Corrugate
Corrugate
Corrugated boxes are a low-cost, lightweight solution for many packaging needs. Sometimes just referred to as “corrugate”, it protects the box contents as well as the Earth – it’s recyclable! They can be printed for customization, die-cut into many shapes and sizes and can also be laminated for extra protection.
Cardboard sheets provide padding and protection between products and can be used to disperse weight between layers on a pallet. They also provide protection from pallet straps and can help keep pallet loads in place.
Corrugated Cardboard 101
We talk about cardboard boxes and corrugated cardboard, but what is it, really? There are many different compositions and types of cardboard that are used for boxes, pallet sheets, edge protectors and more. Corrugated cardboard is generally made of 3 layers of Kraft paper stiffened with a shaped wavy layer in the middle and glue. The rigid flutes give stability and structure to the corrugate that allows it to perform many different functions depending on the exact style, shape and size.
The two components of corrugate are linerboard, which is the flat, outside surface and heavy paper – the wavy part between the linerboard.
Single Face: Only has two layers, a linerboard and a fluted layer. It’s not very durable but is generally used for internal packaging material as extra cushioning.
Order of Layers: Fluting, liner
Uses: Interior packaging
Single Wall: This is the most common type of corrugated cardboard. The corrugated medium is glued between two sheets of linerboard. Also known as doubleface.
Order of Layers: Liner, fluting, liner
Uses: Shipping Cartons
Double Wall: Three sheets of linerboard with two mediums in between. This makes these boxes exceptionally durable.
Order of Layers: Liner, fluting, liner, fluting, liner
Uses: Industrial Cartons
Triple Wall: Four sheets of linerboard with three mediums in between. These are so sturdy that they can be used instead of wooden crates.
Order of Layers: Liner, fluting, liner, fluting, liner
Uses: Shipping crates, chemical containers
The fluting between the linerboard can vary in size. Larger flutes help reduce vertical compression strength while the smaller flutes are better suited to smaller, retail products for structural integrity and graphics printing.
The five most common flute profiles are:
A-Flute
Appx 33 flutes per foot. Original corrugated flute design.
B-Flute
Appx 47 flutes per foot and measures 1/8″ thick; often for canned goods.
C-Flute
Appx 39 flutes per foot and measures 5/32″ thick; common for shipping cartons.
E-Flute
Appx 90 flutes per foot and measures 1/16″ thick.
F-Flute
Appx 125 flutes per foot and measures 1/32″ thick; for small retail packaging.
BC Flute
Double Wall, 6mm-7mm; Combination of B + C flutes; good all performance, mostly used for product shipping containers.
EB Flute
Double Wall, 4-4.5mm; Combination of E + B flutes; provides a perfect balance between transit protection, strength and print finish.Box dimensions are stated as follows: Length, Width and Depth (exceptions include bookfolds, bin boxes and dividers, where the sequence is Width, Length and Depth).
The length is always the longer dimension, and the width is always the shortest dimension, measured along the opening of the box. The depth is the distance between the opening and the opposite panel.
The Edge Crush Test measures the amount of force (lbs. per in.) needed to cause compressive failure of an on-edge specimen of corrugated board. The result is a primary factor in determining the compression strength of a completed box.
Square Container – Layflat Bag
- Measure the width, depth and height of the container to be lined. The depth should be the shorter side.
- To determine the Width(W) of the bag, add the width and depth. Add 2″ for a looser fit.
- The Length (L) of the bag is determined by adding the depth to the height of the box plus 6″ to allow coverage of the box contents.
Example
If the container size is 14″(wide) X 10″(deep) X 32″(high), the bag dimensions are as follows: Width(W) is 26″, Length(L) is 48″.
Square Container – Gusseted Bag
- Measure the width, depth and height of the container to be lined. The depth should be the shorter side.
- To determine the Width(W) of the bag, add 1″ to the width of the box.
