Mould (manufacturing)

“ This is unnecessary. The mould can be easily prepared with a solution of soap so as to leave nothing on the surface but a very thin coating of oil, which is taken up and replaced by the plaster of the cast. ”

“ A mould would be made by pressing the finger into some plastic material, such as fine modelling clay or hot sealing wax, and then, by pouring a warm solution of gelatine into the mould, and allowing it to cool and solidify, a cast would be produced which would yield very perfect finger-prints. ”

“ One end of the mould has a narrow gutter leading from the top to halfway down the mould. This was probably used for the insertion of a piece of iron prior to the metal being run in, thus permitting the easy withdrawal of the block of tin when cool from the mould. This stone also contains a small bevelled ingot or sample mould, 4 inches long, 2 inches wide, and 11⁄4 inches deep. ”

“ The shaft or great body of the mould is a hollow cylinder, finely polished in the inside, and open at both extremities. The top of the mould is a small metallic cup, having a moulding within-side, and a hole to admit the wick. The two parts are soldered together, and when united, as will readily be imagined, have the shape of a moulded candle. A third piece, called the foot, is sometimes added; it is a kind of small funnel, through which the liquid tallow runs into the mould, and, being screwed to the opposite extremity of the shaft, is removable at pleasure. ”

“ For statuary, and “undercut” work generally, an elastic mould—of glue and treacle (80 : 20 parts) —may be used; the mould, when set, is waterproofed by immersion in a solution of potassium bichromate followed by exposure to sunlight, or in some other way. The best results, however, are obtained by taking a wax cast from the elastic mould, and then from this a plaster mould, which may be waterproofed with wax, black-leaded, and used as cathode. ”

“ Respecting this mould we have scarcely more material for conjecture than with regard to the first punches and matrices. The principle of the bipartite mould was, of course, well known already. The importance of absolute squareness in the body and height of the type would demand an appliance of greater precision than the uncertain hollowed cube of sand or clay; the heat of the molten lead would point to the use of a hard metal like iron or steel ”

“ Composition ornaments are now in general demand for all but the most expensive frames, and as this composition—which is formed of glue, water, linseed oil, resin, and whiting—is pressed into moulds when it is of about the consistence of dough, it is evident that the mould maker has partially taken the carver’s place. ”

“ The course followed is to cut up the model in such parts as is determined, to mould these in loam, the cores are then cast in plaster after the thickness that will be occupied by the lead has been first applied to the moulds in sand (terre) . The cores are then removed and dried and baked, for in this as [97] in all founding everything depends on the absolute dryness of the mould. After the first mould had been added to, for the casting of the core, a second mould would be prepared from the original figure and the core supported in that by irons. ”

“ The clay shell becomes smaller as it dries, so there is no trouble about removing it from the mould—if one knows how. If a large article is to be cast, the mould is made in sections. Of course this fine ware must all be made by hand, especially as machines do not work well with the finest clays; but cheap dishes are all made by machinery. ”

“ Plain, or unenriched, mouldings are formed with a running mould of zinc cut to the required profile. Enrichments may be Mouldings. added after the main outline moulding is set, and are cast in moulds made of gelatine or plaster of paris. For a cornice moulding two running rules are usual, one on the wall, the other on the ceiling, upon which the mould is worked to and fro by one workman, while another man roughly lays on the plaster to the shape of the moulding. ”

“ Where worn or splintered parts of a wood-carving, or fissures in a stone, or deep undercutting which is not essential to the design, occur, it is often of advantage to fill them up with clay or paper, to which a smooth surface can be given, so that the mould will come away free from them when it is dry; and careful notes and measurements will often enable one to restore the contour to a mould which has suffered some pressure in transport. ”

“ The mould is made and lowered into one of these pits, the pit is filled up, the sand being rammed as hard as possible all around it. When all is ready, the top of the mould, with the cross by which it is to be lifted and lowered surmounting it, presents the appearance represented on the right hand lower corner of the engraving below. ”

“ As it thus shrinks in dimensions, molten metal is poured into the corners of the pan for the purpose of maintaining the fluid pressure on the mould, and thus securing a good and solid cast. For if the pan were allowed to cool more slowly, the thin metallic film at the back of the inverted plaster mould would probably solidify first, and thus prevent the fluid pressure which is necessary for filling up all the lines of the mould. ”

“ The process of moulding vases is the one most in use nowadays, for the simple reason that when once the required mould has been made the production of any number of vases is a rapid and easy task. But though commercially favored, this method is looked down upon by the artistic potter as being purely mechanical, and there is no doubt that a moulded vase has all the characteristics of machine work.
The material used for moulds nowadays is plaster. The clay can either be poured into a mould in slip form or pressed into a mould while soft and plastic. ”

“ This mixture gradually hardens against the porous sides with which it is in contact, and, when the thickness of the hardened layer is judged sufficient, the mould is emptied by inverting it. The excess of the liquid paste is thus eliminated, while the thicker parts remain adherent to the plaster. Shortly afterward, the absorption of the water continuing, the paste so shrinks in drying as to allow the object to detach itself from the mould. As may be seen, nothing is simpler when it concerns pieces of small dimensions; but the same is not the case when we have to mould a large one. ”

“ The com bined matrix and mould are then adjusted to the type-casting machine, which manufactures types at the rate of from 25 to about 120 per minute, according to the body. The metal is kept fluid by a little furnace underneath and is injected into the mould by a pump, the spout of which is in front of the metal pot. ”

