服装设计论文-译文.doc

Heat-Treating and Drying The rough-cut blocks of hornbeam of European beech are placed in a cylindrical chamber and hear-treated at a pressure of two to three atmospheres and a temperature of 250°F[120°C]to destroy unbonded fluids, acids, and fungi and render the wood insensitive to moisture and temperature differences. Some 7 ounces [200g] of water is evaporated from an 18-ounce [500g] block of wood. The fibers of the wood become denser and at the same time more resilient. When a nail is driven into a piece of wood that has been heat-treated, the fibers are forced apart; when the nail is removed, they return to their original positions. After heat-treating, both ends of the blocks are coated with wax so that in subsequent drying the fluid in the wood will evaporate at the lateral surfaces and the ends will not crack. Now the period of natural drying begins; this lasts some two years. Although the moisture content of the wood falls to 16-18% over this period, it must be further reduced to 10-12% before it can undergo further processing. Forced drying chamber lasts about three weeks. The blocks of wood are exposed to an airflow initially at a temperature of 68°F[20 °C], which is gradually raised to 85-100°F[30-40°C] and finally to 120 °F[50°C] The moisture content of the wood is checked continually. Neither forced nor natural drying (storage in a shed) can be hurried. If the blocks of wood are put into the dryer to soon, for example most of them will crack or become deformed, losing the very quality for which they were selected for lastmaking: their resilience. After many years of preparation the block of wood is ready for delivery to the lastmaker’s workshop to be made into a last. In the following pages we shall find out some of the secrets of the lastmaker’s art and how a good-quality last is made-the basis of a good-quality shoe. Preparing the Custom-made Last by Hand Many lastmakers’ workshop still contain tools that have been in use for over a hundr