Polyester is a fabric that is a polymer-based material made of PET, or polyethylene terephthalate.
What is Polyester?
Some polyesters are plant-based from naturally occurring chemicals, although they are in the minority. Some of these naturally occurring polyesters, and a few synthetic ones such as polybutyrate, are biodegradable, but most are not.
Some polyesters are “thermoplastics,” and these are the type used in polyester fabric.
Polyester fabrics are used extensively in the apparel industry, furniture manufacturing, bedding – sheets, blankets, and coverings – as well as in the graphic advertising universe.
The fiber is also used in ropes, tire reinforcing, conveyor belts, seat belts, and coated fabrics. Other items that can be made with PET are tarps, bottles, LCD displays, holograms, insulating tape, filters, canoes, films for capacitors, films, wire insulation, etc. Polyesters can be used in high quality wood finishing on pianos and guitars and the interiors of cars and trucks. It has the ability to be used as a filler in porous woods such as Oak or Mahogany. It is sandable and polishable and finally, durable.
Polyester fabric is very stain resistant, and only certain specialty dyes are able to permanently color the fabric. These dyes are used in combination with heat and pressure to print designs or commercial graphics on this material. You may have seen this fabric used in front of your favorite fast food restaurant on flab banner poles.
Polyester can be “blended” or spun with natural fibers, such as cotton, to create a fabric that is wrinkle free, rip resistant, and won’t shrink in the washer and dryer like cotton will on it’s own. Polyester, blended with cotton or other natural fibers, will also be resistant to molds and mildews better than just a natural fiber like cotton or linen.
The one negative is that poly-fabrics are susceptible to flame more than other fabrics, although due to the lightweight nature of the fabric, it would be unlikely to add much fuel to an already burning fire.
Polyesters have also been made to mirror natural fibers. An example is “polysilk” fiber, obviously mimicking silk. Polyknits have been used for 50+ years, but now can emulate cotton or wool or taffeta or other natural or synthetic fibers, often with superior durability.
All in all, polyesters are a miracle of science, and life as you know it would go backwards 75 years without it.
Will Polyester Shrink?
Yes and no. If you put a polyester shirt or banner or whatever in the washer on hot, and the dryer on high heat, no. Polyester is susceptible to heat, but greater than what it would typically encounter in either washer or dryer, especially if you have a dryer that automatically shuts off once it senses that most of the moisture has been dispelled. This would mean that the fabric never gets really hot and dry. So, if you don’t overheat it in your dryer, there’s not much to worry about.
So, what will make polyester shrink? If you’ve read any of my articles on dye sublimation printing, you know that a brief exposure to heat and pressure – in order to transfer a CMYO image from a transfer sheet to polyester fabric – not only doesn’t shrink, it creates stunning continuous tone graphics, unlike the dot resolution of a digital printer.
What kind of heat will shrink polyester? Prolonged heat is more likely to cause at least some shrinkage. Could your dryer shrink a flag banner? Sure, but you’d really have to work at it.
What are the Benefits of the Poly-rich Blends
In a sense, we’ve already answered this question in regards to fabrics that are “enriched” with polyester, such as cotton. Risking too much repetition, a 50/50 cotton tee-shirt is really a 50/50 cotton polyester tee-shirt. In the realm of polyester flag banners, cotton is not a necessity and would likely be a liability, as it is very comfortable to wear, but would not be as durable as 100% polyester fabric.
Polyester Flag Banner Printing
What is “Dye Sublimation Printing” and how long is the production time?
First, let me say, thank you for asking me about my personal favorite product and topic!
Second, let me say that this is really two distinct questions, so I’m going to parse it out as if it were two questions, but in paragraph form… actually, multiple paragraph form but with a notice that I’m answering the second part of the question on “how long is production time.”
Dye sublimation printing is a process of creating a graphic, art, or copy, or all three, onto a sheet of polyester fabric. Yes, I realize I just gave you a cliché answer, but be patient, as I am going to explain precisely what that entails.
First, if you’re familiar with ink sets, you likely know that in digital printing – direct to fabric or substrate – that you would use a CMYK color set to produce a 4CP (four color process, or full color) print on anything from static cling decals to corrugated plastic to vinyl or cloth fabric banners (the latter, IMO, is inferior to dye sub printing on polyester banner material).
However, with dye sublimation printing, someone way smarter than me had a revelation, a vision as it were, to print an image on a thermal transfer paper, using not the standard CMYK print colors, but rather to print a CMYO dye set, which stands for CyanMagentaYellowClear. Who even comes up with this stuff?!
Regardless of who, how, or why, the most awesome printing category of all time was conceived of by said genius, using dye, heat, and pressure, I won’t bother going into heat and pressure and why he or she was able to decide to use the heretofore unknown CYMO dye set, printing it onto paper, affixing it to a PET fabric, and sending it through 400F (205C) rollers at 400 lbs. pressure to create beautiful continuous tone prints, but whatever, it worked.. flaggendruck