石蠟鑄造工藝(Paraffincastingprocess)

1、石蠟鑄造工藝(Paraffin casting processThe lost waxcasting process was developed from ancient casting process. More than 5000 years ago in the late Neolithic period, the ancient Chinese craftsmen in the manufacture of bronze, widely used lost wax casting process. At the time of the craftsmen according to th

2、e characteristics of plasticity and heat volatile beeswax, beeswax first carved wax to shape, and then wrapped in wax and clay and set aside a small hole, dry after roasting, the wax and clay gasification volatilization, has become a ceramic shell, the inner wall of the shell left female mold wax. A

3、t this time, the molten metal is injected into the shell along a small hole, and then the shell is broken after cooling to obtain the required metal blank. The basic principle is as modern lost wax casting technology, but more sophisticated. This is mainly reflected in the more stringent requirement

4、s of accurate wax type. Get the wax in modern technology not only directly carved on wax, but also through the metal mold (original version) silicone molding die is obtained, and then the wax wax injectionafter silica gel die.Casting material is no longer clay, instead of casting gypsum. Such produc

5、ts are much finer than those of ancient ones.Lost wax casting process are: plastic mold - plastic mold pressing - wax injection (mold) - dressing wax (welding wax), ash (weighing) - filling - vacuum- tube gypsumgypsum plaster, gypsum, natural solidification baking and casting molten gold - fried pla

6、ster and flushing, pickling, cleaning (weighing) - Blank (shearing rolling light). Each process is described below.I. pressing glue mouldThe adhesive used for making rubber mould is rubber sheet with adhesive on both sides. General use of imported film, Castaldo card for more. Oneof the price is rel

7、atively low, because fewer ingredients contained in natural rubber, vulcanized hardness is slightly larger, but the die time is short, suitable for operation in experienced mold division; another slightly higher prices, with natural rubber more fully, soft texture, full of toughness, suitable for mo

8、re complex, in the patternshape small size and obvious concave silver version of die, not easy to break in when remove the wax wax.The storage of raw films should be kept under the control of the storage temperature of 20 degrees Celsius. Generally, they can be stored for one year and stored at 05 d

9、egrees Celsius for 23 years.In addition, the utility model also has a rubber mold which is madeinto a series of sizes and thicknesses in advance, and the inner wall is provided with convex and concave connecting feet, and the utility model is convenient to use.The apparatus for pressing dies is a (v

10、ulcanizing) press molding machine, and its main components consist of two heating plates with internal live wire and temperature sensitive device, a thermostat, and a timer (some models do not have such a device). Die machine is also equipped with lifting screw, used for die and take out.Matched wit

11、h the press die frame, according to the number of holes, it can be divided into single plate, double plate, four plate and so on. The material for making die frame is usually aluminum alloy. The size of the general die frame is 48mm* 73mm, and sometimes the heavy die frame is used to press the large

12、r original. The size is usually 64mm * 95mm.Glue mould seems simple, in fact, there are many details must pay attention to. Ensure the die frame and the film students must first clean, should as far as possible will die die before the box clean, wash hands and work station operator; secondly to ensu

13、re between the original and not rubber adhesion, to do this, we should give priority to the use of silver, if it should be coated with silver coated after the die, because it is easy to bond with rubber adhesion together; again is to pay attention to according to the specific circumstances to determ

14、ine the proper curing temperature and time, which not only accord with a certain function, but also the complexity and rubber mold thickness, length and width, the original, usually will die the temperature is 150 degrees Celsius, if the rubber mold thickness in the 3 layer (about 10mm), the general

15、 curing time is 2025 minutes, if it is 4 layer (about 13mm), the curing time is 3035 minutes In turn, the temperature at the sametimeis also related to the complexity of the original: if the original is complex and small, the vulcanization temperature should be reduced,Prolong the curing time (if so

16、me master uses the method of reducing the temperature 10 degrees and prolonging the time twice), on the other hand, if the temperature is too high, it will affect the effect of the die.The quality of the die depends on the quality of the pressed template. In general, students should first make the f

17、ilm to tightly bonding together, must ensure the film clean first, do not hand in direct contact with the surface of the film, and the film should be born stick and then torn off the protective film on the surface of film students. To ensure that there is no gap between the rubber and the original.

