HOW IS VINYL MADE?

Calendered Intermediate

This vinyl film is generally made in a 3 mil thickness. "Mil" means "one-thousandth" an inch. Thus 3 mils are three thousandths of an inch. Usually, the thickness refers to the film itself and not the adhesive that is applied. The adhesive can add another 1 to 2 mils to the thickness. First the raw materials (including resins, plasticizers, stabilizers, color pigments, etc) are combined and heated, producing "melt". Then the melt is fed into a two-story high calendering machine that consists of a series of rollers. One group of rollers produces the rough gauge. The next group of rollers determines gloss levels and final thickness. It is important to note that calendered vinyl is manufactured in a continual web process. It's made by putting continuous stress, pressure, and heat on the vinyl; it is literally pulled through the machine. The process resembles the way Salt Water Taffy is made; remember the huge arms that around and stretch and pull the taffy until it cools down?Because the film is stretched and pressured into its final form, it has little dimensional stability. This means that if extremes of heat and cold affect it, it will tend to shrink back to its original size. This caused adhesive ooze around the letters, as well as cracking and peeling. Calendered vinyl must be produced in large quantities due to the sheer size of the machinery involved. These large batches limit the number of colors that are available. It is this fast and economical process that establishes the lower cost of calendered vinyl for the signmaker.

Cast High Performance

This film is made in 2 mil thickness, then the adhesive is added. This thinner film is easier to mold over irregular surfaces and is easier to weed, especially those tiny letters and delicate graphics. There are two main reasons why 2 mil high performance vinyl is much superior to calendered vinyl. The raw materials are of better quality in cast films and the manufacturing process is totally different. There is virtually no stress, no stretching, and no pressure applied to cast films. The high quality cast vinyl raw materials are mixed and then poured out, or cast on the casting roller. The mixture is then transferred through rollers to the casting paper. Since the cast liquid vinyl is supported by the casting paper once the liquid leaves the rollers, very little stress is applied. Heat and pressure are not applied like in the calendering process. This means that the higher quality cast films are suitable for outdoor use and long exposure to extremes of heat and cold. Since the film is not forced into a size that it wasn't originally made for, shrinkage, splitting, and cracking is significantly less than in the calendered vinyl films. Because casting machines are small in comparison to the mammoth calendering equipment, runs are short and a wider variety of colors are available in cast vinyl.

HOW TO CHOOSE THE RIGHT VINYL FOR THE JOB

The first step in choosing the right vinyl is to determine whether or not the signage you are designing will be for indoor or outdoor use. If the sign will be indoors, the less expensive calendered vinyl may do the job. If the sign is to be outdoors or on the inside of an exterior door or window, a premium grade cast vinyl is the better choice. Why?

That’s because the cast vinyl will resist bubbling, fading, and peeling due to long term exposure to the sun's ultraviolet rays. These rays cause eventual deterioration of both the vinyl and the adhesive. For most applications, 2 mil cast vinyl is the best choice. It conforms well to uneven surfaces, is more flexible, and has a longer life expectancy when exposed to harsh weather conditions. The quality of 2 mil vinyl's adhesive usually matches the the quality of the vinyl. Put simply, this means that premium 2 mil high performance cast film will stick better, longer, and faster than the adhesive on calendered vinyl. Lower quality adhesives as in calendered vinyl are more easily affected by moisture, solvents, and sunlight. This may cause the vinyl sign or graphic to turn yellow or curl