Inzetstuk voor een houder met een te verwarmen of te koelen vloeistof, houder met een dergelijk inzetstuk, en werkwijze voor het vormen van een inzetstuk

The invention relates to an insert piece for a container holding a product which is to be heated or cooled, which insert piece defines a substantially elongate space which is intended to accommodate a heating or cooling means, the insert piece having a peripheral wall with a closed end and an open end, which open end is provided with an outwardly projecting rim for attaching to the container. According to the invention, the peripheral wall is provided with a reinforcement means, preferably a stepped form. The invention also relates to a container for a product which is to be heated or cooled, provided with an insert piece of this nature, and to process for forming an insert piece.