18、In the landfill rubber should be careful, especially for somesmall flowers and stone inlay and other fine bottom side pores, must be filled with broken small particles, with sharp objects (such as forceps tip pressure). In order to avoid the rubber mold pressing too hard, rubber should be buried in

19、landfill in the same direction.In order to ensure the film can be used in a considerable period of time, should makethe rubber mold with sufficient thickness, therefore a rubber mold should use at least 3 layers of rubber press. The rubber laminated rubber mold should be good after the original over

20、all is slightly larger than the die frame, i.e. width slightly larger (can be forced into a die box), rubber mold thickness in press die box is slightly higher than the plane frame about 2mm.The die must also pay attention to first preheating, add mould pressing has good rubber box, tighten the hand

21、le to make the heating plate pressing die box, curing early can check the heating plate is pressed, the curing time arrived quickly remove the plastic mold, the best natural cooling (of course, also can use cold water showers) that is not hot, you can serve hot with a sharp scalpel to open mode of o

22、peration of the.Two plastic mold.Plastic mold is a very high technology in jewelry factory, plastic mold because directly affects the quality of the wax and metal blank, but also directly affect the life of rubber mold. Skilled master mold out of the plastic mold, the wax injection after basically n

23、o deformation, fracture, mantle phenomenon, basically do not need to repair welding wax, wax, can save a lot of time dressing, get a higher production efficiency.Plastic mold tool used is relatively simple, and with a scalpel blade, tweezers, scissors, pliers etc. Note that beginners must use new bl

24、ades when using the scalpel so that it is not easy to scratch the finger. In the cutting process, to ensure the lubrication between the blade and the film mold, it can be dipped in water or detergent on the blade (but never oil, because the oil will makethe mold hard and crisp). Rubber mold four pos

25、itioning method is usually used, that is to say, out of the plastic mold has four feet of mutual agreement between the fixed legs part by linear cutting, but also the use of cutting curve. The general order of mold opening (take ring rubber mold as an example) is as follows:1) over the rubber mold c

26、ooling to a hot air, to flash cut with scissors, with pliers take Xiashuikou block, pull to shell.2) glue the mold nozzle up straight, from the side of the nozzle down the knife, along the four sides of the rubber mold center line cutting, the depth of 35mm(can be adjusted according to the size of t

27、he plastic mold), cut the four sides of the plastic mold.3) cut the first foot from the first lower knife. First, cut two straight edges, the depth is 35mm (can be adjusted according to the size of the glue mould), and then pull the straight edge which has been cut and cut a bevel along the 45 degre

28、es to form a right triangle shape foot. At this time, the cut of the mold should be in two halves of the correspondingYin, Yang triangle feet match each other.4) according to the previous step of the operation, cut out the remaining three feet.5) opened the first cut foot, with a blade smoothly alon

29、g the midline inward cutting (if curve cutting rules should be in accordance with the curve of swing blade, a draw scaly or wavy section), while cutting side pull out rubber mold, be careful when approaching the gate line, with the tip gently open therubber mold. A nozzle. Then one end of the outer

30、ring along the open ring, ring and insert mouth until.6) . This is a plastic mould cutting, difficult and complex steps. If the main stone is inlaid with claws,Cutting heads should be cut along the axis. On the side of two claw ring, the outer end face to the other side of the cutting head and cutti

31、ng to the nozzle position, until the. The glue mold has been cut in half, but the silver plate can not be removed.7) rubber die cutting insert, a part. The interval in the main stone on both sides and the side stone mouth, cutting two claw axis along the main outlet of stone cut, the other two jaws

