Image-forming device and method for applying varnish

A method for applying varnish, comprising:

• a printing step of forming images on media using ink;
• a varnish application step of applying aqueous varnish to the media using the printing step using a varnish application portion after the printing step;
• a treatment step of performing a treatment on the media so that a stickiness evaluation value reaches 0.24 or less, which is the stickiness evaluation value indicating a degree of stickiness of the aqueous varnish applied to the media when the media to which the aqueous varnish is applied in the varnish application step are output from the varnish application portion and being derived using a damped vibration percentage of a pendulum caused to do pendulum motions from an arbitrary location of the media where the aqueous varnish is applied, wherein the arbitrary location of the media is used as a pivot for the pendulum to perform the pendulum motions;
• an accumulation step of accumulating the media after the varnish application step and the treatment step;
• and
• a temperature detection step of detecting temperatures of the media after the printing step and prior to the varnish application step,
• wherein the treatment step includes:
• a drying treatment step of performing a drying treatment on the media after the printing step and prior to the varnish application step, and a drying treatment control step of controlling temperatures of the media on which the drying treatment is performed in the drying treatment step by applying drying conditions under which the stickiness evaluation value of the media to which the aqueous varnish is to be applied in the varnish application step reaches 0.24 or less;
• and
• a powder spraying step of spraying powder to the media treated in the treatment step, and a powder spraying control step of spraying powder to the media treated in the powder spraying step in a case in which the temperatures of the media detected in the temperature detection step are lower than 101° C.

An image-forming device, comprising:

• a medium transport portion that transports media in a medium transport direction;
• a printing portion that forms images on the media being transported using ink;
• a varnish application portion that applies aqueous varnish to the media on which the images are formed;
• a treatment portion that is configured to perforin a treatment on the media so that a stickiness evaluation value reaches 0.24 or less, which is the stickiness evaluation value indicating a degree of stickiness of the aqueous varnish applied to the media when the media to which the aqueous varnish is applied are output from the varnish application portion and being derived using a damped vibration percentage of a pendulum caused to do pendulum motions from an arbitrary location of the media where the aqueous varnish is applied, wherein the arbitrary location of the media is used as a pivot for the pendulum to perform the pendulum motions;
• an accumulation portion that accumulates the media to which the aqueous varnish is applied using the varnish application portion and on which the treatment is performed with the treatment portion;
• and
• a temperature detection portion that is disposed at a location on a downstream side of the varnish application portion in the medium transport direction and at a location on an upstream side of the accumulation portion in the medium transport direction and detects temperatures of the media on which the aqueous varnish is applied using the varnish application portion and which are to be accumulated in the accumulation portion,
• wherein the treatment portion includes:
• a cooling treatment portion that is disposed at a location on the downstream side of the varnish application portion in the medium transport direction and at a location on the upstream side of the accumulation portion in the medium transport direction and is configured to perform a cooling treatment on the media to which the varnish is applied using the varnish application portion, and a cooling treatment control portion that controls temperatures of the media on which the cooling treatment is performed with the cooling treatment portion by applying cooling conditions under which the stickiness evaluation value of the media to which the aqueous varnish is to be applied using the varnish application portion reaches less than 0.24;
• and
• a powder spraying portion that sprays powder to the media treated using the treatment portion, and a powder spraying control portion that sprays powder to the media treated using the treatment portion using the powder spraying portion in a case in which the temperatures of the media detected using the temperature detection portion exceeds 40° C.

A method for applying varnish, comprising:

• a printing step of forming images on media using ink;
• a varnish application step of applying aqueous varnish to the media using a varnish application portion after the printing step;
• a treatment step of performing a treatment on the media so that a stickiness evaluation value reaches 0.24 or less, which is the stickiness evaluation value indicating a degree of stickiness of the aqueous varnish applied to the media when the media to which the aqueous varnish is applied in the varnish application step are output from the varnish application portion and being derived using a damped vibration percentage of a pendulum caused to do pendulum motions from an arbitrary location of the media where the aqueous varnish is applied, wherein the arbitrary location of the media is used as a pivot for the pendulum to perform the pendulum motions;
• an accumulation step of accumulating the media after the varnish application step and the treatment step;
• and
• a temperature detection step of detecting temperatures of the media after the varnish application step and prior to the accumulation step,
• wherein the treatment step includes:
• a cooling treatment step of performing a cooling treatment on the media after the varnish application step and prior to the accumulation step, and a cooling treatment control step of controlling temperatures of the media on which the cooling treatment is perfonned in the cooling treatment step by applying cooling conditions under which the stickiness evaluation value of the media to which the aqueous varnish is to be applied in the varnish application step reaches less than 0.24;
• and
• a powder spraying step of spraying powder to the media treated in the treatment step, and a powder spraying control step of spraying powder to the media treated in the powder spraying step in a case in which the temperatures of the media detected in the temperature detection step exceeds 40° C.