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 Investment Casting   Pressure Die Casting   Sand Casting    Resin Shell Moulding   Loast  Foam
 
     Investment Casting                                                     
     This process is suitable for series  production  of high quality  castings  Particularly aluminum,  alloy, non -  alloy ferrous 
     metals .The process is generally used for  small  castings,  often less than 100gm, although steel castings up to250 kg
     & aluminum castings of 30kg in our unit compared to other casting process such as die castings investment casting is an
     expensive process,  but it has versatility approached by few other metals forming processes. Intricate - entrant contours
     can be incorporated so that great freedom  of  design  is  possible in many cases components are cast  are  near  to  net
     shape to minimize or  just eliminate machining cost  above the all  this process gives a very closely packed  metal  grain
     structure with  the least  porosity  as good as a hot forged metal component but ever with very complicated geometrical
     construction.
     One of our common process of investment casting is tust wop method. Patterns of the castings to be made are  moulded
     by injection of special wax into a metal die.  Cores of pre - formed  ceramic may be incorporated into the wax  patterns
     as they are moulded. The  patterns  are assembled into a cluster  ( often comprising tens or even hundred of patterns )
     around a wax runner system. The ‘ tree ’  of patterns is then around a wax runner system . The ‘tree’ of patterns is then
     coated with 8-10 layers of a refractory mould strongly. The hot mould is cast & when cool the mould material is removed
     by impact, vibration, grit blasting, high pressure water blasting or chemical leaving the castings, which are then removed
     from the runner system.
     Various post-casting operations may be carried out to meet customer requirements.                  
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     Special characteristics
    High production rates, particularly for small components.
    High dimensional accuracy & consistency.
    High integrity castings.
      Extremely good surface finish obtained.
      Complex shapes can be cast.
      Long or short runs can be accommodated.
      Machining can be eliminated.
      Minimum shot blasting and grinding needed.
      Almost any alloy can be cast.
      Environmentally good.
      Specialised equipment needed.
      New technology must be learned and  great attention to detail is required.

   The process is expensive because costly refractories & binders are used

      & many operations are needed to make a mould.
     Because of the exceptional surface finish possible &  expected, minute
        defects can cause rejection of castings & scrap rates can be high.
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     Pressure Die Casting
     Process Outline
     Process outline is a hot chamber metal casting process.  The metal for casting maintained at an appropriate temperature in
     holding furnace adjacent to, if not part of, the machine. The injection mechanism is located within the holding furnace and a
     substantial  part  of it is there fore in constant contact with the molten metal.  Pressure is transmitted to the metal  by  the 
     injection  piston ,  which forces it through the gooseneck & into the die. On  the  return  stroke  metal  is  drawn  into  the 
     gooseneck  for  the  next  shot .  In the process there is minimum contact between air  & the metal to be injected , thus
     minimizing the tendency for turbulent entrainment of air in the metal in the metal during injection system,  which effectively
     restricts this process to  zinc base alloys. Some of the most complicated auto mobile components like engine blocks,
     carborators, clutch / brake system etc.are manufactured with pressure die casting process.
 
     The advantages of the pressure die casting process are
  • the ability to produce castings with close dimensional control
  • the ability to produce castings with a good surface finish
  • the ability to produce castings thin walls, & therefore of reduced weight
  • the ability to produce castings at a high rate of production                                               
             

