TAPPI T577

What is TAPPI T577? The Score Bend Testing Standard

TAPPI T577 is the TAPPI standard covering the bending properties of folded cartons and scored paperboard. The test measures the maximum force required to bend a carton sample up to 90°, and can also be used to determine the score ratio, the relationship between the bending force of scored versus unscored paperboard. This data helps paperboard converters and carton producers verify score quality and ensure consistent performance on high-speed packaging equipment.

Thwing-Albert’s TAPPI T577 Equipment

1270 PCA Score Bend Tester

The 1270 PCA Score Bend Tester is a purpose-built instrument for measuring bending force, opening force, and score quality of paperboard and folded cartons. The optional Bending Fixture meets TAPPI T577 and uses a pneumatic clamp operated by a foot-control pedal for secure, repeatable sample holding. The bending plate exerts force to bend the sample up to 90°. A set of three reference plates are included to verify accuracy.

• Bending force: maximum force to bend a carton sample up to 90° (TAPPI T577)
• Score ratio: scored vs. unscored paperboard bending force comparison (TAPPI T577)
• Springback force: carton fold springback after bending
• Opening force: maximum force to open a flat, folded carton along score lines
• Score quality: corrugated container score quality per TAPPI T829
• Coefficient of friction (COF): static and kinetic COF with the optional COF fixture

Related Test Properties and Standards

• Bending Resistance Testing Equipment – measure the force required to bend paperboard and folded carton samples
• Stiffness Testing Equipment – evaluate the rigidity of paperboard and packaging materials
• Folding Force Testing Equipment – measure the force required to fold scored paperboard and carton materials
• Opening Force Testing Equipment – measure the maximum force required to open a flat, folded carton along score lines
• TAPPI T829, Score Quality of Corrugated Containers – companion standard for measuring score quality of corrugated containers, also performed on the 1270 PCA Score Bend Tester
• TAPPI T576, Folding Endurance of Paperboard – related TAPPI standard for evaluating the folding endurance of paperboard materials
• Paperboard Testing Equipment – full range of instruments for testing paperboard materials used in folding carton and packaging applications
• Packaging Testing Equipment – complete line of packaging testing instruments for quality control and runnability testing

Frequently Asked Questions

What does TAPPI T577 measure?

TAPPI T577 covers the bending properties of folded cartons and scored paperboard, including the force required to bend a sample up to 90° and the score ratio between scored and unscored paperboard.

What instrument is used to perform a TAPPI T577 test?

The Thwing-Albert 1270 PCA Score Bend Tester with the optional Bending Fixture is designed to meet TAPPI T577 requirements. The bending fixture uses a pneumatic clamp for repeatable sample holding and a bending plate that measures force through 90°.

What is score ratio testing?

Score ratio compares the bending force of scored paperboard to unscored paperboard of the same material. This ratio is used to evaluate the quality and consistency of the scoring process. TAPPI T577 includes this as part of its bending properties testing scope.

What is springback force?

Springback force is the resistance of a carton fold to returning toward its original position after bending. The 1270 PCA Score Bend Tester measures springback force, which is relevant to sealing and gluing operations on packaging lines.

Can the 1270 PCA Score Bend Tester perform tests other than TAPPI T577?

Yes. In addition to TAPPI T577 bending force testing, the 1270 PCA also supports opening force testing, score quality testing per TAPPI T829, and coefficient of friction (COF) measurement with available fixtures.

What sample sizes does the TAPPI T577 bending fixture accept?

The bending fixture accepts samples up to 152.4 mm (6 in) wide and up to 6.35 mm (0.25 in) thick.

Have Questions About TAPPI T577 Testing?

Have questions about TAPPI T577 testing or the 1270 PCA Score Bend Tester? Contact us or request a quote and our team will help you find the right solution.

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