Lowa Boots - The Production Process
It's no simple task to make boot after boot to the high standards that we've all come to expect from Lowa, here's a little rundown of the various processes that go into making each and every Lowa boot:
1. Die Cutting
Die cutting is a delicate task and requires a boot maker with skill and experience. Firstly the metal die stamps are created for each section of the boot's upper, certain Lowa styles can require up to 30 individual pieces. Next the stamps are laid on top of a flat piece of leather and then carefully cut.
Every Lowa boot's upper is hand stitched in up to 75 separate procedures and the most critical wear zones are double-stitched for extra durability. Each seam is stitched using a synthetic thread that does not absorb moisture, finally the uppers are laced to help maintain it's boot-like shape.
Depending on the style, the shank is stitched or glued to the lasts and the uppers are then passed through a steam chamber. This exposure to the heat and steam renders the uppers supple enough to then be pulled over the lasts. The front of foot section is then glued to the shank and finally the heel and ankle sections are also bonded to the shank.
The bottom section of the uppers material is now roughened (to improve bonding), glue is applied, and the rubber rand is attached by hand. Once in place the rubber rand is press bonded onto the boot using a specially dedicated machine.
5. Fixing the Midsole & Outsole
There are two different methods used at this stage depending on the style of Lowa boot being constructed:
- Cementing: The sole and the boot are glued and then pressed together, it is possible to resole rubber outsoles that have been cemented (this is the more traditional style as seen on the classic army boots such as the Combat and the Mountain).
- Injection moulding: The uppers are pulled over a metal last and bonded to the rubber soles using an injection moulding machine and a special polyurethane. This PU completely covers the sole and ensures the secure and durable bonding of the individual elements (this a more modern production method as seen on styles like the Zephyr Mid Desert)
A little bit about Leather
Leather is probably the most important component in boot production, it boasts a unique combination of essential properties that offer unrivalled advantages for footwear. Leather is simply animal skin that has been made durable through the process of tanning, Lowa footwear exclusively use leather that comes from cows.
Different types of leather
- Smooth leather: Outer hide (papillary + reticular layer), susceptible to scratches
- Nubuck leather (natural or waxed): Outer hide layers (lightly roughed),
- relatively hardwearing and sturdy, perfect for trekking boots
- Suede or split leather: Middle hide layers (reticular layer), visible fibres, very tough, limited tear-strength.
A natural material like leather can never be completely uniform or without any irregularities. Although some scratches and scars are perfectly acceptable (and often part of leather's attraction), hide with particularly severe damage is usually spotted and discarded before the tanning process. These more serious blemishes can be caused by barbed wire marks, pest damage, branding marks or skin diseases (and occasionally deep lying damage is only recognizable much later in the process).
Although leather is tough and durable, it is also stretchable and holds its shape. These properties are essential for fit, comfort and appearance (and also important for the biomechanical roll-off movement). Leather can absorb a lot of liquid in the form of vapour which is ideal for maintaining foot climate, it can also be made water-repellent (hydrophobicized) without sacrificing these moisture vapour transmission properties.
The tanning process
The main purpose of tanning is to preserve the animal skin, this is achieved by treating it with tanning chemicals which are absorbed into the structure of the material. Various tanning and finishing processes help bring out the properties of the finished leather, form the same core product you can produce soft edging leather, silky lining leather, sturdy uppers leather and more.
1. Sorting, cleaning
The various hides are carefully divided into weight categories before being cleaned in large vats where any residual tissue is removed.
The animal hair is removed with chalk and sulphur, the pores are chemically opened and the tanning products are then absorbed. This process can last anything from a few hours to several months, but at the end of it we have leather! However this leather is obviously very wet (known as “wet blues” in the industry) and so has to be passed between large rollers to squeeze out the excess water.
This process categorizes the leather into different classes of quality, the 6-8 mm thick pieces of leather are split into a variety of thickness depending on their potential future use. The upper layer is classified as full grain leather, and the other layer(s) as split leather (the thicker the full grain leather, the thinner the split leather will be and vice versa).
4. Dyeing and drying
The remaining tanning substances that have not fully bonded to the leather are now chemically neutralized. Dyes are added to the huge vats in various stages, whilst the required suppleness of the leather is achieved by adding fats or waxes, finally the leather is then dried and machine softened.
The finishing treatments give the leather its desired appearance