Corrugated fiberboard structure and Properties

Difference between integrated and independent corrugated board supply company

For integrated companies, they carry out all of the productions processes involved of cardboards. These operations include making the containerboard, printing the boxes, and combining the boards into corrugated boards. Inmost cases, the are large companies that supply around half of the materials they use in converting. On the other hand, independent corrugated board supplies will only buy the containerboards or combined boards from integrated producers, which they combine to combine the board for making boxes. Independent suppliers unlike the integrated ones buy most of their materials they use for converting. This poses a stiff competition to both kind of suppliers since they have to sell to the customers the same finished products.

Difference between a sheet feeder plant, a sheet plant, and their descriptive names

A sheet feeder plant also described by the name a corrugator plant is a factory that makes combined boards with the sole purpose of supplying them to box plants. box plants is the descriptive name for a sheet plant, which only makes boxes from the materials is purchases from the sheet feeder.

What kind of pulping and papermaking process is Linerboard made What kind of process is used to make medium? Why?

Linerboards are made in sulfate pulping of softwood using a duplex fourdrinier and papermaking process. The kind of process used is semi chemical pulping for medium since it provides shorter fibers that have a higher stiffness. Additionally, it has a higher resistance to crashing crash as well as higher yield that leads to lower prices that make them affordable.

What kind of adhesive is generally used to combine corrugated board? What is the significance of the adhesive gel point?

Glue is used to combine the corrugated board. The adhesive gel point is significant since it is where the corrugated board pieces and the glue are joined to form the complete board.

Meaning of the engineering beam principle and its application to corrugated board

The engineering beam principle means that two flat panels that are bearing load and separated by a structure are able to resist pressure and bending. In simpler terms, it means that the two flat panels are stronger. This is applied in corrugated boards since they are two linings that bear weight and they are separated by a rigid corrugated web. This allows the corrugates board to withstand pressure and bending from all sides.

Flute letter designations in order of increasing flute size and increasing number of flutes per inch

In order of size

N, F, E, B, C, A, K

In order of increasing number of flutes per inch

K, A, C, B, E, F, N

Which is flexurally stiffer: A-, B-, and C- and why

A- is the stiffest flute flexurally than all the others. The reason is that it was the first made with a main purpose of providing cautioning to materials such as glass bottles. B- is the list flexurally stiff since it was made with a main purpose of reducing flat crash resistance to enable better printing than A-. C- come in between the two for general purposes

How many liner are in a triple wall board?

In a triple wall board, there are four liners since the board has three corrugated mediums. The liners are required to cover all the corrugated mediums or walls

Side of the corrugated board that is printed first or second face applied in the corrugator

The second face applied in the corrugator is the first to be printed since its appearance is uniform than the other is and has less pronounce glue lines

The role of steam in the process of making corrugated boards and the use of heat

In the process of making corrugated boards, steam is used for softening them since the paper can absorb water. After they are softened, heat comes in at the dry-end for drying the newly formed paper where they are heated from the bottom using hot plates. While the moisture makes them softer, the heat makes the, pliable which prevents the medium form being too dry. When it is too dry, it cannot form properly.

How can corrugated board be made more water and weather resistant? Where can standards of water and weather resistance board with names like V3c and W5c be found

Corrugated boards can be made more weather proof through wet-strength, water resistance treatment and adhesives such as corrugated and solid fiberboard sheet stock and fabrication of fiberboard shipping containers. Some earlier methods cannot be accepted today such as the asphalt impregnation and rubber adhesives due to environmental concerns. Names such as V3c and W5c can be found in military application.

What is the difference between wax impregnation, curtain coating and cascading? Which provides the most water resistance?

Wax impregnation in the containerboard in the corrugation process involves a treatment of dry wax. With this method, the penetrating of the wax has to be controlled keenly to avoid inhibition of corrugation and gluing. The maximum wax that is penetrated using this method is 18%. It can be applied on the entire walls of boards. Curtain coating on the other hand is applied on flat blanks only unlike wax impregnation that is applied even on the corrugated boards. This is done through passing the flat boards through a thin continuous curtain horizontally that is modified with polymer wax to form a coat of film on the surface. This cannot be done on the corrugates boards. Cascading, unlike the others can be done on a box and the surface walls. This is done trough passing the surface vertically through cascades of paraffin based wax. The aim is saturating the combined board and can add up to 45%. Cascade waxing provides the most water resistance between the three methods.

