Tensile strength and elongation testing

Tensile strength and elongation tests are made on a wide range of paper and board materials at Pira; including tissue, crepe paper, copier paper, medical paper, carton board, and liner boards. Measurement is made using a tensile tester applying a constant rate of elongation to the test strip. Tensile strength is usually quoted in kN/m.

Tensile index = tensile strength/grammage, quoted in Nm/g.

In addition to the maximum tensile load and elongation, the tensile energy absorbed is calculated from the area under the load/elongation curve. This is the work done in breaking the test strip. Tensile energy absorption units are J/m2.

Our UKAS, ISO 17025 accredited testing is performed to British standard BS EN ISO 1924/2 and International standard ISO 1924/2.

Similar methods are described in Tappi T494 and DIN 53112.The strength of wet paper and board is determined according to BS 2922/2. The physical testing of laboratory prepared handsheets is described in ISO 5270.

Tissue products are tested for dry tensile strength and wet tensile strength (Finch method) in accordance with British standard and International standard BS EN ISO 1925/4 and BS EN ISO 1925/5 respectively.

Tensile strength and stretch at break testing of paper is included in Pira's Paper Proficiency Service.

Zero-span tensile strength

Pira can perform a tensile strength test on paper using a span length close to zero using a Pulmac Zero Span tensile tester. The test is described in International Standard ISO 15361.