MOIRE.
Since we have come to speak of the moiré, we must say what this manipulation consists of, which gives the fabrics a peculiar character, and produces undulating effects.
The tissues most likely to receive moire are those with the most pronounced grain, especially if it is continuous; For example, the silk puffs, large of Tours, & c. , And even also cotton string fabric items. Moire can also be applied to coarse grains of gold, and to a multitude of jaspered, wavy, and so on. The operation of the moiré flattening the grain which is produced by the crossing, the layer by parts in the opposite direction of each other, which makes appear on the cloth a multitude of various undulations, which have their principal cause in the reflections light.
The moirer, or calander, consists of a large and strong case about 3 meters long, about 1 m. 60 c. Of high and 1 m. 30 c. wide; Strong plates perfectly united under it form the bottom. The platform on which the machine acts is firmly seated on the ground; The weight of the box which, according to the requirements of the fabric, goes up to 40 and even 50 thousand Ivilos, is determined by any materials packed in the cashing. As for the operation, here is how it is practiced.
The stuff is folded in two in all its length, and the two edges are brought one on top of the other; So that their superimposition is conserved regularly, they are maintained along the whole length by needle-stitched points, 25 centimeters apart. about. Thus lined the fabric is folded folds on pleats by length of 60 centimeters. The piece thus prepared is then placed on a strong canvas, so that all the folds form an angle of 45 degrees; That is to say, instead of being superimposed vertically, the extremities of each fold must retract on one side, and on the other, exceed the same; In this way, the two sides of the fold of the fabric form an insensible gradation, terminated by the thickness of a single fold.
When the cloth is arranged as we have just said, it is wound in mass on a cylinder made of gaiac wood, with a diameter of 15 to 18 centimeters, and it is covered with several turns of strong canvas , Fixed by twine on both edges; Then this cylinder is placed transversely beneath the box, which is loaded with only half its weight for this first operation, and which is secured by means of a strong rope which, passing over deflection pulleys, goes Winding around a vertical winch controlled by the axis of a merry-go-round; So that the body makes a movement of reciprocity which produces the moire by the effect alone of the pressure.
After this operation, the duration of which is nearly a quarter of an hour, the cylinder is disengaged, in order to judge the arrangement of the moire; Then, if the undulations are not properly marked, this cylinder is replaced. If, on the other hand, these undulations are recognized as sufficiently sensible and well directed, the folds of the fabric are changed by placing in the middle those which were previously on the extremities, but always adopting the angular process; Then the cylinder is put back under the calender, which is then charged with the totality of its weight. This change in the arrangement of the folds is intended to make the moiré equal.
The most beautiful and most successful moire is recognized, that which has great waves terminated by two loose fillets, and which do not form what are called barrages. The moirer-machine system which we have just described is used, although very ancient, and presenting various disadvantages, among which we must place the gigantic form of the machine, the difficulties we have in operating it, and finally And especially the loss of time caused either by the checking of the moire, or by the putting into practice. Thus, these acknowledged disadvantages had induced many manufacturers to abandon this machine of enormous proportions, and to adopt, in preference, the cylindrical grille which one owes to Vaucanson. But the old system has been put into practice for some years now, under the influence of fashion, which has brought back the antipersonnel which is obtained only by the process we have just cited.
The machine of Vaucanson produces only the round moire. We will say a few words.
The Vaucanson calender is made in the form of a rolling mill equipped with two metal cylinders of first strength. Here, the mutual pressure of the cylinders is effected by means of levers of different kinds, the arrangement of these levers enables a pressure to be reached which is equivalent to the loads of the body of which we have spoken in explaining the old system. By the method of Vaucanson, nothing is more easy than to increase and diminish the pressure of the machine on the spot.
The folding of the fabric also differs from the process explained above, in that in the one we are currently describing, the fabric is folded over its entire width, head to head, ie half The piece is folded and lined on the other. This is how it is placed on the lower cylinder. Once the machine is set in motion, it is only necessary to press a trigger so that the cylinders run back, and in this way the reciprocating movement is carried out.
