design for manufacturing - class 7 part 2 - compression molding
TRANSCRIPT
DRAGON INNOVATION, INC. !
DESIGN FOR MANUFACTURING !
COURSE 7: PART 2 - COMPRESSION MOLDING !!!!!!!
SCOTT N. MILLER | CEO | @DRAGONINNOVATE | WWW.DRAGONINNOVATION.COM
Compression Molding Overview
Typical Compression Molded Parts
• Gaskets and Seals
• Couples
• Remote Button Pad
• Hoses and Fittings
Compression Molding Advantages
• Can use variable wall thickness • No flow lines or knitting (O-Rings) • Low Cost • Suitable for high volume manufacturing • Flexible Materials / Can use Thermosets • Good surface finish • Low residual stress
Compression Molding Disadvantages
• Slow cycle time requires multiple cavities (configuration issues and cost)
• Cannot regrind excess material • Simpler parts • Requires workers to place resin and remove flash. • Typically planar parts (limited mold depth)
Compression Molding Process
Process
• Thermoset charge placed in open mold cavity • Mold closed with heat and pressure • Crossing linking • Manual extraction and flash trimming
Process
Compression Molding Part Design
Design Guidelines
• Typically planar / flat parts • OK to have non-uniform wall thickness • Flexible component
Materials
Common Materials
Alloy / Resin Young’s (MN/m2)
Yield (MN/m2)
Spc Gravity (g/cm3)
Cost ($/kg)
Die Life (cycles)
Pressure (psi)
Wall Thickness (mm)
Melting Temp (C)
Silicone 70,000 250 6.6 1.80 500,000 3,000 1.0 – 1.5 420
Natural Rubber 80,000 330 5.8 1.90 500,000 5,100 2.0 – 2.3 430
Neoprene 125,000 150 2.7 1.70 100,000 7,000 2.0 – 2.3 660
Melamine Formaldehyde
45,000 150 1.8 2.93 180,000 7,000 2.0 – 2.3 650
Phenolic 100,000 215 8.4 6.60 15,000 5,800 2.0 – 3.0 950
28,000 70 1.13 4.00 300,000 16,000 2.0 – 3.0 130
• Silicone • Natural Rubber • Phenolic
Common Materials