A century of change in the footwear industry (2)

A century of change in the footwear industry (2)

Developing new machinery

The demands made by innovative designers of modern footwear forced the development of new technology – from the introduction of large automatic footwear-molding machines to an improvement in the quality and strength of some of the smallest elements of the shoemaking process – such as the needles used in the stitching process and threads which also have more color resistance than those used in previous years.

There were a number of ingenious and quite sophisticated shoemaking machines invented in the early part of the 20th century. These included various heel building and heel attaching machines, stiffener moulders, sole moulders, finishing machines, buttonhole sewing machines, eyeletters and skivers. To a greater or lesser degree, these processes have remained very similar even into the modern day.

After cement sole attaching systems were introduced in the mid-1920s, various sole and shoe bottom roughing and cementing machines were developed, as well as a wide variety of attaching presses.

Between 1950 and 1960, high-pressure rubber moulding and vulcanising machines, combined with the introduction of the pre-finished sole, as well as Louis heel and sole units, made considerable impact on the footwear industry.

The decade leading up to 1970 saw the introduction of PVC injection moulding systems, which were followed by the polyurethane reaction injection moulding (RIM) process. The arrival of moist heat setting, invented by SATRA (and for which the Technology Centre received the Queen’s Award for Industry in 1969), dramatically reduced the setting time – and hence, the number of lasts required – and is recognised as one of the great landmarks in footwear manufacture.

In the field of upper preparation, the wider use of synthetic materials led to the use of travelling head cutting presses and, in turn, to processes involving high frequency cutting, welding and embossing. In lasting, the introduction of back-part moulding and seat lasting machines accompanied by developments in forepart pulling and lasting machines – both now with built-in hot-melt cement systems – have also done much to alter the look of the modern shoe factory.

In recent years, computerised machines controlling such processes as pattern cutting and decorative stitching are very common around the world. Little had altered in stitching machinery for more than half of the 20th century, and up to the 1970s, operatives used electric clutch-driven machines, which took great skill and experience to achieve the correct speed. Things changed in the 1970s when the first electronic stitching machines were introduced, allowing the operator to vary the stitching speed by using a foot pedal. Further information on the early use of mechanised stitching can be found in ‘The struggle to develop a reliable stitching machine’.

Sources:

www.satra.com