https://www.avient.com/sites/default/files/2023-11/Cesa Clean Processing Usage Guide.pdf
GUIDELINES FOR USING CESA CLEAN ADDITIVES
• Cesa Clean works best when molded maintaining normal (injection)
pressure/shear
• For best results, Avient recommends a “Running Color Change”
which eliminates breaks in the molding cycle
• Since the Cesa Clean concentrate will expand, it is recommended
to reduce the shot size by 20%
• It is designed for use at a let-down ratio (LDR) of 3.0% or (33:1); however,
use rate can vary depending on the severity of the contamination but
typically is 2.0–4.0% (a use rate higher than 6.0% may not have any
positive affect on the cleaning performance)
• Using Cesa Clean as a routine part of your color change rotation will
allow faster changes and consume a minimal amount of raw material
- Note: If the manifold is not cleaned routinely, this process may be
more time consuming and additional material will be required
• It is best to process at your normal polymer processing temperatures
- For best performance, stock temperature should be at least 400°F
- If 400°F is achieved during the purging process, no additional
activation will occur during the reprocessing of regrind
- All parts produced during the “Running Purge Cycle” should be
captured as regrind, resulting in a scrap-free color change
- If using sequential gates, open and close all gates at the same time
while purging the tool
- If contamination appears to be coming from one gate, open and
close first, and for an extended period of time, to force more material
through this location
- When cleaning in this manner, pay close attention to shot size
- Parts containing the previous or new color plus any Cesa Clean
can be used as regrind
INTRODUCING CESA CLEAN TO YOUR PROCESS
Hand Blend
• Hand weigh enough of the Cesa Clean and
natural resin mix to equate to 3–5 times the
barrel capacity
• Use rate should be 3.0% or 33:1 for routine
cleaning
• For difficult-to-clean tooling, or tooling which
is not routinely cleaned, start at 4.0% or 25:1
• Note: Do not attempt to vacuum load more than
15 feet from source as stratification/separation
may occur
Volumetric Feeder
• Calibrate feeder to dispense 3.0% or 33:1 for
routine cleaning
• For difficult-to-clean tooling, or tooling which
is not routinely cleaned, start at 4.0% or 25:1
• This style of feeder is highly recommended for
at-the-throat metering of Cesa Clean
Blending Units
Most blenders have an extra bin for an additive
• Fill the additive bin with Cesa Clean
• Set blender to introduce the Cesa Clean at
2.0 to 4.0%
• Note: Do not air convey any further than 15 feet
as Cesa Clean has a high density and may separate
from the mix.
GETTING STARTED
TIMING IS THE KEY TO A RUNNING
COLOR CHANGE
Hand Blend
• Have the purge blend ready to load
• If hopper contains a mixture of resin, color and/
or regrind, it should be run dry or drained before
beginning the color change, keeping the screw
full so press cycle continues
• Run the main resin hopper dry or shut off hopper
to hand feed at the throat
• Once press is clean, slide hopper in place
and proceed with next color-resin blend
• The next color can be added while Cesa Clean is
still in the barrel
• When splay is no longer visible in parts, reset shot
size, parts should be ready to pack
(Single) Volumetric/Gravimetric Metering Unit
at the Throat
• Empty and clean feeder while press continues
to run
• Add Cesa Clean to the feeder color hopper and
calibrate to a 3.0% use rate
• When press is clean, start next color
• When splay is no longer visible in parts, reset shot
• Note: If an open/unused secondary feeder is
installed, use it for the Cesa Clean concentrate
Central Blending Unit
• Thoroughly clean unit while continuing to mold
parts, keeping a resin feed to the press
• Using a clean open hopper or regrind hopper, add
the Cesa Clean concentrate
• Set blender for additive/color to 3.0%
• Once press is clean, drain hopper and/or central
blending unit while continuing to mold parts
• Begin new color and continue to mold parts
• When splay is no longer visible in parts, reset shot
Process Adjustments That Can Help
• Increase back pressure
• Increase screw speed
• Increase injection speed (in some tools maximum
injection speed can facilitate cleaning)
• Reduce mold close time (faster cycle)
• Always remember a stock temperature of 400°F
is essential
When press and tool are clean, return all settings to
standard production process profile.