ISO 15319 pdf download.Recycled pulps — Estimation of visible contraries by instrumental means using reflected light
1 Scope
This International Standard specifies a method for the estimation of visible contraries in pulp by instrumental means using reflected light. This International Standard cannot be used for inspection of pulps of low brightness, i.e. for evaluation of light contraries in dark pulp. Spots which look brighter than the surrounding area due to fluorescence will not be detected by the method described in this International Standard. NOTE 1 The evaluation of contraries smaller than 0,04 mm 2 is not covered by this International Standard. See informative annex A. NOTE 2 This International Standard is mainly intended for the assessment of product quality. Modifications may be needed if it is applied to process control.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 638, Pulps — Determination of dry matter content. ISO 41 1 9, Pulps — Determination of stock concentration. ISO 5263, Pulps — Laboratory wet disintegration. ISO 5269-1 , Pulps — Preparation of laboratory sheets for physical testing — Part 1 : Conventional sheet-former method. ISO 5269-2, Pulps — Preparation of laboratory sheets for physical testing — Part 2: Rapid-Köthen method. ISO 721 3, Pulps — Sampling for testing.
3 Term and definition
For the purposes of this International Standard, the following term and definition applies. 3.1 contrary speck any unwanted particle, embedded in the surface of the sheet, including dirt and shives, of specified minimum size and having a markedly contrasting light reflectance with respect to the surrounding area of the sheet, according to the comparison chart in annex B
4 Principle
Laboratory sheets are inspected in reflected light by instrumental means. The areas of all contraries larger than a specified value and having markedly contrasting light reflectance with respect to the surrounding sheet are recorded. The areas are added and the total area of the contraries is reported as square millimetres per square metre of laboratory sheets. If required, the areas or numbers of contraries in different size classes may also be reported.
5 Classification of contraries
Contraries having an area of at least 0,04 mm 2 and minimum contrast according to Table 1 shall be noted. See normative annex C. It is usual to report only the total area, though when required, the area or number of contraries in different size classes may be reported. In this case, the classification given in Table 1 should be used.
6 Equipment
6.1 Disintegrator, as specified in ISO 5263. The disintegrator is not needed if the sample to be inspected consists of pulp in slurry form. 6.2 Sheet-making equipment, for example as specified in ISO 5269, provided with a wire having a mesh aperture of 1 25 µm. 6.3 Clean blotters, of the size corresponding to the sheet-making apparatus. 6.4 Drying plates, of the same size as the laboratory sheets, made of corrosion-resistant metal or other suitable material, such as rigid plastics, glazed or polished on at least one side. It is essential that the wet sheet adheres firmly to the plate. The plate shall be flat and free from any perceptible bulges or distortions. NOTE Drying plates need not be used for Rapid-Köthen sheet forming. 6.5 Automatic device for counting of contraries, using reflected light and so constructed that the contraries having areas and contrasts corresponding to Table 1 can be evaluated, counted and reported. 95 % of the light emitted by the device shall have a wavelength of 380 nm to 750 nm. The device shall not count, as contraries, particles which contrast because of their fluorescence. The repeatability of the device shall fulfil the requirement that the coefficent of variation does not exceed 1 5 % when the determination of the total area of the contraries in a specimen is repeated five times.