All plastics gradually degrade in sunlight. The ultra-violet wavelengths are the culprit. This U.V light penetrates the plastic material and excites the chemicals bonds holding the molecular segment of the polymer together, causing them to chemically change and the polymer bonds tend to break over time with exposure to sunlight.
The end result of this process is complete breakdown of the polymer, but the process is gradual. The plastics will craze and crack and get stiff, and in the case of PVC will discolor.
The chemical bonds in the various types of plastics vary in strength and resistant U.V degradation.
HOW LONG WILL OUR POLYBLEND TOPIARIES LAST?
That really depends upon what part of the country you are located, the number of days of sun, where the plant. Under severe U.V. conditions plants in the Deep South and Southwest in sunny and hot climates have remained intact for three to five years. In the Northern climates where the U.V is less intense, our outdoor trees and plants are lasting seven years and more. There are many installations in the North that look fine after ten years of service.
Of the plastics used in foliages, the poorest is the ordinary imported polyethylene. Next better is the cast vinyl, next is the vinyl used in the bottle-brush shrubbery, and the next is our Polyblend.
Polyblend is a polyethylene blend, but it is a high quality industrial grade material to which have been added several other ingredients to prevent U.V from having effect on resin.
Our Polyblend shrubbery exhibits outstanding resistant to chemical degradation by the sunlight. In a very rugged test we ran on this material in the laboratory, average polyethylene breaks down in from 200 to 500 hours exposure. Our Polyblend material has gone 4,162 hours without noticeable change.
All plastics regardless of pigmentation will experience some color change either in the pigments or the resin, on aging. The change in our topiaries or plants will be very slow and not extreme enough to in any way impair the aesthetic value of the installation.
CONSTRUCTION FOR POLYBLEND OUTDOOR ARTIFICIAL TOPIARY
A characteristic of artificial shrubbery which has a great deal to do with its holding up under weathering is its physical construction. The shrubbery must withstand snow and ice loads, and high winds, without damage.
The ordinary indoor polyethylene’s are nearly all assembled in small segments stacked on relatively weak center rods or tubes. They are not designed to be put out in the weather, and are subject to serious damage.
Silk type plants are just too fragile for exposure to the elements.
Our outdoor topiary are made a new technology which allows almost all the plants to be made with stalk, branches, and twigs molded into one integral unit, with heavy reinforcing wire in all branches running into a buddle of wires in the stem.
The result is very strong, flexible plant which will hold it natural shape in most weather conditions. (See photograph 12)
The leaves on our plants are snapped onto detents on each twig, which will hold the leaves securely in place. No known winds, ice loads, or hail have knocked off our leaves.