Question about whether UV light can penetrate a cardboard box

[gamer87]

Does cardboard absorb or reflect UV from indirect sunlight? does it go through the cardboard and hit the plastic and rubber items inside the shoe box with UV?

 

[Drakkith]

Does cardboard absorb or reflect UV from indirect sunlight?

Both, depending on the angle of incidence of the incoming UV light.

does it go through the cardboard and hit the plastic and rubber items inside the shoe box with UV?

No, the cardboard will either reflect or absorb all of the UV. Your items inside should be perfectly safe assuming the box is closed.

 

[gamer87]

The box is closed but has a small slit opening between the box and the lid shown in the arrows

 

[Drakkith]

The box is closed but has a small slit opening between the box and the lid shown in the arrows

Whatever is in the box should be perfectly safe from UV light, especially if it's already indirectly illuminated.

 

[sophiecentaur]

If it's really important that the cardboard is extremely light proof then you should go into a darkened room and have a small window of that cardboard (well taped up etc.) with the sun falling directly on it. If you can see a silhouette of your hand in front of the board (after you are dark adapted - say ten minutes) then 'some' light is getting through. I would say that the same sort of screening applies to UV. But shorter wavelengths will get through. of course.

 

[gamer87]

any UV reflect e penetrate inside cardboard box and dry plastic and rubber?

 

[gamer87]

Does cardboard reflect or absorb UV present in indirect sunlight?

 

[gamer87]

I don't know but if this cardboard box is closed and outside there is some sunlight, the UV goes through the box, does it reflect on the cardboard or does the cardboard absorb ?, inside the box you have plastic and rubber items

 

[berkeman]

Does cardboard reflect or absorb UV present in indirect sunlight?

View attachment 268401

Please do not start multiple threads on the same question. Your two threads on the subject have been merged into one thread.

 

[DaveC426913]

The simple answer is that it depends on your tolerance expectation. That box is definitely not fully light-proof. But UV is only a small portion of light.

I would not keep a roll of unexposed film or paper in that box, as some light could creep in.
If you're simply concerned about UV damage to delicate items like a painting, you're probably safe.

But why take the chance? Why not just add some extra shielding -either inside or outside.

 

[gamer87]

uv reflect inside this cardboard box?

 

[berkeman]

uv reflect inside this cardboard box?

View attachment 268417

Who knows. It looks like a picture of a bunny rabbit to me. Or clouds, yeah, definitely clouds...

 

[Vanadium 50]

uv reflect inside this cardboard box?

Are you reading the replies? It sounds like you are asking the same question over and over.

 

[gamer87]

Does the cardboard material used in boxes protect from light and UV? I keep objects sensitive to light and UV inside these boxes example: DVD discs and plastics

 

[berkeman]

Are you reading the replies? It sounds like you are asking the same question over and over.

Yep...

Does the cardboard material used in boxes protect from light and UV? I keep objects sensitive to light and UV inside these boxes example: DVD discs and plastics

View attachment 279003

 

[russ_watters]

Yep...

I vote no.

 

[hilbert2]

Usually even colorless liquids that look transparent in visible light, become much less transparent when viewed in UV frequencies. A good example is the absorption spectrum of n-hexane in the left image below:

The absorbance quickly becomes much higher when going below $\lambda = 300\textit{ nm}$.

Microwaves can be used even for viewing objects on the other side of a brick wall, because they are not as well absorbed by solid substances: https://spectrum.ieee.org/tech-talk...its-3d-microwave-camera-can-see-through-walls The resolution is a bit poor, though, because you can't distinguish features smaller than the wavelength of the radiation you use for that. The wavelength range of microwaves is 1 to 1000 millimeters. That kind of devices are used for searching for survivors under a collapsed building, and by anti-terrorist forces to get a rough picture of how many people are in the neighboring apartment and whether they keep metal objects in their hands.

 

[sophiecentaur]

Does cardboard absorb or reflect UV from indirect sunlight? does it go through the cardboard and hit the plastic and rubber items inside the shoe box with UV?

This is an Engineering problem, I think. What is the permissible exposure level for your valuables? (Essential for a proper answer) Will the lid be fastened / sealed or would it be possible for someone just to open it up and nullify all the calculations about attenuation due to the cardboard. (Thinking practically).

If you think of how photographic film and paper are stored - thick black plastic bag inside a cardboard box / envelope with a black internal surface. What 'equivalent' ISO sensitivity are you expecting for the items? The answer to the basic question depends on the signal to noise ratio involved and not just a "does it absorb?".

 

[gamer87]

the cardboard boxes are closed the UV and light penetrates into the box and hits the objects?

 

[A.T.]

the cardboard boxes are closed the UV and light penetrates into the box and hits the objects?

Are you reading the replies? It sounds like you are asking the same question over and over.

 

[Vanadium 50]

Gamer is playing a game with us. Just ask the same question over and over, ignoring the answer. I use to play this game too, and it was big fun. Of course, I was four years old at the time.

 

[berkeman]

Are you reading the replies? It sounds like you are asking the same question over and over.

Yep...

I vote no.

LOL, I should have been more specific. I replied Yep to the 2nd part of V50's statement.

 

[berkeman]

OP's question has been answered multiple times in multiple ways. Thread is done now. Thanks everybody.