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What is the major difference (property) between a thermoplastic and a thermoset?
Describe at least 4 key physical characteristics of an amorphous polymer and at least 4 key physical characteristics of a semi-crystalline polymer.
What's an example of a semi-crystalline commodity thermoplastic?
List 3 examples each of an additive used in plastics.
List 2 examples of a structural reinforcement added to plastic materials before they are molded.
How is mold shrinkage expressed (how is it measured) and why should a designer consider mold shrinkage?
What material is good for light pipes?
List 3 crystalline and 3 amorphous materials.
What does the physical property "HDT" stand for and what does it mean to you as a designer?.
What material are coffee cup lids typically made from and why?
Name the material (full name, no abbreviation) typically used for these products.
Name the material (full name, no abbreviation) typically used for these products
Name the material (full name, no abbreviation) typically used for these products.
List 5 key advantages and 3 disadvantages of thermoplastic injection molding (relative to other plastic molding processes).
List the 4 distinct operations of the injection molding process.
And for each operation, describe what's happening to plastic during that operation.
Which of the 4 operations of injection molding takes the longest time?
What is the term "cycle time" refer to?
Give at least 3 examples of activities/operations that the operator can perform within the cycle time?
What are the two primary halves of the mold called that form the part?
What is PMMA better known as?
What created the marks on this part shown below?
List at least 4 factors that drive part design for injection molding.
Describe what the nominal wall is and list at least 3 reasons why it's the most important decision in plastic part design.
On the illustration showing a part with a hole in the middle, there is a line shown.
What does this line represent? What is it and why is it important?
Name the 10 of the 14 features identified in the illustration shown below.
What is the name for the defect shown in this injection molded part? What causes this defect?
Which is the best boss design shown below (A, B or C) and why?
What does the term "steel safe" mean? Why would you want to make a feature "steel safe?"
What are swimming pool plumbing components (the pipes, joints, valves, etc.) made of and why?
In this illustration, there are two snaps A and B that are molded into a part. What can you tell me about the difference between snap A and snap B in terms of how they are molded?
Gas Assist Injection Molding and Low Pressure Structural Foam are two variants of High Pressure Injection Molding. What common key advantages over High Pressure Injection Molding do they both offer? List at least two, with one being the primary reason, the stating how they are different from each other.
What's the primary difference between the materials used for Low Pressure Structural Foam vs. Reaction Injection Molding (RIM)?
A mold using RTV (room temperature vulcanized silicone) for Reaction Injection Molding (RIM) molds allows you do something unique that you can't do with other mold materials. What is it?
Adding a soft-touch elastomer grip to a rigid injection molded power drill housing is an example of what process?
Molding a metal screwdriver blade into the plastic screwdriver handle is an example of what process?
If I want to mold a part that has an expensive virgin material with strict aesthetic requirements, what process can I use to fill the core of the nominal wall with less-expensive recycled material to reduce costs but maintain that quality look?
What are the 2 differences between plastic profile extrusion and pultrusion? (Hint: it has to do with the material.)
What does SMC and BMC stand for and what process are they used in?
What resin is used in fiberglass?
It is a thermoplastic or a thermoset?
What is the first coating applied to the mold if I want a smooth surface on the outside of a fiberglass part where I don't see the glass fibers?
What does RTM stand for? How does it work?
Describe the rotomolding (rotational molding) process - there are 4 main steps.
What's the primary difference between parts molded with Drape Forming (Male Mold Vacuum Forming) and Female Mold Vacuum Forming?
What's an advantage and disadvantage of pressure forming over traditional vacuum forming?
What's the difference between a parison and a preform in blow molding?
What is Methylene Chloride used for when fabricating acrylic?
Compare blow molding to other processes used to make large hollow parts. What are the other two primary candidates? Which process is best for molding parts with thick rugged outside corners? Why?
What plastic molding process is most similar to sheet metal bending? How does this process work?
How is this plastic tool case made? (Hint: It is rugged and has double walls and a living hinge.)
(Part 1) Two different types of ladders ('A' and 'B') are shown in the images below. Describe how each is made.
(Part 2) What are the advantages of one method over the other?
This plastic storage shed is comprised of large, hollow panels.
(Part 1) What primary material and process was used to make this shed?
(Part 2) Why was this process used? What's a key drawback?
These cylindrical plastic products are assembled using what process?
What was used to hold in these metal contacts (see yellow arrows)?
What is this product? (I brought the upper half of it into class.) What material and process was used?
What are the brass objects shown in this image? What are they used for? How are they installed into the plastic part?
