A framework for model-driven pattern matching

An improvement in the wrapping of successive articles in heat-sealable film supplied in a continuous length to an elongated generally tubular former which progressively wraps the film around the sides of the articles and seals the margins together while air is being evacuated from the interior of the wrapping material comprises the provision of a lengthwise slot in the tubular former and placing the vacuum supply pipe outside the former and near the slot so that the articles do not ride on, or come in contact with, this supply pipe. In the preferred form the margins of the film are sealed along a continuous line outside the supply pipe and along a discontinuous on the other side of the pipe so that air evacuation can take place. In a modification, the margins are overlapped and openings are provided near one margin to allow for the removal of air and in another modification the margins are overlapped and two lines of sealing are employed; one being continuous, to seal the wrapping as a whole, the other being discontinuous and on the other side of the pipe to allow for air removal.