The humble cardboard box is the unsung hero of countless deliveries every day. By using simple test methods such as the Edge Crush Test (ECT), companies benefit from understanding the maximum weight a box can withstand and the overall stacking strength.
ECT gives a good picture of overall strength, enabling cardboard and box manufacturers to better maintain and improve quality control testing, during formulation, processing and production.
Over the weeks of COVID-19 lockdown confinement there has been a surge of home deliveries, with even online retail giants struggling to fulfil demands and hiring fleets of new workers.
Hearing the knock at the door to receive a package provides a small sense of normality and pleasure to many. And it is the humble cardboard box which is neatly and safely enabling the widespread distribution of goods.
Beyond household deliveries, cardboard is also an object serving on the frontline of public health services, enabling mass deliveries of vitally needed medical equipment.
Modern production and shipping have changed drastically, and the testing methods we use to measure a package’s strength have changed accordingly. These days, much of the shipping is done as boxes on pallets, delivering goods from one business to another business (B2B).
Testing the edge wall of a box for its stacking strength is the most sensible and reliable measure of how well the box will hold its form under the vertical weight during transit.
Evolving test methods from Mullen Burst Test to Edge Crush Test (ECT)
For many years the Mullen Burst Test had been the main industry standard for the grading of corrugated board packaging. It required a minimum board base weight. However, as more recycled content is now used in the manufacture of corrugated board, it was discovered that recycled board of the same weight did not always perform so well in the Mullen Burst test.
This was despite the fact that these ‘recycled board’ cases still had very good compression and damage resistance qualities, as evidenced in the Edge Crush Test (ECT).
The Mullen Burst Test measures the force required to puncture the face of corrugated board and is reported in pounds per square inch (psi), boards are thus rated accordingly eg #275.
As such, this test was favoured by companies with heavy, awkward-shaped contents requiring protection where the liner-board must not burst outwards.
|Box type||Bursting test||ECT||Max. load per carton|
|Standard||200#||32 ECT||40 lbs|
|Heavy duty||275#||44 ECT||65 lbs|
|275#||48 ECT||80 lbs|
However for companies who simply wish to know the maximum weight a box can withstand, then knowing the overall stacking strength is the primary concern - this is where the Edge Crush Test comes into its own and has become the more common test nowadays.
ECT is a measure of the edgewise compressive strength of corrugated board. It is measured by compressing a predefined section of board on its edge between two rigid platens.
This compression is performed perpendicularly to the direction of the flutes until the board collapses and a peak load is reached.
This load is reported as force per unit width (lb/in, kN/m, etc). When reported as an ECT value (eg 44 ECT) this relates to a minimum strength value and corresponds to pounds per inch width (lb/in).
Since the edges and corners of a box are mostly responsible for bearing the load, it gives a good picture of material strength allowing cardboard manufacturers to perform quality control, and box manufacturers to select the most appropriate materials and processes to produce their protective packaging
A proper ECT-rated corrugated board provides an equivalent level of strength to a Mullen Burst rated board, but typically uses less material.
Fewer raw materials, meaning lower energy requirements and reduced pollution, are features associated with properly sized ECT-rated cartons incorporating increasing amounts of recycled content.
International standards for measuring crush force in the Edge Crust Test (ECT)
There are a number of international standards from various standards authorities, which address the subject of measuring the crush force by the Edge Crush Test.
A variety of methods are in use in different parts of the world. These can be classified into three groups as follows:
- Those in which a carefully cut rectangular test piece is tested without any special treatment or modification (eg ISO 3037 “Corrugated fibreboard — Determination of edgewise crush resistance -unwaxed edge method”).
- Those in which the edges of the test piece to which the force is applied are waxed, to prevent the test result being influenced by “edge effects“ (eg ISO 13821 “Corrugated fibreboard — Determination of edgewise crush resistance — waxed edge method”).
- Those in which the test piece edges are not waxed but the shape of the test piece is such that the length is substantially reduced at a point midway between the loaded edges, in order to induce the failure to occur away from those edges (eg FEFCO 8, TAPPI T838 and TAPPI T839)
Developing testing solutions for Edge Crush Test (ECT) of corrugated cardboard
Mecmesin has worked together with both producers and users of corrugated cardboard to supply cost-effective and easy-to-use ECT test systems.
