That used for the purpose is specially made, and is in varying qualities of strength and colour. For white goods gelatine of the purest colour is necessary, while for black or dark colours, a gelatine of dark biscuit tint is generally used, as its price is materially less than that of the better colour. The main requirements in a gelatine are 1st, colour; 2nd, no tendency when being used to froth; 3rd, when dry an elastic and firm result. The second condition is probably the most necessary, as although gelatine is capable of being reduced with water to such a degree of fluidity, that it affords the best medium for penetrating the straw and giving it the required strength, if the quality is not good the mixture when used will froth like soapy water, and thus have a tendency to leave a snaily appearance on the hat.
The method of preparation for “stiffening,” as the process is termed in the trade, is by soaking the gelatine in cold water for a sufficient term to enable it to become quite soft and flaccid, and afterwards with heat to melt it down in its softening bath. The weight of gelatine and quantity of water vary according to different formulae for the “stock” mixture, and “stiffenings” of lesser strength are made by the addition of water to a certain quantity of the “stock.” In almost any hat for ladies, the crown is stiffened with a weaker solution than the brim, and therefore two strengths are generally provided for this purpose. Two methods are adopted by the workers for stiffening straw hats, “sponging” and “rolling.” The former consists, when the hat is on the wooden block, of sponging the hot gelatine on to the straw with a “dabbing” motion, and when the plait is thoroughly saturated, using a warm, nearly dry sponge to clear all surplus from the surface. The latter method is effected by rapidly dipping or “rolling” one or more hats into the gelatine bath, and then allowing them to drain, afterwards placing them singly on the block and sponging out the superfluity of gelatine. The first way is generally used for the highest class work, as when well done there is less tendency for the dried hat to crackle and a decided inclination towards a resilient finish. But the second plan is very successful on some materials, and being much quicker to effect is generally practised among manufacturers handling large quantities. It has one advantage, it can be done by less skilled or careful operatives than the “sponging,” which needs careful attention.
The straw boater for men during its stiffening is often soaked in the “stiffening” bath for an appreciable time in order that the gelatine may thoroughly soak into all the fibres of the plait; but that also, when it emerges, is sponged over to remove excess.
The general plan of stiffening a single piece hat (ladies’ hat) with gelatine is for the operator to place the crown of the hat correctly on the wooden block. The sponge having been dipped into the proper bath, the crown is evenly and thoroughly saturated with the gelatine. It is then “dry sponged” to clear the surface, and the operator carefully arranges the rows to synchronize with the edges of the block and with each other. Withdrawing the crown block, the hat is next put on the brim block, and the sponging and arranging operations are repeated, but in the case of a wide brim the “stiffening” used is from a stronger solution bath. Before the sewer hands over the hat to the “stiffener,” the hat has to be “strung,” i.e. a fine thread is so attached to it as to afford a convenient means of hanging the hat up to dry, and when the stiffener has finished his operation he suspends the hat on a wooden rod, which is placed near him in a convenient position. These rods are from 3 ft. to 4 ft. long, according to individual needs, and about 1 in. square: on the longer ones from four to six hats can be hung, and when full the rod is placed in a suitable rack with covering overhead, but in a position freely open to the air.
The best results are obtained from natural air drying, whether by wind or by a mechanically arranged draught from a centrifugal fan, but in cases of time pressure, where goods are wanted quickly, recourse is made to a drying room, which warmed either by fire or by steam heated coils is able to ensure a dry heat, by which the moisture in the hats is soon evaporated and the gelatine allowed to set. This plan is only useful in extremity, for in the early stages while the moisture in the hats is at its greatest volume, the gelatine has a tendency to run towards the lowest hanging portions of the hat, with the result of uneven strengths; and further, when the moisture is driven off, the gelatine retained is rendered more or less brittle, losing entirely the much desired toughness and resiliency. Another point against drying by heat is that it requires a stronger, and therefore more costly, solution of gelatine to be used, in order to counteract the wastage caused by running and the weakness consequent on the dried up gelatine.
The above methods are those in use for all straw, tagal or hemp, and for all chip plaits. It is also used for real horsehair crinoline, but the imitations of this article being of viscose, cellulose, or similar foundation fibres, require special mixtures of gelatine with some acid, such as acetic, to harden the fibre and prevent it shrinking or dissolving, and with some volatile fluid such as methylated spirit, to encourage the rapid evaporation of the stiffening and thus reduce to a minimum the deteriorating effects of a liquid of any kind on the artificial fibres.
Fig. 16
STIFFENING STRAW HATS
Another method of stiffening these susceptible plaits is by some mixture of a resinous nature, preferably that of shellac dissolved in spirit. This method has, of course, several variations which are jealously guarded by the inventors, but the foundation of all of them is on the above lines. In these cases the “stiffening” or really “proofing” (for it is, of course, waterproof) is applied with a brush and care has to be used not to clog the interstices of the fabric. There are many disadvantages to the use of this medium, and its use is not general.