Frame Materials Flashcards
What are the two types of plastic used for frames?
Thermoplastic
Thermosetting
What temperature does cellulose acetate soften at?
57 degrees
What are the characteristics of a cellulose acetate frame?
Fully reinforced sides
Can be the same colour (colour extruded), 2-tone (laminated) or see through (dyed)
Made from blocks of acetate sliced into sheets
What is the flash point of cellulose nitrate?
70 degrees
What are the disadvantages of cellulose nitrate?
Low flash point
Becomes brittle and yellows with age
What are the characteristics of Optyl?
Made from epoxy resin - injection moulded around metal elements
15mm of sides reinforced or full reinforcement or metal sides
Lightweight
Hypoallergenic
What temperature does Optyl soften at?
88 degrees
What are the characteristics of SPX?
Co-polyamide
Injection molded and coloured
Sides always reinforced
Flexible
Lightweight
Hypoallergenic
What temperature should SPX be adjusted at?
95 degrees
What are the characteristics of Silicone-based rubber?
Highly durable
Soft and pliable
No hinges or metal elements
Lightweight
Solid colour
Can use additional strap
How is gold added to a base metal on a frame?
Welding or plated via electrolysis
What base metals are used for gold frames?
Nickel silver
Bronze
What are the advantages of a gold frame?
Colour keeps well
Resistant to corrosion
What are the characteristics of Nickel Silver?
Assembled by soldering
Fairly corrosion resistant
Easily adjusted
Flexible
How can allergies to Nickel Silver be overcome?
Plastic Tips and bridges
Inert coatings
What are the components of Nickel Silver?
20% Nickel
Mostly Copper
No Silver
How is colour applied to Nickel Silver?
Electroplating or lacquering
What are the characteristics of Stainless Steel?
Assembled by welding
Lightweight
Corrosion resistant
Rigid but flexible
Hypoallergenic (if pure)
How is colour applied to Stainless Steel?
Electroplating
What are the characteristics of Titanium?
Cut and pressed, then laser soldered
40% lighter than other metals
Flexible
Corrosion and abrasion resistant
Hypoallergenic
What are the components of Titanium?
If pure: 98% titanium
If beta: 80% titanium, other metals (aluminium, iron, tin) and titanium alloys (nickel and cobalt)
What are the characteristics of Memory metals?
Return to their original shape after extreme distortion
What are memory metals made from?
Nickel-titanium
Can be other alloys but normally contain nickel or titanium
What are some other more recent materials?
TR90 Nylon - lightweight, flexible, v durable, thermoplastic
Wood/Faux wood - good shock absorber
Recycled materials - e.g. acetate
3D printed - castor beans or polyamide, not fully biodegradable