When there have been ten or twelve passes, the corner of the canvass is raised to check the first impression, for which a charge equivalent to about 3,000 kilograms has only to be laid; It is produced by the weight of the levers and by their arrangement. As soon as it has been observed that the waves are arranged as they ought to be, the operation is continued by increasing the charge by a weight of 25 kilograms; Which, by the combination of the levers, produces a load one hundred times stronger, that is to say 2,500 kilos in addition; So that the sixth load is about 40,000 kilograms; Then, in order that the whole surface of the cloth may also receive moire, the folds must be changed from place to place; For this second operation, the charges must be given and increased gradually as for the first.
In order to be able to place and move the fabric on the lower cylinder as quickly and as readily as possible, a tablet placed opposite the junction of the cylinders, and seated in a solid manner, and levers which are Arranged purposely to serve the elevation of the upper cylinder.
Moire antique, known as English Moire
We believe it necessary to give here, as a necessary continuation and complement to the processes of the moire, the indication of those which are used to obtain the ancient moire, also called the English moire. First, the fabric is doubled in its entire length, so that the two edges meet perfectly. Then the edges are sewn one on top of the other, by means of dots 35 centimeters apart, so that the place of the stuff is inside, and the back outside.
If one of the two edges was longer than the other, which might prevent the obtaining of a beautiful moire, the longer the seam is made, Weft is encountered when the fabric is lined. For it sometimes happens, in these shaped fabrics, that the drawing does not meet exactly by folding the fabric as it is said above. In this case, one of the edges will run as much as it takes to make the shape meet well.
Then, along the entire length of the piece, and on the two edges sewn together, light scissors, not in the direction of the weft, are given, but obliquely, because the selvedges were sometimes more taut than the middle of The fabric, would produce a bad effect for the moire.
The fabric being thus lined, adjusted and sewn, it is folded into rods on a table in which are fixed four pieces of wood placed perpendicularly to hold the rods on the table. The distance to be observed for the length shall be 57 to 58 centimeters; The tray adjoining the table on which it is folded, and which is to be pierced with several holes to introduce the pieces of wood which hold the sticks, at a distance or less, according to the length of the material to be folded.
The piece of cloth being folded by folds 57 to 58 centimeters in length, is placed on a tight, close-fitting cloth, about 11 meters long, and 75 to 80 centimeters wide. The part of the stuff which is strongest is placed beneath and against the canvas, because it is more liable to wrinkle than the part which is extended last. We shall also place at the head of the cloth pieces of canvas, of the same quality as the large canvas we have just mentioned, and being 40 to 50 centimeters high; They are destined, as much to guarantee the stuff of the action of the stone, iron and wood, between which it will be pressed, and enlarge the roller, when one does not have to mock a large Amount of fabric.
When the canvas is new, it should be soaked in water before being used, dried and placed about an hour under the calender, alone, ie without cloth, but With the other pieces or strips of linen which have also been mentioned. The object of this precaution is to render these canvases more united, and to prevent the grain from being printed on the stuffs.
When the fabric has been prepared, the edges are cut obliquely as has been done for the fabrics, because they do not extend, the pressure not being as strong for them as for the middle of the fabric .
Placed on the canvas, the fabric is stretched taut by fold, between each of which one leaves an interval of 5 centimeters.
In this way, 80 to 100 meters of cloth can be placed at the same time: but care must be taken to put a strip of plain cloth, or even sometimes a sheet of a rather heavy paper, between one piece and the other, In order to facilitate the sliding of the fabric and to prevent the formation of folds.
The fabric is folded lengthwise into the fabric, in the width of the latter, the selvedges being maintained on the top side of the same fabric. (In this description, the side which is opposite to the roller on which the fabric is folded to be placedUnder the grille.)
Thus prepared, the canvas is wound round a wooden roll, tightly clasped by a crank, and placed under the grille in its upper part, and on a polished stone. It is essential that the roller be placed under the perfectly square grille; Without this precaution, the fabric and fabrics would crumple and be damaged.
