Windows and Lenses Flashcards
What are the 2 main categories of plastics?
Thermoplastics
Thermosetting plastics
1st category of plastic:
plastics that can be softened by heat and dissolved in various organic solvents.
example: toluene, turpentine, acetone, methyl
Thermoplastics
Why we use plastics usually?
It’s more lighter than glass windshields
Cellulose Acetate Plastic
Acrylic plastic
Polycarbonate plastic
3 categories of thermoplastic
Type of thermoplastic?
-can be softened by heat and dissolved in various organic solvents
- not commonly used anymore
- Subject to dimensional instability. Extracts too much with heat
- turns yellow with time
Cellulose Acetate Plastic
Type of thermoplastic?
-quite common in the industry, moderately strong, easy to handle
- can be quite brittle when under load, easily scratched
- Trade names are Plexiglass, Lucite, Perspex
Acrylic Plastic
Type of Thermoplastic?
-Contains Bisphenol. Use safety gear and VERY COMMON to aviation industry
- Trade names: Lexan, Makrolon, Makroclear
- Extremely effective at transmitting light, very high impact resistance, but easily scratched
- It can undergo large plastic deformations without breaking
Polycarbonate plastic
2nd Category of plastic
- do not soften under heat. Molded to it’s final shape
- Blisters at temperature of 400⁰F to 500⁰F
Thermosetting Plastics
a POLYCARBONATE transparent plastic that has excellent cold working properties and can be bent to a fairly tight radius without having a failure.
Lexan
an ACRYLIC transparent plastic may also be cold bent if material thickness is thin and bending radius is at least 180x the thickness of the material
Plexiglass
If acrylic plastic is bent beyond limits, local stress at the surface will cause tiny fissures or cracks to form. This type of damage is called _____?
CRAZING
How to store plastic sheets?
Lay it 10 degrees angle or stack it horizontally
Store away from heat !very important!
What do you need cleaning in cleaning the window?
Plenty of water, the palm of your hand and your fingernails.
Best thing to remove bugs on your windshield?
At DAWN, dew will begin to form on the windows.
products containing ______ are extremely damaging acrylic plastics. (Windex)
Ammonium
Are you allowed to use standard metal or wood cutting drill bits?
Fucking NO, you will risk chipping or cracking the material.
Grind the tip angle (usually a relatively flat ___-___) to a sharp 60⁰ - 90⁰ This sharp angle allows the bit to easily enter and exit acrylic sheet without chipping.
118⁰ - 120⁰
Always drill _____ holes to allow everything to move around.
oversized/larger
Never drill holes in ______ process. Start with smaller hole and work way up to finish size.
One
Largest hole you should drill in one step is _____?
1/4” (0.250”)
Using ______ may help you accomplish smaller holes to finish size holes.
Step drill
ATA chapter for Window Damage limits?
ATA 56
Always remember to find the ______ of the scratch before working on it.
deepness
Which sandpaper is coarser? 400 or 800?
400
Water also acts as a ______ to prevent acrylic plastic from being overheated.
coolant
When sanding with the finer abrasives, cross your sanding pattern at _______ degree angles from one step to the next, to be sure of total removal of previous sanding pattern.
90 degree
When cutting plastic windows. Never use a saw that has a _____ blade.
reciprocating
use a BAND saw instead
When trimming acrylic plastics to FIT IN A GIVEN AREA, the fine detail work is best accomplished through the use of a small hand held 90⁰ ________ equipped with a small sanding disc with a 80 grit or 100 grit pad.
die grinder
In the case of a crack, all of the ends of the crack can be stop-drilled with _____ drill bit.
30 (0.1285” or 1/8”)
Permanent repair can be made to acrylic plastic by using a _____ such as PS-30 or weld-On and a hypodermic syringe.
“Polymerizable cement” such as PS-30 or weld-On and a hypodermic syringe.
