ASTM D5331 Mechanical Handling of Unitized Loads

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Summary of ASTM D5331 Mechanical Handling of Loads Secured with Stretch Wrap Information

ASTM D5331 applies to common material handling methods, including forklifts, push/pull systems, clamp trucks, cranes, and spade lift attachments. Additionally, you can adjust test levels to match actual field conditions. The standard also defines sample preparation and evaluation procedures for stretch film used to unitize loads.

The standard defines several key terms:

• Large shipping case or crate – A shipping container of any material that requires mechanical handling. These containers can weigh from 100 pounds to several tons. Manufacturers often secure them to a pallet or base. Additionally, they may include a frame to improve rigidity.
• Spade lift attachment – A lift truck attachment that handles products from the top. It commonly lifts interlocking flange cartons (IFC), folded cap cartons, and folded flap-style cartons.
• Unitized load – Two or more packages wrapped or banded together to form a single shipping unit.

Scope of ASTM D5331 Mechanical Handling Package Testing

Unitized loads typically weigh more than 100 pounds. Manufacturers create these loads with shrink wrap, banding, strapping, tape, or adhesive. Additionally, the load may include a pallet or slip sheet, but the standard does not require one.

ASTM D5331 often compares the performance of different unitizing films. However, you can also use the standard to compare the same wrapping material across different wrap cycles.

It is important to note that ASTM D5331 does not directly correlate test results with field performance. Instead, the standard simulates mechanical handling throughout the distribution process. Furthermore, users can customize the test to match a specific distribution environment. They can adjust the test levels and the number of test cycles to reflect real-world conditions.

Significance of ASTM D5331 Unitized Loads Package Testing

ASTM D5331 uses two primary pieces of equipment: a load-wrapping system and a mechanical handling system. First, the load-wrapping system wraps the test load. The wrapping method should closely match the production process used before shipment.

Next, select the mechanical handling method required by the test procedure. Arrange the packages to match the production configuration. For example, stack them in layers or place them on a pallet or slip sheet. Then, wrap the load with the unitizing film using the specified stretch percentage and wrap cycle.

Additionally, the user determines the stretch percentage and wrap cycle based on the application. After wrapping, allow the unitized load to rest for at least 16 hours. This period allows the stretch film to reach stress equilibrium before testing. Then, perform the selected test procedure.

The standard includes several handling methods. These include palletized load handling, spade lift handling, clamp handling, and push/pull handling. Furthermore, ASTM D6055 provides additional guidance for these compliance procedures.

Finally, the laboratory records the test data and prepares a report. The report includes information required by ASTM D5331, such as:

• Unit dimensions
• Weight of each unit
• Test procedures used
• Rotational drop height

Expert Unitized Loads Secured with Stretch Wrap Films Package Testing

Keystone Package Testing can accommodate flexible and rigid packages of all sizes, including large pallets. Our team strives to give our customers more time and energy on product development instead of testing. In addition to ASTM D5331 testing, Keystone has a full scope of expertise including drop, vibration, and sterile barrier.

Request a quote or contact us at (724) 657-9940 to learn first hand why so many companies partner with Keystone to achieve their package testing certification needs.

For more referenced ASTM standards and similar testing, please follow the links below:

• ASTM D996 Terminology of Packaging and Distribution Environments
• ASTM D4169 Practice for Performance Testing of Shipping Containers and Systems
• ASTM D6055 Test Methods for Mechanical Handling of Unitized Loads and Large Shipping Cases and Crates
• ASTM D6179 Test Methods for Rough Handling of Unitized Loads and Large Shipping Cases and Crates

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