Package testing

Packaging testing might have a variety of purposes, such as:

• Determine if, or verify that, the requirements of a specification, regulation, or contract are met
• Decide if a new product development program is on track: Demonstrate proof of concept
• Provide standard data for other scientific, engineering, and quality assurance functions
• Validate suitability for end-use
• Provide a basis for technical communication
• Provide a technical means of comparison of several options
• Provide evidence in legal proceedings: product liability, patents, product claims, etc.
• Help solve problems with current packaging
• Help identify potential cost savings in packaging

Packaging tests can be used for:

• Subjecting packages (and contents) to stresses and dynamics found in the field
• Reproducing the types of damage to packages and contents found in actual shipments
• Controlling the uniformity of production of packages or components

Testing the ability of packages to resist insect infestation[3]

For some types of products, package testing is mandated by regulations: food. pharmaceuticals, medical devices, dangerous goods, etc. This may cover both the design qualification, periodic retesting, and control of the packaging processes. Processes may be controlled by a variety of quality management systems such as HACCP, statistical process control, validation protocols, ISO 9000, etc.

For unregulated products, testing can be required by a contract or governing specification. The degree of package testing can often be a business decision. Risk management may involve factors such as

• costs of packaging
• costs of package testing
• value of contents being shipped
• value of customer's good will
• product liability exposure
• other potential costs of inadequate packaging
• etc.

With distribution packaging, one vital packaging development consideration is to determine if a packaged-product is likely to be damaged in the process of getting to the final customer. A primary purpose of a package is to ensure the safety of a product during transportation and storage. If a product is damaged during this process, then the package has failed to accomplish a primary objective and the customer will either return the product or be unlikely to purchase the product altogether.[4]

Package testing is often a formal part of Project management programs. Packages are usually tested when there is a new packaging design, a revision to a current design, a change in packaging material, and various other reasons. Testing a new packaging design before full scale manufacturing can save time and money.[5]

Many suppliers or vendors offer limited material and package testing as a free service to customers. It is common for packagers to partner with reputable suppliers: Many suppliers have certified quality management systems such as ISO 9000 or allow customers to conduct technical and quality audits. Data from testing is commonly shared. There is sometimes a risk that supplier testing may tend to be self-serving and not completely impartial.

Large companies often have their own packaging staff and a package testing and development laboratory. Corporate engineers know their products, manufacturing capabilities, logistics system, and their customers best. Cost reduction of existing products and cost avoidance for new products have been documented.[6]

Another option is to use a paid consultant, Independent contractor, and third-party independent testing laboratory. They are commonly chosen for specialized expertise, for access to certain test equipment, for surge projects, or where independent testing is otherwise required. Many have certifications and accreditations: ISO 9000, ISO/IEC 17025, and various governing agencies.

Several standards organizations publish test methods for package testing. Included are:

• International Organization for Standardization, ISO
• ASTM International
• European Committee for Standardization. CEN
• TAPPI
• Military Standards[7]
• ISTA (International Safe Transit Association)[8]

Governments and regulators publish some packaging test methods. There are also many corporate test standards in use. A review of technical literature and patents provides good options to consider for test procedures.

Researchers are not restricted to the use of published standards but can modify existing test methods or develop procedures specific to their particular needs. If a test is conducted with a deviation from a published test method or if a new method is employed, the test report must fully disclose the procedure.

Materials and components are often evaluated on a universal testing machine

The basis of packaging design and performance is the component materials. The physical properties, and sometimes chemical properties, of the materials need to be communicated to packaging engineers to aid in the design process. Suppliers publish data sheets and other technical communications that include the typical or average relevant physical properties and the test method these are based upon. Sometimes these are adequate. Other times, additional material and component testing is required by the packager or supplier to better define certain characteristics.

When a final package design is complete, the specifications for the component materials needs to be communicated to suppliers. Packaging materials testing is often needed to identify the critical material characteristics and engineering tolerances. These are used to prepare and enforce specifications.

For example, shrink film data might include: tensile strength (MD and CD), elongation, Elastic modulus, surface energy, thickness, Moisture vapor transmission rate, Oxygen transmission rate, heat seal strength, heat sealing conditions, heat shrinking conditions, etc. Average and process capability are often provided. The chemical properties related for use as Food contact materials may be necessary.

Some types of package testing do not use scientific instruments but use people for the evaluation.

The regulations for child-resistant packaging require a test protocol that involves children. Samples of the test packages are given to a prescribed population of children. With specified 50-child panels, a high percentage must be unable to open a test package within 5 minutes.[9] Adults are also tested for their ability to open a child-resistant package.

Consumer packages are often evaluated by focus groups. People evaluate the package features in a room monitored by video cameras. The consumer responses are treated qualitatively for feedback into the new packaging process.

