Below is an explanation of the most common terms and descriptions of the materials that are used to make plastic bags. Our customers have found the plastic bag education page to be a valuable resource in figuring out the correct type and size of plastic bag they are looking to source.
Low Density Polyethylene (LDPE)
Polyethylene is the most commonly used plastic in the world. Low Density Polyethylene is the material used in most poly bags mainly because it provides great strength, clarity and flexibility.
High Density Polyethylene (HDPE)
High Density or HD bags are made out of a thin and light substance, which helps to lower cost of the bags as well as the freight. High Density bags are not as clear as Low Density poly bags however they are very strong, tear-resistant, and stiff. These bags are both strong and economical.
Cellophane:
Cellophane offers excellent film clarity for display. The cellophane film works as a barrier to preserve aromas and keeps food fresh. Cellophane also enhances the appearance of products. Cellophane however is not recommended for use in extreme temperatures.
Polypropylene:
Polypropylene has the highest clarity available. This is an excellent material to protect against moisture and vapors. It is suitable for food, crafts, photos, cards, and scented products. Polypropylene is the preferred option for display.
Bag Dimensions
Flat Bags
Flat Poly Bags W: Width L: Length Gauge: The gauge indicates the thickness of the bag. For more information check the conversion chart below |
Gusseted Bags
Gusseted Poly Bags W: Width D: Depth (gusset x 2) L: Length Gauge: The gauge indicates the thickness of the bag. For more information check the conversion chart below |
Round Container
Round Container Length: Add ½ of the diameter to the length plus 4″ for overhang. Choose next larger size for best fit. Width: Measure around the container top or multiply the diameter by 3.14, divide by 2 and add 2″ for a looser fit. |
Cartons or Boxes
For a Cover: Add 3″ to the width and 3″ to the depth for a loose fit. Add half of depth to the length. Example: W: 25″+3″= 28″ D: 20″+3″ = 23″ L: 40″ + 10″= 50″ Size to order: 28 x 23 x 50For a Inner Liner:Add 4″ to either width or depth. Add all the depth to the length plus a few inches for overlapping ends. Example: 25 + 4 = 29 20 = 20 40 + 20= 60Size to order: 29 x 20 x 60 |
Conversion Chart
Gauge in Mil | Gauge in Inches | Gauge in Microns |
---|---|---|
.30 | .0003 | 7.50 |
.35 | .00035 | 8.75 |
.40 | .00040 | 10.00 |
.45 | .00045 | 11.25 |
.50 | .00050 | 12.50 |
.55 | .00055 | 12.50 |
.60 | .00060 | 13.75 |
.65 | .00065 | 15.00 |
.70 | .00070 | 16.25 |
.75 | .00075 | 17.50 |
.80 | .00080 | 20.00 |
.85 | .00085 | 21.25 |
.90 | .00090 | 22.50 |
.95 | .00095 | 23.75 |
.100 | .00100 | 25.00 |
Liners Weight and Applications
Description | LLDPE | LDPE |
---|---|---|
Light | 0.38 mils | 1 or 1.25 mil |
Medium | 0.58 mils | 1.5 or 2 mil |
Heavy | 0.78 mils | 3 or 4 mil |
X-Heavy | 0.98 mils | 5 or 6 mil |
Glossary
- Can Liner
- Term used for garbage, trash or waste bags. Used in industrial, institutional and medical applications
- Colors
- Can liners come in standard colors: clear; black, white, gray, red, blue and yellow (Other colors available)
- Food and Utility Bags
- Small clear bags designed to hold a variety of small objects (e.g., bread, poultry, vegetables, etc)
- Film Strength
- Refers to the physical strength of the can liner. Some resins have a higher film strength than others. Our bags are made from highest quality resins, giving them the highest quality film in the market place.
- Dart Drop Test
- ASTM test used to determine the resistance of a bag to local failure or puncturing of the film.
- Elmendorf Tear Test
- ASTM test used to measure the resistance to tearing.
- Wet Load Capacity
- Measurement of how much wet weight a bag will hold.
- Dry Load Capacity
- Measurement of how much dry weight a bag will hold.
- Gauge
- Term used to describe thickness, LDPE and LLDPE bags are measured by mil thickness and HDPE bags are measured by micron thickness.
- Mil
- (One thousandth of an inch) Term used in the measurement of LDPE and LLDPE bags. One mil is .001”. Can liners range between .35 to 4.0 mil.
- Micron
- Term used in the measurement of HDPE bags. 25.4 microns equals .001”. 1,000 microns (M) = 1mm. HMW-HDPE can liners are 6 to 24 microns.
- Resin
- Short term for Polyethylene (PE) resin. The three types of PE resins are LDPE, LLDPE and HDPE (see below). Other plastics resins include vinyl, polypropylene, styrene and nylon.
- LDPE
- (Low Density Polyethylene) This resin was used with older bag technology. Resin has good clarity but weak film strength. Today it is used primarily for Food and Utility Bags.
- LLDPE
- (Linear Low Density Polyethylene) This is the primary type of resin used in modern can liner manufacturing technology. Bags made from LLDPE film provide excellent combination of film strength, puncture resistance and tear resistance.
- HDPE
- (High Molecular Weight-High Density Polyethylene) Bags made from HDPE resin provide excellent film strength and puncture resistance, but less tear resistance than LLDPE.
- HAO
- (Higher Alpha Olefin resin) A high-grade Hexene or Octane-based resin used in all of our LLD liners. The properties of this resin allow for a higher-quality can liner.
- Butene
- One of three types of LLDPE resin. Butene has weaker film-strength properties than Hexene or Octene.
- Hexene
- One of three types of LLDPE resin. We use Higher Alpha Olefin (High Grade Hexene) in the manufacturing of our bags. Properties include high film strength and increased tear resistance.
- Octene
- One of three types of LLDPE resin. We use Higher Alpha Olefin (High Grade Octene) in the manufacturing of our bags. Used in other applications because of its excellent physical properties.
- Prime Resin
- Refers to the usage of high-quality, “fresh from the reactor,” resin. We use only prime resins in all of the products we produce, unless specified otherwise.
- Blended Resin
- Refers to the combination of two or more types of resin.
- Reprocessed Resin
- Refers to resin that has been used at least once before. Can be post-industrial (scrap) or post-consumer (recycling). Property of resin is decreased each time it is reused.
- Seal
- Term used to describe bottom of a can liner. The three types of seals are flat, gusseted and star.
- Flat Seal
- Straight seal along bottom of a bag. Though Flat Seals are strong, they may have a tendency to leak from the corners.
- Gusset Seals
- A flat-style bag manufactured with both sides tucked in to form gussets. Has a tendency to leak from the center at gusset points where four layers of film meet two.
- Star Seal
- This multilayered seal is full gusseted and then folded prior to sealing, allowing for the contents to be evenly distributed.
- Top-Side Dispenser Box
- An innovative style of box that allows stacking in small spaces. It is just as easy to pull a can liner from the side as it is the top.
- Individually Folded
- Bags are separately folded, then stacked on top of one another. This allows the end-user to pull bags out of the box with much more ease vs. bulk-folded bags.
- Cored Rolls
- Bags are rolled together on cardboard cylinders.
- Coreless Rolls
- Can liners are rolled in groups of 25 or 50 per roll. There are 4 to 10 rolls per case. Rolls are perforated or interleaved.