Since flexographic printing utilizes water-based inks, excessive moisture or heavy ink coverage can easily cause the paper to swell. This leads to localized unevenness after printing-which subsequently interferes with downstream printing processes-and also increases the likelihood of wrinkling. Furthermore, substrates prone to swelling exacerbate tension fluctuations, resulting in significant variations in registration accuracy and making it difficult to produce high-quality products.
Secondly, due to the poor wet strength of sanitary tissue paper, contact with the printing plate can easily dislodge loose fibers from the paper surface; these fibers then accumulate on the plate, causing "plate clogging" (ink buildup). This interrupts continuous printing operations and severely compromises both print quality and product yield. Standard facial tissues typically consist of a simple assembly: two or three plies of creped tissue are laminated together, subsequently flexographically printed, and finally embossed using a combination of gear-shaped and foil rollers. The majority of napkins produced in China fall into this category.
Today, most napkins found on dining tables in Europe and North America are manufactured using a process involving micro-bonding (light adhesive lamination) of the material 'prior' to printing. Such napkins are flat, wrinkle-free, and possess a distinct texture and substantial feel. A particularly advanced variant-known as a micro-bonded composite product-features a three-layer structure in which the printed layer is sandwiched between two outer layers; this configuration endows the product with exceptional texture and flexibility, resulting in a visually more appealing surface finish.
Domestic printing manufacturers producing napkins should strive to transition from the traditional method of embossing-and-bonding to a process involving micro-bonding *prior* to printing; only through such a shift can the quality of domestic napkins achieve a qualitative leap forward. Furthermore, domestic napkin manufacturers must intensify their efforts to improve raw materials in order to narrow the quality gap between their products and those from abroad. Specific measures should include, for instance, utilizing raw paper produced from high-purity wood pulp whenever possible, incorporating sufficient wet-strength agents, and striving to ensure that both surface smoothness and wet strength meet the rigorous requirements of the printing process.
