Packaging Terminology

Additives– A group of chemicals added into plastic materials before or duringprocessing, or added to surfaces of any finished products afterprocessing.The main function is to modify behaviors of plastic or addhelpful properties to the materials.

Antiblock – Blocking is the term used to describe what happens when polyethylene film sticks together. Anti-block is an additive that roughens the surface of film at a microscopic level. This makes it easier for layers of film to separate. Anti-block makes bags easier to open, too.

Anti-static – Additive that dissipates static electrical charges. Amine-free that works better in lower relative humidity and won’t corrode polycarbonate surfaces. Meets static decay requirements of MIL-8170SE, Type III and EIA-541.

ASTM D6400 – This specification covers plastics and products made from plastics that are designed to be composted in municipal and industrial aerobic composting facilities. The properties in this specification are those required to determine if plastics and products made from plastics will compost satisfactorily, including biodegrading at a rate comparable to known compostable materials. The purpose of this specification is to establish standards for identifying products and materials that will compost satisfactorily in commercial and municipal composting facilities.

Auto Bags – Continuous poly bags are perforated on rolls with a slit-front opening. The slit-front offers quick and easy product insertion.

Bags on a Roll – Continuous poly bags are perforated on rolls. The bags need to be torn off to open.

Barrier Film – Specially formulated film typically used to extend the shelf life of food products. Prevents transmission of moisture and gases.

Biodegradable – A material that is capable of undergoing decomposition into simple compounds such as carbon dioxide, methane, water, inorganic compounds and biomass. The predominant mechanism for decomposition is the enzymatic action of micro-organisms. There are no requirements regarding residues or time to breakdown.

Bottom Seal Bags – There are three types of bottom seals. A flat seal is a straight seal along the bottom of a liner and is used to create a very strong seal for heavier bags. A star seal is the most common seal and eliminates gaps along the seal where leaks are prone to happen. Star seals will generally conform to the shape of the container and content weight will be more even. Star seals are non-gusseted and maximize carrying capacity and minimizing leaks. A gusset seal is a flat-style and manufactured with both sides tucked in to form gussets.

BPI – (Biodegradable Products Institute) The U.S. standard in compostability. The BPI Logo Program is designed to certify and identify plastic products that will biodegrade and compost satisfactorily in actively managed compost facilities. The BPI and US Composting Council (USCC) use American Society for Testing and Materials Specifications (ASTM) to approve products for their “Compostable Logo” effort. These specifications are the result of 8 years of intensive work by researchers, product manufacturers, composters, and resin producers to identify plastic and paper products, which disintegrate and biodegrade completely and safely when composted in a municipal or commercial facility, like kraft paper, yard trimmings and food scraps. In order to be BPI certified, products must meet ASTM D6400 or D6868 standards based on testing in approved independent laboratories.

Blown Film – The most common method of producing film and bags. Resin is melted in the extrusion process and blown vertically into a bubble to cool.

Can Liner – Can Liners are bags that are used for garbage, trash or any kind of waste.These are typically used in industrial, institutional and medical applications. Typically clear in color.

Cast Film – Extruded in sheet form through a slotted die.

Clarity – Bags that are described with high-clarity refer to the exceptional clearness of the material.

Compostable – Capable of undergoing biological decomposition in a compost site as part of an available program, such that the material is not visually distinguishable from other compost and breaks down into carbon dioxide, water, inorganic compounds, and biomass, at a rate consistent with known compostable materials (usually 90 days). These compostable materials leave no toxic residue.

Cored Rolls – Bags or tubes which are rolled on cardboard (much like your paper towels at home, for example)

Coreless Rolls – Bags which are rolled with perforations and not on a cardboard roll.

Custom Printing – Adding images, such as logos or pictures along with wording in 1-8 colors. Printing can be done on either 1 or 2 sides of a bag.

Degradable – Material that will undergo a process of deterioration or breaking-up by the action of natural forces (air, light, water) or by the addition of certain chemicals, with no micro-organisms involved.

Denier – Unit of measurement that expresses fiber thickness of individual threads or filaments in fabric or textiles. A single strand of silk is considered 1 denier. The higher the number, the thicker the fabric.

Door Knob Bags – 1 ½” hole just below the top of the bag allows for the bag to be hung over a door knob.

Elasticity – The tendency of a material to return to an original shape after being stretched out or pressed in.

Electrically Conductive Film – Poly that has carbon additives for exterior protection against damaging static charges. Meets the requirements of MIL-P82646 Rev B.

Embossed – Raised pattern or texture on the material which aids in gripping, especially for wet items. Commonly seen in poly gloves and aprons.

