Glossary of Terms

A-Flute is the highest flute size offering excellent cushioning and stacking qualities and short column crush resistance. There are 32 to 37 flutes per foot producing board approximately 1/4″ thick when combined with inner and outer liners.

Adhesive: Material capable of adhering one surface to another. As used in connection with fibre boxes, a material to glue plies of solid fibreboard, to glue facings to corrugating medium in combined corrugated board, to glue to overlapping sides of a box forming the manufacturers’ joint, or to glue the flaps in closing a slotted box.

Alternate Rules: In 1991, the National Railroad Freight Committee and the National Classification Committee of the Motor Carrier industry adopted proposals to Rule 41 and Item 222, respectively, to allow box makers an option to use either minimum bursting strength specifications or minimum edge crush specifications.

B-Flute has lower arch heights than A and more flutes per foot. This means that the medium contacts and supports the liners at a greater number of points, providing a stiff, flat surface for high quality printing and with excellent crush resistance. There are 45 to 52 flutes per foot producing board approximately 1/8″ thick when combined with inner and outer liners.

Basis Weight: The weight of liner board, corrugating medium or corrugated board expressed in terms of pounds per 1000 square feet.

Box: A rigid container having closed faces and completely enclosing the contents.

Boxboard: The thin, lightweight material used for cereal packages and shoe boxes etc.

Box Maker’s Certificate: A stamp printed on a corrugated or solid fibreboard box which identifies the box maker and states that applicable container board requirements have been observed.

Brightness: A measure of the percentage of light reflected by the paper liner. It is compared to the amount reflected by a known standard which has a brightness of 100. Higher brightness is normally desirable in producing containers with visual appeal.

Bursting Strength: The strength of a material expressed in pounds per square inch as measured by the Mullen tester.

C-Flute splits the difference between A and B Flutes. It’s thinner than A-flute, thicker than B, and offers good cushioning, stacking and printing properties. C-Flute is by far the most widely used flute size. An estimated 80% of today’s corrugated containers are made of C-Flute board. There are 39 to 43 flutes per foot producing board approximately 3/16″ thick when combined with inner and outer liners.

Caliper: The thickness of a sheet of linerboard, corrugating medium or corrugated board expressed in terms of thousandths of an inch.

Closure: Refers to the manufacture’s joint where the box panels are joined by taping, stitching or gluing.

Combined Corrugated Board is made of liner-board, or liners, on the outer surfaces, and corrugated medium in the middle.

Combined Weight of Facings is determined by adding the basis weights of the liners used in the manufacture of a particular board. This weight is stated on the Box Maker’s Certificate printed on the bottom flap of a carton.

Compression Resistance: A measure of the stacking strength of a box, expressed in terms of pounds of force required to cause a dynamic failure in the box. It is measured in either the top-to-bottom, side-to-side, or end-to-end direction, usually depending upon how the box is stacked during shipment or storage. This is the key property in a box in most modern applications. Top-to bottom compression is a function of edge crush, caliper of the corrugated board, cross direction ring crush of the linerboards and medium as well as the manufacturing quality of the box.

Concora Crush: The compressive force expressed in pounds required to crush a fluted 11/2″ by 6″ specimen of corrugating medium.

Containerboard: A term to describe corrugated board with its two components: linerboard and corrugating medium. It is like a sandwich. The liner is the bread on both sides and the arches in the middle are the medium that gives the container strength.

Corrugator: The machine which takes large rolls of paper and combines them to produce the flat corrugated board. At the heart of a corrugator are two corrugator rolls. These gear-like rollers press flutes into the softened medium fed between them and then adheres an inner and outer liner to the medium.

Corrugating Medium: Paperboard used in forming the fluted or arched portion of the corrugated board.

COW: Cut Out Wrap

CSSC: Centre Special Slotted Container. All the flaps meet at the centre of the carton.

DCC: Die Cut Container.

DCS: Die Cut Sheet.

Die Cutting: Forming shapes, cuts and scores by stamping board with a steel rule die.

