Plastics

Plastics are a very useful group of materials which come in a dizzying variety of chemistries, properties, colors and thickness. Great advances in polymer science and processing technologies has given us many choices of high quality plastics. CRC can die cut, slit and laminate most plastics.

The most difficult aspect of choosing a plastic material is sorting out the properties to find the right one and then figure out what is available. Here we will provide a little bit of information that may help you sort through the most common materials. This list is by no means complete, but aims to be helpful.

Polyethylene is produced in the great quantities. It comes in two basic flavors: high density HDPE and low density LDPE. These account for most plastic bags, milk bottles, and tubing. In the converting industry we see it often as a blow molded continuous tube. This is one of the lowest cost materials used extensively in packaging, as release liner and as a protective layer.

PVC Poly vinyl chloride is the second most common plastic used. Most of it goes into plastic piping, floor tiles and building siding, but a lot of PVC film is used in industry. It is a relatively inexpensive material that can be cut bent and heat sealed against itself relatively easily. It comes in a variety of colors from clear to deep black and thickness from 1 mil (.025 mm) to several inches thick, though it is hard to die cut material thicker than .040. PVC does have its limitations. In its pure state, PVC is a hard brittle material. Plasticizers are added to make it pliable and soft. These plasticizers can interfere with adhesives that you might want to use on it and the plasticizers tend to leach out with time and temperature leading to enbrittlement (note the cracked dash boards of older cars). PVC, especially in its optically clear form, is used extensively in packaging.

PETG is an other low cost material that is becoming more popular due to its low cost and ease of forming. It has better resistance to outdoor elements than does PVC and is also clear. It is often used in making signs, packaging, tabs of various sorts, and bottles. Its limitation is its softness and, because it is less common, there are fewer choices of colors and thickness. Of course you can get almost anything you want if you are willing to buy 5,000 pounds and wait 8 weeks.

PET, also know as Mylar® (Mylar is a registered trademark of E.I. Dupont Co and only Dupont Teijin Films makes Mylar® polyester film). While Dupont makes Mylar and Melinex (a Mylar filled with titanium dioxide, a whitening pigment), there are many other makers of this remarkable film. It is about twice as expensive as the materials mentioned above but its hardness, tear resistance, smoothness of surface, and accuracy in thickness make it useful in a variety of products. Because it is used so much in the converting industry, it is relatively easy to get. The industry has created gauge (thickness) standards. Click here to see a table which gives the standard gauges and the yield (how many square inches per pound at a given thickness)

There are many other materials such as Nylon, Teflon, Polypropylene, Styrene, ABS and Lexan, but they are used in much smaller quantities in the converting industry.