Printable Guide Can Liners 101
Commercial can liner sizes are expressed in two numbers e.g. 38” x 58” . The first number is the size of the opening of the liner and the second number is the height of the liner. To find the correct size liner, first measure the can's circumference then measure its height.
Each container should have a gallon capacity, or size printed on it. Just match the picture to your receptacle and it will tell you which size trash bag you need.
Bag Width: To calculate the proper width of the trash can liner for your container, simply divide the circumference of your container by 2.
Square Container Circumference: Circumference = sum of all four sides added together.
Round Container Circumference: Circumference = diameter multiplied by 3.14.
Bag length: (round & square containers) add the height of the container, plus 4-5 inches for overhang.
|General Industral Trength Rating||Linear Low Density Mil Thickness Range||Old Low Density Strength Rating|
|Regular (R)||.35 to .50||1.25|
|Medium (M)||.45 to .75||1.5|
|Heavy (H)||.60 to 1.0||2.0|
|Heavy Plus (H+)||.74 to 1.3||2.5|
|Extra Heavy||.90 to 1.5||3.0|
|Extra Extra Heavy||1.3 to 2.0||4.0|
Film thickness is no longer a satisfactory standard for judging overall strength. The development of improved LLDPE resin in the liner industry has completely changed the standard method for selecting the correct can liners. These materials have allowed manufacturers to produce thinner, lighter trash bags which are stronger and more durable than the thicker bags previously made from low density resin. This is why gauge is no longer an effective way to determine liner strength. Instead of stating actual thickness, it is now generally accepted to use terminology such as "Light", "Medium", "Heavy", and "Extra Heavy".
Each manufacturer has its own blend formulations, so the proportions of these materials vary from one producer to another. The best way to determine the correct liner is to actually test some suggested samples. At Pitt Plastics, we have our own testing laboratory where we can test our liners or those of another manufacturer and provide you with the test results.
It's important to know a little bit about what can liners are actually made of, and how thicknesses are measured. That way you can determine which of the polyethylene resins and liner gauges will work best for your particular application.
Resin- The basic raw material from which can liners are made. There are 3 types of resins: Low Density, Linear Low Density and High Density Polyethylene.
Linear Low Density Polyethylene - This resin is highly puncture and tear resistant. These properties make this the best choice for applications where additional strength and stretch are required. Works well for waste with sharp or jagged edges.
-High Density Polyethylene- Liners made from this resin are generally available in lower gauges, and are more temperature resistant.
Low Density Polyethylene- An older resin still used mainly in lower end utility liners. It has largely been replaced by Linear Low Density Polyethylene. Pitt Plastics does not use this resin in any of our can liners!
Post- Consumer and Post-Industrial Polyethylene- This is made from recycled post-consumer plastics such as milk jugs and industrial scraps. These are reprocessed and blended with other types of resins to produce new high quality liners.
Gauge- A term used to describe the thickness of a liner. Low density liners are measured in mils, while High Density liners are generally measured in microns.
Mil- Measurement based on one hundred thousandths of an inch (.000). For example, a .55 mil bag would be 55 thousandths of an inch thick. Common low density liners range from .37 to 1.8 mil in thickness.