By means of tables and pulleys adapted to its mechanism, the grille going and comingWith the roller about two thirds of a turn on one side and the other on the other, the pressure taking place over the entire circumference of the roller.
The operation runs for half an hour; After this time, the roll is lifted to examine whether the cloths and the fabrics are not disturbed or wrinkled. This is frequently the case. If folds are found there, they are effaced by passing the nail on; Pieces of paper are placed over the folds; These pieces of paper make the layer thicker where they are, hence the higher pressure, which causes the disappearance of the folds. When the end is well arranged, the canvas and its contents are placed again around the roller, which is put back under the grille, where it rolls for another half-hour. After this time has expired, the roll is lifted, the parts on it are folded a second time, taking care to change the folds, so that those already formed on the piece are not in the same place on the canvas, but in the middle of it.
When the pieces are folded up, they are put back into the canvas, and the roller is placed under the calandria for half an hour; Then we raise it, we visit it, we put the whole well in order, then we put the roll under the grille for the fourth time, and always for 1/2 hour. Finally, after this fourth passage of the roll under the calender, the pieces are removed and folded a third time, but with more care and precautions than in the previous folds.
This last folding is called folding to finish, to repent to the merchant. It is essential that all the folds be equal, that the cloth be well erected, and that the folds be erased. For this fifth turn of the grille, unless the merchant has recommended that his cloth be very soft, a portion of the cloth necessary for the placing of the stuffs, Have already passed four times under the grille; If we have other fabrics that have not been worked, or have only passed twice under the grille, we will place them at the top of those we want to finish, but we do not wet the Place where they are placed.
The roller, for the fifth and sixth calendars, must pass under the grille, half an hour each time. The manner of proceeding is, moreover, absolutely the same as for the first four submissions to the grille; But as the fabric must not be folded, it is advisable to give greater care either to extend it, or to remove the folds which might have formed there.
Sometimes, even after they have passed six times under the grille, there are still folds of cloth. You have to erase them, put some papers on them, and replace the roll under the grille for 10 or 15 minutes, so that these folds disappear completely.
Then the coins that are finished are removed from the roll; They are placed on a table, so that the side which is more flattering to the eye lies beneath. All the folds are then taken one after the other to place them in an opposite direction and to equalize them perfectly. This is what is called the turning of the piece; It is put into the press a few hours, and after this operation it may be returned to the merchant.
All that has just been said applies in general to all the cloths intended for moire; But there is another special preparation for light fabrics, which consists in preparing them when they have passed four times under the calandria. For this purpose, 170 grams of glue of Flanders, or of white and very clear gelatin, is placed in a liter of water; The glue is allowed to dissolve for a few hours, and boiled until it rises. When it has been mounted three times, it is passed through a fine silk screen, then spread with a sponge on both sides of the fabric, upside down. If soft or gold-plated colors are used, the priming water must have a low degree of heat, because if the water is too hot, there is a risk Change shades or blush the lamé. The pieces being prepared in this manner, they are dried, avoiding exposing them to currents of air; They must also be avoided too near the fire, for the primer would fall and the operation would be annihilated.
When the room is very dry, it is folded, as it has been done for the former, it is passed half an hour under the calandre; And finally it is folded a fourth time, finally, as has been explained above.
It should be observed that the pieces so prepared leave a part of their finish in the cloth in which they are placed, and by the effect of the pressure, which gives this cloth firmness, renders it smooth, consequently More suited to work, because the fabrics slip more easily and are less prone to wrinkling.
If one passes for some time without dressing cloths, and if the cloth has become too soft, it is remedied by making a water of dressing, as has been indicated above; But it must be less strong, that is to say that only 50 to 60 grams of glue per liter of water will be used.
This finish is spread over the part of the cloth which is intended to receive the workpieces; The canvas is then dried, and before putting stuffs on it, it is subjected to the calender for half an hour.