Polyester is a category of polymers that contain the ester functional group in their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in the cut in of plant cuticles, as well as synthetics through step-growth polymerization such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. The material is used extensively in clothing. Polyesters are also used to make bottles, films, tarpaulin, canoes, liquid crystal displays, holograms, filters, dielectric film for capacitors, film insulation for wire and insulating tapes. Polyesters are widely used as a finish on high-quality wood products such as guitars, pianos and vehicle/yacht interiors. Thixotropic properties of spray-applicable polyesters make them ideal for use on open-grain timbers, as they can quickly fill wood grain, with a high-build film thickness per coat. Cured polyesters can be sanded and polished to a high-gloss, durable finish. Masking tape, also known as painter’s tape, is a type of pressure-sensitive tape made of a thin and easy-to-tear paper, and an easily released pressure-sensitive adhesive. It is available in a variety of widths. It is used mainly in painting, to mask off areas that should not be painted. The adhesive is the key element to its usefulness, as it allows the tape to be easily removed without leaving residue or damaging the surface to which it is applied. The tape is available in several strengths, rated on a 1–100 scale based on the strength of the adhesive. Most painting operations will require a tape in the 50 range. Household masking tape is made of an even weaker paper and lower-grade adhesive. An easily removed adhesive tape used temporarily for definingmargins, protecting surfaces, etc., as when painting, and sometimesalso for binding, sealing, or mending. Masking tape is a variety of adhesive tape that is recommended for the temporary concealment of surfaces not intended for a finishing process. Masking tapes temporarily protect areas from painting, soldering, blasting, spraying, coating, plating, and polishing while these procedures are administered to nearby surfaces. The composition of masking tape depends on the activity for which it is designed.
