a smooth conversion in the extruder. We send
the ground resins through a metal detector and
separator to insure no foreign materials are
present. The resins are fed into a hopper that
smoothly feeds the extruder barrel. This barrel
contains heating elements that convert the pel-
lets into a molten, flowable vinyl that is extruded
through a mono-extrusion die positioned at the
other end.
Using a mono-extrusion process insures that
the resins are bonded at identical temperatures
throughout the cross section, precluding any
possibility of delamination problems. Northstar
chooses to mono-extruded through a die (see
below) to create a high performance monolithic
piece. Unlike "co-extruded" parts which consist
of an inexpensive substrate laminated with a
"paper" thin layer of weatherable capstock
material, mono-extruded pieces do not delami-
nate and function as one unit as demonstrated
by flexural, tensile, and creep testing. Mono-
extrusion has withstood the test of time; the
oldest vinyl seawalls that are in existence are
ones that were mono-extruded. The molten
PVC material exits the die as a formed piece,
which then goes through a series of "sizers" that
bring the product into proper tolerance as it
goes through cooling baths in order to set the
final shape. As the product exits the baths, it is
cut into specific lengths by an automatic circular
saw, palletized, banded and prepared for
shipment.
4.2 The only additives added to this process
would be small amounts of colored virgin resin
in order to obtain a consistent color balance.
4.3 The addition of a small amount of virgin
resin has no effect whatsoever on the physical
or chemical properties of the finished products.
5. Testing of Products:
Bench Testing, Field Testing, Quality
Add anything from the attached QCS sheet
Our final product testing begins with constant
Control Testing, ASTM D4216, ASTM
for the CL9000 or the QC impact test. (Note: I
visual inspection and random caliper
What testing, if any, you perform
D4226, ASTM D256, ASTM D638,
have the QCS and CL9000 hard copies if
measurements to insure that the product is
on the manufactured sheet piles to
ASTM D790, ASTM D1435
anyone needs them. -PKD)
within acceptable physical dimensions
make the products conform to the
according to our specifications. [Rest of the
declared specifications of your
response is attached as Attachment #1]
products. Please mention if those
tests conform to any ASTM or any
other nationally recognized tests.
6. Specifications:
See Appendix
See Appendix
See Appendix
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