-shrinking sleeve and ovencured.As the sleeve contracts, entrapped gases are squeezed out the ends of the tube.When curing is complete, the mandrel is removed to yield a rolled FRP tube.The operation is simple, and tooling cost is low.There are variations in the process such as using different wrapping methods or using a steel mold to enclose the rolled prepreg tube for better dimensional control.
(Mikell P. Groover,Fundamentals of Modern Manufacturing: Materials, Processes, and Systems, p.341)