A century of change in the footwear industry (1)

A century of change in the footwear industry

Reflecting on how the global footwear industry has changed in many significant ways over the past hundred years.

1) New technology in last design

Other than the initial design, the first stage in the footwear manufacturing process is the production of the last. In pre-First World War Europe, lasts were often made from cast iron. As the war started to use up significant amounts of metal, wood was increasingly utilised and became the preferred material from 1919. This was often maple, sourced from Canadian forests that in many cases were owned by the last manufacturers themselves. Copy lathes allowed lasts to be produced rapidly following the creation of a correctly-sized model.

There was no significant change in the way lasts were made until the Second World War, when the first commercial plastics started to be manufactured. Following the end of the conflict, brittle thermoplastics were used to make lasts until the early 1960s. At that time, polyethylene was used for the first time, which proved to be a durable and tough material. Later, injection molding made the process faster, with a roughly-shaped block being turned down to an accurate last. Between 50 per cent and 60 per cent of the material was cut away during this process, but this was reusable.

Today, manufacture of lasts is a fast process. Computerized digitizing allows for the scanning of a model last so it can be reproduced accurately on the screen (see the article ‘The value of digital last assessment’). Software can be used to manipulate the last in digital form, altering such elements as the heel height or adding allowance for an insock. Data stored in a program can be used to cut accurate lasts quickly, with modern machinery allowing a number of different sizes to be formed at the same time. In addition, digitised last information can be shared by e-mail between last manufacturers around the world. Last making was once a craft needing the trained skills of a foundry worker and a carpenter. Nowadays, it requires knowledge of programming and CAD-CAM systems.

At the beginning of the 20th century, cast iron lasts were made in a number of sections which were then often fixed together with interlocking pins. This allowed for the last to be taken apart in order to remove it from the partly-finished footwear without causing too much damage. Wooden lasts also were designed to be broken down, with removable ‘scoop blocks’ held in place by screws or brass springs. Today, plastic lasts are normally hinged to allow removal after the shoemaking process, although in Asia lasts are often made of solid polyethylene to speed up the process.

In the early part of the 20th century, a well-made last would stay in use for 25 years and may have remained in an individual shoe being manufactured for three to six months. Because of this, a large quantity of lasts was needed. Today, a typical shoe stays on a last for a maximum of 20-30 minutes, due to the use of a heat-setting process during footwear production, described in the article ‘Heat setting in footwear production’

Sources:

www.satra.com