- To determine the Depth(D) of the bag, add 1″ to the depth of the box.
- The Length (L) of the bag is determined by adding the depth to the height of the box plus 6″ to allow coverage of the box contents.
Example
If the container size is 18″(wide) X 12″(deep) X 14″(high), the bag dimensions are as follows: Width(W) is 19″, Depth(D) is 13″, Length(L) is 32″.
Round Container – Layflat Bag
- Measure the diameter and height of the container to be lined.
- To determine the Circumference(C) of the container, multiply the diameter by 3.14
- To determine the Width(W) of the bag, divide the circumference(C) by 2. Add 1″ for a looser fit.
- To determine the Length (L) of the bag, add the diameter to the height. Add 5″ for overhang.
Example
If the container size is 12″(diameter) X 30″(height), the bag dimensions are as follows: Width(W) is 20″, Length(L) is 47″.
Pallet Cover – Gusseted Bag
- Measure the width, depth and height of the pallet to be covered. The depth should be the shorter side.
- To determine the Width(W) of the cover, add 1-2″ to the width of the pallet.
- To determine the Depth(D) of the cover, add 1-2″ to the depth of the pallet.
- The Length (L) of the cover is determined by adding 1/2 the depth to the height.
Example
If the pallet size is 40″(wide) X 36″(deep) X 50″(high), the cover dimensions are as follows: Width(W) is 42″, Depth(D) is 38″, Length(L) is 68″.
The most common types of box styles are: Slotted Boxes, Telescope Boxes, Folders, Rigid (or Bliss) Boxes, Self-Erecting Boxes and Interior Forms. As always, we can also create custom designs to suit any need.
Slotted Boxes
Generally made from a single piece of corrugate, slotted boxes arrive flat and are folded using scored slots.
Regular Slotted Container (RSC)
All flaps have the same length. The two outer flaps are one-half the container’s width, so that they meet at the center of the box when folded. The RSC is the most common box style.
Half Slotted Container (HSC)
Same as a Regular Slotted Container (RSC), but without one side of flaps.
Overlap Slotted Container (OSC)
All flaps are all the same length with the outer flaps overlap by one or more inches. It’s usually closed with staples attached through the overlapping area.
Generally, this style is used when the length of the box is significantly greater than the width, resulting in a long gap between the inner flaps. The sealed overlap helps to keep the flaps from coming undone.
Full overlap Slotted Container (FOL)
All flaps are the same length which, in this case, is the width of the box. When closed, the outer flaps come within one inch of complete overlap as opposed to having an overlapping structure as in previously discussed with OSC boxes. This style can resist rough transport and handling and has extra cushioning and stacking strength.
Center Special Slotted Container (CSSC)
Unlike the previously discussed styles, the CSSC box has inner and outer flaps that are cut to different lengths. All sets of flaps meet at the center of the box. The double thickness of corrugated board at the top and bottom allow this style to be exceptionally strong. And the lack of a gap between the inner flaps provides a stable base for the product.
Center Special Overlap Slotted Container (CSO)
All flaps have the same length – which is one-half the length of the box. The length of the box can be no more than two times its width. The inner flaps meet at the center of the box, providing a stable, level base and full protection at the top.
Center Special Full Overlap Slotted Container (SFF)
As we have seen, some styles, like CSSC and SFF, have the inner and outer flaps cut to different lengths. When closed, the inner flaps meet at the center of the box, and outer flaps completely overlap. This style provides extra cushioning and stacking strength by having three full layers of combined corrugated board over the entire top and bottom.Telescopic Boxes
A telescope box consists of two pieces that fit over each other to form a bottom and top where the cover extends over at least two-thirds of the depth of the bottom box so the top “telescopes” over the bottom. A box with a cover generally refers to box tops that cover less than two-thirds of the bottom of the box. There are a few types:
Full Telescope Design Style Container (FTD) and Design Style Container with Cover (DSC)
Two-piece boxes made from two scored and slotted blanks (trays).
