Polyurethane (PU) is frequently used in safety shoes as it offers several positive properties.
- Very light
- Very flexible
- Very good shock-absorbing properties
- Highly abrasion-resistant
- Good anti-slip properties
All of this has a very beneficial effect on the user’s natural movement patterns and when it comes to the product life of the sole as regards mechanical influences.
The specific composition of PU produces these material qualities, but it also affects the service life of the material.
Above all, the PU sole material is subject to a natural ageing process – hydrolysis.
What happens when soles age?
PU consists of long polymer chains that are gradually split apart due to the effect of moisture. As a consequence, PU loses flexibility over time and gradually becomes brittle. As the shoes reach an advanced age, this can lead to signs of disintegration in the soles.
But why can storing shoes often be more detrimental to their useful life than if they are worn?
Work shoes are often stored in the basement, shed or garage – places where poor sunlight & higher levels of moisture are normally present. And it is precisely this moisture that amplifies the hydrolysis process and causes the shoes to age even more quickly, even though they are not actually being worn.
Our recommendation for you and your safety shoes
Ageing of safety shoes is an entirely normal process that all shoes go through. If we want to benefit from all the positive properties of a safety shoe, we need to be aware of the limited product life of shoes.
We recommend adoption of First In First Out during storing & distribution, regular use by user. Due to long storage, the shoe sole gets weak & loses it’s properties & does not last long. Further information can be found in the Maintenance Tips leaflet that comes with every Warrior Safety Shoe.
