Plastic parts must have the proper UV stabilizers added when molded to ensure a long life of resistance to degradation in sunlight. Some compounds of plastics inherently have better resistance to UV than others. Properties of different plastic compounds will determine performance based on whether the part must flex, bear diflerent kinds of loads, and how the part will behave in diflerent temperature and weather conditions.
Most plastic parts are injection molded, while a few are extruded or dip molded.