Dimensions: Refers to the interior size of the box. With a box the dimensions are expressed as Length, Width and Depth. The Length is the larger of the two dimensions of the box opening. The Width is the lesser of the two dimensions of the box opening. The Depth is the distance between the innermost surfaces of the box measured perpendicular to the Length and Width.

When measuring Pads or Sheets the dimension running parallel with the flutes is referred to as the Width and the dimension running perpendicular to the flutes is the Length.

Doublewall: Two corrugated mediums layered between three linerboard facings.

E-Flute has a greater number of flutes per foot which gives it the greatest crush resistance and the flattest surface for high quality printing applications. The thin profile of E-Flute reduces bulk and saves storage space. There are 92 to 98 flutes per foot producing board approximately 1/16″ thick when combined with inner and outer liners.

Edge Crush Test (ECT): The edgewise compressive strength, parallel to the flutes of a short column of corrugated fibreboard. Test results are reported as the pound-force per inch required to cause compressive failure. ECT correlates directly to box compression strength.

F-Flute, the newest flute, is just a little more than half the thickness of E-Flute and is the newest growth segment in the corrugated industry. It reduces the total amount of fibre in the packaging and creates a more rigid box. There are 128 flutes per foot producing board approximately 1/32″ thick when combined with inner and outer liners.

Facings: Linerboard used as the flat facings of a corrugated fibreboard sheet.

Fibreboard Box: A container made of either corrugated or solid fibreboard. For classification purposes, when the term “box” is used, the structure must comply with all requirements of Item 222 or Rule 41.

Flat Crush: A measure of the resistance of the flutes in corrugated board to a crushing force applied perpendicular to the surface of the board. Test results are reported in pounds per square inch.

Flute: One of the “wave” or “arch” shapes formed in the corrugated medium. There are five basic flute sizes – A, B, C, E, & F. Their measurement is expressed in ‘flutes per foot’ of corrugated board. Combinations of the different flutes may be combined in the separate layers of Doublewall or Triplewall board.

FOSC: Full Overlap Slotted Container. The outer flaps fold across the full width of the box.

FPW (5PW): Five Panel Wrap

Gross Weight refers to the maximum total weight of the box and its contents.This weight is stated on the Box Maker’s Certificate printed on the bottom flap of a carton.

HSC: Half Slotted Container. An open box with no flaps on either no flaps on the top or no flaps on the bottom.

High Ring Crush Facings: These improved facings are the result of advanced papermaking technologies and offer superior stacking strength to conventional facings.

High-Performance Containerboard: Containerboard manufactured to provide greater box compression strength, improved corrugator runability and better converting machinability than standard, corrugated industry box components. High-performance materials have higher cross- direction ring crush values than standard materials of the same basis weight and they also have tighter specifications for moisture content, caliper profile and sheet formation.

K.D.F.: Abbreviation for “Knocked Down Flat” – indicating the box is not assembled.

Kraft: This term refers to unbleached linerboard which has at least 80% virgin wood pulp.

Liners: An erroneous but commonly used term for facings.

Liner: A corrugated sheet which is scored to fit within the perimeter of a box.

Manufacturer’s Joint: Where the box panels are joined by taping, stitching or gluing.

McKee Formula: Mathematical formula used to predict the top-to-bottom compression strength of corrugated boxes.

Mullen Test: A method of determining the bursting strength of corrugated board. It is measured in pounds per square inch. Attention is turning away from this traditional measurement of bursting strength to a measurement called Edge Crush Test.

Partition: Dividing strips of corrugated interlocked to form multiple cells inside a box.

Porosity: A measure of the time in seconds required to pass 100 cubic centimeters of air through a square inch of container board. lt is measured by the Gurley Desimeter. Porosity has some affect on the glueability and printability of linerboard.

