Web feeder with controlled electrostatic force and method

A method for applying a controlled force to a web, comprising

• directing an electric current between a source of electrostatic energy and an electrically conductive member to create an electrostatic force to urge a substantially non-conductive web toward the member, and
• controlling the electric current to control the electrostatic force applied to the web to a selected value.

A method for applying a controlled corona wind to a substantially non-conductive material for maintaining a constant force on the material, comprising

• directing a corona wind toward he substantially non-conductive material, and
• controlling current of the corona wind to maintain a substantially constant current of the corona wind to maintain a substantially constant force on the material although electrical impedance in a path of the corona wind may vary.

A method of controlling tension in a substantially non-conductive web traveling along a path, comprising directing a corona wind toward the substantially non-conductive web to urge the web against a surface, and adjusting current flow in the corona wind to control force urging the web against the surface to a selected value.

A method of spreading or smoothing a coating located on a surface, comprising applying a corona wind to the surface with sufficient force to distribute a coating on the surface, and controlling electric current causing the corona wind to control the corona wind to a selected value.

A method of avoiding distortions in a moving substantially non-conductive web, comprising applying an electrostatic force to the substantially non-conductive web to urge it into engagement with another surface to resist movement and to create a tension in the web, and controlling the force with which the web is urged into engagement to control the tension and to maintain length characteristics of the web substantially constant across the width of the webs said applying comprising applying an electron wind to the web, said applying an electron wind comprising measuring current creating the electron wind and maintaining the current substantially constant while impedance in a path of the electron wind may vary.

A method of removing curl from a substantially non-conductive web traveling along a path, comprising applying moisture to the substantially non-conductive web, and stretching the web between a drive roll and a hard nip, and forming the hard nip by applying an electrostatic force between a source of electrons and an electrically conductive member to urge the web toward the member, further comprising supplying electrical current from the source of electrons to establish the electrostatic force, and controlling electrical current establishing the electrostatic force to maintain control of the force on the web at the hard nip at a selected value.

A method of controlling the dimensionality of a web travelling along a path, comprising stretching the web between a drive roll and a hard nip, and forming the hard nip by applying an electrostatic force between a source of electrons and an electrically conductive member to urge the web toward the member, and fiber comprising supplying electrical current from the source of eletrons to establish the electrostatic force, and controlling a electrical current establishing the electrostatic force to maintain control of the force on the web at the hard nip at a selected value.

A method of curing a coating on a substantially non-conductive web, comprising applying a controlled electrostatic energy field to the substantially non-conductive web and a coating to effect curing of the coating, and said applying comprising controlling current of the electrostatic energy field at a selected value.