Earlier this year, the DPDA, which was formed as a collaboration between leading digital manufacturers including HP, Océ, Kodak and InfoPrint in 2008, claimed success in de-inking inkjet print within what it described as "a procedure designed to replicate a typical European mixed grade waste paper recycling system".
The process involved using bleaching chemicals, which it said were typically used in the repulping process and rebuffed the work of the Ingede body, saying its Method 11 lab test "may not be appropriate for all aqueous-based inks, since the test is primarily a single-step flotation test".
With dye-based inks, there is no ink particle to float, hence the futility of trying to meet this requirement, according to Dr Matthias Fromm, R&D Manager for Océ.
Ingede, which represents European paper manufacturers, has now responded and, in a statement, it "invites DPDA for a genuine scientific cooperation to develop a sustainable inkjet printing business that covers all environmental aspects from printing to recycling".
However, it took issue with a number of the DPDA claims in its research, saying that, although it "welcomes this kind of study", bleaching would add an additional process, chemicals and cost to the standard flotation process operated by the most recycling mills, and reiterated that its Method 11 remains a valid test to simulate conditions of a typical de-inking plant and is as relevant for inkjet as it is for offset and gravure.
Ingede's digital print de-inking expert Axel Fischer confirmed that the body is "intensifying its talks with DPDA".
Nils Miller, HP's senior scientist for media research and environmental technology for HP Labs, said: "HP has not yet discussed this [statement] with our DPDA colleagues but, from HP’s perspective, it does represent a more collaborational tone from Ingede."
He added: "We will endeavor to collaborate with the paper industry, including associations such as Ingede that represent components of the paper industry, on the topic of of deinking of digital prints."
