Printing Apparatus Varnish Coating Uniformity
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Solution Overview
Problem
The existing varnish coating process experiences coating abnormalities due to the aggregation reaction between the solidified varnish and acidic surfaces, leading to uneven varnish application, particularly at the boundary between coated and non-coated regions.
Innovation Solution
A printing device is designed with a processing liquid having a contact angle of 70° or greater applied to the recording surface, along with a varnish coating time of 9 minutes or longer, and the use of an anti-drying agent to adjust the coating forming time, ensuring robust varnish application by balancing the processing liquid and varnish coating amounts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If varnish is transferred from anilox roller to varnish plate and then to paper, then varnish coating is achieved, but coating abnormality occurs at the boundary between coated and non-coated regions due to aggregation reaction between solidified varnish and acidic paper surface
Solution Approach 1:
The patent applies a preliminary liquid to the paper surface before varnish coating to modify the surface properties. This preliminary action prevents the aggregation reaction between solidified varnish and acidic paper surface by creating a barrier layer, thereby eliminating coating abnormalities at boundaries and ensuring uniform varnish application throughout the coated region.
Solution Approach 2:
The patent introduces a preliminary liquid as an intermediary substance between the varnish and the paper surface. This intermediary layer mediates the interaction between varnish and paper, preventing direct contact between solidified varnish and acidic paper surface, thus avoiding aggregation reactions and coating defects.
2Manufacturing precision
If varnish coating time is extended to 9 minutes or more, then coating abnormality is prevented, but production efficiency decreases
Solution Approach 1:
By applying preliminary liquid to the paper surface before varnish coating, the patent creates optimal surface conditions that enable rapid and uniform varnish adhesion. This preliminary preparation eliminates the need for extended coating times, allowing high-quality coating to be achieved within 9 minutes or less while maintaining production efficiency.
Solution Approach 2:
The patent modifies the paper surface parameters through preliminary liquid application, changing surface energy, wettability, and chemical composition. These parameter changes enable the varnish to coat uniformly and rapidly, reducing the required coating time from potentially extended durations to 9 minutes or less without sacrificing coating quality.
3Reliability
If processing liquid with contact angle of 70° or greater is applied to recording surface, then varnish coating abnormality is prevented, but additional process steps are required
Solution Approach 1:
The patent combines the preliminary liquid application step with the existing varnish coating process into an integrated system. The preliminary liquid application and varnish coating are performed in sequence without breaking the production flow, merging two functions into a unified coating process that prevents abnormalities while maintaining operational simplicity.
Solution Approach 2:
The preliminary liquid serves multiple functions: it modifies paper surface properties, prevents aggregation reactions, ensures uniform varnish adhesion, and prepares the surface for subsequent coating steps. This multi-functionality reduces the need for additional specialized process steps, as one preliminary treatment accomplishes multiple objectives.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively prevents varnish coating abnormalities by ensuring uniform varnish application and extending the varnish coating time, thereby enhancing the quality and durability of the printed material.
Implementation Method 1
a processing liquid having a contact angle with a recording surface of a recording medium equal to or greater than 70° is added to the recording surface
Implementation Method 2
a varnish is applied by transferring the varnish from an anilox roller to a varnish plate and further transferring the varnish from the varnish plate to paper
Data Source
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AI summary
An object is to provide a printing device which prevents a coating abnormality of a varnish, a printing method, a varnish information output method, and a recording medium information output method. The object is achieved by a printing device including: a processing liquid adding unit which adds a processing liquid containing acid as an aggregating component which aggregates components in an ink and having a contact angle with a recording surface of a recording medium equal to or greater than 70°, to the recording surface; an image recording unit which applies an ink to the recording surface, to which the processing liquid is added, from an ink jet head to record an image; and a varnish coating unit which includes a varnish coating roller which brings the varnish plate into contact with the recording surface, to which the ink is applied, to transfer and applies the varnish held in the varnish plate to the recording surface, and an anilox roller which transfers the varnish supplied from a chamber to the varnish plate, in which a coating forming time of the varnish is 9 minutes or longer.