Injection Molding quiz

More questions about Injection Molding

These visible examples show the question style. LearnClash turns the full topic into ranked duels and spaced repetition.

1. 1 Easy

   What design feature allows a plastic part to slide out easily?

   Answer: Draft angle

   Why: A degree or two of taper on every vertical wall is usually enough, and a textured surface needs more still.

2. 2 Medium

   What are the circular marks on injection molded storage bins called?

   Answer: ejector pin marks

   Why: Cooling plastic shrinks and grips the mould core, so pins must shove the bin off, and each pin leaves its own small round print.

3. 3 Hard

   What is the thin "overflow" of plastic that leaks between mold halves?

   Answer: flash

   Why: It squeezes out along the parting line when injection pressure beats the clamp, and factories often freeze parts in liquid nitrogen to snap the fins off.

4. 4 Easy

   What part of an injection molding machine melts and injects plastic?

   Answer: Reciprocating screw

   Why: Filed in 1952 and patented in 1956, William Willert's screw also acts as the injection plunger, and its shear friction adds melting heat.

5. 5 Medium

   What term gives the percent by which plastic gets smaller as it cools?

   Answer: Shrinkage rate

   Why: Amorphous resins like ABS pull in about half a percent as they cool, while unfilled nylon can shrink a full two percent.

6. 6 Hard

   What defect occurs if the mold opens before the plastic solidifies?

   Answer: Part deformation

   Why: Ejected too early, a part keeps shrinking outside the mold without support, so one that looked fine can bend later.