BLOCKING BY MACHINE
The blocking of hats by machinery is a process much more recent in
operation than hand work, and although its origin is more or less
inside the possibility of a living man’s memory, so confused are the
_data_ connected with it that little or no reliability can be placed
on the greater number of the traditions. One thing alone stands out
clearly as a definite indication of first use, and that is the certain
seniority of the pressing of Leghorn hats. It is almost self-evident
that neither machinery or blocks to stand machine pressures would
be made for the manufacture of unlikely or transient materials and
shapes, and while the fashion of “Granny” bonnets, etc., was constant
for nearly half a century, the details of their shapes offered too
many difficulties to the would-be maker of a machine to press them,
to induce any great inventive effort on his part. It needed something
simple in outline, and something that could be done in large and
recurring quantities, to give to the inventor the necessary impetus
to produce a machine to impart to the hats their final finish. And
100 years ago there was nothing in the straw market, used either
for hats or bonnets, that fulfilled the above conditions except the
Leghorn hat. The making of this has been described in a former chapter.
The early methods, either by wood mallet or slickenstone did not
adequately fill the requirements; hand ironing was nearly as tedious
and was rather dangerous, as the Tuscan straw of the Leghorns was so
easily scorched, and as the demand increased the desire for a more
expeditious, safe and uniform method of pressing grew with it. The
earliest information, _given with some reserve_, is that an iron pan
or dish was made, moulded to the shape of the hat, and that this was
fixed over a metal cauldron in which water was kept at the boil, or
was warmed direct by charcoal fires. These heated the pan sufficiently
for the purpose; in fact, to-day, with all the improvements, and they
are legion, steam heating in this manner to blocking machines is still
general. The hat was damped and laid properly in the pan to its shape,
and was pressed on the inside by a convenient tool of hard wood or
stone, either of which was sufficient to squeeze the wet-softened
straw into the crevices attendant on the edge of the crown and the
corner made by the junction of the crown and the brim, and to impart
the necessary shape to all sections of the hat. The next move towards
the present models, was to have the pan as above, with a wooden, or
sometimes iron, block which would, when the hat was laid in position,
fit into it in such a manner as to convey an equal impingement on all
parts. This was adjusted by means of an over working screw, by which
some large pressures could be given. But these simple methods had great
disadvantages; it was impossible to entirely synchronize the pressure
on every hat, and it was extremely lengthy and tedious. A Mr. Samuel
Howard, of Luton, invented a press on similar lines, but the action was
horizontal instead of vertical, this served a very good purpose for a
period until MM. Desbordes,[2] of Paris, introduced their hydraulic
press. This consisted of a steam heated chamber in which was placed the
metal “pan” or “dish,” it being the “female” mould of the required
shape. The pressure was obtained by an overhead chamber to which an
india-rubber bag was fastened. This chamber was very strong and heavy,
and was, as it were, one end of a balance, working on trunnions, at the
other end of which were two large metal balls as counterpoise.
To bring into operation, the chamber was pulled down so that the centre
of the india-rubber bag, which was made with a teat, came into the
crown opening of the pan; the chamber was securely fastened by means of
screw lugs to the portion holding the pan, and a hydraulic press was
put into action which filled the rubber bag with a sufficient pressure
of water to distribute the power all over the hat in the pan; a gauge
showed the pressure obtained and consequently an equal amount could
be given to every hat. The results, therefore, were all alike, and
as the press could be locked and unlocked in a fraction of the time
required by the screw process, the work was greatly accelerated. Many
improvements have been made in blocking machines since then (about
1860), but all the later models embody the important feature of the
hydraulic pressure through the rubber bag. The next important step
in the evolution of mechanical blocking was that introduced by Mr.
Henry Keston, of Luton, adapted from a model made by a Mr. Beresford,
of Stockport, Cheshire. This improvement consisted of erecting round
steel uprights on the bed of the steam heated chamber, allowing the bag
chamber, attached to which were slides fitting the uprights, to rise
and fall vertically. The counterpoise was effected by a chain, attached
to the top of the bag chamber, passing over a wheel supported by a
bracket at the back of the machine and loaded with sufficient weights
to adjust the balance. A hand or foot lever pressure was sufficient
to raise or depress the bag chamber, and water connection to it was
obtained by means of a corded re-inforced india-rubber swan neck. When
the chamber had descended to its proper position it was locked by means
of a stout steel three-armed part like the hub of a wheel, with three
spokes radiating from it at equal distances. The hub was pivoted on the
centre of the top of the bag chamber, and a short lateral movement of
this part brought all three spokes under very strong hook-like lugs,
and locked the bag chamber securely to the pan chamber.
[Illustration: Fig. 18 MACHINE BLOCKING
By Press of Beresford-Keston Type]
Water pressure above the supply pressure was effected by means of a
hand worked hydraulic pump, and the force was reckoned by a pressure
gauge. This method was so much simpler and easier to work, and also
was so much more rapid, that it quickly superseded its predecessor;
and now, after forty years’ experience, is still the favourite model,
although the machines of to-day contain many improvements not to be
found in the original. By all these descending bag chamber models
the blocking of the hat is identical. The only difference made is in
the amount of pressure, some straws taking more than others without
injury. The hat having been properly “roughed out” or “sweated,” that
is shaped to its exact size without pressure by hand or machine, and
still holding a little steam moisture, is placed accurately in the pan,
the outside of the hat to the metal; inside the hat is distributed as
evenly as may be a thick felt dummy (to prevent the straw from cutting
the bag). If the edge of the crown is very sharp, such as one finds in
a man’s boater, a ring of vulcanized rubber or similar material with
angles corresponding to the crown edge is placed in position inside
the crown before the felt dummy is introduced. The bag chamber is
then brought down, securely locked, and the water pressure applied.
Different materials require different periods of time to properly set,
but while one is setting the operator “roughs out” another hat, so that
when the mechanical process on the one is complete, its successor is
ready for the operation.
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.
[Illustration: 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.
FOOTNOTE:
[2] About this there is some uncertainty; the writer, from personal
recollection, believes it to be correct, but some modern Frenchmen
claim the honour on behalf of M. Desireau, while others assign priority
to M. Légat.