EVA – An additive, Ethylene Vinyl Acetate, adds strength and improves sealability. For use in cold temperatures to prevent breakage.

Extrusion – A very common plastics processing technique where resins are melted, heated and pumped for processing. Extrusion machines shear the material to be processed between the root of the screw and the wall of the barrel that surrounds it, producing friction which heats and melts the substance as it moves down the barrel.

Faraday Cage – prevents the entry (interior) or escape (exterior) from static and other charges.

FDA – The Food and Drug Administration is responsible for protecting the public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, and medical devices; and by ensuring the safety of our nation’s food supply, cosmetics, and products that emit radiation.

FIBC – A flexible intermediate bulk container (FIBC), also referred to as a bulk bag or super sack, is an industrial container made of flexible fabric that is designed for storing and transporting dry, flowable products.

Flap Lock – Bag has lip folded back with side seals. Commonly known as a sandwich bag.

Flat Bags – Length and width measure these two-dimensional bags.

Flexographic Print – Print that is solid colored – also known as line art. Each color requires a separate plate to print a solid color.

Gauge – Gauge is a term used to describe the thickness of plastic and is measured in mil’s or microns. Mil (one thousandths of an inch) is used in the measurement of LDPE and LLDPE can liners. One mil is .001?. Micron is used in the measurement of HD can liners. 25.4 microns equals .001?. 1,000 microns (M) is equal to 1mm.

Grommet – A small metal ring or eyelet inserted in a hang hole to prevent tearing.

Gusseted Bags – Gussets are indented folds found on the side or bottom of plastic bags which allow for expansion up to the limits of the fold to accommodate for added volume or shape. Gusseted bags are designated in three dimension measurements.

Hang Hole – A small hole is added to allow it to hang on a hook or add a tie.

Header Bags – Side-weld bag with continuous seal along top, 2″-3″ below fold. Bag is loaded and sealed from the bottom and typically has a hang hole.

High Density Polyethylene – The chemical structure of high density polyethylene (HDPE) lends itself to greater toughness – roughly twice the tear and puncture strength and better chemical resistance than low density polyethylene (LDPE) and linear low density polyethylene (LLDPE). On the downside, HDPE film is less flexible and less clear than its LDPE and LLDPE cousins. Up to three times stronger and more durable than traditional polyethylene of the same thickness. Performs well under extreme temperature. Offers superior vapor and moisture protection which helps to confine odors. Also non-porous. Not recommended for sharp or jagged objects.

Hot Stamp Printing – Thermal bonding process that results in the permanent adhesion of the print to the bag.

Linear Low Density Polyethylene – Low density polyethylene (LDPE) is a popular choice for a wide range of light-weight packaging needs. LDPE provides moderate strength and good clarity for general purpose applications. A commonly used type of LDPE is actually called Clarity. Superior stretch properties provide maximum puncture and tear resistance. Stronger than traditional low density material and non-porous. Better clarity than high density material

  • Hexene – Hexene is a very strong linear low density polyethylene (LLDPE) that stands up to more rigorous demands. Hexene is the most common choice where added strength is important.
  • Octene – Octene is the strongest linear low density polyethylene (LLDPE). For a few pennies more per pound, Octene delivers the highest tear and puncture strength of any LLDPE material.
  • Non-Scratch – There’s really only one component in most low or linear low density polyethylene bags, film or tubing formulations that can be at all scratchy: anti-block. Anti-block additives work by making the surface of the film rougher. Non-scratch bags, film and tubing contain no anti-block additives and therefor provide smoother film surfaces.

Lip – Extension or extra material on one side of a bag, which makes it easier to open the bag and for product insertion.

Low Density Polyethylene – Original all-purpose film which is flexible, durable and resistant to most chemicals. Popular choice for a wide range of light-weight packaging needs.

M – Per thousand. Generally used in reference to pricing, such as $25.00/m.

Metallocene – Metallocene’s prime benefit is its ability to make film more resilient. Metallocene may not improve the force needed to tear a film, but it will allow it to stretch more under force and seal better. Even at lower temperatures, items formulated with metallocene don’t become brittle. That’s why metallocene is the choice for freezer or ice bags.

Mil – Refers to the thickness of a material. Also referred to as the gauge. Each mil is equal to 1/1000 of an inch. The higher the mil (gauge), the thicker the material.

Natural Kraft – Unbleached paper in its natural form – brown in color.

