I am thinking about setting up a white shirt laundry. I would like
details about the market in the US (ie who is doing it ? profit? ),
what it involves in investment and other info that I may need

Interesting, basically a dry cleaning business
(or maybe a scrubbing operation)

Could I suggest that you are providing shirts for males who have no
wish to wash and iron their own uniforms. AKA a Chinese laundrey.

Therefore packaging is extremely important, ie: something that is easy
to carry, easy to rip open, carry, and the wrapping is easy to get rid
of.

I would also suggest, that if you do set up such an operation, you
take down the size and manufacturer of all your clients shirts, and
offer them an easy replacement option.

Personally I would not mind re-stocking my drawers/wardrobe with Van
Heusen Cotton 100 size 16 shirts, and if I were working back in the
'smoke' I would  certainly appreciate a 'shirt replacement' service.

Remember - no pins, no cellulose, and an easy to carry bulk pack that
doubles as a bin bag for bringing in the 'empty bottles'.

Personally I would find the (correct) Chinese ideogram for 'Shirt' or
'Laundry' and put a discreet address and Anglish logo at 45 degrees on
a bottom corner.

I reckon you have a very good business idea, it is not exactly new,
but with the right location and embellishments, you could be on to a
winner.

The best ideas are old ideas - with a twist.