ISO 21993:2020 pdf free download.Paper and pulp-Deinkability test for printed paper products.
The types and sources of paper for recychng are manifold. The most significant grades by volume are packaging products from industry, trade and households, followed by graphic papers from households and to a lesser extent From offices. These papers are blends of a variety of individual products. T’pical blends of graphic paper for recycling recovered from households contain many different products printed on papers with a high content of wood-containing pulp fibres and a lesser share of woodfree pulp fibres. Graphic paper for recycling originating from printing and converting operations is typically rather pure and may contain just one type of paper (wood-containing or woodiree). Paper for recycling from printing and converting, as well as special grades, constitute only a minor share of the total volume of paper for recycling. Special grades (e.g. liquid packaging or label stock release liners) sometimes require specific treatments during recycling.
Deinking, the removal of ink from the substrate, is an important step in reprocessing graphic paper for recycling to new paper. A wide variety of papers are produced entirely or partially from deinked pulp and these Include:
— graphic papers (ofdifferent quality levels);
— hygienic papers (such as toilet paper, hand and kitchen towels);
— white top layers of packaging paper and board.
Good deinkability of printed paper products is crucial for the sustainability of the graphic paper loop. The key process steps for deinking are the detachment of the Ink film from the paper, ink fragmentation Into a suitable size range and removal from the pulp slurry. Flotation deinking under alkaline conditions is the most widely used technology for ink removal in the paper recycling process. A wider range of the process pH may be utilised for separately collected printed products on predominantly woodiree substrates.
A simplified method herein has been developed to simulate the principle process steps for ink detachment and ink removal under standardised alkaline conditions at a laboratory scale. This gives an indication on how print products will perform in an industrial deinking operation. The method defined in this document is based on INGEDE Method 11. When the first version of INGEDE Method 11 was published, the deinking industry was predominantly using wood-containing raw material. INGEL)E Method Ills widely used by the paper Industry and by many stakeholders in the paper value chain. The method is not designed to model additional or alternative process steps, such as dispersing, post-flotation, washing and bleaching. Cleaning and screening stages, which are designed to remove Impurities and unwanted materials in the industrial process, are also not included in this method. An alternative deinking test method with near-neutral or neutral flotation conditions may be suitable for paper products mainly consisting of woodfree pulp fibres. However, the near-neutral or neutral flotation conditions are not within the scope of this document.
In most cases, the industrial flotation deinking process is designed and operated to remove a variety of Inks and toners. Alkaline pulping conditions and fatty acid based collectors are widely used. However, fatty acid based collector chemistry Is not singly used in industrial deinking processes in soft water areas. Assessments based on this laboratory scale method give an indication of how the tested print product will perform in a full-scale alkaline flotation deinking plant, but It will not necessarily provide the same absolute result. An example of this type of reLation Is given by INGEDE Method 1I(il and the Deinking Scorecard of the European Paper Recycling CouncilUl.
7.2 Sampling and sample preparation
7.2.1 General
Take a sample which is representative of the printed material to be tested. The recommended amount of each printed sample Is 1 000g. llavailable. sample also some unprinted material and store separately for additional testing.
7.2.2 IdentificatIon
Describe, ii possible, lull details of each paper In the printed material to be tested. II available, the following shall be included:
a) Identification of the printed paper product as to title, publishing company, date of issue, product category;
b) the print process, printing and drying/curing parameters and press settings;
c) the name and exact identification of inks or toner and of varnishes (if applicable);
d) any pre- or post-treatment applied (if any);
e) the paper grade, manufacturer and brand name, ash content of the printed paper sample.
Specify whether the printed sample contains inserts and/or supplements.
7.2.3 Non-paper material/loose and glued Inserts/InsertIons
Remove any non-paper material, all Inserts, glued-In inserts, stickers, sachets and similar Items from the printed sample.
7.2.4 Adhesive applicatIons
in order to avoid any interference with the test procedure and the results, remove any visible adhesive material — i.e. adhesives used in inserts, stickers, spines and similar — from the printed sample.
7.2.5 Accelerated ageing
Place the printed sample in a drying oven for accelerated ageing at (60± 3) °C for 72 h. Individual stacks should not contain more than 20 sheets.
NOTE I Accelerated ageing Is necessary because the age of printed paper products can influence their deinkability. These accelerated ageing conditions correspond to 3 months to 6 months of natural ageing.
NOTE 2 lIthe age of the printed product is three months or higher, the accelerated ageing can be omitted. This Is to be noted In the report as deviation of the procedure.
7.2.6 BreakIng up of samples
Tear the accelerated aged printed sample Into pieces of about 2 cm x 2cm and allow them to equilibrate in the laboratory environment,
7.2.7 Measurement of moisture
Determine the moisture content olthe air-dry sample by testing a portion according to ISO 638. Based on the results obtained, calculate the appropriate air-dry mass olthe printed sample which corresponds to the oven-dry mass prescribed.
9.4 Dirt particle measurement
9.4.1 Scanner
For the determination of the dirt particle area A, a scanner-based image analysis system is needed for optical analysis. The scanner shall be calibrated to ensure reproducibility olthe measurements.
Requirements on measuring accuracy of flatbed scanner after warm-up period (see scanner manual) and under scanning conditions (see 9A2) are described in Annex E.
Repeatability of mean grey value (8 * 1) bit: An ISO A4 sample shall be scanned 10 times without any movement of the sample. All mean grey value of total sample area should be within two grey values.
Deviation of colour value (RGB-8 bit) s5 (after calibration a scanned image of lT8-Target should not have more deviation to associated reference file than ±5 values In every colour channel — RGB).
NOTE For suitable scanners see Annex E.
9.4.2 Procedure for dirt particle measurement
The top and the bottom side of at least two laboratory handsheets per specimen shall be assessed by the image analysis system. The arithmetic mean of mm. four measured values shall be calculated. This mean value shall be taken as the dirt specks area A. The results shall show at least the dirt speck area A above 50 tin circle equivalent diameter and above 250 im circle equivalent diameter.
The sheets should be free of crinkles and waves to lie flat on the scanner. The sheets shall be scanned individually. As background an opaque batch of woodiree copy paper (mm. live sheets with a luminance of Y = 84 ± 2 measured with illumination C/2° and 420 nm edge lifter) should be used. Every handsheet should be scanned one time from top and from the bottom with 8-bit grey modus, 600 dpi and reflective light.
If the scanner is idle icr more than 15 mm a blank scan shall be made in advance of any new measurement.
NOTE For Image analysis software paramelerlsation see Annex £ [or values of the threshold and size classification ee Anmx F.
10 Test report
The test report shall include the following information Ifor items c) to f) include all information which is availablel:
a) a reference to ISO 21993, i.e. ISO 21993:2020;
b) the identification of printed paper product as to title, publishing company. dite of issue, product category;
c) the print process, printing and drying/curing parameters and press settings;
d) the name and exact identification of inks or tonem’ and of varnishes (If applicable);
e) any pre- or post-treatment applied (if any);
f) the paper grade, manufacturer and brand name, ash content of the printed sample;
g) the exact designation of the laboratory testing equipment used — pulper, flotation cell, image analysis;
h) the p11 after pulping, before and after storage and before flotation;
i) the chemical dosage for pulping.