Oxo-Degradable – Often mistakenly called Oxo-Biodegradable, it is a plastic made from fossil fuels that has been treated with an additive that allows it to disintegrate over time through interaction with microbes. The chemical structure of the plastic is broken down with the help of oxygen and heat or sunlight, and then the smaller particles are utilized by micro-organisms as food. They do not pass ASTM 6400 regulations, however, because they do not degrade as quickly as the definition requires. They compost well and are safe for landfills.

Perforation – A row of tiny holes made in a poly bag to allow for easier opening or tearing off. Also used in tamper proof bags and mailers. Pocket – An additional piece of material added to outside and sealed on 3 sides to from a pouch.

Polypropylene – Polypropylene (PP) is the choice when clarity is paramount. Polypropylene offers about five times the clarity (one-fifth the haze values) of low density polyethylene. Polypropylene is a common choice when packaging for display. Crystal like clarity. Rigid and stronger than polyethylene. Deters evaporation and dehydration as well as extending shelf life. Provides excellent vapor and moisture barrier to lock in freshness.

Plastic Film – Plastic film is thin and considerably larger in length than width. Typical thicknesses is 10 mil or less and averages 0.5 mils to 1.5.

Postal Approved – These items are formulated to comply with the USPS T-3204 protocol for use on automation rate flat-size mail pieces. Performance standards met include haze, blocking, coefficient of friction and static charge decay.

Random Print – A repeating print that appears in full on a bag at least once. A partial print may be visible on either side of the full print.

Reclosable Bag – Also referred to as zipper bags or seal top bags. Zipper closure can be opened and closed repeatedly with slight finger pressure.

Recyclable – A product or package that can be collected, separated or otherwise recovered from the solid waste stream for reuse. The term may also be applied to the manufacture or assembly of another package or product through an established recycling program. Claims of recyclability should be qualified to the extent necessary to avoid consumer deception about any limited availability of recycling programs and collection sites.

Registered Print – The print shows up in the same spot on every bag in a production run.

Renewable Resource – A natural resource that can be replenished by natural processes at a rate comparable or faster than its rate of consumption by humans or other users. Renewable resources may also mean commodities such as wood, paper, and leather.

Side Weld Bags – Poly bags are sealed on the sides, unlike the bottom sealed bags which are sealed on the bottom. There is no skirt or tail on side weld bags.

Slip – Slip additives decrease the coefficient of friction (increase the slipperiness) of the surface of a bag, film or tubing. Standard formulations have enough slip additive to keep bags, film or tubing from sticking together but not so much as to make them difficult to handle.

  • High Slip – Some users require increases in slip additive to increase the degree to which their bags, film or tubing glide in a handling or packaging process.
  • Low Slip – Some users require low slip bags, film or tubing to decrease the likelihood of their product sliding when packaged. Mattress bags are a good example. Low slip bags are formulated with no slip additive.

Star Seal – Manufactured by folding the bottom of a liner over several times and then sealing it, making a star shaped design. This type of construction virtually eliminates leaks. Also make liners conform better to the shape of the waste receptacle or container by spreading the refuse around the can liner.

Static Shielding – Transparent metallic Four layer construction offers Faraday Cage protection and visibility for the interior and exterior of the bag, which means static charges are stopped on the inside as well as the outside of the bag. Provides longer and greater protection than anti-static bags. Meets electrical and physical requirements of ANSI/ESD S541, EIA 625 and are ANSI/ESD S20.20 program compliant Tested per MIL-STD-3010 4046 and ANSI/ESD STM11.11.

Tensile Strength – The force required to pull something to the point where it breaks. Specifically, the tensile strength of a material is the maximum amount of stress that it can be subjected to before failure.

UVI/UVA – Direct sunlight (UV light) causes unprotected film to discolor or become brittle. UVI/UVA (ultraviolet light inhibitor / ultraviolet light absorber) protects both the film and its contents from the damaging effects of the sun and inhibits thermal degradation of the film. Do not use UVI/UVA additive for film that may come in contact with agricultural chemicals or pesticides as they may reduce the product’s efficacy.

VCI – Packaged metal items can corrode during storage or shipment if exposed to oxygen, water and other contaminants. A Vapor Corrosion Inhibitor (VCI) is a film additive that has enough vapor pressure under normal circumstances to become a gas. VCI fills the interior of a sealed bag with molecules that adsorb onto the surface of a metal item to form a microscopic, protective barrier.

Vent Hole – One or more small holes in a poly bag to allow air and/or moisture to flow though.

Wicketed Bag – Side weld bags are mounted on a heavy wire wicket placed through two holes in lip for fast and easy manual loading.

Write-On® Area / White Block – A white area printed on one side of the bag that allows for labeling or writing with permanent markers, pens and pencils.