Some food packagers use organoleptic evaluations. People use their senses (taste, smell, etc.) to determine if a package component has tainted the food in the package.

A new package may be evaluated in a test market that uses people to try the packages at home. Consumers have the opportunity to buy a product, perhaps with a coupon or discount. Return postcards or Internet sites provide feedback to package developers. Perhaps the most critical feedback is repeated sales items in the new package. Packaging evaluations are an important part of marketing research.

Legibility of text on packaging and labels is always subjective due to the inherent variations of people. Efforts have been made to help better quantify this by people in a laboratory: still using people for the evaluation but also employing a test apparatus to help reduce variability.[10][11]

Some laboratory tests are conducted but still result in an observation by people. Some test procedures call for a judgment by test engineers whether or not pre-established acceptance criteria have been met.

Environmental chamber to simulate temperatures and humidities encountered by packages

The environmental conditions of testing are critical. The measured performance of many packages is affected by the conditioning and testing atmospheres. For example, paper based products are strongly affected by their moisture content: Relative humidity needs to be controlled. Plastic products are often strongly affected by temperature.[12]

Conditions of 23 °C (73.4 °F) and 50% relative humidity are common but other standard testing conditions are also published in material and package test standards. Engineering tolerances for the conditions are also specified. Often the package is conditioned to the specified environment and tested under those conditions. This can be in a conditioned room or in a chamber enclosing the test. With some testing, the package is conditioned to a specified environment, then is removed to ambient conditions and quickly tested. The test report needs to state the actual conditions used.

Engineers have found it important to know the effects of the full range of expected conditions on package performance. This can be through investigating published technical literature, obtaining supplier documentation, or by conducting controlled tests at diverse conditions.

Heat sealer used to prepare bag of lettuce for shelf life testing

Laboratory tests can help determine the shelf life of a package and its contents under a variety of conditions. This is particularly important for foods, pharmaceuticals, some chemicals, and a variety of products. The testing is usually product specific: the mechanisms of degradation are often different. Exposures to expected and elevated temperatures and humidities are commonly used for shelf life testing. The ability of packaging to control product degradation is frequently a subject of laboratory and field evaluations.

Packages can degrade with exposure to temperature, humidity, time, sterilization (steam, radiation, gas, etc.), sunlight, and other environmental factors. For some types of packaging, it is common to test for possible corrosion of metals, polymer degradation, and weather testing of polymers. Several types of accelerated aging of packaging and materials can be accomplished in a laboratory.

Exposure to elevated temperatures accelerates some degradation mechanisms. An Arrhenius equation is often used to correlate certain chemical reactions at different temperatures, based on the proper choice of Q₁₀ coefficients.

As with any laboratory testing, validating field trials are important.

Vacuum chamber for testing leaks in packaging component

Vacuum chambers are used to test the ability of a package to withstand low pressures. This can be to:

1. Determine the ability of packages to withstand low pressures that might be encountered. this could be in an air shipment or high altitude truck shipment.[13]
2. A laboratory vacuum places controlled stress on a sealed package to test the strength of seals, the tendency for leakage, and the ability to retain sterility.

Instrumented drop test of cushioned package to measure the transmitted shock

Both primary (consumer) packages and shipping containers have a risk of being dropped or being impacted by other items. Package integrity and product protection are important packaging functions. Tests are conducted to measure the resistance of packages and products to controlled laboratory shock and impact.

Testing also determines the effectiveness of package cushioning to isolate fragile products from shock. Instrumentation is used to measure the shock transmitted to a cushioned product. Simple drop tests can be used for evaluations.[14]

Many packages are used for products that are sensitive to temperature. The ability of insulated shipping containers to protect their contents from exposure to temperature fluctuations can be measured in a laboratory. The testing can be of empty containers or of full containers with appropriate jell or ice packs, contents, etc. Ovens, freezers, and environmental chambers are commonly used for this and other types of packaging.

Digital temperature data loggers are used to measure temperatures experienced in different distribution systems. This data is sometimes used to develop unique laboratory test methods for that distribution system.

Some packages, particularly glass, can be sensitive to sudden changes in temperature: Thermal shock. One method of testing involves rapid movement from cold to hot water baths, and back.

Package handles (and hand holes in packages) assist carrying and handling packages. Objective laboratory procedures are frequently used to help determine performance. Fixtured ‘’hands’’ of various designs are used to hold a handle (sometimes two handles for a box). Most common are “jerk testing’’ by modified drop test procedures or use of the constant pull rates of a universal testing machine. Other procedures use a static force by hanging a heavily loaded package for an extended time or even using a centrifuge.

