Jewish Festivals: Opening Plastic Bottles

You may completely open plastic bottle caps on plastic bottles on Jewish festivals (even if doing so will leave a plastic ring on the bottle), as long as it is theoretically possible to dispense the liquid without completely separating the cap from its seal.
Reason Since liquid can be poured with the cap still attached, we have not violated the Jewish festival by making a sealed bottle into a “new utensil.”
Note If you will destroy letters that are printed on the cap, you may not open the bottle.