1、 STD.BSI BS EN 12877-2-ENGL 2000 Zb2qbb9 0822b88 753 m BRITISH STANDARD Colouring materials in plastics - Determination of colour stability to heat during processing of colouring materials in plastics - Part 2: Determination by injection moulding The European Standard EN 12877-2: 1999 has the status
2、 of a British Standard ICs 83.040.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 12877-2:2000 STD-BSI BS EN 12877-2-ENGL 2000 lb24bb9 0822b87 87T 9 BS EN 12877-2:2000 been prepared under the direction of the Sector Committee for Materiais and Chemicals, was published
3、 under the authority of the Standards Committee and comes into effect on 15 January 2000 Amd. No. O BSI 01-2000 ISBN O 580 36858 5 National foreword Date Comments This British Standad is the English language version of EN 12877-2: 1999. “he UK participation in its preparation was entrusted to Techni
4、cal Committee STV1, pigments, which has the responsibiiity to: - aid enquirers to understand the text; - present to the responsible European committee any enquiries on the - monitor related international and European developments and promulgate interpretation, or proposals for change, and keep the U
5、K interests informed them in the UK A list of organizations represented on this committee can be obtajned on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Cataiogu
6、e under the section entitied “International Standards Correspondence Index“, or by using the Find“ facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contsact. Users of British standards are responsible for their corre
7、ct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 5 and a back cover. The BSI copyright notice displayed in this document indicates
8、 when the document was last issued. STD-BSI BS EN 12877-2-ENGL 2000 Lb2LibbS 0822b70 501 = EUROPEAN STANDARD EN 12877-2 NORME EUROPENNE EUROPAISCHE NORM October 1999 ICs 83.040.30 English version Colouring materials in plastics - Determination of colour stability to heat during processing of colouri
9、ng materials in plastics - Part 2: Determination by injection moulding Matires colorantes dans les plastiques - Dtermination de la stabilit de la couleur la chaleur au cours de la mise en oeuvre des matires colorantes dans les plastiques - Partie 2: Dtermination par moulage-injection Farbmittel in K
10、unststoffen - Bestimmung der Bestndigkeit der Farbe gegen Hitze beim Verarbeiten von Farbmitteln in Kunststoffen - Teil 2: Bestimmung durch Spritzgieen This European Standard was approved by CEN on 5 September 1999. CEN members are bound to comply with the CENICENELEC Internal Regulations which stip
11、ulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard e
12、xists in three official versions (English, French, German). A version in any other language made by traislation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as tie official versions. CEN members are the national standards
13、bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMU
14、NG Central Secretariat: rue de Stassart. 36 6-1050 Brussels O 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12877-2:1999 E _ , STDmBSI BS EN L2877-2-ENGL 2000 Page 2 Foreword This European Standard has been prepared by Techn
15、ical Committee Secretariat of which is held by DIN. EN 12877-2: 1999 Lb2qbb7 0822bL 4118 M CEN/TC 298, Pigments and extenders, the This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2000, and c
16、onflicting national standards shall be withdrawn at the latest by April 2000. According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, G
17、ermany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Introduction This is one of a number of Parts of EN 12877 dealing with methods for determining the colour stability of colouring materials under the influence of the
18、 thermal stress encountered during plastics processing. It should be read in conjunction with EN 12877-1. 1 Scope This pari of EN 12877 describes a method for determining the colour stability of colouring materials under defined conditions in plastics by injection moulding. The result of the determi
19、nation is a relative value, not an absolute one. The method is applicable for testing colouring materials in thermoplastics that are processible by injection moulding. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These
20、normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated
