A machine, the principle of which was intended to apply to the making of buckram shapes, was also adopted by the straw trade. Its first adoption was due to the introduction of the felt hat manufacture into the districts hitherto peculiar to the straw hat making, but it was found to possess points of advantage in the blocking of certain materials. This machine has a “female” pan of metal into which a properly fitted “male” block, with the accurate amount of space for the material to be used, may enter, forming with the pan and the hat one solid piece. This “male” block is also of metal. They were first of iron and afterwards were generally of spelter or aluminium. In the particular case for which they were most extensively used, the hat was made of a cotton braid, the stiffening of which was effected by a shellac and methylated spirit mixture, as gelatine was not found entirely satisfactory. Both the “male” and the “female” blocks were heated by gas jets, and when the hat was still wet with the highly inflammable stiffening it was placed in position on the lower block, the other was adjusted to it, and when in proper place the heat of the blocks, or the light of the gas jets, fired the stiffening, which rapidly burned the spirit out, leaving the shellac or other resinous material in the fibres of the braid in sufficient quantity to render the hat hard enough for its purpose, and at the same time creating an almost waterproof fabric, that enabled the cotton to withstand the softening influences of damp weather. The operation was completed by releasing the movable block and taking out the hat.
An entire revolution in the system of blocking straw hats was introduced in 1913–14 by a M. Stoffel, of Paris. This method depends for pressure on air only, and by its means shapes almost if not impossible by any other method can be beautifully blocked. The apparatus consists mainly of a vacuum reservoir from which all air is extracted, creating a suction pressure of about 13 lb. to the square inch, exhausted by means of a vacuum pumping engine and perforated blocks placed over copper tables that are also perforated and connected with the vacuum chamber. The blocks are of wood or metal, and both crowns and brims are made to the form of the outside of the hat, and are in themselves quite independent of the copper table. The modus operandi is as follows: the block to be used is warmed by steam and is placed bottom uppermost on the copper table. The hat, slightly moistened by steam, is adjusted carefully on or in the block, covered with a large water and air proof cloth which can envelop the whole of the block and table, and leave a sufficient quantity to fill up the cavity caused by the interior of the crown, or the undulations of the brim. The vacuum force is then brought into action, and the suction created draws the cloth, with a pressure of about 10 to 12 lb. to the square inch, into every crevice or corner formed by the shape of the hat and block; the suction set up draws off as well any moisture evaporated by the heat of the block, and in a few moments the hat is sufficiently dry to be removed. By this method crowns of hats with concertina-like folds and creases can be perfectly “ironed,” using a block made of only two sections, whereas in any other form of blocking, where similar blocks must be made in five sections, the result obtained, comparatively speaking, is more or less imperfect. Moreover the process, while being much more rapid, does not require anything like the same amount of force expenditure on the part of the workman as do either hand or machine blocking. Another important benefit of this invention is that the actual working apparatus can be arranged in ordinary blocking benches, the copper perforated table taking up no more room than that usually occupied by a hand blocker, whereas, while other blocking machines do not occupy in themselves a greater area, the “roughing out” or “sweating” necessitates the ordinary hand blocking space which makes the actual amount nearly double. It must not be forgotten that the preliminary, as one may call it, apparatus of the “Stoffel” system requires space for the vacuum engine and pump, while the vacuum reservoir tank is, of course, of considerable magnitude, according to the services required. Both these, however, can be placed in some basement, etc., quite away from the actual blocking room. Whereas the earlier models need no extra area than the actual working spaces, with the exception of the steam generating plant, which, however, is common to all systems, and further is a necessity for other purposes such as heating the various work and drying rooms, and also for melting and keeping warm the gelatine used for stiffening, etc.
But compared with the Desbordes and Keston models, this system is not so well adapted for men’s boaters work. Up to about 1910, the great bulk of rustic boaters was blocked on presses of the Keston type, and even to-day boater makers still make use of them. The hard-natured straws that are generally utilized for boaters require heavy pressure in varying degrees according to the different varieties of plaits, and in this respect the suction method is not sufficient for the high powers.
Fig. 19
MACHINE BLOCKING
By Press of “Brochier” Type
About 1910 another French engineer put a blocking machine on the market with special claims for boater work. M. J. B. Brochier, of Lyons, introduced the model now known wherever boaters are made by the name of “Carre Vive,” of which the free translation, “sharp edge,” sufficiently indicates the peculiar claim of the inventor. This machine in structure is a combination of some other blocking presses, but with a special contrivance for creating the extra sharp edge, and of extra lightness and simplicity in working. It has the guillotine frame of the machine mentioned for blocking cotton braids stiffened with shellac stiffening, the pan chamber heated by steam, the india-rubber bag for hydraulic pressure, and the bag-chamber moving vertically on uprights of the “Keston” or “Beresford” type. But it differs from that machine in, first, the bag chamber is really a plate with a hole in the centre to carry the bag, and is only of the most meagre dimensions of the least possible weight. Second, this is caused to descend into the pan chamber by a lever actuated by the operator’s foot, the little weight of it is balanced at the end of a lever with a small counterweight, obviating the overhead chain and pulley. Third, the fixed contact with the pan chamber is made by means of a screw wheel, a small turn of which when the hat and bag are in position, firmly tightens and locks the two portions together. Fourth, the special crown edging action is done by a rising and falling movement made by the bottom of the boater pan, which is actuated by means of a lever working on a ratchet by which the pressure can be retained until the hat is ready for removal. This model is now extensively used for boaters, although at the moment of writing that extreme sharpness, desirable in boaters a few years ago, is not required in the season’s models for the home trade, the crown edges of which are an almost imperceptible bevel. These practically exhaust the machines for blocking, but there are in use throughout the trade blocking presses for the brims of boaters and of some varieties of hats with rolling brims. These consist either of a flat metal plate, or open pan conforming to the curves of the rolled brim, heated either by gas or steam on, or in, which the brim of the hat is arranged, and a wooden block placed over it. Affixed to the plate or pan are two uprights with a crossbeam, in the centre of which is a long quick acting screw with a small plate at the bottom. This descends on to the wooden block and creates sufficient pressure to put the brim of the hat in correct shape. It is found very useful in “touching up” the shape of a brim that may have been bent or damaged in the trimming, as to put the hat into either of the other machines would necessitate the taking away of all trimmings and linings. The mention of these articles brings our history to its next stage—that of the actual “Finishing,” as the trade calls all the operations done to the hat after blocking.