Know
About Your Finishing Mold
When
it comes to lubricity and mold release characteristics of finish is taken into
account, as well as the opportunity to use the coating. Some finishes mold can
increase the need for coating the mold.
There
are four standard SPI finishes: diamond, stone, paper and Blast. Each casting
surface gives a different look, from a shiny mirror-like surface (A-1 diamond)
in a fairly rough, grainy texture (sand blasting with glass beads or aluminum
oxide) . All four finished three grades as well.
The
A-1 Diamond finish is the most perfect finish available, which means it has the
lowest average roughness or the value of PR. There are no high or low peaks.
For example, a scrap paper to steel gives an RA 2-4, while a diamond A-1 is the
objective of fine quality, usually a PR or less. Roughness is almost
incalculable.
But
such a perfect finesse can be harmful in many molding applications because a
number of plastics tend to stick like glue to the flawless mirror finish.
Molded polystyrene on a polished wall on the right baseline with 1 or less
resistance is one example. Streak lines or drawing can be displayed on the
individual parts. This can be solved by the kernel flash plating, creating a
surface with micro-cracks. Sealing cracks with PTFE and then re A-1 diamond
finish solves the problem in more than 95% of cases.
Molding
thin-walled container adds another dimension to the use of a diamond finish.
Erosion of sour cream, cheese and yogurt container cottage find their products
more attractive to the customer if they have a slight sheen. For this purpose,
these parts require a high-gloss polished diamond with a little out of control
so that the show will be brilliant. This adjustment also allows much more
complete liberation of parts.
In
applications molding thin-wall like this, a glossy ball explosion applied-just
enough to very few interruptions perfect A-2 surface of diamond. The surface is
polished again, so only a few bumps almost invisible. This finish with a
coating of nickel-PTFE Nicklon will greatly improve free up some and improve
mold filling.
Phenolic
compounds and other thermoset almost need a perfect polish and work
exceptionally well with a diamond finish. Combine that with a hard coating,
protection such as chromium or chromium-diamond, and you will strengthen the
mold surface and to optimize the release. Again, using a PTFE current minimal
beneficial because it will not last long. Usually it's just not worth it, in
our opinion. The successful use of straight PTFE depends on the presence of a
grain in the mold quite ready to continue to be covered. Since the
thermo-setting molding requires a perfect finish of the tool, the PTFE itself
has limited adhesion to the surface, and thus will fail relatively quickly.
Contact
Us:
Impreglon
Coatings
Phone:
780-465-5050
No comments:
Post a Comment