Why is corrugated board the paper material with the highest recycling rate

The first reason corrugated paper is the highest recyclable paper material is because 80% of goods packaged in paper are packaged using the corrugated paper. This also means it will be discarder in the highest volumes. It is easy to collect them in large numbers from retailers who have them in bulk after purchasing of goods. This further makes it quite economical to recycle them. another benefit is reducing disposal costs since retailers and user do not have to dispose them. rather, the company will recycle them.

14.To what properties of the linerboard is the combined board Mullen burst test most closely related? What is the effect of the medium in the Mullen test?

The Mullen burst test is closely related to the tensile strength of linerboards and is not affected the medium tensile strength that unfolds when the linerboard stretches due to the slack. Consequently, the linerboard tensile strength is related directly to the facings’ combined weight and their quality.

What is meant by “200 lb test” board?

A “200” lb test” board means a board that has a Mullen burst strength of 200psi

Under what conditions is the Beach Puncture test used instead of the Mullen Burst Test

The Beach Puncture test in used in place of Mullen Burst test where the corrugated board has heavier grades such as the triple wall corrugated board because of the Mullen Burst’s inability to pop through the thicker boards. It measures the ability of the board to resist penetration by sharp agents where the test uses a pendulum with weight and a sharp pyramid tied to the end. Strength is tested at different heights.

Are Beach Puncture Units the measure of force, pressure, energy, or momentum?

The Beach Puncture test is a measure of force where it measures the force that can penetrate the board. It is measured by multiplying the weight used by the height at which it is released. Weight * height = force. Thus, it measures the force.

In which direction do the flutes run in most boxes? Why? In what direction does the MD of the containerboard run in most boxes? Why?

Ni most boxes, flutes run form top to bottom of the box, which helps them in acting like columns that provide support for the boxes above. Acting as columns helps in stronger. Additionally, they act as arches that resist flat crashing and provide cautioning through trapping air. the MD of the containerboard in most boxes runs in the cross-machine direction or perpendicular to the flute direction, which is the most common orientation of stacking in boxes. This is aimed at improving the compression strength in the combined boards.

ECT of an ECT sample of (2” × 1.5”) that buckles at 64lbs

ECT = W/L – 63/2 = 32 lb/in.*W = load weight; L = sample length

What purpose is served by waxing the edges of ECT sample?

Waxing the edges of the ECT sample serves the purpose of stiffening the and preventing the edges from crinkling or rolling over. This will force the failure of the board to occur at the center of the board, rather than at edges, hence reducing errors during the test. It is done in preparation of the ECT in order to reduce the errors likely to occur. When waxing of the edges is not done properly and the edges re not parallel and straight, the ECT value is reduced. Thus, waxing comes in to eliminate this error.

What properties of containerboard and of converter boxes are related to ECT? How can the papermaking process improve ECT?

The containerboard and converter box properties that are related to ECT are the stacking ability. Containerboards and converter boxes are meant to stack so that they are easily packed. Additionally, it related to the cross-machine direction performance of linerboard medium found in the RCT test.

What characteristics of corrugated board does the flat crush test evaluate

The flat crash test that is abbreviated as FCT evaluates the rigidity of the flutes. The board that scores a low flat crush test is likely to crush easily during conversion and printing processes. A crushed board is less stiff and can bend easily.

If a 3” disk of C-flute buckles in the flat crush test at 140lbs, what is flat crush value?

Flat crush test is measured by = force (lbs)

Area (in”)

Area = 2 × 3.143 × 3 × 3 = 56.56

FCT = 140 / 56.56 = 2.475 in²

What does the pin adhesion test evaluation?

The pin adhesion test evaluates the glue bond strength of the combined board. It is used for quality testing, and on should note that the stiffness of the liner influence the result.