First, it is important to know that PVC coated Screen manufacturers use one of the following two as the base in their extrusion of the PVC coated YARN:
- A multi strand, non twisted, Fiberglass yarn
- A multi filament, twisted Polyester yarn
Only Vertilux, uses as its core yarn a specially treated Polyester yarn called High Tenacity (HT) Polyester yarn.
The Polyester filaments are coated and twisted into a yarn that is highly resistant, fire retardant, antimicrobial, and very flexible at all temperatures, making it clearly superior to the Fiberglass counterparts.
POLYESTER SCREEN WILL ALLOW AN ACCURATE WEAVING PROCESS...
Screen weavers that use a polyester yarn or HT Polyester yarn can be guaranteed that the extruded PVC coated yarn will be cylindrical, which results in an accurate weaving process. Fiberglass extruded PVC coated yarn does not have a rounded shape, which creates uneven spaces in the woven material. This unevenness can be readily seen in any Fiberglas screen, demonstrated by intermittent blotches that can be seen in the fabric when placed in the window. It is a key element to have a coated yarn that has a standard cylindrical diameter in order to have a woven product that has a very small percentage of deviations in the “drawing” of the shade fabric. The HT Polyester yarn offers optimum properties for the yarn to adequately anchor itself to the PVC coating during the extrusion process and those same properties will contribute to a better and more accurate behavior in the looms.
POLYESTER SCREEN IS MORE STABLE AND FLEXIBLE
Another aspect that plays a major role in the "hanging" of the shade fabric is the lineal dilation or expansion, between the core yarn and the pvc coating. Polyester and HT Polyester coated yarns "coexist" with much greater harmony starting at the extrusion level and continuing throughout the life of the shade cloth. This coexistence allows for a polyester screen fabric to remain stable in climates that have high temperatures variations. The Fiberglass based screen will not allow the PVC coating to sufficiently expand or dilate with changes of temperature. This is a result of the Fiberglass's rigidity and resistance to either expand or dilate even to the smallest degree, while the PVC coating is "asking" for a linear movement depending on the temperature…
POLYESTER YARN WILL NOT BREAK
The aforementioned rigidity is a known trait in fiberglass strands, and also associated to that fact is the common occurrence for a fiberglass strand to break when the yarn is being straightened to its original position after having been bent. This breakage with fiberglass yarns will occur systematically once the fabric is folded or slightly creased during the fabrication or installation process, resulting in the loss of internal structure, which will allow the PVC coating to dilate or expand to its maximum capability and thus creating “changing waves” in the hanging fabric with temperatures variances.
POLYESTER SCREEN DOES NOT REQUIRE SPECIAL CUTTING TOOLS
Using a screen with Polyester or HT polyester yarn will not necessitate any special cutting tools, such as a hot knife or an ultrasonic device commonly required in the cutting of fiber glass based screens. This has a direct bearing on production and machinery costs. Any Polyester Screen can be accurately cut with a razor blade.
POLYESTER SCREEN IS ODORLESS
Additionally, there is the fabric odor… Because of certain additives used in the PVC coating with fiberglass yarn, transpiration occurs and it will emit a strong PVC like odor which remains with the fabric for as much as a year. On the other hand, the HT polyester yarn is totally enrobed by the PVC coating, that does not need any additional additives used for adhesion to the core yarn and this result is that Polyester-based screens do not “gas-out” any odors...
POLYESTER SCREEN MANIPULATION DOES NOT REQUIRE PROTECTIVE GARMENTS
From a fabrication perspective, using a Polyester based screen will not require protective hand gear during the manipulation of the fabric. Whereas fiberglass screens will create a health hazard environment when cutting the fabric which exposes and liberates small particles of fiberglass in the air. It also requires workers to wear protective garments while handling this type of screen fabric.
POLYESTER SCREEN CAN BE RECYCLED
Lastly, from an ecological point of view, polyester or HD Polyester screen remnants can be recycled or discarded as regular trash due to its non-harmful substances. This is not the case with fiberglass based screen, which cannot be recycled due to the inlay of fiberglass and it is also supposed to be, following most municipal or state laws, to be discarded in bins that will require special handling due to the contents of fiberglass.