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      Sand Casting
      Clay-bonded sands have provided the principal medium from which moulds to castings have been produced for centuries. In
      essence the mould material consist of sand, usually silica in a quartz form, Clay & water. The water develops the bonding
      characteristics of the clay, which blind the sand grain together.  Under the application of pressure the mould material can be
      compacted  around  a  pattern  to  produce  a  mould  having  sufficient rigidity to enable metal to be poured into it produce a
      casting. When the mould is used in its moist condition it is referred to as green  &  the method of producing the moulds as a
      green  sands moulding process. If the mould is dried at a temperature  just  above  100°C (212°F)  the  majority of  the free
      moisture  will  be  removed.This  is the principal of  the  dry  sand  moulding  process. Removal  of  the free  moisture  is
      accompanied by a significant increase in the strength & the rigidity of the mould . The enables the mould to with stand much
      greater  pressure  &  so ,  traditionally,  the  dry and process  has  been used in the manufacture of large,  heavy  castings 
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      Castings of engineering items Structures of machine tools, loads of machine tools, Rolling mill parts, Big gear box fly wheel
      etc. these casting can be of weight 5kgs to 5000kgs.
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      The green sand process remains unchallenged as the process  capable  of  the  mass  production  of  casting  at  low  cost,
      especially in cast iron. However, the engineering has progressively increase demand for casting with  improved dimensional
      accuracy, surface finish & soundness. The led to the development of the so-called high-pressure moulding machines, which
      produce high density moulds necessary to meet the customer’s demand.
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      Process Capability

    We can manufacture  in the range  of 500 gms to  500 kgs

    like small machine components, pump parts, Gear Box parts,

    Bearing Housing etc.

   

               

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    Resin Shell Moulding
    The  shell  moulding  process is a precision  sand  casting  process capable  of  producing casting  with a superior surface
    finish  &  better dimensional accuracy than conventional sand casting .  These qualities of precision  can  be obtained  in  a
    wider range of alloys & with greater flexibility in design than die-casting & at a lower cost than investment casting.
    The fundamental feature of the process is the use of fine - grained,  high purity sand  that  contributes  the attributes of  a
    smooth  surface  &  dimensional accuracy  to  moulds cores  &  casting alike .  In conventional sand  moulding  the use of
    such  fine  sand  is  precluded  because  it  would  dramatically reduce mould permeability . This has the effect of retarding
    the escape of air the mould gases, causes short run castings or casting containing gas defects. However the distinguished
    feature of the shell moulding process is that the mould literally a shell,  being in the region
    of only 10mm ( 0.4 in ) thick. It was the ability to produce such a thin shell mould,  which    
    made the  process  a  volutionary  development  in  metal  founding. The  coincident

   development of Plastics like Bakelite, which were based on thermosetting resins such as

   phenol formaldehyde,  provides  the basis of shell moulding. In the shell moulding the fine  

    sand  is  coated  with a  thermosetting   resin  which  provides  the  relatively  high  strength

   required enabling a thin section, or  shell, mould to be produced  mostly automobile components

   wheel  / brake components, valves & other brass / gun metal castings with good accuracy are

   manufactured with this method.    

 

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     Loast Foam Process
     It is very typical method of investment casting for very precise but small components & economical as compare to lost  wax
     castings  but  for only high production  rates.In the process the desired shapes structures the various types of  foams  are 
     made just similar to the end product of any complex shape. These foam shapes are then kept in fine day mixed with binders
     just similar to core sand  casting.Here Molten  metal takes shape of foam by burning it  slowly &  a  very  compact  grain
     structure is achieved due to pressure of gas emmitrans from burnt foams.
     Special characteristics of  Lost foam casting 

  • High production rates are possible.

  • High dimensional accuracy is achieved.

  • No cores are needed.

  • Complex shapes can be cast.

  • Machining can be eliminated.

  • Minimum shot blast & grinding is needed.

  • All sand is re-usable.

  • Environmentally good.

  • Expensive tooling restricts the process to long run castings.

  • Specialised casting equipment is needed but the capital cast if lower

         than for other high volume processes such as green sand.

  • New technology must be learned.

  • Long lead times are needed to develop new castings.

      

           

 

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Anand Concast Limited

    Giaspura Road, Dhandari Kalan, Ludhiana-INDIA

    Tel : +91-161-2510525, 2510526,2510527

  Fax : +91-161-2510625, 2301884

E-mail : info@aclmetals.com