Determining Viscose Wool Dry Mass Ratios through ISO 1833 Chemical Separation
Determining viscose wool dry mass ratios through ISO 1833 requires selective chemical dissolution, reagent mass correction, and commercial regain adjustments.
Viscose Ratio
Composition Metric
Quantitative proportion of regenerated cellulose in a blended yarn defines the physical properties and the commercial value of the fabric. Calculation of the viscose ratio involves dissolving the secondary fiber in a specific reagent and measuring the weight of the remaining material. This figure determines how the product must be labeled according to international trade laws.
Laboratory Verification
Analysis of a polyester and viscose blend requires the use of sodium hypochlorite or dimethylformamide to isolate the components. Establishing the viscose ratio correctly requires the application of a correction factor to account for the loss of minor amounts of non cellulose matter. Precise weighing of the oven dry sample is essential for an accurate result.
Production Quality
Variations in the feeding speed of the sliver during the spinning process can alter the intended blend proportions. Monitoring the viscose ratio throughout the production run ensures that the fabric maintains a consistent handle and drape. Deviations from the target specification can affect the dye uptake and final appearance of the garment.
Sourcing Strategy
Buyers compare the laboratory results against the supplier invoice to verify the value of the shipment. A correct viscose ratio confirms that the product meets the technical requirements of the contract.