Vibration tester to simulate vibration frequencies at which packaged products are subjected during shipments

Vibration is encountered during shipping (vehicle vibration, rough roads, etc.) and movement on conveyors. Potential vibration damage may include:

• fractures and fatigue damage
• loose wires, screw caps, etc.
• bruises on soft products (fruit, etc.)
• surface abrasion
• etc.

The ability of a package to withstand these vibrations and to protect the contents can be measured by several laboratory test procedures. Some allow searching for the particular frequencies of vibration that have potential for damage. Modal testing methodologies are sometimes employed. Others use specified bands of random vibration to better represent complex vibrations measured in field studies of distribution environments.

Compression test for steel drum

Compression testing relates to stacking or crushing of packages, particularly shipping containers. It usually measures of the force required to crush a package, stack of packages, or a unit load. Packages can be empty or filled as for shipment. A force-deflection curve used to obtain the peak load or other desired points. Other tests use a constant load and measure the time to failure or to a critical deflection.

Dynamic compression is sometimes tested by shock or impact testing with an additional load to crush the test package. Dynamic compression also takes place in stacked vibration testing.

Rotational corner drop test of wooden box

Large pallet loads, bulk boxes, wooden boxes, and crates can be evaluated by many of the other test procedures previously listed. In addition, some special test methods are available for these larger loads.

Package bar codes are evaluated for several aspects of legibility by bar code verifiers as part of a continuing quality program. More thorough validation may include evaluations after use (and abuse) testing such as sunlight, abrasion, impact, moisture, etc.

Shipping containers are often subjected to sequential tests involving a combination of individual test methods. A variety of standard test schedules or protocols are available for evaluating transport packaging. They are used to help determine the ability of complete and filled shipping containers to various types of logistics systems. Some test the general ruggedness of the shipping container while others have been shown to reproduce the types of damage encountered in distribution. Some base the type and severity of testing on formal studies of the distribution environment: instrumentation, data loggers, and observation. Test cycles with these documented elements better simulate parts of certain logistics shipping environments.

ASTM International

ASTM D4169- Standard Practice for Performance Testing of Shipping Containers and Systems

ASTM D7386- Standard Practice for Performance Testing of Packages for Single Parcel Delivery Systems.

ISO

ISO 4180:2009 Packaging – Complete filled transport packages – General rules for the compilation of performance test schedules

International Safe Transit Association

Procedure 1A: Packaged-Products weighing 150 lb (68 kg) or Less

Procedure 1B: Packaged-Products weighing Over 150 lb (68 kg)

Procedure 1C: Extended Testing for Individual Packaged-Products weighing 150 lb (68 kg) or Less

Procedure 1D: Extended Testing for Individual Packaged-Products weighing Over 150 lb (68 kg)

Procedure 1E: Unitized Loads

Procedure 1G: Packaged-Products weighing 150 lb (68 kg) or Less (Random Vibration)

Procedure 1H: Packaged-Products weighing Over 150 lb (68 kg) (Random Vibration)

Procedure 2A: Packaged-Products weighing 150 lb (68 kg) or Less

Procedure 2B: Packaged-Products weighing over 150 lb (68 kg)

Procedure 2C: Furniture Packages

Procedure 3A: Packaged-Products for Parcel Delivery System Shipments 70 kg (150 lb) or Less (standard, small, flat or elongated)

Procedure 3B: Packaged-Products for Less-Than-Truckload (LTL) Shipment

Procedure 3E: Unitized Loads of Same Product

Procedure 3F: Packaged Products for Distribution Center to Retail Outlet Shipment 100 lb (45 kg)

Procedure 3H: Performance Test for Products or Packaged-Products in Mechanically Handled Bulk Transport Containers

Project 3K: Fast Moving Consumer Goods for the European Retail Supply Chain

Project 4AB: Enhanced Simulation Performance Tests (online test planner)

6-FEDEX-A: FedEx Procedures for Testing Packaged Products Weighing Up to 150 lbs

6-FEDEX-B: FedEx Procedures for Testing Packaged Products Weighing Over 150 lbs

6-SAMSCLUB, Packaged-Products for Sam’s Club® Distribution System Shipment

Procedure 7D: Thermal Controlled Transport Packaging for Parcel Delivery System Shipment

ISTA 7E: Testing Standard for Thermal Transport Packaging Used in Parcel Delivery System

In addition, package testing often relates to the specific product inside the package. Some broad categories of products and special package testing considerations follow:

• Data analysis
• Nondestructive testing
• Verification and validation

Wikimedia Commons has media related to Package testing.

• Institute of Packaging Professionals
• International Safe Transit Association (ISTA)
• American Society for Testing and Materials
• Safe Load Testing Technologies, 'All you need to know about Amazon ISTA Test', 2018
• Test Method Validation, Westpak, 2021