“ The highest economies of machine-moulding are obtained when (1) several small patterns are mounted and moulded at once on a single plate (fig. 10) ; (2) when top and bottom parts of a mould are produced on different machines, carrying each its moiety of the pattern; (3) when the machine and pattern details are simplified so much that the labour of trained moulders is displaced by that of unskilled attendants who are taught in a month or two the few simple operations required. That is the direction in which repetitive casting is now rapidly tending. ”

“ HANDLE
MOULD.
Here’s the way. First the man cuts off 189 a piece of the biscuit, and kneads it on the plaster Paris slab. Then he takes one piece of the mould, fixes the clay in nicely, shaves off what he don’t want, then puts on the other piece of the mould, and sets it on the wheel. He gives it a shove and sets it spinning. It stops itself after a while, then he opens the mould, and there is the dish. The clay keeps the same thickness all through, and fills both pieces of the mould.
MAKING A SUGAR-BOWL.
Then the man takes it out and sponges it. ”

“ The article, at all seasons, becomes sufficiently plastic when “worked” in the mortar, or in very cold weather, with the addition of a drop or so of almond or {263} other proper oil, to admit of being rolled with the spatula into form, the most convenient one for which I have found to be that of a cylinder about an inch long, weighing twenty grains, and fitting exactly the calibre of the instrument used for introducing them, which I generally use as a mould. The active ingredients used are mostly sulph. ”

“ I soon had the metal mould ready for casting. It consisted of a base plate of cast iron, on the surface of which I placed a ring or hoop of iron turned to fully the diameter of the intended speculum, so as to anticipate the contraction of the alloy. The result of the very first trial of this simple metal mould was most satisfactory. It yielded me a very perfect casting: and it passed successively through the ordeal of the first rough grinding, and eventually through the processes of polishing, until in the end it exhibited a brilliancy that far exceeded that of the sand mould castings. ”

“ A mould is familiar to all in domestic and industrial matters, but there are two sides to the metaphorical conception. A plastic object may be moulded by the hand of man as in his ruder, but more laborious days, or it may be pressed into an artificial mould that he has made by means of his hands and tools. ”

“ The funnel of the clay mold is filled with pieces of metal, and the entire thing is buried in the fired charcoal. In fifteen minutes the metal melts and runs down through the gate at the bottom of the funnel into the hollow, wax-lined mold. Since the entire mold is hot, the metal does not cool or harden promptly, and the pipe maker taps and jars the mold in order to make the metal penetrate and fill every part. ”

“ The operator mixes sugar or resin with the India-rubber, prepared in the usual manner for vulcanizing, in the proportion of one-quarter of a pound of sugar or resin to each pound of India-rubber; and after the compound has been worked and treated in the usual manner, he forms the clog thereof, in a mould, and subjects it to the curing or vulcanizing process, by which it is rendered spongy and light. The mould is so formed as to make the sole thin, with a rim all round and protuberances within, for the boot or shoe to rest on, to give the foot the required elevation from the ground. ”

“ The man at the angle of the wall should beat carefully against the head of the mould.
“Care must be taken that no fresh earth is received into the mould till the first layer is well beaten, which may be ascertained by striking it with a rammer; the stroke should leave hardly any print on the place. They must proceed in this manner to ram in layer after layer, till the whole mould is full. When this is done, the machine may be taken to pieces, and the earth which is contained will remain firm and upright, about 9 ft. ”

“ The vatman takes a mould, places the deckle upon it, dips the mould into the vat of diluted pulp, and lifts just the quantity of pulp necessary for the weight of paper being made. A slight shake is given to the mould, a small side shake and a greater shake backwards and forwards, something like the shake given to a type case, but less violent, the object being to cause the individual fibres to cross and felt together. The mould is kept perfectly level, or the sheets are thinner at one edge than at the others, the mould is pushed ”

“ Subsequent shrinkage allows its removal from the mould. After a partial drying, the ware is dressed or “shaved.” The process is a very delicate one, especially in the finer kinds of ware, in which a finely polished surface is necessary. The piece is placed on a lathe, and cut to the necessary thickness, and receives its ornamental lines, or has the mouldings applied. The handles are then attached, and, after drying, the piece is ready for the kiln.
The moulding of porcelain requires very great care, on account of the fragility of many of the pieces. ”

“ How to Make a Waste Mould.—When a soft or fleshy object is to be cast, one which will yield, and draw out of the mould regardless of undercuts, a very quick and satisfactory process (provided a second copy of the cast will never be wanted) is to make what is called a waste mould. This, with a fleshy subject, is a short cut to a perfect cast, and often saves hours of valuable time. In obtaining casts of mammal heads, legs, or other parts, or casts of fishes and reptiles, it is the method par excellence. Let us learn the principles of it by making a waste mould and cast of a human hand. ”

“ Permanently cast metals generally show 20% increase in tensile strength and 30% increase in elongation as compared to the products of sand casting.
The only necessary terrestrial input is the coating applied before each casting. Typically, permanent mold casting is used in forming iron-, aluminum-, magnesium-, and copper-based alloys. The process is highly automated and state-of-the-art easily could be adapted for use in an extraterrestrial manufacturing facility. The main disadvantage is that the mold is not easy to design or produce automatically. ”

“ When finally assured of this fact, take out the mold, open it, and blow it out, to make sure of absolute cleanness. Close and bind again and place on a hearth of fine, hot sand. The mold should still be glowing when the casting is made. The ladle should contain plenty of metal, so as to hold the heat while the casting is being made. The presence of a little zinc in the metal ensures a sharp casting. Finally, to ensure success, it is always better to provide two molds in case of accident. Even the most practiced metal molders take this precaution, especially when casting delicate objects. ”