Fibre surface composition Information about the chemical structure of fibre surface is important when investigating the effect of delignification reactions on the components in pulp fibre surface layers. A more detailed understanding about the interactions between the fibres is also desirable. Electron microscopy for chemical analysis (ESCA) is a very suitable tool for such investigations.
Dirt and shives in pulp Although not a chemical property, the amount of dirt and shives (generally referred to as contraries in the international community) is a common measurement in the chemical evaluation of pulp. A contrary in pulp is any unwanted foreign particle that is visible in the sheet and has a markedly contrasting
Colour reversion Exposure of pulp to elevated temperature, high humidity and visible or ultraviolet light, such as in accelerated aging, may provide information concerning the natural change in brightness or colour reversion that might occur in the material over a period of years. Literature provides many examples of different methods for accelerated aging of cellulosic
Inorganic matter The inorganic matter present in pulp originates not only from the wood raw material but also from the pulping process. The total inorganic matter in pulp is usually reported as residue on ignition or ash. Ash and its components The procedure used for ignition may cause inorganic salts to decompose. The rate of
Properties and components of water extracts pH and conductivity of water extracts of pulp pH measurement indicates the presence of acidic or basic ions in pulp. Conductivity measurement indicates the level of residual ionic impurities. A sample is extracted with water under specific conditions (standard concentration, temperature and time). The pH and conductivity is then
Analysis of dissolving pulps Chemical analysis of dissolving pulps includes analysing those pulp components that may prevent complete dissolution of the pulp or cause other problems in processing of final products. The pulp components in question vary to some extent depending on wood species, location of growth and end product. The ordinary chemical test methods
Chemical analysis of pulps Introduction The purpose of chemical characterisation of pulp is to obtain information about quality aspects and special properties of the pulp. Chemical analyses also have use for controlling pulping and bleaching processes, estimating the applicability of different pulp grades and performing research and development. Many methods for chemical characterisation of chemical
TAPPI Industrial branch standards The industrial branch standards are issued by the technical corporations in some countries or regions. These are not standards in the strict sense since they have no official recognition. National standardisation bodies may eventually adopt them as national standards, and they can be used as the basis of proper international standards.
ISO General aspects The International Organization for Standardization (ISO) is a global federation of national standardization bodies that has 165 member countries in 2021. Individuals and companies cannot be ISO members. The object of ISO is to promote the development of standardisation and related activities in the world to facilitate international exchange of goods and
CEN General aspects The European Committee for Standardization (CEN) is an association of 34 National Standardization bodies of European countries. CEN is officially recognised by the European Union and by the European Free Trade Association (EFTA) as being responsible for developing and defining voluntary standards at European level. CEN provides a platform for the development
