| Mold Life
Enhancement
Disclaimer: The
following information is being supplied for the purpose of improving
your operation by reducing mold wear, improving cycle times and
improving the quality of the product. It is understood that at times, it
is necessary to use mold and/or machine components that are not in ideal
condition. Therefore the specifications which are identified below,
refer to the use of new components. Deviations from these specifications
may result in increased mold wear if it becomes necessary to utilize
worn components.
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Adhering to the
following techniques can greatly improve mold life, reduce cycle times
and improve product quality.
Mold
Adjustments
- During mold
assembly, assure that all mating surfaces are clean and in good
condition
.
Improper cleaning and buildup of concrete, dirt and grease can result
in molds that are not square and fasteners that may loosen during
operation. Inspect mold components for wear or damage to maintain
proper fit between components such as; division plates, mold side
bars, end liners, stripper shoes and plungers.
Mold should be
square within 1/16" (1.5 mm) when measured corner to corner –
across outside division plates.
Molds that
are not within this specification are typically the result of damaged,
worn or dirty components (see item #1).
Assure that the
Posapac bolts and nuts are positioned properly.
Vibrator
shafts on both sides of the mold should have the nuts facing the outside
of the mold while the weight is hanging in the down position as viewed
from the front of the mold. This will assist in even vibration and help
synchronize the vibrator shafts. It will also enhance motor life,
improve mold life, and assure even feeding of material to each mold
cavity.
Center Posapac
weights to the mold cavity.
Use proper length
bolts.
Care should
be taken to select the proper length bolts to prevent "bottoming
out" of the fastener when installing mold components such as end
liners. Bottomed out bolts could give the impression that a component is
secure in the mold when it is not, or could cause damage such as cracked
liner keys
Check to make
certain that the core assemblies are properly aligned.
It is
important that the cores are suspended vertically in the mold. This can
be checked by measuring the distance from the bottom of the core to the
mold opening. This measurement should be within +/- 1/32"(.8mm) for
molds that produce CMU’s with face shells of the same thickness.
Alternatively, the core assemblies can be checked by placing a square on
the top plate and checking the core bars.
Always keep vibrator
assemblies in pairs.
Do not mix
and match sheaves. When replacing sheaves or belts on one side of the
mold, always replace the sheave and or belts on the other vibrator
shaft. Miss matched sheaves result in uneven vibration, mold shifting,
reduced mold feeding and reduced mold life. It is important to note that
belts should be purchased in matched sets and should not be mixed.
Follow proper torque
specifications for all fasteners. Refer
to Technical
Service Bulletin 96-4.
Pallet guides must
not touch the mold compartment.
This will dampen the mold vibration. Recommended clearance is 1/8"
(3 mm).
Mold cavities must
be parallel from top to bottom.
The
recommended tolerance is .015" (.3 mm) as measured from top to
bottom. It is essential to proper stripping of the unit that the mold
not be smaller at the bottom than it is at the top.
Always use the
shortest feed and finish times possible to produce your product.
This will
help to increase production rates and greatly reduce mold wear. Use the
auto-feed religiously.
Keep agitator grids
free from excessive material buildup.
Clean agitator grids every 8 hours or more frequently if you are using a
wet or sticky material. This will improve mold feeding.
Add 1-2 fluid ounces (in
volume not weight) of grease to vibrator bearings every 8 hours of
production
(pertains to both standard vibration and SmartPac vibration).
Make sure stripper
head plate is installed correctly.
Current
models have a V-notch in the front, right side to help reduce the
possibility of putting the stripper head plate in backwards.
Do not weld or bolt
additional material to the mold top plate fence.
Modifying
the fence will increase stresses applied to the mold top plate itself as
well as to the welds holding the fence on. These additional stresses can
cause premature failure of the mold top plate.
The use of stripper
shoe gages can greatly improve mold life.
They ensure
that the proper clearances within the mold are held.
Mix design has
tremendous effects on abrasiveness.
The
"sharper" harder aggregates are significantly more abrasive
than the "rounder", softer ones. Admixtures can improve mold
life by reducing feed times.
Machine Adjustments
- Assure that the
block machine is level within 1/32" (.812 mm) maximum. Refer to
the To Install A Vibrapac
section of the V3-12K
Installation Manual.
- Install the Mold.
Refer to section 5.4 - Installing
the Mold of the V3-12K
Operation and Maintenance Manual. Make certain that all
4 sheaves are in alignment.
- Adjust the mold.
Assure that the mold is level, centered and located 5/8" (15.875
mm) above
the mold throat. Refer to section 5.5
- Adjusting the Mold of the V3-12K
Operation and Maintenance Manual.
- Level the apron
plate/feedbox to the mold. Refer to section 5.6
- Apron Plate Adjustment of the V3-12K
Operation and Maintenance Manual.
- Level and align the
stripper head to the mold. Refer to section 5.8
- Adjusting Stripper Head of the V3-12K
Operation and Maintenance Manual.
- Check for proper
synchronization of vibration. Refer to Technical Service Tip: The
Importance of Synchronizing Vibration.
- Air compaction
improves mold life by smoothing out the stripper head and reducing
finish times.
Additional Information on Molds
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