Full Telescope Half Slotted Container (FTHS)
The two-piece body is made from two half-slotted containers.RIGID (BLISS) Boxes
Rigid Boxes have two identical end panels and a body that folds to form the two side panels, an unbroken bottom and the top. Flaps are used to form the joints. Once the joints are sealed, the box is considered “rigid”.
Rigid (Bliss) Boxes
Self Erecting
Self-Erecting Boxes typically feature regular slotted containers or telescope-style tops.
Self-Erecting Boxes
Folders
This type of box consist of one or more pieces of combined board, with an unbroken bottom surface and scored to fold around the product. Common styles include:
One Piece Folder (OPF)
One piece of board is cut so that it provides a flat bottom, with flaps forming the sides and ends, and extensions of the side flaps meeting to form the top.
Five Panel Folder (FPF)
A single cut and scored piece features a fifth panel used as the closing flap, completely covering a side panel.
Trays
Trays are formed from a single piece of combined board, with the design featuring an unbroken bottom and several layers of corrugated in the end panels. They are frequently used as inner containers for parts, delicate produce or mail pieces.Forms
These include a wide variety of build-ups, dividers, partitions and other inner packing pieces. They can be used to separate or cushion products, to strengthen the box or to fill voids. They may be simple rectangle, scored, slotted or die-cut shapes. Common formats include:
Pads
Pads are plain shapes of corrugated or solid fiberboard, used to fill spaces or separate layers or sections of products.
Tubes
Tubes are scored rectangles, folded to form a multi-sided structure.Partitions (or Dividers)
Partitions (or Dividers) provide a separate cell for each item in a box. Primarily used for packaging glassware or other fragile items.
Inner Packing Pieces
Inner Packing Pieces are scored and/or folded pieces of fiberboard used for cushioning, suspension and separation, and to fill voids.
Inner Pack Forms
Inner Pack Forms are usually die cut fiberboard pieces designed to position and support products away from the walls of the box for added protection.
GThe Box Maker’s Certificate (BMC) is found on an outside bottom flap. It identifies the manufacturer, as well as, serves as a symbol of compliance with the stated specifics. The stamp identifies the material and certifies the results of the Mullen Bursting Test or the Edge Crush Test.
The Mullen Bursting Test measures a box’s ability to withstand external or internal forces, and to contain the contents during handling. The test certifies that the box can withstand the stated pressure (lbs. per sq. in.) as applied by a Mullen Tester
The Edge Crush Test measures the amount of force (lbs. per in.) needed to cause compressive failure of an on-edge specimen of corrugated board. The result is a primary factor in determining the compression strength of a completed box.
FireBoard Performance Standards
Single Wall
Max Wt. Box/Contents(lbs)
20
35
50
65
80
95
120
Min. Burst Test(lbs. per sq. in)
125
150
175
200
250
275
350
Min. Edge Crush Test(lbs. per in. width)
23
26
29
32
40
44
55
Double Wall
Max Wt. Box/Contents(lbs)
80
100
120
140
160
180
Min. Burst Test(lbs. per sq. in)
200
275
350
400
500
600
Min. Edge Crush Test(lbs. per in. width)
42
48
51
61
71
82
Triple Wall(min. puncture test, oz. per in. of tear)
Max Wt. Box/Contents(lbs)
240
260
280
300
Min. Burst Test(lbs. per sq. in)
700
900
1100
1300
Min. Edge Crush Test(lbs. per in. width)
67
80
90
112
Sun Packaging – South Florida’s Trusted Polybag Packaging Specialists
If your products are packaged in bags, the only call you need to make for complete service is to Sun Packaging Technology, Inc. Let our bagging specialists work with you to create a smooth-running packaging operation using high quality equipment and supplies. We’ll help you with every aspect of your packaging needs from application engineering to next day delivery of supplies. Contact us today to discuss your needs and let us find a solution that spells success.