Corrugated Boxes – A Master Guide

Purpose and Types of Packaging Boxes

The primary purpose of packaging is to protect and preserve a product. Nowadays, custom packaging is gaining importance. It can serve the above definition and be used to display and advertise a product and its brand.

There are many types of packaging materials. These include Rigid, Kraft, Corrugated, Cardboard, aluminum foils, folding cartons, etc.

Corrugated and cardboard are the most common and widely used packaging materials. These are often considered similar. But these packaging boxes have different characteristics.

Difference between Corrugated and Cardboard

Corrugated Packaging

Corrugated packaging boxes consist of three layers. These are called inside liners, a flute, and outer liners. The middle layer is called a flute. It is a zigzag or wavy layer glued between these two line boards.
Corrugated packaging boxes are like cartons.

They are heavier than cardboard and durable. They are more sturdy and capable of carrying medium to heavy weight products.

Corrugated boxes are primarily used to safely deliver a product from one place to another. Their design of three layers gives extra protection to a product. Its structure can sustain a considerable amount of pressure relative to its weight.

Cardboard

Cardboard is lighter than corrugated. It can hold small to medium-weight products. Cardboard is thinner than corrugated. It is composed of a single layer of paperboard.

Cardboard is made of thick or heavy paper pulp and is mainly used to display a product at retailers’ shops. It is used to pack perishable food items, makeup products, board games, etc. Due to their softer material structure, they can easily be adjusted to product size and shape.

Their strength in carrying a product and their composition make these materials different.

The Corrugated Industry

Corrugated packaging is ideal for shipping bulk quantities of a product to far destinations. Nowadays, the world is becoming a global village. Due to the internet, every manufacturer, business and product is accessible. Pandemic has also increased the trend of online shopping.

Corrugated boxes are best for efficient and smooth shipping of a product. It prevents any damage to the product during its shipping. With the increase in online shopping, corrugated box demand is also increasing.

Corrugated packaging is the strongest of all packaging materials. It can hold heavy-weight commodities. They are versatile, stable, and durable.

Types of liner paper used in corrugated packaging

A typical corrugated box consists of three sheets. One is an inner liner, outer liner, and Flute. These liner boards are composed of different materials.

Kraft Liners

Kraft Liners are packaging paperboards. It contains 70-80% virgin fiber content. This fiber is produced from chemical sulfate or soda processes. These Kraft liners can withstand pressure. They are very stiff and are not easy to tear or distort. Kraft is very environmentally friendly, but it is expensive as well. They have a very smooth surface and are ideal for printing. They are primarily used as the outer layer or liner board of a corrugated box. There are various forms of Kraft Liners. These are:

• White Top Kraft consists of a white top on one side and a Kraft on the other. It enables the printing of high-quality designs.
• Oyster Kraft has blotches on its surface.
• Fully bleached White is a form of white Kraft liner. It is through a bleaching process to give a white and natural look to its surface. This paper is not sustainable.
• Brown Kraft comes in different shades of natural brown color. They vary in color due to different concentrations of fiber used, paper mill location, and pulping process.

Test Liners

Test paper is another form of packaging paper. It is more economical than Kraft paper.
It contains a high amount of recycled fibers. They are not as durable as Kraft. Its composition contains a high amount of recycled fiber content, so its surface is not smooth. It is difficult to print on such paper.
Test papers are mainly used as the inner layer or liner board of corrugated boxes.
These test papers have different forms:

• A fully recycled test liner is known as Test 3 Liner.
• Partially recycled liners are known as Test 2 Liners.
• Liners with a white coating and recycled are known as a White top
• Liners with blotches and marks are known as Oyster

Flutes layer

These are wavy and zigzag layers in between liner boards. They give extra protection and strength to the design of a corrugated box. Paper is used in making them, but these flutes are in the form of arches. There are two main types of flute papers:

• Recycled flutes

This fluting paper is made from 100% fully recycled fibers. It is also known as Waste based fluting paper. Additional starch is used to make it more robust and sturdy.

• Semi-Chemical Fluting paper

It is produced from 80% hardwood purified and 20% softwood fibers in a neutral sulfite semi-chemical process.