Post Consumer Waste: While some amount of reclaimed fibre is used in virtually all grades of linerboard and medium, recycled facings and recycled medium can actually contain up to 100% post-consumer waste. A key source of reclaimed fibre is the corrugated industry itself. Waste paper and corrugated board are routinely recycled from corrugator plants and boxmaking operations. The largest and fastest growing source of reclaimed wood fibre is post-consumer waste: old corrugated containers (OCC).

PTN: Partition.

Puncture Test: The strength of material expressed in inch ounces per inch of tear as measured by the Beach puncture tester.

Ring Crush: This test is used to measure the edgewise compression strength of linerboard or corrugating medium. A ½” by 6″ long sample strip is placed in a circular holder and compression force is applied to the edge of the “ring” of containerboard. Test results are reported in pounds of force required to crush the 67″ specimen. Cross-direction ring crush correlates to the edge crush test (ECT) of combined corrugated board and to box compression strength.

RSC: Regular Slotted Container.

Rule 222: A rule in the National Motor Freight Classification containing requirements for corrugated and solid-fibreboard boxes.

Rule 41: A rule in the Uniform Freight Classification of the rail carriers containing requirements for corrugated and solid fibreboard boxes

Score: A crease in corrugated board to permit folding.

Seam: Where two flaps meet.

SFCS: Short Flap Slotted Container

Shipping Container: A box which is sufficiently strong to be used for packing, storing and shipping product.

Single Face: A corrugated medium glued to a single facing. It is usually produced in rolls of 250 feet.

Single Wall: One corrugated medium glued between two facings.

Size Limit is determined by adding the overall length plus the width plus the height of the carton. This number is stated on the Box Maker’s Certificate printed on the bottom flap of a carton.

Slot: A wide cut used to form flaps in a corrugated blank.

Slotted Box: A rectangular structure having four walls and top and bottom flaps.

SSS: Slit Scored Sheet.

Smoothness: A measure of the variability of the surface finish of paper on linerboard. It is usually measured by the Sheffield Smoothness Tester, with values ranging from 0 to 400 (lower numbers indicate a smoother surface).

SS: Scored Sheet

SSLS: Scored and Slotted Sheet.

Stacking Strength: The ability of a carton to hold up under a stacking load. Edge Crush Test has become especially important because in the distribution environment, stacking strength is essential. The focus is more and more on ECT for stacking strength rather than bursting strength for containability.

STFI: A test instrument and method used to measure the short-span, edgewise compressive strength of linerboard or corrugating medium. STFI test results correlate to the edge crush test (ECT) of corrugated board and to box compression strength.

Stitching: Closing the manufacturer’s joint with stitches of metal wire.

TEL: Telescope. A carton consisting of two trays which fit one over the top of the other.

Tear Resistance: A measure of the force required to tear a sheet of containerboard. This property is important in boxes requiring resistance to rough handling abuse.

Tray: An open container, usually rectangular, having a bottom and four walls.

Triplewall: Three corrugated mediums layered between four linerboard facings.

Tube: A liner or sleeve having no flaps.

Unitize: Describes the action of stacking K.D.F. boxes into a pallet sized cube called a ‘unit’ for shipment to the user. The unit of boxes is held together with plastic or steel straps.

Servicing: Toronto (GTA) and communities in Southern Ontario including:

Ajax, Alliston, Ancaster, Aurora, Barrie, Beamsville, Belleville, Bolton, Bowmanville, Bradford, Brampton, Brantford, Brighton, Burlington, Caledon, Cambridge, Concord, Cobourg, Georgetown, Grimsby, Guelph, Halton Hills, Hamilton, Kawartha Lakes, Kitchener, Lindsay, Markham, Milton, Mississauga, Newmarket, Nobleton, Oshawa, Peterborough, Pickering, Port Hope, Port Perry, Richmond Hill, Scarborough, Schomberg, Stouffville, Trenton, Uxbridge, Vaughan, Waterloo, Whitby, Woodbridge


Shipmaster Containers Limited
380 Esna Park Drive
Markham, Ontario Canada
L3R 1G5

Telephone 1: (416) 493 9193
Telephone 2: (905) 474 1556

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