Softwood Kraft Digestion Yield Fundamentals and Hemicellulose Degradation
Preserving softwood galactoglucomannan during kraft cooking through redox chemistry increases pulp yield by three percent while reducing refining power.
EN 645 Extract
Sample Preparation
Cold water extraction defines the laboratory procedure used to obtain soluble substances from paper and board materials intended for food contact. The preparation of an en 645 extract requires tearing or cutting a specified mass of the dry board into small pieces to maximize the surface area exposed to the solvent. This physical reduction ensures that soluble components like sizing agents, mineral fillers, or residual chemicals are readily accessible to the water.
Accurate mass measurements of the dry board establish the ratio of sample to solvent required by the standard protocol.
Extraction Procedure
The process of leaching water-soluble substances utilizes deionized water as the extraction medium under controlled temperature and time. A prepared paperboard sample is placed in a flask containing two hundred milliliters of water and left to sit for twenty-four hours at twenty degrees Celsius. Gentle agitation is maintained during this period to keep the fibers in suspension and ensure uniform contact.
Once the extraction time concludes, the mixture is filtered through a fine mesh or sintered glass funnel to isolate the liquid phase from the solid paperboard residue. This clear filtrate must be stored in a sealed glass container if analysis cannot proceed immediately to prevent contamination from the laboratory environment.
Chemical Analysis
Evaluating the obtained liquid phase provides data on the migration of substances like sensory-active compounds or potential contaminants. Analytical laboratories run tests on the filtrate to measure organic carbon levels or specific chemical species. This quantitative assessment verifies compliance with food safety regulations for food packaging.