32、until symmetrical; a residual direction along the main outlet ofstone cutting, cutting just intersect with the surface, so that the main stone mouth is zhilizhuang. Then cross in the main roots of the claw stone and stone inlay mouth mouth side knife, to become the two part. Open cut section, observ

33、e whether by glue wire (usually elongated hollow part side stone mouth of the pore and flower formation), if there should be cut off.8) take off the silver plate, and pay attention to observe the adhesion between the silver plate and the glue mold, if any, cut off.9) open the bottom. Close the entir

34、e circle along the inner ring of the ring so that the incision is close to the bottom. Do not cut it through. Flip the plastic mold, rubber mold with finger bending towards both sides, can be observed in the inner circumference of the incision and with mouth, head part of the incision marks (without

35、 cutting through the rest of the rubber stretch forming slightly concave shallow marks). Cut along these traces to the position of the corresponding nozzle, then cut the width of the 812mmwidth along the parallel direction of the nozzle, and the length is close to the nozzle. At this time, the botto

36、m forms a mushroomlike shape that has been able to pull the inner part of the ring out of the cut bottom. Can this rubber mold successfully remove the wax.The pressed glue mould should be examined carefully. Pay attention to the glue mold can not have any defects, such as obvious broken flowers, lac

37、k of angle, adhesion and so on. These are likely caused by the defects of wax, so should repair ofthese defects, such as incision without cutting position, welding wax welding broken flower, missing foot place etc. In addition, for the complex structure of the original should be adjusted according t

38、o the specific circumstances of the cutting surface, such as disc insert jewelry should be stratified multilayer cutting, sometimes need to set cut sleeve core; for chain brand multi pendant, large and complex can not be opened at the end of direct slicing etc. The storage environment of glue mold s

39、hould be low temperature, dark, and avoid the influence of oil and acid. If the use is not very frequent, the mold can be used for ten years. However, if used frequently, the general use of two years will not be used, because this time the mold due to repeated injection of wax heating has been harde

40、ned, the use of greatly reduced. Coupled with the need for changes in design considerations, the general rubber die life between 23 years.Three. Wax injectionWhen the glue die is opened, the wax injection operation can be carried out. The operation of wax injection should pay attention to such facto

41、rs as wax temperature, pressure and compression of glue mould.Making use of the wax wax is paraffin model blue, the melting temperature at 60 degrees Celsius, the wax temperature at 65 degrees celsius. There are some other colors of wax, slightly different in nature. The wax temperature and injectio

42、n pressure are determined by wax injection machine. The types of wax injection machines usually have two types: air pressure type and vacuumtype. The principle of waxinjection of the two kinds of wax injection machines is basically similar, that is, the wax is injected into the glue mould by using a

43、ir pressure. The difference between them is that the vacuum type wax injection machine can vacuum the mold first and glue the wax to the glue mould. So it is easy to control the vacuumwax injection machine, and the pneumatic wax injection machine needs someexperience.The heater and temperature senso

44、r in the wax injection machine can make wax liquid reach and maintain a certain temperature.Normally, the wax temperature in the wax injection machine should be kept between 7075 degrees centigrade, so that the temperature can guarantee the fluidity of the wax liquid. If the temperature is too low,

45、the liquid wax is not easy to fill the wax wax, resulting in incomplete; and the wax liquid temperature is too high, it will lead to the liquid wax from the rubber mold gap from the mouth overflow overflow or wax, easy to form flash or burn your fingers.The pressure in the wax cylinder of the wax in

46、jection machine is supplied by an external air pump, and should normally be kept at 0.50.7at (or kgf/cm2) is between 0.0510.071Bar, can also be adjusted according to the size and complexity of the pattern.Before the wax injection, the rubber mold should be opened first to check the integrity and cle

47、anliness of the mold. If the rubber mold used, should be to the rubber mold especially fine shape complex position of spray dewaxing agent (also sprinkle a little talcum powder), in order to remove the wax; secondly should preheat wax injection machine, open air pump, adjust thepressure and temperat

