1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58printing ink sets for four-colour printing Part 5: Flexographic printingICS 87.080Graphic technolog
2、y Colour and transparency of BRITISH STANDARDBS ISO 2846-5:2005BS ISO 2846-5:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2006 BSI 2006ISBN 0 580 48831 4The British Standards which implement international publications referred
3、to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions
4、of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 13
5、and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this committee can be obtained on request to its secretary.Cross-referencesenquiries on the
6、 interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 2846-5:2005 and implements it as the UK national standard. The UK participati
7、on in its preparation was entrusted to Technical Committee PAI/43, Graphic technology, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any Reference numberISO 2846-5:2005(E)INTERNATIONAL STANDARD ISO2846-5First editio
8、n2005-03-01Graphic technology Colour and transparency of printing ink sets for four-colour printing Part 5: Flexographic printing Technologie graphique Couleur et transparence des gammes dencre dimpression en quadrichromie Partie 5: Impression flexographique BS ISO 2846-5:2005ii iiiContents Page For
9、eword iv Introduction v 1 Scope 1 2 Normative references . 1 3 Terms and definitions. 2 4 Requirements 2 4.1 General. 2 4.2 Colorimetric values. 2 4.3 Transparency characteristics 3 5 Test methods. 3 5.1 Principle . 3 5.2 Test print preparation. 4 Annex A (informative) Spectral data.5 Annex B (infor
10、mative) Colorimetric values for non-normative conditions. 8 Annex C (informative) Detailed explanation of the test method, including examples 9 Annex D (normative) Reference substrate. 12 Bibliography . 13 BS ISO 2846-5:2005iv Foreword ISO (the International Organization for Standardization) is a wo
11、rldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented o
12、n that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted
13、 in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standa
14、rd requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 2846-5 was prepared by
15、 Technical Committee ISO/TC 130, Graphic technology. ISO 2846 consists of the following parts, under the general title Graphic technology Colour and transparency of printing ink sets for four-colour printing: Part 1: Sheet-fed and heat-set web offset lithographic printing Part 2: Coldset offset lith
16、ographic printing Part 3: Publication gravure printing Part 4: Screen printing Part 5: Flexographic printing BS ISO 2846-5:2005vIntroduction The demand for the flexographic printing process to become more consistent and predictable has required standardization of the process to ensure that the vario
17、us parties involved in flexographic printing production are able to control their part of the process in a meaningful way. An essential component in this process is the specification of the colorimetric and transparency characteristics of the ink set. The purpose of this part of ISO 2846 is to defin
18、e the colorimetric and transparency characteristics of standard sets of flexographic process inks. Standard inks allow flexographic printers to obtain different sets of inks which will all produce a similar colour when printed on the same substrate (paper, board, plastic, etc.). So, by meeting the r
19、equirements of this part of ISO 2846 a standard set of inks can be supplied by any ink manufacturer to any printer, who can then supply prints to a print buyer confident that the colour of the work produced will be that required. In addition, this part of ISO 2846 will allow colour separations for f
20、lexographic printing to be produced to known colour standards. The colorimetric characteristics specified may only be obtained when the inks are printed on the specified reference substrate. However, two inks that are similar in colorimetric characteristics and transparency, according to this part o
21、f ISO 2846, will normally ensure similarity between the results obtained when both inks are printed on another substrate. BS ISO 2846-5:2005blank1Graphic technology Colour and transparency of printing ink sets for four-colour printing Part 5: Flexographic printing 1 Scope This part of ISO 2846 speci
22、fies the colour and transparency to be produced by each ink in a process colour ink set (including extender) intended for four-colour flexographic printing, when printed under specified flexographic printing conditions. It also describes the conformance test method. This part of ISO 2846 does not sp
23、ecify pigments (or spectral reflectance), in order not to preclude developments that may enable different pigment combinations to be used advantageously, while still achieving the colorimetric requirements specified in this part of ISO 2846. 2 Normative references The following referenced documents
24、are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 535, Paper and board Determination of water absortiveness Cobb method ISO 536, P
25、aper and board Determination of grammage ISO 2144, Paper and board Determination of residue (ash) on ignition at 900 C ISO 2846-1, Graphic technology Colour and transparency of ink sets for four-colour printing Part 1: Sheet-fed and heat-set web offset lithographic printing ISO 6588:1981, Paper, boa
26、rd and pulps Determination of pH of aqueous extracts ISO 8254-1, Paper and board Measurement of specular gloss Part 1: 75 degree gloss with a converging beam, TAPPI method ISO 8791-4, Paper and board Determination of roughness/smoothness (air leak methods) Part 4: Print-surf method ISO 13655, Graphi
27、c technology Spectral measurement and colorimetric computation for graphic arts images BS ISO 2846-5:20052 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 extension addition of a transparent material (colorant-free ink) to the ink to reduce t
28、he pigment concentration without significantly influencing the rheological properties of the ink 3.2 press-ready ink ink that has all necessary components and is at press viscosity 3.3 transparency T ability of an ink film to transmit and absorb light without scattering NOTE It is generally expresse
29、d as some measure of the unwanted scattering. ISO 2846-1 4 Requirements 4.1 General For an ink set to conform to this part of ISO 2846 each ink shall meet the specification for colour defined in 4.2, at some percentage of press-ready ink, as well as the specification for transparency defined in 4.3.
