Critical Quality Tests for Various Grades of Paper

Critical quality tests for various grades of paper. All products at Century Pulp & Paper undergo various stringent tests to maintain quality and consistency.

  • Absorbent kraft

    • COP (Castor Oil Penetration): This method is used to measure the absorbency rate of paper for printing inks with an oil-based vehicle. It is used only for easily permeable papers such as newspapers, books and mimeographs. However, this method can also be used for any paper where the absorbency of an oil-based vehicle is important. A correlation has been established between the results of this test and the printing quality of uncoated papers. The oil absorbency of paper is related to its porosity and internal structure.
  • MICR

    • Sensitivity Test – In MICR paper we put various types of chemicals which react when these solvents are put and turn the paper into some color. This property is to avoid forgery. The various chemicals used are Benzyne, Cloroform, Alcohol, Sodium Matabisulphite, Oxalylic acid, Amonia, Acetone, Calcium Hypo etc.
    • For these papers to meet quality standards, the following requirements must be met: a. Water mark should be clear b. Smoothness achieved c. UV light should not glow d. Other BIS norms like GSM and tear factor must also be met.
  • Overlay Tissue

    For these papers to meet quality standards, the following requirements must be met:


      • Wet Strength should be from 500-1000 g/cm
      • Smoothness level should be from 100-150 ml/min
      • Strength should be more than 5000 in breaking length
      • Uniform Caliper
      • Uniform GSM
  • ARSR

    For these papers to meet quality standards, the following requirements should be met:


      • Bulk should be more than 1.4
      • GSM should be from 100-185
      • Alkali Stain Number should be less than 3
      • Passing of the Floro Glucinol test
      • Passing of the Soap Jelly Test
      • Addition of Anti-fungal chemicals during the stock preparation stage
  • Base Paper for Cromo/Artpaper

    For these papers to meet quality standards, the following requirements should be met:


      • Surface strength
      • Uniform caliper
      • Cob value
  • Wax Match

    For these papers to meet quality standards, the following requirements should be met:


      • Uniform corrugation
      • Uniform GSM, caliper
      • High brightness
      • Breaking length should be very high
  • Shuttering Base

    For these papers to meet quality standards, the following requirements should be met:


      • Smoothness
      • Opacity level of 95%
      • Wet Strength
  • Carbonless Paper

    For these papers to meet quality standards, the following requirements should be met:


      • Smoothness
      • GSM should be from 45-50 for duplicate books of various colours
  • Century Parchment

    For these papers to meet quality standards, the following requirements should be met:


      • Good Strength
      • Clean Water Mark
      • Smoothness
  • Bible Printing

    For these papers to meet quality standards, the following requirements should be met:


      • High opacity of 95%
      • Good strength properties
      • Scattering co-efficient
      • ISO Brightness of at least 88%
  • Other general tests which are conducted for various WPP are:

    • GSM
    • Caliper
    • Brightness ISO
    • Bulk
    • Burst Factor
    • Ash Content
    • Breaking Length
    • Smoothness
    • Porosity
    • COBB Value
    • Opacity

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