DESIGN GUIDE FOR PLASTIC MANIFOLDS

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What is a plastic manifold and why use them?

 

At its simplest, plastic manifolds are used in applications requiring control of liquids or gasses. Plastic manifold opportunities span from medical devices to in vitro diagnostics, gene sequencing and space applications, wherever the precision control of fluids is needed. Manifolds are the response to the need for smaller, more efficient devices. A manifold allows a design engineer the ability to take what are originally discrete components and consolidate them on a single block of plastic. Pumps, valves, and sensors combined together create the smallest footprint while simplifying servicing and reducing leak points.

Controlled Fluidics produces fully machined manifolds as a single layer or multilayer assembly. Multilayer manifolds allow for internal geometries not possible with only machining. Created layer by layer the multilayer manifolds are bonded together using heat, pressure and time.

All About Materials for Manifolds

  • Drilled manifold material choices
  • Bonded manifold material choices
  • Material sizes
  • Material colors
  • Material cost
  • Material certifications
  • Availability
  • Chemical resistance
  • Radiation resistance
  • Temperature resistance
  • Stress sensitive plastics
  • Misc information
  • Ease of machining

Processing

  • Intro - Bonded vs machined vs printing
    • Critical feature density
    • Printing
      • Good for coring out parts (metal printing)
      • Poor finish, Manifolds need good finish. 
    • Compare and contrast approaches
      • Footprint
      • Flexibility
      • Finishes
      • Tubing approach
      • Chemical resistance
      • Temperature resistance
      • Accuracy
      • Threads
    • How to handle a manifold
    • Delivery
      • Batch Flow
  • All about machining
    • Size of part
    • What happens when parts crack
      • Polariscope
      • Causes
    • Drilling
      • Length limitations
      • Dia. limitations
  • All about bonding
    • Number of layers
    • Max/Min size for bonding
      • Diminishing returns.
    • Pressure limitations
      • Common working pressures
    • Feature size
    • Bonded in components
    • Fixturing requirements
    • Datum location
    • Injection molded blanks
    • Channel 
      • Intersections
      • Size and sizing
      • Finish
      • Shapes
        • Liquid app
        • Pneumatic app
      • alignment
    • Bubble traps/reservoirs/accumulators
      • Size
      • supports
      • cleanout
    • Feature spacing
      • channel to channel
      • channel to reservoir
      • channel to edge
    • Features on bond line
      • Threads
      • Ports
      • channels
    • Cost drivers
      • Material
      • Number of layers
      • Feature density
    • How to bond
      • Thermal
      • Solvent
      • Tape/PSA
      • Laser
      • Vibration
      • Adhesive
    • Defects
      • Delamination
      • Bubbles
      • Foreign objects
    • How to inspect a bond line
      • Expected strength
      • Torque test
      • Visual check
      • Pressure check
      • Decay Test

Design Approach

  • How to request a quotation
    • Design complete
      • DFM
      • Quantity
      • Material choice
      • Solid model and pdf
    • Full design request
      • Working pressure
      • Flow rate
      • Foot print
      • Liquid or gas
      • Chemical exposure
      • Sensing requirements
      • Schematic
  • Tolerancing
  • Surface roughness
    • Bottom of port
    • Valve seat sealing face
  • Good practice
    • Dimension to bottom of counter bores
    • Avoid large flanges
    • Control of insert insertion depths
    • Avoiding chemical exposure like thread locker
    • Sharp channel blends
  • Clarity
    • How to make parts clear - polishing
    • Definition of clear
    • Other finishes – blead blast, tumble, as machined. 
  • Connections
    • Straight Tubing
    • Push to connect, john guest
    • Value plastic fitting
    • Beswick/memco fitting
    • Barb fitting
    • Full machined barbed fittings
    • port design
      • upchurch, high/low pressure
        • torques
        • thread engagement
      • NPT
      • Ministac
  • Marking
    • engraving
    • printing
    • laser marking
    • coloring & logos
  • Plugging
    • Press in Ball, ceramic or SS
    • Plastic plug
      • Solvent
      • UV cured 
      • press
  • Cleanliness of manifolds requirements
    • Methods of cleaning
    • Sterilization
      • Oxygen service
  • Avoiding stress cracking
    • Material choice
    • Proper coolant
    • Only plastics machine shop
    • Proper machining
    • Threading care, tapered
    • Chemical resistance
  • threading
    • drilled/tapped
    • self tapping screws Stanley Threaded Fasteners for Plastics,
    • inserts – always last
      • straight
      • npt
      • heat affected zone
      • Heli coils – tang-less
      • Examples of ways to install an insert to support a valve mount.
        • Clippard
        • Small valves - smc
  • torques

Assembly

  • Testing
  • Cost
  • Components
    • Valves
      • Design considerations
        • Pressure/vac range
        • Flow requirements Cv, sizing
        • Internal volume
        • Dead volume
        • Operating temperature
        • 2 way or 3 way
        • Mount
        • Cost
        • Operating media
          • Gas
          • Liquid
            • Chemical resistance
            • Particulate
            • Viscosity
            • temperature
      • Electrical requirements
        • Voltage
        • Power consumption
        • Duty cycle
        • Connections
        • Response time
      • Type
        • Poppet Valve
        • Diaphragm Valve 
        • Rocker diaphragm valve
        • Pinch valve
        • Lever valve
    • Pumps
      • Types
        • Syringe pump
        • Diaphragm Solenoid pumps
        • Diaphragm Motor
        • Gear
        • Rotary vane
        • Peristalitic
        • Rotary ceramic piston
      • Design considerations
        • Accuracy
        • Precision
        • Repeatability
        • Cost
        • Wetted materials, chemical resistance
        • Pressure requirements
        • Speed/increment – dispense/aspirate
        • Electrical requirements
        • Foot print
        • Mount
        • Life cycle
        • Self priming
        • Operating temperature
        • Fluid
          • Liquid
          • Gas
          • Viscosity
          • temperature
    • Wetted materials
    • Pressure sensors
    • Flow sensors
    • Check valves
    • Pressure relief
    • Fittings
      • Barbed
      • Flanged fitting – omin lok
      • Super flangeless fittings – upchurch
      • Heat form Teflon flare - diba
    • Bubble sensors
    • Orifice – Lee/Bird
    • Calculating flow in valves, tubing, Reynolds number

Appendix

  • Material specification sheets
  • Property comparison
  • Fittings
  • Inserts