What is the primary material used in Bakelite injection molding?
This is a common thermoplastic, not used in Bakelite molding.
This is another thermoplastic, not related to Bakelite.
This is a thermosetting plastic known for its heat resistance.
PVC is a versatile plastic but not used in Bakelite production.
Phenolic resin is the primary material in Bakelite injection molding due to its high heat resistance and electrical insulating properties. It differs from thermoplastics like polyethylene, polypropylene, and PVC, which do not undergo the same curing process.
Which of the following is NOT typically added to phenolic resin in Bakelite molding?
These enhance mechanical strength.
These aid in material flow and demolding.
These initiate the cross-linking process.
This material is unrelated to Bakelite production.
Silicone rubber is not added to phenolic resin in Bakelite molding. Fillers, lubricants, and curing agents are commonly used to enhance properties and processing.
What is a crucial step before injecting phenolic resin into the mold?
Cooling is not done before injection, but after curing.
Preheating ensures the resin solidifies quickly upon injection.
Water would cause defects in the final product.
Phenolic resin is used alone or with specific additives.
Preheating the mold is crucial as it reduces curing time and enhances product quality. This step prevents issues such as warping that could occur if the mold were cold.
What challenge is associated with handling phenolic resin?
Moisture can lead to defects in Bakelite products.
Phenolic resin does not melt like thermoplastics.
It has excellent heat resistance.
It has excellent electrical insulation properties.
Phenolic resin is highly sensitive to moisture, which can cause defects during molding. Proper storage and handling are critical to maintaining its integrity.
What role does post-processing play in Bakelite production?
Post-processing does not directly affect material costs.
Techniques like polishing improve these aspects.
This is related to pre-processing, not post-processing.
Viscosity adjustments occur during molding, not post-processing.
Post-processing involves techniques like grinding and polishing to enhance surface finish and ensure dimensional accuracy, crucial for both aesthetic and functional purposes.
What is a common defect caused by uneven curing in Bakelite molding?
This defect results from inconsistent curing conditions.
Brittleness is more related to material composition than curing issues.
Bakelite is typically opaque regardless of curing conditions.
Elasticity isn't a concern as Bakelite is a rigid material.
Warping occurs due to uneven curing, leading to deformations in the final product. Consistent temperature and pressure are essential to avoid this defect.
Which of these does NOT enhance Bakelite's performance during production?
These are used for aesthetic purposes.
They improve safety by reducing flammability.
Moisture should be avoided, not absorbed into the resin.
These modify mechanical and electrical properties.
Moisture absorbers are not used as phenolic resin must remain dry. Other additives like fillers and flame retardants enhance specific properties of Bakelite products.
What is a primary benefit of automated visual inspection in post-processing?
While beneficial, speed increase isn't a direct result of inspection.
Automation uses sensors and AI for detailed inspection.
Waste reduction is more related to efficient processing than inspection.
Curing complexity isn't directly affected by inspection techniques.
Automated visual inspection systems use advanced technologies to detect minute flaws that might be missed by human inspectors, ensuring high quality in Bakelite products.