Z
Corporation
Z810
System
User
Manual
www.zcorp-users.com
72
Preparation
1. Starch-based powder parts should be used. Oven-drying the part at 104
o
F (40
o
C) after
removal has been included in the process at some locations, especially where humidity may
be an issue with ‘green’ part characteristics. Additional gate(s) may be incorporated in the
set-up of the mold to increase air flow during burn-out of the casting pattern.
2. Patterns should be infiltrated with either wax or resin. Wax infiltration is an excellent
treatment for investment casting patterns. Wax infiltrated parts will behave similarly to
common wax patterns when they expand. The ZW4 or ZW3 Waxer and hand application
methods have both been successfully used on Z Corp. parts. Some users briefly blast their
parts with a consumer hairdryer or heat gun to quickly heat and re-cool the wax to improve
surface finish.
Patterns can also be infiltrated with resin for increased strength. Surfaces should be sanded
to their desired finish after this step. Then coat with wax.
Casting
1. Z Corp. patterns can be assembled on standard wax gates and runner systems. They
should be coated with the normal 6-8 shell layers of slurry.
2. When using wax patterns assembled on wax runners, the tree assembly should go though an
autoclave process for 10 minutes before being put in the firing oven. The autoclave should
be 380
o
F (193
o
C) and 130 psi (9 bars). The pattern should then be put in the burnout oven.
Note: this process has been omitted by some users to their satisfaction.
Patterns infiltrated with resin should skip the autoclave process and go directly to the burnout
oven.
3. Z Corporation patterns should be burned out at 1750-1800
o
F (954-982
o
C) in an oxygen rich
environment. Burnout time will depend on the part volume and air circulation. If the part is
an inch thick or less, it should burn out completely in two hours. For larger parts, a longer
burnout time should be expected. The patterns will burn out completely if they are left in the
oven for a sufficient amount of time.
Low-temperature furnaces with air treatment devices using ionized air have also been utilized
successfully to burn out Z Corporation patterns. Refer to the furnace manufacturer for
guidelines for this process.
4. After burn-out, allow the shell to return to room temperature. In some cases, a small amount
of residual ash may remain (less than 1%). This can typically be washed or blown out of the
mold. Wash the shell out with water. Allow the shell to dry and thoroughly pre-heat shell
before pouring metal to entirely eliminate any water vapor that may remain.
Results
•
2% shrinkage should be expected when going from the Z Corp. pattern to a cast part. The
surface finish will depend on the surface of the original pattern, but can be expected to be
around 3-5 mils.
