There are many types of feed systems. Each system has certain advantages as well
as disadvantages. Choosing what type and style of feed system can be a
difficult decision. The information presented below is designed to help the die
designer to plan and develop the best feed system for their particular
die-casting situation.
The function of the feed system is to spread the metal flow from the runner to
the whole gate as well as to ensure all of the gate works. The design of the
feed decides the flow angles and therefore the fill pattern.
The designer must decide the filling pattern he is aiming for and this must be
reconciled with the casting shape. In all cases, the gate area controls cavity
filling conditions and this must be given priority. PQ2
calculations should be done prior to die design to ensure that the proper gate
area is chosen.
Basically, there are two types of feeds: Tangent feeds and Fan feeds. Tangent
feeds give a wide flow angle with flow biased toward the ends. These feeds are
best applied to long, thin gates. Fan feeds, on the other hand, produce a
narrow flow angle with a strong central bias, which suits narrower, thicker
gates.
Choose the feed system to suit the gate length available, and the fill pattern
desired. Both may be used in combination to achieve the fill pattern required.
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Feed Types
| Fan Feed |
Fan
feeds favor short thick gates and develop a strong, centrally biased
fill pattern. Fan feeds are simple in shape making them easy to machine. |
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|
| Single-Tangent Feed |
The
single tangent feed runs along the edge of the component, and is more
suitable for long thin gates. Metal enters the cavity at approximately 40
degrees to normal, which establishes the fill pattern, which must be matched
to the shape of the part and the area that are critical to fill. Maximum
flow occurs at the ends of the tangent feed, which can be useful under
certain situations. |
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| Double-Tangent Feed |
The
double tangent feed is a variant of the single tangent feed consisting
of two single tangent feeds back to back. It is useful for feeding
symmetrical or near symmetrical parts via a long thin gate. Maximum flow
occurs at the end of the tangent feeds, with restricted flow in the center
of the gate. |
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here to request the program. |
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