Board Types

As we have discussed earlier, corrugated packaging comprises multiple layers. They include a liner board layer and a flute layer called a corrugated fiberboard layer. These layers’ quantity can be varied to change the thickness of corrugated boxes.

These layers can be adjusted according to the weight and characteristics of the product. Corrugated packaging, by changing these layers’ quantity, can take the following forms:

• Single Face

It includes a single flute and a liner board layer. It shows a corrugated or zigzag layer on the side of the packaging. This packaging style exists in roll form. It is used for the wrapping of a product.

• Single-wall

It is the most commonly used corrugated packaging form. It comprises a single corrugated fiberboard or flute layer that is clubbed between liner board layers. They are lighter in weight.

• Double-Wall

Double-wall corrugated packaging is relatively sturdy and heavy in weight. It is composed of a two-layer corrugated fiberboard glued between three layers of liner board. Such packaging is used to carry heavy-weight products. It is very durable.

• Triple-Wall

This is the strongest of all forms of corrugated packaging boxes. It consists of three corrugated fiberboard and four liner board sheets. These corrugated fiberboard sheets are clubbed between three liner board sheets. They can carry weights up to 300lbs.

Flute Categories

The wavy layer of corrugated packaging boxes is known as a flute. These flutes give extra strength to corrugated packaging. The fluted layer consists of arches with a proper curve. This flute layer can vary by changing the number of turns and thickness.

These arches can be stretched to modify flute strength and number. Corrugated boxes come with different flute categories. These are:

• A-Flute

A-Flute is the strongest and thickest. The arches are very close to each other. It has 36 flutes per foot and a thickness of ¼”. It is a very sturdy design.
Its closely joined flutes enable it to protect the product from adverse atmospheric effects.

• B-Flute

Corrugated boxes with a B-Flute layer have less strength than A-flute. It has 49 flutes per foot and a thickness of 1/8. Its surface is very suitable for producing high-quality prints and die-cut designs. Its inner surface design is best for including additional features like dividers, partitions, etc.

• C-Flute

C-Flute is the second category regarding the number of flutes per foot. It has 41 flutes per foot with a thickness of 11/64″. Its arches height is lower than A Flute arches height. Its surface is also very smooth for printing. It is used to transport items like furniture and glass.

• E-Flute

Corrugated flute boxes with E-type flutes are fragile. It is used to display and pack consumer products. It has 90 flutes per foot with a thickness of 1/16″. Such box has excellent crushing resistance quality.
Its surface is flattest, which male it best for producing high-quality print results.

• F-Flute

F-flute corrugated boxes have 125 flutes per foot. They are half the thickness of E-flute packages. It is very lightweight and thinner. They have the most negligible fiber content in their composition.
It is more environmentally friendly.

These flute categories can be combined to add some variation to the corrugated box style. Many combinations of flutes for corrugated boxes, like AC, EB, BC Flute, etc. They combine features of two flute types.

We can change the number of layers and flute thickness, and heights. IN this way, we can mold corrugated boxes according to the product specifications.

Quality control tests

Many tests can be administered to judge the quality and strength of corrugated boxes. These tests include:

• Edge Crush Test

It measures the stacking strength and durability of a corrugated box. This test is performed by applying a force perpendicular to its edges. The force is applied to the corrugated box until it distorts.

The value of the result is shown in pounds. This pound value shows the linear capacity of corrugated box edges to bear pressure.

• Flat Crush

Another test for measuring the strength and carrying capacity of corrugated boxes is the flat crush test. In this test, a force is applied to the surface of the corrugated fiberboard. It is applied until the Flute loses its structure and becomes flat. It is used to measure how much compression a corrugated fiberboard can resist

• Burst Test

It is also known as the Mullen Test. It tests the durability of a corrugated force. This test measures the amount of pressure required to break the line board. The results are given in pounds per square.

• Water Absorption Test

Merely measuring the carrying capacity and durability of corrugated boxes is not essential. Another factor that determines their strength is their water-absorbing power. It measures the strength of a material to withstand any liquid or moisture. This test determines how much a corrugated box can protect a product by preventing any liquid from entering it.

