Clamp testing is one of the essential laboratory simulations to guarantee the safety of the goods during handling and warehousing in automated warehouses. 

Here we analyze what clamp testing is and why it is important to have the ability to perform package clamping tests.

What is clamp testing?

During automated warehousing, packages are not only subject to vertical compressions, but also horizontal compressions that might affect the properties of a package’s base, causing the product inside to fall. The recent emergence of clamp testing and clamp testing equipment is aimed at preventing those risks.

The purpose of clamp testing is to verify the protective capabilities of a product’s package when subjected to horizontal pressures and vertical motions during automated warehousing.

The importance of clamping force testing has increased with the arrival and proliferation of clamp handling – a product handling technique that consists of clamping it from the sides by applying compression forces. 

While it reduces the amount of manual labor required to move loads, it has also led to horizontal compression forces becoming a new threat. This being the case, clamp compression testing through the use of suitable equipment allows for the simulation of these forces in a laboratory setting in order to anticipate how they will affect the packaging and evaluate whether they pose a threat to the product’s integrity.

Measuring the clamping force for clamp compression testing

One of the first steps to use a package clamp testing machine is to calculate the clamping force to be applied. To this end, companies first focus on the standard with which they want to comply.

Worth mentioning is the fact that there are variables that can modify the calculation of the clamp force, such as the type of material that will be subject to clamp testing or the depth of the item.

Clamp testing equipment

A package clamping test machine simulates the clamp forces caused by the mechanical handling of a sample. This allows for evaluating the potential threat to the goods posed by these movements. 

Therefore, clamping force testing provides companies with information related to the protective ability of a packaging to validate a design or develop optimized packaging

Clamp testing is performed based on the type of package and the specifications of the testing methods chosen by the company. With this in mind, the InnClamp product family is composed of two different models: SF-CL1200 and SF-CL200.

  • These machines are designed to test samples ranging from 400 mm to 2,000 mm, with a maximum weight of 500 kg.
  • Additionally, thanks to their design, the clamp testers can simulate clamp forces of up to 10000 N with a load precision of ± 5%, moving at a constant speed so as to apply a uniform compression on the load.
Success case: BFSV implants ISTA thanks to Safe Load TT

Which testing protocols include clamp testing?

Some of the protocols that include clamp testing among their testing sequences are the ones developed by ISTA, as part of Series 6. These protocols are designed in collaboration with certain ISTA members to cater to their specific goals and applications.

One such example is Amazon, which has developed two projects – Amazon ISTA 6 SIOC and Amazon ISTA 6 Over-boxing – in jointly with ISTA, with the purpose of guaranteeing the integrity of the products that move along their distribution chain.

In addition, both testing protocols are part of Amazon’s Frustration Free Packaging (FFP) program, which aims to optimize the supply chain at each of its stages, offering a better purchase experience to the user, and reducing logistical and packaging costs for its vendors. To this end, vendors wishing to distribute their products via Amazon need to subject their products to the tests outlined in Amazon ISTA 6 SIOC and Amazon ISTA 6 Over-boxing.

The simulations required by ISTA 6 Amazon include environmental, drop & impact, vibration, compression and stability tests, in addition to the aforementioned clamp testing.

  • Each of these distribution tests are performed through the use of different machines that allow for them to be conducted with different levels of stringency. For this purpose, Safe Load Testing Technologies has developed the Amazon Lab, which is composed of 5 machines that enable the performance of the simulations outlined in the ISTA 6 Amazon protocols within as single laboratory.
  • Another simulation protocol is ISTA 6 Samsclub, aimed at companies that use the Samsclub distribution system to ship packaged products within the United States. This simulation protocol tests the resistance of packages to the hazards of warehousing and transportation. The sequence of tests established in this protocol includes clamp testing to measure the resistance of packages to horizontal compressions.
  • Additionally, there are other protocols such as:
  • ASTM D6055 – 96(2019) Standard Test Methods for Mechanical Handling of Unitized Loads and Large Shipping Cases and Crates, designed to test a load unit and its ability to withstand mechanical handling.
  • ASTM Standard D4169 Standard Operating Specification for Shipping Containers and System Protection Performance test.


optimized packaging

  • ASTM Standard D6055 Standard Test Method for Compositional Load and Mechanized Transport of Large-scale Shipping Containers or Crates,
  • ASTM Standard D6179 Standard Test Method for Compositional Load and Rash Transport of Large-scale Shipping Containers or Crates,
  • ASTM Standard D999, Standard Test Method for Shock Test of Shipping Containers,
  • ASTM Standard D5445 Geographical Symbols for Standard Operational Actions in Cargo Transport.
  • ISTA Packaging Test EHP Cold, LTP-2001 Clamping test,
  • ISTA (International Safety Transit Association) 1A Packaging Performance of Independent Packaging Products That is No Heavier Than 1501b (68kg),
  • GB/T 4857.4-2008 Basic Experiment of Packaging and Transporting Packages,

Does your company need new packaging testing machines, but you don’t know where to start? Are you looking to improve your packaging laboratory following the latest trends and methods? At Safe Load Testing Technologies, we put our two decades of experience in the packaging industry at your service. Get in contact with us and let us find the solution that suits your company.

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