Materials and Finishing Flashcards
6 cards from real 3D Product practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Materials and Finishing flashcards as text
What is the difference between thermoplastics and thermosets in product manufacturing?
Answer: Thermoplastics soften and reshape when heated repeatedly; thermosets cure permanently and cannot be remelted
Thermoplastics (ABS, nylon, polycarbonate) can be melted and reformed, making them recyclable; thermosets (epoxy, phenolic) cure through irreversible chemical reactions.
What is 'Shore hardness' and what product property does it measure?
Answer: A scale measuring the hardness or resistance to indentation of rubber, elastomer, and plastic materials
Shore hardness (A and D scales) measures how resistant a material is to permanent indentation — Shore A is used for soft rubbers, Shore D for harder plastics.
What is 'overmolding' in plastic product manufacturing?
Answer: Molding a second material over a rigid substrate to add soft-touch grip, sealing, or color accents
Overmolding injection molds a soft TPE or TPU layer directly onto a rigid plastic or metal substrate, creating two-material products like toothbrush handles or tool grips.
What is 'anodizing' and to which base material is it applied?
Answer: An electrochemical process that grows a hard, corrosion-resistant oxide layer on aluminum surfaces
Anodizing electrochemically converts the aluminum surface into aluminum oxide, creating a hard, porous layer that can be dyed and provides corrosion resistance.
What is 'surface roughness' (Ra) in manufacturing, and why does it matter for product design?
Answer: The average deviation of surface peaks and valleys from the mean line, affecting feel, friction, and coating adhesion
Ra (arithmetic average roughness) is specified on engineering drawings to control tactile feel, tribological performance, sealing capability, and paint/coating adhesion.
What is polycarbonate (PC) known for in consumer product applications?
Answer: Very high impact resistance and optical transparency, used in safety lenses, phone cases, and headlight lenses
Polycarbonate is one of the toughest engineering thermoplastics, offering near-unbreakable impact resistance combined with optical clarity for demanding consumer applications.