In this test, we use an open container with some amount of liquid in it. Paper material is placed in this container. This container is then turned upside down. This is used to test how much water material is capable of absorbing.

• Ring Crush Test

The compression of paper and board materials is measured using the ring crush test. A ring is made from a fixed length and breadth strip of paperboard. The paper is pushed perpendicular to its edge until it buckles.

• Box Maker’s Certificate

It is a label or tag on a corrugated box. It provides valuable information about box dimensions and specifications. This is known as a box maker’s certificate or shortly as BMC. A BMC comes in two forms.
One is called ECT-Rated BMC, and the other is Mullen-Rated BMC.

It states information about the manufacturer of the corrugated box. It also specifies the board type, the box, and the weight it can carry. Lastly, it also contains the box’s manufacturing state or city name.
This certificate is in circle form. It consists of two circles. The box manufacturer’s name is written in the outer box only. The inner box represents a box certificate.

It tells us about corrugated box board type, i.e., whether it is a single face, single-wall, double-wall, etc.
It contains various labels like board construction, minimum combined weight, gross weight limit, and city and state.
Board construction tells us about a corrugated box’s thickness, layers, and flutes.
Minimum Combined Weight Facing indicates the combined weight of the line board before it is cut down to make various corrugated boxes.

The Gross Weight limit specifies how much weight a specific box can carry.

Size limit indicates the width or external dimensions of a corrugated box. This information can represent how much space a package can take during shipping. This dimension information is also helpful in determining the amount of product easily fitted in a corrugated box.
Lastly, it provides state and city information. It is indicated at the bottom of the box. It represents the destination where the box is constructed and shipped from.

Benefits of Corrugated Boxes

Corrugated boxes have a lot of benefits. They are mainly used for the safe delivery of a product. These benefits are:

• Protection

Corrugated boxes are very sturdy in structure. They are capable of firmly holding bulk quantities and ensuring their safe transit. They are designed in a way that many products fit closely inside them. These boxes prevent movement, collision, and breakage of a product during transportation.
They can also withstand adverse atmospheric pressures. Three protective layers of a corrugated box act as a shield for preserving a product for a longer time. They can also withstand the pressure exerted on them without affecting the product’s shape.

• Durable

Corrugated boxes are very durable. These boxes cannot be easily punctured. They have a well-built and robust structure. Flutes and layers make them an appropriate option for product delivery without damage.

• Environment Friendly

Corrugated boxes are environmentally friendly. Their composition consists of recyclable fibers. They are not harmful to the environment.

• Customizable

Nowadays, customization of packaging is very significant. It helps to grab customer attention and increase the display of an item. Corrugated boxes can easily be molded according to product specifications. The number of layers, flutes’ thickness, and height can be changed and adjusted to a product’s features.

Similarly, they lend a very smooth surface to produce high-quality printing designs. We have many options to customize corrugated boxes according to product requirements.

Industries that can benefit from Corrugated Boxes

Many industries can benefit from corrugated packaging. It is an ideal option for the shipping of a product long distances. In recent years’ e-commerce and online shopping trends have shown exponential growth.
This also increases the importance of corrugated boxes. They can withstand heavy pressure and atmospheric pressure. They prevent a product from breaking during its delivery.

Its multiple layers provide extra protection to a product during its shipping. So, manufacturers engaging in e-commerce business find it a very ideal option. They can deliver the product safely to consumer destinations with these boxes.

Moreover, their sustainability feature also makes them more preferred packaging. Many businesses use them as a competitive edge. It gives an impression to customers that companies care about the environment they are living in.

Conclusion

Corrugated boxes are the sturdiest packaging types among all packaging boxes. They are gaining more importance due to the increase in online shopping trends. They facilitate smooth and safe shipping of a product.
Corrugated boxes are multilayered, and these layers act as cushions to protect inner products from breakage. They can be used to pack various products from light to the heaviest material.

They are perfect for wholesale order delivery. Another distinctive feature of corrugated boxes is that these layers’ quantity and thickness can vary. These can be changed according to product weight.
Lightweight products require thin corrugated boxes. On the contrary, heavy weight requires thick layers of corrugated boxes. So these layers can be adjusted to product weight and size.