21、references the latest edition of the publication referred to applies. EN 12877-1 :I 999 EN 201 05-AO2 IS0 7724-2: 1984 IS0 7724-3 Colouring materials in plastics - Determination of colour stability to heat during processing of colouring materiais in plastics - Part 1 : General introduction Textiles
22、- Tests for colour fastness - Part A02: Grey scale for assessing change in colour (IS0 105 - A02:1993) Paints and varnishes - Colorimetry - Part 2: Colour measurement Paints and varnishes - Colorimetry - Part 3: Calculation of colour differences 3 Principle The colouring material to be tested, where
23、 appropriate together with titanium dioxide pigment, is mixed with the uncoloured thermoplastic material (test medium). The mixture is processed, using a suitable dispersing equipment, into a form suitable for injection moulding.The coloured test material obtained is injected into the plate-shaped m
24、ould cavity of a screw-injection moulding machine. Commencing at the lowest recommended processing temperature suitable for filling the mould cavity, the test temperature is increased in intervals of 10C or 20 OC up to the highest practicable processing temperature, and the dwell time is increased t
25、o 5 min. The colour differences between the moulded plate obtained at the lowest temperature and those prepared at the higher temperatures are determined either colorimetrically or visually. The highest test temperature at which any colour change does not exceed a stipulated degree is taken as a mea
26、sure of the colour stability of the colouring material under the test conditions (test medium and concentration of the colouring material). 4 Materials 4.1 Test medium Thermoplastic moulding material, to be agreed between the interested parties. 9BSI 01-2000 STD-BSI BS EN 12877-2-ENGL 2000 H 1bZLibb
27、S 0822bS2 38Li 9 Page 3 EN 12877-211 999 The coloristic behaviour of the test medium when subjected to heat shall be tested with and without titanium dioxide pigment, using the same procedure. If there are changes, these may be taken into account when expressing test results. 4.2 Titanium dioxide pi
28、gment, grade as recommended for use in plastics. 5 Apparatus 5.1 Laboratory mixers 5.1.1 High-speed mixer, for test media in powder form. 5.1.2 Low-speed mixer, for test media in pellet form. 5.2 Suitable dispersing equipment, for example extruder, internal mixer or two-roll mill. 5.3 Suitable grind
29、ing equipment, for example pelletizer or chipping machine. 5.4 Screw-injection moulding machine, preferably with hydraulic rotary drive, and non-return valve. NOTE The machine used should preferably have a screw diameter of 18 mm to 30 mm and an effective screw length of at least 15 times the screw
30、diameter. 5.5 Injection-moulding tool, preferably with bar gate and temperature control, for test specimens as specified in clause 7. The ratio of the volume of the material injection-moulded in a single shot to the maximum swept volume should be in the range from 1 : 3 to 1 : 5. 5.6 Electrical temp
31、erature sensor, fitted between the screw and the nozzle of the injection moulding machine. Alternatively, an immersion temperature sensor may be used. 5.7 Spectrophotometer or tristimulus colorimeter, for colour measurements in accordance with IS0 7724-2. 6 Sampling See EN 12877-1. 7 Test specimens
32、7.1 Form and dimensions Plate-shaped test specimens, of thickness at least 2 mm, suitable for colorimetry, shall be used 7.2 Concentration of colouring material The colouring material shall be tested in reduced shade (7.2.1) andlor in full shade (7.2.2). 7.2.1 For testing in reduced shade, 1 % of ti
33、tanium dioxide pigment shall be added to the plastics material, unless otherwise agreed. The concentration of the colouring material in the test medium shall correspond to: a) 113 standard depth of shade (SD) in accordance with EN 12877-1:1999, annex A, or b) 1/25 standard depth of shade (SD) in acc
34、ordance with EN 12877-1:1999, annex A, or c) an agreed ratio of colouring material to titanium dioxide pigment. NOTE In cases of plastics showing stronger yellowing at higher processing temperatures, higher additions of titanium dioxide pigments can be used. 7.2.2 For testing in full shade, the conc
35、entration of the colouring material in the test medium shall correspond to 7.2.1 a). Alternatively, a concentration of 0,l % (preferred for organic pigments and dyestuffs), or 2 % (preferred for inorganic pigments) or another agreed appropriate concentration shall be taken. OBSI 01-2000 STD.BSI BS E
