What you should know about vinyl!
Like many competitive businesses, vinyl fencing manufacturers and contractors
try hard to find ways to differentiate themselves. Building cases to establish a
perceived superiority of a particular type of vinyl material is one way this
competitive pressure is expressed. In the interest of capturing a customer,
exaggerations, misimpressions, misinformation and even misrepresentation can and
does occur.
Vinyl fencing is made primarily of Poly-Vinyl Chloride (PVC) with critical additives
for flexibility, crack resistance, and color stability. Continuous exposure to
sunlight (actually the Ultra-violet or UV component of sunlight) can cause "virgin" PVC to
become brittle and to change color. A protective additive to PVC to resist the effects
of exposure to UV is Titanium DiOxide (TiO2), which is a significantly expensive ingredient
in the manufacturing of vinyl fencing product.
MONO-Extrusion Process
The first vinyl fencing products were produced through a process called "Mono-extrusion"
whereby a uniform mixture of PVC and beneficial additives including TiO2 is
"extruded" into the desired shapes. While this produces a quality product, the problem is
that it requires a lot more TiO2 than is actually useful since it is uniformly
distributed throughout the product, not just at at the surface where the UV light affects
the material.
CO-Extrusion Process
A Second generation manufacturing method called "Co-extrusion" allows the production of
vinyl fencing material that concentrates TiO2 only on and near the surface, and
not in the interior of the material. While the equipment to produce "Co-extrusion" product
is more expensive than the simpler "Mono-extrusion" machinery, the savings in unnecessary
TiO2 offsets the equipment investment, resulting in a functionally equal product
at a potentially lower cost to the customer.
Notes
Contrary to some claims, "Co-extrusion" is NOT a lamination process where two distinct
layers are bonded together ... consequently there is NO danger of "delamination" of the
co-extrusion regions.
The surface region containing the protective TiO2 in "Co-extrusion" material
is much deeper than typical scratching can penetrate, but severe damage could
potentially reach the inner material. It is arguable though that any damage
this severe to either "Co-" or "Mono-" extruded material would be both aesthetically visible
and structurally compromising by itself ... any additional UV damage over subsequent
years would be pretty much irrelevant.
Trust who you are dealing with
Even knowing what constitutes quality material and what is required for a quality
installation, it is not always obvious looking at a fence what it's actually made from and
how it was installed. It is critical to be confident in the knowledge and integrity of the
contractor that you choose to provide, install, and warranty your vinyl fencing.
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