ROTOCON recently completed trials on a specially designed embossing (EMB) unit for an eight-colour flexographic press at Redfern Long Run Labels’ Johannesburg branch.
According to Patrick Aengenvoort, Rotocon director, this EMB technology – developed in-house – offers label printers and converters a reasonably priced alternative to standard embossing units.
‘We’re receiving increasing numbers of requests for embossing work but couldn’t justify the cost of installing a standard embossing unit on the press, which handles a lot of small-run, high-quality colour work with cold foil finishing,’ remarks Lance Zeeman. ‘Rotocon proposed an alternative solution – consisting of two anvil rollers (very similar to magnetic cylinders) that are undercut allowing a raised male and indented female flexo plate to be mounted on them.’
Delivered last year, the EMB unit drops into one of the press’s die stations, effectively acting as a print cylinder. The main difference, however, is that unlike a foam cushion mount the mounting tape is similar to double-sided sticky tape, eliminating unwanted resilience. Additionally, printing plates need to exhibit high Shore hardness levels to punch the impression on to substrates.
Redfern Long Run Labels’ designers had the challenge of keeping the logo the same for the entire range of products to ensure brand conformity,’ Lance explains. ‘Furthermore, creating samples on a standard substrate – rather than on specialised premium materials – kept the price down while creating the desired effect for the customer.’
Another limitation, he notes, is that the converter needs to buy one cylinder set per machine to accommodate its particular cylinder gearing system and match the tooth size of its print cylinder. The upside of these restrictions, however, is that the EMB unit can be used as many times as the converter has to run the cylinder set. In Redfern Long Run Labels’ case, there are a number of jobs going through on the same cylinder set and all that’s required is to change the plates as with any standard labelling job.
Article featured in the March 2019 issue of PPM.