Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

35 Cards in this Set

  • Front
  • Back
Portuberance on a plastic part designed to add strength, facillitate alignment, provide fastenings
Clamping plate
plate fitted to a mold and used to fasten the mold to a plate
Daylight opening
clearance between 2 platens of a clamping press in the open position
surface of the finished part separates or apperas to be composed of layers-- fish scale appearance
diaphragm gate
used in symmetrical cavity filling to reduce wel-line formation and improve filling rates
extrusion or leakage of molten resin from a nozzle
pause in application of pressure to a mold -- made just beore the mold is completely closed allowing gas to escape
fan gate
used to help reduce stress concentrations in the gate area by spreading the opening over a wider area
web of material reminging in holes or openings in a molded part which must be remove for final assembly
extra plastic attatched to along parting sides
master model of hardened steel--sink the shape of a mold into soft metal block
turbulent flow in the resin melt caused by an undersized gate or where a thin section becomes thicker
tool for holding parts of an assambly
knit lines
marks visible on a finished part made by the meeting of 2 flow fronts during molding
laminar flow
flow of a resin in a mold is accompanied by solidification of the layer in contact with the mold surface that acts as an insulator through which material flows to fill the remainder of the cavity
machine shot capacity
(polystyrene--determines) max weight of plastic which can be displaced or injected by single stroke
raised edge around mold cavity that seals off the part and separates excess material as the mold closes around the parison in the flow-molding operation
delivers a shot of resin to the nozzle and mold
restricted gate
very small orifice between runner and cavity in an injection mold--when part is ejected, this gate breaks free of the runner system
channel that connects the sprue w/ the gate for transferring the molten plastic into cavities
side bars
loose pieces used to carry one or more molding pins and operated outside the mold
side draw pins
projection used to core a hole in a direction other than the line of closing of a mold and which must be withdrawn before the part is ejected from the mold
split-ring mold
mold in which a split cavity block is assembled in a chase to permit the forming of undercuts in a molded piece
streamlined metal block placed in the flow of molten resin in the heating cylinder or extruder systems to spread the flow into thin layers for better heat trans.
sprue brushing
hardened steel insert in mold that accepts extrusion nozzle and provides opening for transferring molten plastic
marks on the molded par surfaces that indicated resin flow directions or impingement
occurs between the finished part and the sprue--when mold opens, resin in this area has not cooled enough
stripper plate
plate that strips a molded piece from core pins or force plugs--set into operation by opening the mold
submarine gate (tunnel gate)
type of edge gate where the opening from runner into mold is located below the mold parting line
tab gate
small removable tab -- same thickness as molded item but perpendicular to it for easy removal
having a protuberance or indentation that impedes withdrawal from a two-piece rigid mold
valve gating
gate--pin held in gate/channel by sprin tension & as spring comes forward, compresses plastic into runner. when pressure overcomes tension of spring, pin is pushed back & fast decompression of plastic fills cavit @ high speeds
vertical flash rin
clearance between force plug & vertical wall of cavity in a pos. or semi-pos. mold; the ring of excess material which escapes from cavity into clearance space
dimensional distortion in molded object
(smaller than stringing) flashing when mold overpacked, forced open or due to mold parting line wear