• about: config print.always_print_silent Boolean true
• install R-kiosk plugin

Create a shortcut with command line options

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" " --user-data-dir=c:\Users\Public --kiosk --kiosk-printing http://demo.dreamapps.com

You may not need to have the user-data-dir option.

• Use command line option -k

• For directly printing without dialog box you need to use a script like in POS receipt printing.

A new script in html/scripts that will work for all browsers is under test.