Cushion material evaluation consists primarily of shock and vibration inputs designed to determine the dynamic levels transmitted through a given thickness of the cushion material as a function of the loading on the material. These tests result in a cushion curve describing the shock characteristics of a cushion material and amplification/attenuation plots describing the vibration characteristics of the same material

Other cushion characteristics include density, compression set, compressive creep, water absorption, flexibility, dimensional stability, thermal conductivity, anti-static treatment, etc. APT is equipped to conduct all of these and more in our laboratory facility using calibrated equipment operated by trained engineers and technicians.

Why Conduct These Tests?
The purpose of these tests is to help define the mechanical, chemical, and thermal characteristics of cushion materials so that designers can best match them with the requirements for protecting a product with known characteristics.

The information can also be used to help compare one material to another using the same standard inputs.

Cushion Curves
Cushion impact data is generated using procedures such as ASTM D1596 for right rectangular prisms (solid materials) or ASTM D4168 for loose-fill, foam-in-place or similar type cushion materials.

Using either standard, a cushion curve is generated by allowing a pre-determined mass to impact the cushion from a known drop height. The deceleration level produced at impact is recorded and the test is repeated a total of 5 times.

The mass of the impact platen or enclosed test block is then increased, and the process is repeated with fresh samples. The data from a minimum of 5 static stress loading are recommended in order to draw a cushion curve. Separate curves are normally presented for data from the first impact as well as the average of the second through fifth impacts.

If conducted properly using the correct test procedure, the information generated can be used to help design a protective package system using an optimum amount of cushion material, both thickness and loading.