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Matchplate Conversion System
Foundry Products:
Matchplate Conversion System
Benefits
- Low green sand to no-bake tooling
conversion cost
- Highly efficient molding operation
- Virtually no lifting by the machine
operator
- Less operator training
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General
Through the years, more and more foundries have
converted from greensand matchplate molding to no-bake. Often, the
conversion of tooling has been of exorbitant cost or the cost of
inefficiency due to lack of conversion has resulted in the same, high
long-term cost.
For these reasons, Palmer has developed a line
of basic matchplate conversion systems designed with simplicity, low tooling
cost, and high efficiency in mind. The concept is to convert a green sand
tool to the no-bake process with minimal rigging costs while maintaining
high productivity.
Systems range from a simple single molding
station to a multi-station carousel operation. Based around the inherent
efficiency of no-bake molding, the systems are easily expandable to
virtually any conversion application.
One of the greatest problems in converting to
no-bake is the handling of molds. Flaskless molding is the method of choice.
Conversion of a pattern to flaskless molding involves simply building a
durable wooden or metal frame on each side of the pattern to replace either
tight or snap flasks and attaching either a fixed or removable trunion to
each end of the plate.
This low cost conversion eliminates the need to
schedule around flask and mold jackets. The frame created should be
sufficiently well built to stand up to rapping from mallets and should
contain sufficient draft to allow the mold to draw easily after cure.
As far as the equipment goes, Palmer has done
everything possible to minimize components and controls and keep the systems
as simple as possible.
Matchplate Conversion System – Single Station
Similar to "Roto-Lift" methods, the MCS-1
features dual lifting arms that are used to lift a matchplate set for
stripping and rolling. This system most closely resembles a typical single
pattern jolt squeeze type green sand molding station and would be the
easiest for a squeezer molder to learn.
- Place the matchplate set with frames
into the device. The lifting arms mount semi-rigidly to trunions located
on the original matchplate.
- With the drag facing up, mold and
compact the drag as necessary. Note: Sand is produced by an
appropriately sized continuous mixer.
- Allow the drag to cure.
- Once cured, activate the lifting arms
and roll the mold so that the drag is in the stripping position..
- Lower the matchplate set down to the
conveyor.
- Actuate the stripping cylinders to
slightly raise the mold box off of the conveyor.
- Rap the drag and draw. Once the drag
releases from the box, lift the arms and push the mold off to the
closing station.
- Lower the mold box.
- Fill the cope, compact, and strike off.
Repeat the above procedure for the cope.
- Repeat.
Please note that this design, while simple, is
not the most efficient as the operator must wait for the sand to cure. For
this reason, we recommend the following.
Matchplate Conversion System – Dual Station
The dual station MCS retains the simplicity of
the single station yet is capable of producing double the mold quantity in
the same allotted time. The concept is to have a swiveling mixer between two
molding stations. Each molding station has its own discharge conveyor. The
molding process is:
- Fill drag #1.
- Swing mixer to #2.
- Fill drag #2 while #1 is curing.
- Roll and strip drag #1.
- Swing mixer to #1.
- Fill cope #1.
- Roll and strip drag #2.
- Fill cope #2
- Roll and strip cope #1.
- The process continues as above.
This method is ideal for motivated molders that
have a good sense of timing based on traditional greensand operations.
It is important to note in this design that the
mixer should be sufficiently sized such that the speed of the mixer’s fill
time does not affect the overall process time. System speed should be
dictated by resin system cure time.
Matchplate Conversion System – Four (Or More)
Station Carousel
The MCS-4 is a slightly more advanced molding
system designed to run four or more matchplate sets at a time. It is based
on the carousel molding principle where the machine does the material
handling and the operators are stationary.
There are two primary operators for this system,
one for molding and one for stripping. The basic order of operations is:
- Molder fills first drag and indexes the
carousel 90 degrees.
- Molder fills second drag and indexes.
- Molder fills third drag and indexes. At
the same time, the secondary individual strips the first drag. To strip
the mold, the operator inverts the matchplate set on the plate trunions
and locks it into position. A hydraulically actuated scissor lift table
is raised to just below the mold box. The pattern is rapped and the mold
falls out onto the scissor lift table. The table is lowered and the drag
is pushed onto the holding conveyor located on the carousel. The mold is
left in the inverted position (cope up) for filling.
- Molder fill fourth drag. Helper strips
second drag.
- Molder fill first cope. Helper strips
third drag.
- This process continues as required.
- When the first cope and drag set are
stripped, they are pulled out together and sent to the mold prep and
closing area, this frees the hold zone for the next drag of this
pattern.
It is important to note in this design that the
mixer should be sufficiently sized such that the speed of the mixer’s fill
time does not affect the overall process time. System speed should be
dictated by resin system cure time.
There are several process items that need to be
addressed by the particular foundry in question when considering this type
of system. The basis of the system is constant strip time. Jobs that run
together on the carousel should have the same strip times to allow for the
smoothest operation. In some instances, mold pins will be required when the
molds are inverted to prevent the molds from falling out. Generally, a
simple pin / holes method works. Two pins are sufficient to retain the mold.
There are many options that can be installed on
system of this sort and they are highly installation dependant. For
assistance in specifying the MCS-4, please feel free to contact out offices.