A software-controlled compression tester, featuring a rigid loading column and precision loadcell, is equipped with rectangular plattens. Two free-standing guide blocks serve to support the corrugated test specimen thus keeping it parallel to the plattens.
The test programme controls the tester to descend at a constant speed until a set-load is reached at which point the guide blocks can be removed. The tester then continues further until the corrugated board collapses and the software automatically calculates the Edge Crush Resistance value in the desired unit of measurement (lb/in, N/mm).
Bench-top models of ECT Compression Testers are available in capacities of 2.5kN - 10kN depending on the range of board to be tested.
ISO 3037 Corrugated fibreboard - Determination of edgewise crush resistance (unwaxed edge method)
TAPPI T 839 Edgewise compressive strength of corrugated fiberboard using the clamp method (short column test)
Release torque testing of Champagne and sparkling wine corks
The Mecmesin CombiCork is a Quality tool that allows Korbel to test cork materials, ensuring they match with Korbel’s stringent quality standards. Testing removes subjectivity from the uncorking of champagne corks, troubleshooting our process or material variation, so our customers are able to have a consistent experience every time they open a bottle of the finest Korbel California Champagne
Adhesive test on capsulated cork stoppers
A capsulated stopper (T-top, Bar-Top or Altop) is a natural or synthetic cork stopper where the end is glued into a cap of wood, PVC, porcelain, metal, glass or other material. Testing the quality of the adhesive bond between cork and cap is a fundamental check performed by manufacturers of capsulated stoppers and their customers
Vial stopper needle penetrability residual seal force and torque testing
COVID-19 vaccines, as parenteral medications, enter the body by injection through the tissue and circulatory system. Testing the physical properties of these vital drug container systems is a key factor in quality-control testing
Sales of antibacterial gels have soared enormously following National Health Service advice telling the public to thoroughly wash hands in order to stay protected from Coronavirus. In fact, even before the 2020 pandemic crisis, the presence of hand sanitisers had already become commonplace, not only in hospitals but also in schools, restaurants and offices.
In the wake of the Covid-19 lockdown, there have been clear guidelines issued to businesses on keeping staff and customers safe. These include wall signs encouraging people to follow hygiene guidelines through to purpose-made floor tape to help enforce social distancing rules. For successful long-lasting application to surfaces, they all rely on the stickiness provided by the humble self-adhesive.
Break-loose and sustaining force tests of pre-filled drug cartridges to ISO 11608-3
Mechanical pen injectors for delivering drugs, such as insulin, have found increasing acceptance over the traditional vial-and-syringe method. To validate new pen injector designs and maintain quality when they are mass-produced requires extensive testing.
Vaccine delivery device and packaging testing
As COVID-19 has rapidly spread around the world, there is a concerted global effort to find a vaccine. Whether administered via an oral, subcutaneous, intramuscular, intradermal, or intranasal route, vaccines need to be administered via a medical device, and these must be tested to esnure they are safe and meet stringent standards and regulations
PET preforms - repurposing production for COVID-19 test kits
PET preforms are typically blow-moulded to create the ubiquitous plastic bottles containing carbonated and still beverages. The production process to fill and seal these bottles with a screw-cap is a demanding one, so a number of tests are performed to ensure quality control specifications are met for this core packaging.
Probiotic drink packaging testing
As demand for dietary supplements continues to surge, immune-boosting products, such as prebiotics and probiotics, are amongst the most popular. Getting these liquid probiotic products noticed by the consumer relies on eye-catching innovative packaging which must be easy-to-open and reseal whilst remaining economic to use for the beverage producer.
Testing Ventilator and Breathing Assistance Apparatus Components
A ventilator (respirator) provides ‘mechanical ventilation’ by moving breathable air into and out of the lungs of patients unable to breathe sufficiently well unaided. Such fundamental hospital equipment is essential for all patient care where assisted breathing is necessary.
Face mask strength testing
Manufacturing masks is not as easy as you might imagine. International test standards exist to make sure the face masks can be verified to protect clinicians and patients from pathogens spread by blood, body fluids and secretions and now to limit the spread of COVID-19 coronavirus.