36、N L2877-2-ENGL 2000 9 Lb24bb7 0822b93 210 9 Page 4 EN 12877-211 999 8 Preparation of the test material Premix the required quantities of coloured pigment to be tested and titanium dioxide pigment (if applicable) with the test medium, using the high-speed mixer (5.1.1) for test media in powder form,
37、and the low-speed mixer (5.1.2) for test media in pellet form. Process the mixture, using a suitable dispersing equipment 2), into a form suitable for injection moulding. The temperature of the melt during processing shall not be higher than the starting temperature for preparing test specimens for
38、injection moulding. NOTE 1 The colouring material should be well dispersed in order to ensure reliable results. NOTE 2 In the case of test media in pellet form, a suitable adhesion-promoting agent (0,l Yo to 0,2 Yo, calculated on the test medium) can be added before mixing to facilitate dispersion a
39、nd homogenization of the colouring material. 9 Procedure 9.1 Injection moulding tests 9.1.1 Preliminary tests Carry out preliminary tests to determine a processing schedule for the test medium used. The required cycle in the injection moulding process without back pressure shall be suitable for prep
40、aring test specimens at relatively low and relatively high processing temperatures. Measure the test temperature of the medium by using the meit-temperature sensor. Alternatively, use an immersion temperature sensor and measure the temperature of the medium by freely expelling it from the nozzle ont
41、o a wooden board. The test temperature shall be a multiple of 1 O. Make allowance for test temperatures in intervals of 20 OC within the determined processing schedule. In the case of more temperature-sensitive colouring materials or test media, intervals of I O “C may be used. 9.1.2 Test procedures
42、 NOTE Method A leads to less machine-dependent differences in thermal stress. A series of plates can be moulded. This allows equilibrium to be achieved and multiple measurements to be carried out, thereby enhancing the reliability of the result. 9.1.2.1 Method A Process the test material (clause 8)
43、using the normal injection-moulding cycle at the lowest test temperature determined in accordance with 9.1 .l. Discard sufficient mouldings until injection-moulded plates consisting of pure test material are obtained. Use these plates as reference specimens. The injection-moulding cycle is then prol
44、onged so that the specified dwell time of 5 min in the barrel is obtained. The resulting plates shall be used as test specimens for this prolonged dwell time. NOTE The dwell time is given by free barrel volume mould volume Cycle time x Then, whilst the moulding machine is in operation on the prolong
45、ed cycle, increase the processing temperature until the next higher test temperature is reached. After reaching this temperature discard mouldings until the plates that are produced have received the full thermal stress at this higher temperature. These plates shall be used as test specimens for thi
46、s processing temperature. Repeat the same procedure for all further predetermined test temperatures. 9.1.2.2 Method B Process the test material (clause 8) at the lowest test temperature determined in accordance with 9.1.1. Discard sufficient mouldings until injection-moulded plates consisting of pur
47、e test material are obtained. Use these plates as reference specimens. Then, interrupt the cycle for 5 min. Use the second moulding obtained after this period as the test specimen for this prolonged dwell time. OBSI 01-2000 STD-BSI BS EN 12877-2-ENGL 2000 = lb2Libb9 0822b94 157 Page 5 EN 12877-2:199
48、9 Repeat the same procedure for all further predetermined test temperatures. 9.2 Evaluation of colour difference Determine the colour difference between the test specimen prepared at the lowest test temperature and those prepared at the higher test temperatures. NOTE Colouring materials such as C.l.
49、 Pigment Red 48, 53 and 57 and dyestuffs can change colour reversibly after moulding and the mouldings should be maintained at room temperature for at least 16 h before assessment. If colour measurement is specified, proceed in accordance with IS0 7724-2:1984,4.1.1, and IS0 7724-3. For visual comparison, use the grey scale specified in EN 201 05-A02. 10 Expression of results Express the test results in one of the following ways: a) as a graph, giving the colour difference as a function of the test temperature; b) as the temperature at which the