30、 4.2 Colorimetric values To meet the specification for colour, each ink in the set shall produce a colour that falls within the tolerances specified for the appropriate colorimetric values given in Table 1, when printed as defined in 5.2.1 at some percentage of press-ready ink. Table 1 Colorimetric
31、values for 0/45 and 45/0 geometry, illuminant D50, 2 observer Ink CIELAB values Tolerances L* a* b* Eab* a* b* L* Yellow 91,0 5,0 95,0 5,0 Magenta 52,0 71,0 1,0 6,0 Cyan 58,0 38,0 45,0 6,0 Black u 18,0 0,5 0,0 1,5 2,0 a0,018,0aThis means that for black there is no symmetrical tolerance for L* but an
32、 upper limit. NOTE 1 Typical spectral data for inks conforming to this part of ISO 2846 are provided in Annex A. Reference spectral data for 8/diffuse (specular included) are also included in Annex A. NOTE 2 CIELAB data calculated from the CIE 1931 (2) standard colorimetric observer, together with C
33、IE standard illuminant D65, are included in Annex B for both geometries. CIELAB data for 8/diffuse or diffuse/8 (specular included) geometry and illuminant D50are also included in Annex B. BS ISO 2846-5:200534.3 Transparency characteristics To meet the specification for transparency, each ink in the
34、 set shall produce a value greater than that specified in Table 2 when determined according to the principles and test methods outlined in 5.2. Table 2 Transparency requirements Ink Transparency T Yellow 2 Magenta 5 Cyan 8 For highly transparent inks, the slope of the regression line may be zero or
35、negative. In such a situation the transparency value, T, meets the specification. NOTE For further information concerning transparency evaluation using instruments with different geometry see C.3.2. 5 Test methods 5.1 Principle Colorimetric conformance is verified by printing each ink on the referen
36、ce substrate described in Annex D at a range of colorations obtained by varying the extension of the press-ready ink. The colours of the resultant test prints are measured and the colour difference determined between the sample and the pertinent value given in Table 1. If at least one of these sampl
37、es has a smaller colour difference than that specified in Table 1 the ink conforms colorimetrically to this part of ISO 2846. It is often more convenient to determine the colorimetric conformance of an ink by graphic means. This is achieved by calculating the colour difference (E*ab) from the values
38、 given in Table 1, for each print made from the extension series and plotting this against the percentage by mass of press-ready ink. The ink conforms if the resultant curve shows a pronounced minimum which is below the E*abvalue specified in Table 1. If the ink series does not produce such a curve,
39、 another series of specimens should be prepared starting from a different ink extension. A lower extension should be applied if the colour difference decreases with an increasing percentage of press-ready ink; a higher extension if the colour difference increases with a increasing percentage of pres
40、s-ready ink. See Annex C for further information. Transparency, T, is determined by printing or applying each of the chromatic process inks on to a black substrate at a range of ink extensions. The CIELAB colour difference, E*ab, is determined for each sample, between the overprinted and unprinted b
41、lack substrate. These values of E*abare plotted against the percentage by mass of press-ready ink over a range of extensions. The linear regression coefficient (slope of the regression line) of this plot is determined. An ink conforms to the transparency requirements of this part of ISO 2846 if the
42、reciprocal of the regression coefficient is greater than the value specified or negative, see Annex C for further information. If one or more printed samples of each ink conform to the colorimetric values within the tolerances specified, and the ink also meets the transparency criteria, that ink can
43、 be said to comply to this part of ISO 2846. BS ISO 2846-5:20054 5.2 Test print preparation 5.2.1 Prints for colorimetric evaluation For each ink to be evaluated an extension series with 50 %, 60 %, 70 %, 80 %, 90 % and 100 % of press-ready ink shall be prepared using an extender diluted to press vi
44、scosity. The series of extended inks shall be applied to the reference substrate specified in Annex D by a method that produces an even ink film thickness. (Typical methods for producing the test prints are printing with a printability tester for flexographic inks, or by using a coating applicator.)
45、 The ink film thickness applied shall be close to practice and approximately the same for all prints made from the extension series. 5.2.2 Prints for transparency evaluation Test prints for transparency evaluation shall be produced by printing the inks to be tested over a black such that a range of
46、samples is achieved, each with a different percentage of press-ready ink. The black shall have a lightness, L*, less than 6 when determined in accordance with ISO 13655 and the CIELAB values of the unprinted black shall be measured prior to overprinting. NOTE Although in principle it is possible for
47、 the user to produce the black by printing, it is difficult to ensure that the lightness is sufficiently low without adversely affecting the gloss and printing properties of the substrate. It is usually preferable to use a black substrate or a substrate pre-printed commercially. One appropriate subs
48、trate is the contrast card1). 5.2.3 Drying of test prints Prior to colour measurement all samples shall be thoroughly dried. 5.2.4 Colour measurement procedure Test prints shall be measured in accordance with ISO 13655, except that a substrate backing consisting of at least 3 sheets of the unprinted
49、 reference substrate shall be used. NOTE Conformance to ISO 13655 means that the samples are measured spectrally with a 0/45 or 45/0 geometry instrument. The CIE 1931 (2) standard colorimetric observer data are used, together with that for CIE illuminant D50, for calculation of CIELAB values and colour differences. Where spectral data are obtained at wavelength intervals greater than 5 nm, the weighting functions for the standard colorimetric ob