48、ure.Wax injection should be used when the hands will splint (can be organic glass plate or wood, aluminum etc.) in plastic mold clamping, note the finger distribution should be uniform compression of rubber mold; plastic mold injection nozzle will be aligned parallel Grosbeak forward, hands firmly s

49、upported real injection wax, wax injection combined with the feet tread lightly the switch and then loosen the hands, stay 12 seconds after the rubber mold to place a moment, to open the mold (if the rubber mold bottom, will be the first, remove the wax out of the mold bottom). Removethe wax after c

50、areful examination, if there is serious lack of edge, feet, so the wax belongs to waste. If the number of relatively small defects, it should wax dressing.Four. Wax dressingIn general, the wax wax removed after all more or less there are some problems, such as edge, edge, multiple broken claws, visi

51、ble blisters, in part or in whole structure deformation, pore obstruction, flower line is not clear, take the edge and so on. For flash, multiple edges, flower is not clear, head of edge defects can be used for surgical blade repair; trachoma, broken bones can be used for welding wax by welding; dif

52、ferent holes can penetrate the welding needle; for wax deformation can be calibrated at 4050 DEG C hot water.In addition, for different hand ring, if you wait until they die and then change the ring, it is time-consuming material costs. So the general production enterprises are in the repair of wax

53、directly change the finger ring. It is very convenientto use the wax welding machine to change the finger ring. After welding, the welding seam can be repaired with a knife blade.Five kinds of ash.Waxafter finishing, which need to further the operation of ash.Which is to make a good wax wax tree in

54、a certain order, with welding wax along the circumferential direction are welded on a layered wax rod, to finally get a tree shape resembles a tree and then pouring ash ash, gypsum etc. The basic requirements for the red ash is wax to orderly arrangement, the key is not to contact between the wax, t

55、o maintain a certain gap, but also as much as possible will be welded on the wax wax tree, that is to say, a red ash should be the highest number of species on the wax pattern, to meet the needs of mass production.A red ash must be "kind" in a circular rubber chassis. The diameter of this

56、rubber chassis is matched with the inside diameter of the stainless steel cylinder. The general rubber chassis has a diameter of 3? Muscle? and dispatch? 5 a muscle got angry for sputum? And Huang Huan Lu Wei Ji Zhu Ji idiotic? Makethe team the vertebral Rongmu?the thin broken grits sigh! 爸擲？鰲領牡遍徊劍？

57、褪墻？?枚凡空閡恍T渾？睦？海？萌快迦氟著痰陌 伎字校？估?粲笳伎捉岷俠喂獺5詼？劍？鴆憬？:附釉談？羯希？梢源永？ 臚撞靠？跡生上李蛭希？部梢源永？枚凡靠？跡坦繕舷獅攏？H綣？爸質 鰲領募際醵冉鮮尬罰？街址椒皿僮眼鵠吹牟畋鴆淮蛆壞？且話鬧褂么 永?枚凡靠？跡立由舷卿攏姆椒U冉隙瞰？蛭？庵址椒皿淖畬笥諾鬧強 梢苑樂谷渾？睦？旱溫沫膠負玫睦？1希？花槐范庖蛆？旱溫溫斐傻牟槐 匾？姆倒25 ？BR>The operation process of ash should pay attention to the following questions.1) generally have an

58、angle of 45 degrees between the waterway and the ash for wax wax rod, that is to say, the wax is tilted to the direction of. Only in this way can the gold water be smoothly injected into the plaster mold. This angle can be adjusted according to the size and complexity of the wax, wax small and compl

59、ex angle can be reduced; conversely, the larger angle can increase the wax.2) in ash before, should first of the rubber chassis for weighing. A red ash after another weighing. The two weighing results can be obtained by subtraction, ash weight. The ash weight according to the density ratio of paraffin wax and metal casting is converted into metal weight, we can estimate howmuch metal casting.3) kinds of ash) is completed, must check whether each have wax. If th