Gating System
Manufacturing Process
Manufacturing Technology
INTRODUCTION
COMPONENTS OF GATING SYSTEM
TYPES OF GATE
FUNCTION OF GATING SYSTEM
CHILLS
GATING RATIO
DEFECTS OCCURING DUE TO IMPRORER DESIGN OF GATING SYSTEM
2. IND
EX
INTRODUCTION
COMPONENTS OF
GATING SYSTEM
TYPES OF GATE
FUNCTION OF GATING
SYSTEM
CHILLS
GATING RATIO
DEFECTS OCCURING
DUE TO IMPRORER
DESIGN OF GATING
SYSTEM
3. • Mould is used for producing a casting,
Molten metal is conveyed into the
mould cavity by using Gating system.
• In casting process, gating system plays
an important role to produce a high
quality casting.
• A poorly designed gating system results
in casting defects.
• A gating system controls mould filling
process. The main function of gating
system is to lead molten metal from
ladle to the casting cavity ensuring
smooth, uniform and complete filling.
5. POURING
BASIN
IT IS THE FUNNEL-
SHAPED OPENING,
MADE AT THE TOP
OF THE MOULD.
THE MAIN
PURPOSE OF THE
POURING BASIN IS
TO DIRECT THE
FLOW OF MOLTEN
METAL FROM
6. IT IS A VERTICAL
PASSAGE
CONNECTS THE
POURING BASIN TO
THE RUNNER OR
INGATE. IT IS
GENERALLY MADE
TAPERED
DOWNWARD TO
AVOID ASPIRATION
OF AIR. THE CROSS
SECTION OF THE
SPRUE MAY BE
SQUARE,
7. IT IS A LONG
HORIZONTAL
CHANNEL WHICH
CARRIES MOLTEN
METAL AND
DISTRIBUTE IT TO
THE INGATES IT
WILL ENSURE
PROPER SUPPLY OF
MOLTEN METAL TO
THE CAVITY SO
THAT PROPER
FILLING OF THE
8. RISER
A RISER, ALSO
KNOWN AS
A FEEDER, IS
A RESERVOIR
BUILT INTO A
METAL CASTING
MOULD TO
PREVENT
CAVITIES DUE
TO SHRINKAGE.
11. • It is most commonly
used gate and is a
compromise between
top and bottom gates.
• The gate is provided at
the parting line of the
mould .
12. • Molten metal from pouring
basin is fed directly into the
mould cavity.
• The hottest metal remains
at the top of casting, this
promotes directional
solidification from the
casting towards the gate
13. • The molten metal enters
from bottom to the
mould cavity.
• It minimizes turbulence
and erosion in the
mould cavity.
• Provides unfavourable
temperature gradients
that do not promote
directional
solidification.
14. 1. It helps the molten metal entry in mould cavity with as
low velocity as possible and free from turbulence, to avoid
erosion of mould surface.
2. It prevent the molten metal from absorbing air or other
gases while flowing through it.
3. It resist to flow slug and other impurities to enter in
cavity.
4. It develops temperature gradient so directional
solidification is achieved.
5. It helps proper filling of metal inside cavity. (6) Proper
design minimise cost and makes process
15. • The chills are us to provide progressive
solidification and to avoid the shrinkage cavities.
• Chills are large heat sinks.
• When the geometry of the moulding cavity
prevents solidification from occurring naturally, a
chill can be strategically placed to help promote it.
• Whenever the thickness of the walls of the casting
is unequal, the chills are placed close to the wall
with larger thickness, so that the heat is quickly
absorbed by the chill from larger mass making the
cooling rate equal to that of thin sections.
• It does not permit the formation of shrinkage
cavity.
16. Gating ratio is defined as ratio of sprue base area to total
runner area to total gate area.
SPRUE AREA : RUNNER AREA : GATE AREA
Sprue area is taken as unity.
Two types of Gating system based on gating ratio:
1. Pressurized gating system
2. Non-Pressurized gating system