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Why we must focus on Top-load Testing of Packaging Material?

Packaging for consumable goods must provide product protection. PET bottles, cans, and cartons have to withstand the compressive forces incurred during handling, transportation, and storage. Manufacturers of beverage containers face the additional challenge of ensuring containers have sufficient strength to tolerate the capping process.

Key to quantifying the design and quality of containers is measuring resistance to top-loading. Top-load testing or “compressive strength testing” evaluates a packaging material’s structural resistance to a compressive load, to the point of deformation or collapse. Packaging manufacturers use top-load testing to ensure packaging integrity, and to eliminate material excess while maintaining quality – a process known as “down gauging” or “light-weighting”. Down gauging is a process with high environmental and business significance, since packaging soon becomes waste material, and excess material has powerful cost ramifications.

Industries which are benefited from Top-load Testing


Manufacture of PET (polyethylene terephthalate) bottles is regulated by strict environmental standards limiting use of material. For standards compliance and business economy, both volume of original material and number of production line rejects must be minimized. Production of PET bottles is a long and involved process that begins with the bottle as a four inch pre-form.

These tiny half formed bottles are blow moulded then sized and shaped. They are then cooled in water and placed on the filling line, where they are filled, capped, and finally boxed. PET bottles are weak around base and neck and deformation at these areas is characteristic when under compression. Top-load testing reduces the possibility of “light-weighted” capped PET bottles experiencing crush failure during the handling and storage phases of the supply chain.


The range of materials used in food packaging is extremely broad and covers many varieties of plastics, cardboard, and metal. Consider the material used to create a basic cookie carton – at the very least, manufacturers require certainty of the cardboard quality so that product will reach consumer in saleable form. Firstly, material structure must support all processes, which include production, palletisation, and stretch wrapping. Secondly, handling activities are critical considerations – possibility of material distortion is high during pallet stacking and storage. Other factors include humidity resistance and shelf life longevity.


Presto’s Top Load Tester is designed to provide Compressive buckling load. The instrument is used for testing the load bearing capacity of the PET containers when subject to an extreme load from the Top direction. It determines accurately the maximum load a PET container can bear without any deformation or failure.

For more information or product quotation, kindly contact our support team.

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