Sheet Fabrication Plet 370 Matt Eury Brian Martonik Mike McElhaney

Objective To understand sheet fabrication and how it’s processed and to learn the applications that sheets can be used in.

Outline Materials Processes Equipment Secondary operations Applications

Materials Acrylic Polycarbonate Polypropylene Polyethylene Nylon Acetyl PVC

Processes to Form sheets Cell Cast Continuous cast Extrusion

Cell Casting Poured between two sheets of glass PVC gasket Heat process causes reaction –Produces good surface quality and optics –Low optical distortion

Cell Casting Sizes –2 m by 3 m Thickness –2 to 12 mm

Continuous Casting Poured between two highly polished steel belts –Belts heat and cool material –Highest productivity –High molecular weight –Harder surfaces –Isotropic shrinkages

Continuous Casting Sizes - varies Thickness mm

Extrusion Resin pellets melted by extruder Shaped by die

Extrusion Sizes –Up to 4 meters Thickness –.25 to 15 mm

Equipment Auxiliary Equipment needed to achieve desired results in sheet extrusion –Blenders –Screen changers –Melt Pump –Static Mixers –Texture Rolls

Equipment –Grinders –Dryers –Feedstock

Secondary Operations Cutting Decorating Drilling Forming Jointing Finishing

Secondary Operations Cutting –Band Saws –Circular Saws –Knife –Laser Cutting –Water jet Decorating –Printing –Painting –Stamping –Decals

Secondary Operations Drilling –Tapping –Hole saw –Drill Bits Forming –Thermoforming –Presses –Clamps –Cold Forming

Secondary Operations Jointing –Cementing –Adhesives –Dip and Soak –Ultrasonic Welding Finishing –Sanding –Filing –Ashing –Polishing

Desired Properties of sheets Sheet properties have a significant influence on process ability of a sheet. –Dimensions –Surface type –Orientation –Contamination

Desired Properties of sheets –Toughness –Moisture content

Why are Sheets used? Light weight Weather Resistance Colors Good optical qualities High impact resistance Cost (glass)

Disadvantages Cracking Bubbles Crazing Low Tolerances (Cell Casting)

Applications of Sheets Signs Picture frames Instrument panels Safety shields Hot Tubs Glass Replacement

Applications continued