The Juicing Room is where all the fruit goes to juice but Willy Wonka has add extra big juicers for the Oompa Loompa Blueberries. Violet is taken on the Candy Boat to the Juicing Room after her blueberry incident.
The 1971 Movie
The 2005 Remake
Although it is not stated in the film, it is heavily implied due to Violets massive size that she will explode if she is not juiced quickly.
It's unknown exactly how Violet was juicing, but along with her highly suggestive inflation and her moaning cries for help, it's probable that Violet's juicing was inappropriate.
Although you don't see the Juicing Room in the movie or novel, In the game its one of the two Violet levels. After rolling Violet to the Juicing Room door, you enter the room itself which is full of floor levels that are inverted domes. to move violet towards the BIG Juicer you have to juice Oompa Loompa Blueberries so they can fix the doors to roll Violet through. You also see her get Juiced and turn into her normal, rude, but blue self!