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Sheet FabricationPlet 370
Matt EuryBrian Martonik
Mike McElhaney
Objective
• To understand sheet fabrication
• Learn it’s processability
• Learn the applications
Outline
• Materials
• Processes
• Equipment
• Secondary operations
• Applications
Introduction
• Several Sheet fabrication processes
• Many materials used
• Wide range of applications
Advantages
• Light weight
• Weather Resistance
• Colors
• Good optical qualities
• High impact resistance
• Cost (glass)
Disadvantages
• Cracking
• Bubbles
• Crazing
• Low Tolerances (Cell Casting)
Materials
• Acrylic
• Polycarbonate
• Polypropylene
• Polyethylene
• Nylon
• Acetyl
Processes to Form sheets
• Cell Cast
• Continuous cast
• Extrusion
Cell Casting
• Poured between sheets of glass
• PVC gasket
• Heat process causes reaction – 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 polished steel belts– Belts heat and cool material– Highest productivity – High molecular weight– Harder surfaces – Isotropic shrinkages
Continuous Casting
• Sizes
- varies
• Thickness
- 1.5 mm
Extrusion
• Resin pellets melted by extruder
• Shaped by die
Extrusion
• Sizes – Up to 4 meters
• Thickness– .25 to 15 mm
Equipment
• Auxiliary Equipment– 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
Secondary Operations
• Decorating – Printing – Painting – Stamping – Decals
Secondary Operations
• Drilling – Tapping – Hole saw– Drill bits
Secondary Operations
• Forming – Thermoforming – Presses– Clamps– Cold forming
Secondary Operations
• Jointing – Cementing – Adhesives– Dip and soak– Ultrasonic welding
Secondary Operations
• Finishing – Sanding – Filing – Ashing – Polishing
Desired Properties of sheets
• Sheet properties– Dimensions– Surface type– Orientation– Contamination
Desired Properties of sheets
– Toughness– Moisture content
Applications of Sheets
• Signs
• Picture frames
• Instrument panels
• Safety shields
• Hot Tubs
• Glass Replacement
Applications continued
Conclusion
• Great glass replacement
• Many applications
• Mass production easily accomplished