Taga’s new document on UV printing on plastic substrates was unveiled at Taga Day 2021. Also on the program were in-depth reports on specific aspects of processing and a documented excursus on the complex issue of the end-of-life of plastics.
Hosted by the Daimon Foundation in Saronno, which manages the technical institute and professional training center for the Graphic Arts named after Father Luigi Monti, Taga Day on November 24 was well attended, with a full program of topical issues. Opening with a remembrance of the great men who developed the association of technicians in the sector, outgoing president David Serenelli took the stage together with Adalberto Monti and Angelo Meroni (with Manuel Trevisan “absent with justification”), who coordinated the large group of technicians who drafted the new Taga doc.20 document on UV printing of plastic supports, presented for the occasion. The document is the result of work carried out by experts in all the technologies involved in plastic printing, and was proposed by Meroni as a “draft” to underline the complexity of the subject, with an invitation to colleagues to produce useful integrations to enrich what is in fact a work in progress.
UV technology applied to plastics
Doc.20 follows the previous work (doc.19) dedicated to the various types of UV technology applied to printing, starting from litho-offset, with a detailed review of machines, equipment and processes.
Similarly, doc.20 starts from the growing importance of plastic substrates and the difficulties they present (also) in the printing phase, to review first of all the main families of polymers and then the various factors that come into play in the printing process, starting also in this case from sheet-fed offset printing and specifying that the indications of the document are also suitable for semi-rotary machinery. With an appropriate premise: “printing on plastics is not a problem, it is a technique”.
The full-bodied document sets out with meticulous precision precisely the steps of the technique: the characteristics of plastic materials not coated with primer or coating, and therefore not absorbent; the consequences of an almost zero thermal transmission coefficient; the factors of static electricity and surface tension; the various materials (inks, primers, rubberized fabrics, solvents, fountain solutions…); the extensive chapter on quality control and related tools, with various insights (for example on opaque white) and much more. Attached is a valuable table, to be expanded with the experiences that will mature gradually, with a list of possible defects, their causes and proposed solutions.
Insights
In addition to the presentation of the new document, Taga Day 2021 hosted five presentations dedicated to specific aspects of plastic printing, conducted with meticulous precision and thoroughness by five experts in the field, members of the Doc.20 working group.
The speeches focused on the sustainability of plastics (Edoardo Elmi, Guangdong); the parameters to be kept under control in the printing of plastic substrates starting from temperature, humidity, adhesion, rubbing (Piero Pozzi, Colorgraf); the correct use of the polarizer in measurements (Andrea De Rossi, Tecnologie Grafiche); the characteristics and performance of different measuring instruments (Luca Morandi, ColorConsulting); the recycling of polymers – waste, scrap, finished products (Francesco Bordoni. Ci.Ti.O), the latter unfortunately confined to the last, with time almost up, and certainly to be resumed.