Pharmaceutical tablet crush and break strength
Many products come in tablet form, with a durability designed for both packaging and for use. Too brittle or too hard, and they may not be fit for use, or at best perform below expectation. The only way to determine consistency is mechanical testing of samples.
Lipstick tube force and torque testing
Testing the mechanical performance of the lipstick tube is a crucial part of the quality-control process for cosmetics manufacturers. Leading players in the cosmetics industry have come to rely on Mecmesin’s range of affordable force and torque testers to carry out checks on batches of lipsticks produced.
Mecmesin's materials testers
Testing the physical strength properties of materials, in accordance with international or in-house standards, is a key part of determining their characteristics to better understand the effects of process improvements. With this in mind, Mecmesin has designed a range of static-load Materials Testers powered by intuitive VectorPro MT software.
Top-load crush of plastic bottle with semi-automated test process
To guarantee their containers would perform as expected along customer production lines and remain intact during transportation and storage, US company, Silgan Plastics wanted to undertake top-load tests according to internal, customer and Supplier Packaging Information (SPI) standards.
Dispensing pump assembly testing
Mecmesin's customer manufactures a range of dispensing pumps for the cosmetic and beauty-care industry. A requirement was identified to measure the actuation force of the pump assembly and the pull-off force of the pump handle. The VersaTest motorised test stand was chosen as it gave the necessary repeatability and consistency independent of operator, which a manual stand could not.
Powdered drink container - Mecmesin's compressive strength & lid peel tests
An international supplier of a powdered hot-chocolate drink wanted to test several aspects of their packaging. The client was then able to use their Mecmesin universal tester for all four tests, with quick and easy exchange of fixtures, allowing rapid throughput of samples for testing.
The food packaging industry has long had concerns about pinholes, flex cracks and leaks in the flexible materials and seals of retort flexible lidded packaging. A famous global food and drink maker needed to test the laminated retort (and other thin film) packaging solutions that protect products such as their popular microwaveable stir-in pots.
Battery terminal weld integrity tensile test
BMZ is one the largest European suppliers involved in the design and manufacture of specialist custom made battery systems for mobile power applications. As part of their production process, BMZ Poland in Gliwice needed to test the integrity of the welding on electrical connections fixed to each end of one of their rechargeable cells
Wine cork extraction test to ISO 9727-5
The customer, AMORIM & IRMÃOS, S.A – Unidade Industrial da Valada, required an economic and easy-to-use system to test the extraction force of corks from glass wine bottles. The test specifies a speed of 300 mm/min according to ISO 9727 and the corkscrew should be applied to a depth of minimum 3 mm below the base of the cork.
Nail varnish bottle closure removal torque and capping check
Barry M Cosmetics Ltd is a leading British colour cosmetics brand, offering a comprehensive range of products for face, eyes, lips and nails. The company required a quick, reliable and repeatable test method to check the capping equipment of their nail paint range. Mecmesin supplied a Tornado digital torque tester of 3 N.m capacity, which is a complete, portable, benchtop instrument.
Cosmetic packaging pull-off test
A bench-top testing system was required to repeatably test the pull-off force on a variety of cosmetic containers. The system needed to allow a relatively high volume of containers to be tested with the minimum level of training required for users. Mecmesin's solution avoided the risk of damaging the loadcell by excessive torque on tightening the collet grip, and the lipstick barrel was first inserted in the grip and then connected to the gauge by a flexible chain-link.
Coefficient of friction test
A print factory needed to test the packaging material they were using in order to improve their processes and establish optimum machinery settings. The company sought a solution, which provided consistent results and reliable performance. Mecmesin advised the company to use a coefficient of friction test to determine the 'slip' properties of the packaging.
Closure torque tester validation check
The customer had a number of Tornado closure torque testers, and wished to carry out regular validation checks without the need to return the units to either Mecmesin or an approved laboratory. The closure tester was securely mounted in the vertical plane and a load beam was placed centrally in the universal-clamping fixture.
A system was required to measure the push-on force and removal force of an injection-moulded cap from a new design of oil can. Mecmsin's test was set-up by sliding a can into the lower fixture, while locating a cap, resting on the can's neck, into the self-centering swivel fixture attached to the gauge.
- Jo Webb
- Product Info
- Created 20 Jul 2020
- Modified 05 Aug 2020
- Hits 970