Hydraulic Bursting Strength Tester for Corrugated Board

What is the Hydraulic Bursting Strength Tester for Corrugated Board?

A hydraulic bursting strength tester for corrugated board uses a large test area and a support plate so that the combined structure bursts rather than collapsing. It is used for carton board quality control and specification testing.

Overview

The specimen is clamped over a large circular aperture, usually about 31 mm or 112.8 mm depending on the standard, and a support plate beneath the diaphragm spreads the load so that the flutes are not crushed locally before the liners rupture. Clamping pressure is higher than for paper because the board is thicker and stiffer, and the pressure range must extend to several thousand kilopascals to accommodate double-wall and triple-wall constructions. Specimens are taken from flat panels of the board or the finished box, avoiding scores, printing and crushed areas, and the direction of the flutes relative to the clamping ring should be consistent. Results are reported as bursting strength in kilopascals and form part of the basis for carton strength specification.

How does it work?

A circular specimen is clamped between two platens under a defined clamping pressure and a rubber diaphragm expands against it as hydraulic or pneumatic pressure increases at a controlled rate. The maximum pressure reached at rupture is recorded as the bursting strength, and the value is affected by clamping pressure, diaphragm condition, the rate of pressure rise and specimen conditioning. Standards define the clamping force, the free test area, the pressure rise rate and the diaphragm material and thickness, so the instrument must be configured exactly as the method specifies. Because the diaphragm stretches with every test, it must be replaced at defined intervals and its condition checked, since a stiff or hardened diaphragm gives high and erratic readings. Corrugated board requires a larger test area and a support plate to prevent local crushing.

What are the key features?

• Large test area with support plate
• High clamping force for stiff board
• Extended pressure range to 6000 kPa
• Flat specimen preparation guidance
• Digital maximum pressure recording
• Interchangeable apertures per standard

What are the technical specifications?

A typical hydraulic bursting strength tester for corrugated board configuration offers measuring range of 0–6000 kPa, test area diameter of 31 mm or 112.8 mm per standard, clamping pressure of Higher than for paper, per method, support plate of Provided to spread load over flutes, pressure rise rate of Per standard edition and diaphragm of Thicker grade for board testing. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Hydraulic Bursting Strength Tester for Corrugated Board is used in corrugated carton board specification testing, incoming inspection of box board deliveries, comparison of single, double and triple wall structures and quality control in box plants. Across the wider Burst Analysis class, laboratories also deploy it for bursting strength of packaging papers and boards, corrugated board quality control and paper bag and sack grade verification.

Which standards and certifications apply?

Relevant standards and methods include ISO 2758, ISO 2759, ISO 12625-11, ASTM D774, TAPPI T403, TAPPI T810 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Condition specimens to the standard atmosphere, since bursting strength changes markedly with moisture content. Clamp each specimen centrally and without creases, since edge positions and wrinkles cause premature rupture and low readings. Replace the diaphragm at the interval stated in the method or whenever it shows hardening, cracking or permanent deformation, and record the replacement in the instrument log. Verify the clamping pressure and the pressure rise rate periodically, and check the pressure gauge or transducer against a reference. After each test, inspect the rupture pattern: an off-centre or irregular burst usually indicates a clamping or centring problem rather than a material fault.

How do I select the right Hydraulic Bursting Strength Tester for Corrugated Board?

Specify this configuration when the specimen is corrugated board, and confirm the test area, support plate and clamping force match the standard you follow. Check that the pressure range covers your heaviest construction with headroom, and that specimen preparation instructions keep the flutes from being crushed before the test.

How does it compare with other Burst Analysis variants?

Choose the instrument from the standard and the product. Paper and tissue use the smaller hydraulic test area, board uses the larger area with a higher pressure range, and corrugated board needs a pneumatic or hydraulic instrument with a support plate and a sufficiently wide clamping ring. Confirm the pressure range covers the expected bursting strength with adequate headroom, since a range that is too low prevents reaching rupture and one that is too wide reduces resolution. Specify automatic clamping if many specimens are tested, and always choose an instrument whose diaphragm and pressure rise rate match the standard edition you follow, because values from different configurations are not interchangeable.