Performance Packaging

By working with GWP Group, your business can take advantage of one of the few design teams in the UK to utilise a revolutionary piece of software. This software enables a precisely calculated level of shock protection to be engineered into your cushion packaging. In effect, you get precisely calculated packaging performance.

Specifically, it enables the accurate calculation of cushioning performance for any Plastazote® polyethylene foam packaging designs, over a huge range of accidental damage scenarios.

Using this software, your foam inserts can be designed by GWP to reduce the level of shock experienced by delicate, highly calibrated and expensive items if they are dropped during transit or storage.

This shock can be reduced to such a degree that the packaged product sees only a tiny fraction of the shock experienced by the outer case.  On impact with the ground, a well designed foam insert will control the level of deceleration, thereby minimising the G-force experienced by your product.

The bottom line?

It ensures that your products, tools or components benefit from the exact level of cushioning performance required – eliminating breakages and damage in transit.

The software essentially works by using data known as “dynamic cushioning curves”. Different foams, grades and densities exhibit their own characteristics, and the “curves” show the level of shock (peak G-Force) transmitted through each of the foams at a given thickness against a range of loadings.

These curves have been generated through extensive drop testing conducted by the manufacturer of the material, Zotefoams PLC.

The tests were conducted by measuring the force transmitted through a foam block of known dimensions, with the impacting force being altered by using a set of weights and variable drop heights.

If static loadings are too low, the impact energy is insufficient to compress the cushion. This results in a sudden deceleration of the impacting weight and therefore an increased transmitted force. This, in turn, leads to potential breakage of the equipment.

If too high, the impact energy compresses the cushion too rapidly until the cushion “bottoms out” onto the supporting surface. This scenario is also likely to see damage caused to the packaged components.

Another key parameter for the design is the fragility of the article that needs to be cushioned  by the foam inserts.

This can obviously only be determined accurately by subjecting the item to a series of gradually increased decelerations to determine the deceleration at which damage is caused. Such destructive testing is however not always practical (especially with high value equipment).

As such, typical values are provided by the software, as the table below indicates.

The below table details peak deceleration figures for a range of items that are most commonly affected by transit damage. Please get in touch if you require assistance with products outside of those listed below.

Besides the static load calculations detailed above, most foam protection & insert designs are based only on first drop data. For certain grades of foam it is important consider changes of the foam properties with repeated impacts when designing the insert.

Tests indicate however that the fatigue effects caused by repeated impacts reduce significantly after the initial 3 impacts. The cushioning calculator software allows for this, ensuring that regardless of the end use, any foam insert designed using this methodology will offer your products a customised level of protection.

The calculated packaging performance system can also take into account varying drop heights.

By default, the software uses drop heights defined for the design of packaging for military level J (UK Ministry of Defence specification for packages that are required to last a minimum of 2 years worldwide), although this can be modified as required.

Creep (compression of the material by long term loading), and temperature (foams are generally thermoplastic, i.e. they will soften at higher temperatures and harden at lower temperatures) are also considered.

Depending on the dimensions of the article it may be necessary to subdivide the required area of foam to achieve a stable cushion or use load spreaders to spread the weight of the article over a larger area than its natural side.

To maintain a stable cushion when subdividing the foam the thickness of the cushion should not exceed twice its length or width.

Finally, the effects of vibration – accounting for the fact that at certain frequencies vibrations may be attenuated by the cushion, even though this is an uncontrollable factor – can also be factored in.

The below table provides information on drop height / weight figures used (in both metric and imperial units) as well as the likely / recommended handling type associated with this.

Please view the video below for further details of the full, in depth design process carried out when creating high performance protective packaging.

If you have issue with transit protection, damage to important items, or just want to improve the performance of your packaging, please do speak with a member of the GWP design team today.

Please note: AZOTE, Plastazote and Zotefoams are registered trademarks of Zotefoams plc.