11.12 Rain Repellent

Question 1

What are the most common ways of removing rain from the windshield?

Answer 1

-Chemical rain repellent
-Pneumatic rain removal (jet blast)
-Coating windshields with a hydrophobic surface seal

Question 2

What are the most common ways of removing rain from the windshield?

Answer 2

-Chemical rain repellent
-Pneumatic rain removal (jet blast)
-Coating windshields with a hydrophobic surface seal

Question 3

What is the trade name for chloroflourocarbon ?

Answer 3

RainBoe

Question 4

What is the problem with RainBoe?

Answer 4

Banned in 1996, as it is an o-zone depleting substance due to it containing CFC 113

Question 5

What is the problem with RainBoe?

Answer 5

Banned in 1996, as it is an o-zone depleting substance due to it containing CFC 113

Question 6

After RainBoe was bannned, what did this lead to?

Answer 6

Certain manufacturers chose to use a CFC-free alternative

Question 7

How does chemical rain repellent work?

Answer 7

It forms a transparent film on top of the glass, which causes the water to draw up into beads , which makes the water easy to remove from the glass

Question 8

When should chemical rain repellent be used ?

Answer 8

When it is very wet, never use on dry windows as heavy undiluted repellent restricts window visibility

Question 9

What does hydrophobic coating do?

Answer 9

Causes raindrops to bead up and roll off, with clear visibility and minimal distortion

Question 10

What does hydrophobic coating do?

Answer 10

Causes raindrops to bead up and roll off, with clear visibility and minimal distortion

Question 11

How must windshields be cleaned when they have a windshield surface coating ?

Answer 11

Using a 50/50 solution of isopropanol alcohol and de-ionised or distilled water with a soft cloth or non abrasive towel

Question 12

What are the two basic problems with windshield wipers ?

Answer 12

-the tendency of the Slipstream aerodynamic forces to reduce the wiper blade loading pressure on the window, causing ineffective wiping
-they struggle to move fast enough to keep up with rates of downpour during heavy rainfall

Question 13

How does the pneumatic rain removal system work and what does it do ?

Answer 13

Air is supplied by an electric blower or bleed air, where hot air is directed over the windshield, breaking the raindrops into smaller particles to be blown away and heating the windshield to prevent moisture from freezing