https://www.avient.com/sites/default/files/2020-10/2020-gravi-tech-design-guide-.pdf
Unfortunately, this method only has limited durability and has a minimum amount of assembly repeatability.2 FIGURE 19 - Mechanical Fasteners Design Guidlines Potential high stress due to wedging action of screw head Potential high stress due to wedging action of screw head Poor DesignsPoor Designs Preferred DesignsPreferred Designs Planned gap between added bosses prevents excessive bending of hosing as bosses touch and go into compression Planned gap between added bosses prevents excessive bending of hosing as bosses touch and go into compression Alternative recessed head design avoids potentially dangerous wedging action Alternative recessed head design avoids potentially dangerous wedging action Truss or Round Head ScrewTruss or Round Head Screw Potential high bending stress as bolt is tightened Potential high bending stress as bolt is tightened Flat-head Screw Standard Screw Plastic Part Metal Sub-frame Shoulder Screw Plastic Part Metal Casting FIGURE 20 - Mechanical fasteners design guidelines F= π × µ × DShaft 1engage × σH W I = D – 0.373 = 0.0002" σH = 1 × W DShaft W + v E( ) σH = = 200psi 0.002 × 1.998 0.375 1.998 + 0.4 450000( ) W = = 1.998 1 – 0.375 0.650( )2 1 + 0.375 0.650( )2 W = DShaft ODHub 1 – ( )2 DShaft ODHub ( )2 1 + FIGURE 16 - Interference fit variable F= π × µ × DShaft 1engage × σH W I = D – 0.373 = 0.0002" σH = 1 × W DShaft W + v E( ) σH = = 200psi 0.002 × 1.998 0.375 1.998 + 0.4 450000( ) W = = 1.998 1 – 0.375 0.650( )2 1 + 0.375 0.650( )2 W = DShaft ODHub 1 – ( )2 DShaft ODHub ( )2 1 + FIGURE 17 - Geometry factor variable F= π × µ × DShaft 1engage × σH W I = D – 0.373 = 0.0002" σH = 1 × W DShaft W + v E( ) σH = = 200psi 0.002 × 1.998 0.375 1.998 + 0.4 450000( ) W = = 1.998 1 – 0.375 0.650( )2 1 + 0.375 0.650( )2 W = DShaft ODHub 1 – ( )2 DShaft ODHub ( )2 1 + FIGURE 18 - Hoop stress equation F= π × µ × DShaft 1engage × σH W I = D – 0.373 = 0.0002" σH = 1 × W DShaft W + v E( ) σH = = 200psi 0.002 × 1.998 0.375 1.998 + 0.4 450000( ) W = = 1.998 1 – 0.375 0.650( )2 1 + 0.375 0.650( )2 W = DShaft ODHub 1 – ( )2 DShaft ODHub ( )2 1 + FIGURE 19 - Press fit pull-out force .400 .500 .375 .373 .650 FIGURE 15 - Press fit example Design Guide 13 ADHESIVE TYPES A chart containing the various specific adhesive types, with advantages and disadvantages of both can be seen in the appendix.
DEFECTS Design Guide 37 SOURCES Mold Machine Material Process Hot spots Improper cooling Venting plugged Leaking check ring Barrel too hot Contamination Too hot No cushion Hold pressure too low Melt temperature too high Reduced transfer position Back pressure too low RECOMMENDED ADJUSTMENTS Check venting Add a flow leader Insure cushion position Insure proper screw recovery Add a foaming agent Increase hold pressure Increase hold time Reduce injection speed Reduce melt temperature Reduce mold temperature Increase mold temperature Sink Root cause: Material is shrinking away from mold surface. 38 Gravi-Tech SOURCES Mold Machine Material Process Venting impaired Condensation Heater band overriding Wrong screw configuration Wet material Contamination Injection speed too fast Residence time too long Excessive decompression RECOMMENDED ADJUSTMENTS Increase gate size Check mold surface for condensation Check for condensation in feed throat Check dry material dew point Dry material Increase mold temperature Reduce melt temperature Reduce back pressure Reduce screw speed Reduce decompression Splay • Silver streaks on part Root cause: Material degradation DEFECTS Design Guide 39 SOURCES Mold Machine Material Process Venting impaired Leaking check ring Heating band burned out New lot Contamination Melt temperature too low Hold pressure too low Back pressure too low Transfer position too high Injection speed too low RECOMMENDED ADJUSTMENTS Clean mold surface Check vents Increase gate size Increase melt temperature Increase mold temperature Increase hold pressure Increase hold time Increase injection speed Increase back pressure Decrease transfer Surface Finish Root cause: Material is not reproducing the mold surface finish. 40 Gravi-Tech SOURCES Mold Machine Material Process Tooling damage Heater band overriding Leaking check ring Contamination Wet material Melt temperature too high Back pressure too high No cushion Pack pressure too high Hold time too low RECOMMENDED ADJUSTMENTS Reduce gate size Increase cooling in gate area Check gate for blockage Check thermocouples for continuity Ensure cushion is maintained Dry material Reduce melt temperature Increase hold pressure Increase hold time Reduce back pressure Increase cooling time Reduce tip temperature Gate Vestige Root cause: Material doesn’t have a clean break at gate.
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Continuous Glucose Monitors (CGM)
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Continuous Glucose Monitors (CGM)
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Continuous Glucose Monitors (CGM)
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Continuous Glucose Monitors (CGM)
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Continuous Glucose Monitors (CGM)
https://www.avient.com/resource-center?document_type=221&document_subtype=0&industry=0&product_family=0&product_name=0&op=FILTER RESULTS&form_id=resource_filter_form&page=3
Made from continuous glass-fiber reinforced thermoplastic face sheets and polyester foam cores, Hammerhead Marine Composite Panels are engineered to provide simplified installation, long-lasting components, and overall cost reduction for boat manufacturers.
https://www.avient.com/resource-center?document_subtype=0&document_type=221&form_id=resource_filter_form&industry=0&op=FILTER RESULTS&product_family=0&product_name=0&page=3
Made from continuous glass-fiber reinforced thermoplastic face sheets and polyester foam cores, Hammerhead Marine Composite Panels are engineered to provide simplified installation, long-lasting components, and overall cost reduction for boat manufacturers.
https://www.avient.com/news/avient-highlight-achievements-global-growth-latest-innovations-plastindia-2023
The efficiency-enhancing features ensure continuous and consistent delivery of liquid colorants and additives, reducing overall waste.
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Continuous Glucose Monitors (CGM)