TAPPI/ANSI T 409 sp-15 is an official TAPPI Standard Practice covering multiple procedures for identifying the machine direction of paper and paperboard. It explains the scope, significance, definitions, required apparatus, sampling and specimen preparation, and interpretation of observations.
The document includes curl, bend, bursting, tensile, surface fiber, tear, folding endurance, drying, hand tearing, wire marks, and flexing procedures, along with guidance for uncertain sheet orientation, verification using multiple procedures, reporting, limitations, keywords, and related methods. It is a concise four-page PDF reference for paper laboratories, manufacturers, converters, packaging professionals, and quality-control personnel.
Application Scope: Use this standard practice to identify machine and cross directions when evaluating paper and paperboard for folding, scoring, creasing, testing, converting, and quality-control applications.
