There are two main factors that can contribute to your soles coming apart in new and near-new shoes. They are the eco-friendliness of the sole material and the glue.
To make rubber (TPU) soles and mid-soles eco-friendly they are made to hydrolyze (chemical decomposition in which a compound is split into other compounds by reacting with water)...ie break down with water contact. Great, except when they start breaking down before you've finished with them. When they break down, they form a granular or powder-ish texture which breaks away from the adhesive glue holding the soles to the upper. So your "sole comes apart".
So if you've worn your shoes even only once, sweat from your feet, or moisture from outside start the hydrolysis process on your soles. When you come back to wear the shoes again for that special occasion a month or two later you are shocked to find that during the evening the soles come apart. But you've only worn them once before! And it can seem like the "quality" of the shoes is poor, when this is in fact not the case.
How can you prevent this from happening? The first is to be more careful in cleaning your shoes each day. Even using a cotton-bud to run around the edge where the sole meets the upper can be useful in absorbing outside water and moisture that may be trying to seep into the sole. The second is wear the shoes at least twice a month. Physical weight and compression holds off the hydrolysis process.
Regarding the glue, the more eco-friendly glues are water based and generally last about a third as long as other glues. Eco-friendly glues can be expected to last up to one year before losing its bond. The good news is that it's very easy to re-glue them again. Often durability is considered an environmental offset or positive.
The other property of the glues is that they go brittle if they are not used. So if the shoes have been sitting in a warehouse for 4 years before you purchase them, there is a very good chance that the soles will come apart almost instantly. Again, it's very easy to remedy by freshly gluing them once they have come apart.
If your shoes were recently made when you purchased them, and you wore them a couple of times, but you put them in cupboard for a few months after that then the glue can go brittle from under use. So the easiest remedy, as with preventing hydrolysis, is to wear them regularly. At least a couple of days a month.
I can hear some people saying that's why you should shoes with a stitched sole. And it gets a little complicated. If you have a stitched (Blake-stitched) rubber sole you can avoid the sole completely flapping off in regards to the glue issue, but the stitching is not right at the edge of the shoe. So brittle glue will still come apart at the edges where the upper meets the sole. It still looks like the sole is coming apart. In a close-edge sole, there is no hiding it. If you have a rand (built up edge of sole) it could mask it for a while. However a stitched (Blake-stitched) rubber sole is much less water resistant. The holes for the stitching suck up water and rapidly increase the hydrolysis of the rubber soles. So soles start to break down around the stitches and the glue more rapidly.
The long and short of the situation is it's best to have at least two pairs of shoes and rotate and wear them all regularly. Don't wear the same pair every day because the sweat and moisture will rapidly deteriorate the soles and the upper leather. Let them rest and dry while you are wearing the other pair on the alternate day. Using a shoe tree will soak up even more moisture and keep the upper shape while they are resting. But don't let them rest too much. Like a pedigree Husky your shoes need to be worked. Between 3 and 15 days out of the month is prime!
For more shoe care tips come and talk to us or visit http://www.veinwear.com/shoeCare/shoeCare.aspx.
