Material Selection & Properties Flashcards
7 cards from real CAR practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Material Selection & Properties flashcards as text
What is 'prepared 1' (P1) grade copper scrap, and why is it relevant to appliance recycling?
Answer: Copper with less than 0.5% impurities, achieved by stripping insulation from motor windings
P1 copper (clean uncoated copper pipe, wire, and fittings) commands premium prices, and proper preparation by removing insulation from motor windings achieves this grade.
Polystyrene (PS) inner door liners in refrigerators are identified by which resin code and property?
Answer: #6, brittle and produces a metallic ring when tapped
Polystyrene (#6) is rigid and somewhat brittle, and it makes a characteristic hollow ring when tapped, distinguishing it from other refrigerator liner plastics.
In the context of appliance shredder residue (ASR), the 'fluff' fraction primarily consists of:
Answer: Mixed plastics, foam, rubber, glass, and dirt classified as waste
ASR fluff is the light, mixed residue of plastics, foam, fabric, glass, and fines that remains after metals are extracted, typically sent to landfill or energy recovery.
Why is it important to identify whether an appliance uses R-410A versus R-22 refrigerant before recovery?
Answer: They require different recovery equipment and cylinders; mixing them creates contaminated waste refrigerant
R-410A operates at nearly double the pressure of R-22 and requires separate recovery cylinders; cross-contamination destroys the reclaim value of both refrigerants.
Ballasts in older fluorescent light fixtures found in commercial refrigeration cases may contain:
Answer: PCB-containing dielectric oil requiring hazardous waste management
Pre-1979 magnetic ballasts may contain PCB-based insulating oil, classifying them as PCB-containing equipment regulated under TSCA.
The 'decoating' or 'delacquering' process applied to aluminum scrap from appliances serves to:
Answer: Remove paint and coatings to reduce slag and improve melt quality
Thermal decoating burns off paints and coatings before smelting, reducing dross formation, improving alloy chemistry control, and lowering emissions during melting.
Which ASTM standard classification system is most relevant for grading recovered ferrous scrap from appliances?
Answer: Institute of Scrap Recycling Industries (ISRI) Scrap Specifications Circular
The ISRI Scrap Specifications Circular is the industry-standard reference that defines grades and specifications for all categories of recovered scrap metals.