Stretch film winder

An apparatus for indexing winding cores on a winder, comprising:

• a winding drum configured to carry a continuous plastic web;
• as plurality of winding stations configured to translate toward and away from the surface of the winding drum, each winding station carrying:
• a winding turret with a plurality of winding positions, a mandrel attached at each winding position, the winding turret rotating about a hub;
• a knife edge coupled to an actuator that presses the kneife edge against the continuous plastic web on the surface of the winding drum, thereby cutting the continuous plastic web between two positions when actuated;
• a controller configured to:
• press a first mandrel against the winding drum such that the continuous plastic web winds on the first mandrel;
• move a second mandrel against the winding drum into contact with the continuous plastic web;
• actuate the knife edge to cut the continuous plastic web between the first mandrel and the second mandrel to start winding the continuous plastic web on the second mandrel;
• thereafter move the first mandrel away from the surface of the winding drum;
• and,
• a friction drive that contacts the second mandrel prior to the controller moving the second mandrel against the surface of the winding drum and accelerates the second mandrel to substantially match the second mandrel surface speed with the surface speed of the winding drum.

An apparatus for indexing winding cores on a winder, comprising;

• a winding drum configured to carry a continuous plastic web;
• a plurality of winding stations configured to translate toward and away from the surface of the winding drum, each winding station carrying:
• a winding turret with a plurality of winding positions, a mandrel attached at each winding position, the winding turret rotating about a hub;
• a knife edge coupled to an actuator that presses the knife edge against the continuous plastic web on the surface of the winding drum, thereby cutting the continuous plastic web between two positions when actuated;
• a controller configured to:
• press a first mandrel against the winding drum such that the continuous plastic web winds on the first mandrel;
• move a second mandrel against the winding drum into contact with the continuous plastic web;
• actuate the knife edge to cut the continuous plastic web between the first mandrel and the second mandrel to start winding the continuous plastic web on the second mandrel;
• thereafter move the first mandrel away from the surface of the winding drum;
• wherein the knife edge presses against the continuous plastic web on the surface of the winding drum at a shallow angle;
• the apparatus further comprising:
• a pressurized air source;
• and
• one or more passages through which air from the pressurized air source is directed along a flat surface of the knife edge and thereupon impinge on the surface of the winding drum at substantially the shallow angle, the impinging air lifting a leading edge of the plastic film from the surface of the winding drum when the knife edge cuts the continuous plastic web.

An apparatus for indexing winding cores on a winder, comprising:

• a winding drum configured to carry a continuous plastic web;
• a plurality of winding stations configured to translate toward and away from the surface of the winding drum, each winding station carrying:
• a winding turret with a plurality of winding positions, a mandrel attached at each winding position, the winding turret rotating about a hub;
• a knife edge coupled to an actuator that presses the kneife edge against the continuous plastic web on the surface of the winding drum, thereby cutting the continuous plastic web between two positions when actuated;
• a controller configured to:
• press a first mandrel against the winding drum such that the continuous plastic web winds on the first mandrel;
• move a second mandrel against the winding drum into contact with the continuous plastic web;
• actuate the knife edge to cut the continuous plastic web between the first mandrel and the second mandrel to start winding the continuous plastic web on the second mandrel;
• thereafter move the first mandrel away from the surface of the winding drum;
• and,
• a cylindrical roller around a circumferential portion of which the continuous plastic web is directed prior to being carried by the winding drum;
• a plurality of circumferential grooves located at longitudinal positions on the roller, the circumferential grooves located underneath the position of the continuous plastic web on the roller;
• a knife edge, at least a portion of which is located within one of the plurality of circumferential grooves;
• and
• at least one finger that is outboard of the knife edge and is located in at least one circumferential groove, the at least one finger configured to lift a cut edge of the continuous plastic web and direct the cut edge of the continuous plastic web to a conveyor that transports the edge of the plastic web away from the apparatus.