Manufacturing Terms

Adhesive Laminations—Solvent, Solventless, Water-Based

Solvent based adhesive laminations are made with adhesive that uses a solvent to dilute and carry the adhesive and disperse it on the web. Solventless adhesives (used exclusively at Overwraps) is an adhesive type that uses a 100% solids chemistry combining a mixture of polyol and isocyanate to bond two films together with little or no VOC’s at a lower application weight cost than solvent based adhesives. A water based adhesive is typically a water and polyurethane or acrylic mixture used to bond two films together and is generally a lower performance adhesive for light weight snack food packaging.

Area Measurement: MSI, Yield, (Square Inches/LB. OR KG – MSI

Thousand square inches calculated by multiplying the web width in inches by 12 by the length of the material in feet divided by 1,000. Yield - The measure of a film's coverage per unit weight. Values are expressed as (in2/lb.) in US standard and (m2/kg) in metric (or SI) units. Most packaging raw materials are sold by weight. However, because of density differences, the same weight of similar materials can produce different amounts of finished product. It is calculated by using this formula: 27.68/Density (g/cm3) x Thickness (inches) = Yield (in2/lb.). Metric calculation is 1,000/Density (g/cm3) x Thickness (micron).

Back Web

A film that is laminated to the printed web. Typically used as a sealant web in the lamination.

Bags: Side Weld, Bottom Seal, Wicketed, Non Wicketed, Side Gusseted

Side weld bags are folded and sealed on the sides with one opening. Bottom Seal bags are typically made from a tube of polyethylene film and sealed at the bottom. Wicketed bags have holes punched in the top, opened end of the bag and are placed on a wire wicket for ease of use. Non Wicketed bags are not hole punched and placed in cartons for shipment. A side gusseted bag is folded in the side of the pouch, allowing it to expand when contents are inserted.

Bottom Gusseted, Star Sealed

A Bottom gusseted bag is folded in the bottom of the pouch, allowing it to expand when contents are inserted, and stand upright on the store shelf. Star Sealed bags are typically found in the trash bag industry and are manufactured by folding the bottom of the trash can liner over several times and then sealing it.

Duplex Laminations

Laminating two film layers together.

Extrusion Laminations

A lamination by extrusion coating a plastic melt onto a base material while simultaneously pressing the coated stock against a second material, and then cooling rapidly to establish the bond between two layers.

Fin Seal

A fin seal brings the inside surfaces together and creates the seal, usually by heat sealing. The fin seal is generally not as aesthetically pleasing and uses more material than the lap seal. However the laminate can be simpler since the inside heat seal material is sealed to itself.


An acronym for Hazards Analysis and Critical Control Points. It is the backbone of SQF system. HACCP is a management system in which food safety is addressed through the analysis and control of biological, chemical, and physical hazards from raw material production, purchasing and handling, to manufacturing, distribution and consumption of the finished product.

Ink Coverage - %, LBS/MSI, LB/REAM

The amount of ink printed on the film. Typically expressed as a percentage of ink on the web. LBS/MSI – a measurement of total coating weight on an order. LB/REAM – A measurement of the amount of ink in a ream of film.

Job Jacket

The internal order contract that Overwraps uses to define customer orders. The job jacket outlines everything from the item requested, quantities, have ready dates, materials, processing instructions, finished specification requirements and special instructions specific to the job.

Lap Seal

A lap seal overlaps the material for the distance required by the seal and creates the seal, usually by heat sealing. During sealing, the inside of the laminate must be able to seal to the outside, requiring that both sides of the laminate be heat sealable. The lap seal is generally more aesthetically pleasing and uses less material than the fin seal.

Master Web Width

Roll width which is the measurement of the raw material to be printed or laminated from edge to edge.

Print Web

A film that the press prints and is the top layer of most packaging laminates. It may or may not be laminated to another layer of film. Surface printed films are typically not laminated to another layer of film. Reverse printed films are almost always laminated to another layer of film to lock in the inks, and protect the food from contamination.


432,000 square inches. The basic unit of measure on which product specifications are built. The 432,000 square inch ream is basic in figuring percentage of multiple components of a structure. To determine the percentage of a component, one needs the yield (square inches per pound) of the components, then divide the 432,000 by the yield of each component to get the pounds per ream for each component. Total all the pounds per ream of all components for a total weight per ream. Divide the total pounds for one ream of your structure by the pounds of each component to get the percentage for each component.

Recyclable - Non-Recyclable

Recyclable Plastic scrap that is capable of being removed or sorted from the solid-waste stream in an established program and returned to use in the form of raw materials or products. Most of the plastic waste we generate is recyclable. Examples of non-recyclable film are co-mingled plastics such as Clear OPP/Metallized OPP or foil laminates.

RTO, Oxidizer, Incinerator

Regenerative Thermal Oxidizer (RTO) is an industrial process for the treatment of exhaust air. The system is a type of thermal oxidizer that uses a bed of ceramic material to absorb heat from the exhaust gas. It then uses this captured heat to preheat the incoming process gas stream and destroy air pollutants emitted from process exhaust streams at temperatures upwards to 1,500 F. Each press exhausts the solvent laden air into the RTO and the exhaust is cleansed per compliance with clean air standards.


An acronym for Standard Production Pounds of film required to produce an order.

Solvent Inks

Inks that use solvent to carry the ink pigment and disperse it onto the printing substrate. Solvents are widely used to dissolve solid resins in order to produce a fluid base. Solvent is used to dilute, render more fluid, or control the viscosity of the ink. Major solvents used by Overwraps include Isopropyl Alcohol, Ethyl Alcohol, Normal Propyl Acetate, Normal Propyl Alcohol, Glycol PNP, and Ethyl Acetate. Siegwerk is our current ink supplier for surface printed inks (CT III, and Colorgloss systems), and reverse printed laminating inks (Access Lam system).


An acronym for Safe Quality Foods and is recognized by retailers and foodservice providers around the world who require a rigorous, credible food safety management system. SQF is a system that is recognized by the Global Food Safety Initiative (GFSI) and links primary production certification to food manufacturing, food packaging, distribution and agent/broker management certification. It’s administered by the Food Marketing Institute (FMI). There are three levels of SQF certification. Overwraps attained the highest lever (3) in October of 2011. Level 3 certification incorporates quality management criteria. We are audited annually in the fall.

SUP, Quad Seal PTC Zipper, Velcro Style

SUP or stand up pouch. It has a bottom gusset to enable it to stand on the store shelf. Quad seal pouches have four sided seals and are typically found in coffee and pet food bags. A PTC Zipper is the most common zipper material used in pouches and refers to a zipper that requires pressure to close. Velcro Style zippers are a hook and loop fastener used to seal pouches.


Stand Up Pouch – A package of flexible film that stands up on the shelf and mimics the point of sell characteristics of rigid packaging. The package is supported by forming a gusset or fold in the bottom of the bag. This gusset adds stability allowing the package to stand up on the shelf. Gusset size, height and width of bag are dimensions needed to create a template of the pouch. Additional specifications include the need for a reclosable zipper, “easy open” laser score, hang hole and tear notch.

Triplex Laminations

Laminating three layers together.


A measurement of the amount of film that was not converted to good saleable film. Usually calculated by dividing the amount of lbs. or impressions, or footage shipped vs. what was used on an order.

Water-Based Inks

Ink that uses water and a very small percentage of Normal Propyl Alcohol to carry and disperse the ink on to the printing substrate. Overwraps purchases water based ink from Sun Chemical (Aquasurf ink system) to print non-woven face mask material.