This is an ageing process which occurs over a number of years but which can be accelerated by certain factors. Damp and humid conditions are specific catalysts for hydrolysis as they increase the amount of contact the PU has with water molecules. For this reason, Hydrolysis is more likely to occur in leather boots which are worn in wet and muddy conditions without being cleaned afterwards. However, one of the most common factors accelerating hydrolysis in leather boots is actually lack of use. By leaving your leather boots at the back of a dark cupboard for too long, you’re increasing their exposure to moisture absorption and consequently hydrolysis.
When we witness the ‘sole-destroying’ moment the soles of our leather boots start to fall apart our first thought might be to blame the manufacturer. We might question if we have a faulty pair, particularly if the boots have only been worn a few times before. Unfortunately, this scenario is far more common than we might think and hydrolysis is the invisible culprit to blame. Whilst your leather boots are on holiday in the cupboard, hydrolysis is likely to be hard at work. As the PU in the leather boots is exposed to increasing amounts of moisture over time it becomes more porous allowing hydrolysis to get to work at destroying the PU in the soles. As the process of hydrolysis is invisible it is only when we notice the sole disintegrating that we can physically see its effects.
This is where the LOWA manufacturing process works in opposition to the damaging effects of Hydrolysis. All our leather boots are designed to be durable and resistant to damage and our production method enables this quality to be realised.
The soles of our leather boots are fitted with a protective edging called a rand which runs all the way around the edge of the boot in between the upper and the insole. The rand is a rubber edging which protects the leather from moisture and damage. Once the rand has been fitted, the PU midsoles can be assembled. The midsoles add an important element of cushioning to the sole which makes the leather boots comfortable and wearable. We ensure the sole is pre-treated and assembled with durability using one of two trusted methods. The sole is either cemented to the upper using a pneumatic press or attached to the upper using a LOWA-exclusive Monowrap frame rubber mould which PU is injected directly into. If this method is used the bonds are cured immediately in a cooling chamber to ensure optimum connectivity.
The spray-on glueing process that we use throughout the treatment of the outsoles is crucial to ensuring our leather boots are durable but also breathable. It is vital that air and moisture can flow freely out of the boots whilst maintaining their waterproof properties. With these considerations in mind, LOWA uses an exclusive spray-on glueing process which provides the strong connection these leather boots require whilst allowing the pores of the material to remain open and circulate moisture out of the boot.
How To Prevent Hydrolysis
As durable as our leather boots are manufactured to be, it is crucial that they are cared for in the correct way to ensure this level of quality is maintained. To prevent the effects of hydrolysis we’ve put together a shoebox of tricks on how to store and care for your leather boots. In order to successfully combat the damaging effects of hydrolysis we recommend that you keep your leather boots clean and cool by doing the following:
- Store your leather boots in a dry and well-ventilated space
- Keep your leather boots away from sources of heat and avoid exposing them to high temperatures
- Clean your leather boots regularly, especially after walking through muck and manure
Providing the correct storage and care for your leather boots is crucial to ensuring they live a long and happy life. However, the wisest piece of advice which we can really give to keep your leather boots healthy is to get outdoors. Before longer trips take your leather boots on a short test run to check for signs of hydrolysis- this is particularly important if you know your boots have been hidden at the back of the cupboard for a while.
It’s crucial to remember that leather boots are designed to be worn in outdoor terrain and so the easiest way to prevent hydrolysis is to keep your boots moving in the open air. This way Hydrolysis doesn’t have the right conditions to wreak its usual havoc allowing the soles of your leather boots to remain intact. Whether it’s a hike, a trek or a short stroll, any outdoor activity will be doing those leather boots a massive favour.
With this advice and the right quality leather boots, hydrolysis shouldn’t be troubling you too much in the future. For more information on the durable footwear options available at LOWA please explore the products on our website.