Most items at your favorite supermarket, discount store, or shopping mall were safely delivered in boxes made of corrugated cardboard, and many are displayed in the same boxes, which were manufactured so they could be opened và used for this purpose. Other items may arrive in their own corrugated or uncorrugated paperboard boxes. Because corrugated cardboard is such a versatile packaging material, millions of tons are used each year lớn protect & display products. During 1992, more than 25 million tons of corrugated cardboard were produced in the United States. Another 6 million tons of uncorrugated boxboard or paperboard were also produced for use in folding cartons.Quý khách hàng vẫn xem: Corrugated là gì
Corrugated cardboard is a stiff, svào, & light-weight material made up of three layers of brown kraft paper. In 1884, Swedish chemist, Carl F. Dahl, developed a process for pulping wood chips into lớn a strong paper that resists tearing, splitting, and bursting. He named it the kraft process because it produces a svào paper that resists tearing, splitting, & bursting.
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From the paper mill, rolls of kraft paper are transported khổng lồ a corrugating, or converting, plant. At the plant, layers of kraft paper are crimped & glued to size corrugated cardboard, which is then cut, printed, folded, và glued lớn make boxes. At the beginning of this process, kraft rolls from the paper mill are loaded into lớn a huge machine called a corrugator. A typical corrugator is as long as a football field—300 feet (91.44 meters). Some rolls of kraft paper are used as the corrugating medium, và others are used as liners, the layers of kraft paper glued on each side of the medium. After the corrugator has heated, glued, và pressed the kraft paper to khung corrugated cardboard, the continuous sheet of cardboard is cut into wide box blanks that then go khổng lồ other machines for printing, cutting, and gluing. Finally, batches of finished boxes are banded together for shipping to the food processor, toy maker, autođiện thoại parts distributor, or any of the thousands of businesses that depkết thúc on corrugated cardboard packaging.
Fast-growing pine trees provide the primary raw material used to make corrugated cardboard. The largest packaging companies own thousands of acres of l& where trees are matured, harvested, and replaced with seedlings. After the trees are harvested, they are stripped of their limbs; only the trunks will be shipped by truông chồng to lớn a pulp mill. The largest packaging companies also own the mills where trees are converted to kraft paper. At the mill, the harvested tree trunks are subjected to lớn the kraft process, also known as the sulfate process because of the chemicals used to lớn break down wood chips into fibrous pulp. After pulping và other processing, the fibers are sent directly khổng lồ the paper machine where they are formed, pressed, dried, & rolled inkhổng lồ the wide, heavy rolls of kraft paper sent to lớn corrugating plants lớn be made inlớn cardboard.
At the corrugating plant, only a few other raw materials are needed lớn make a finished box. Com starch glue is used to bond the corrugated medium khổng lồ the liner sheets. Because so much glue is used, rail cars or large tanker trucks deliver it as a dry powder that will be stored in huge silos at the corrugating plant until it is needed. Drawn from the silo, the dry com starch is mixed with water & other chemicals & pumped inlớn the corrugator to lớn be spread on the corrugated medium as the layers of liner are added. Other raw materials are used to finish the corrugated cardboard after production. Waxes made from paraffin or vegetable oils can be applied khổng lồ make a water- or grease-resistant container for food products. Brightly colored inks are also applied khổng lồ create bold graphic designs for self-supporting displays featuring product name, information, và company name and logo sản phẩm. Teams of salespeople & designers work together to create the manufacturing & printing patterns, called dies, that are used to cut and print a specific box thiết kế. The dies are created in a pattern siêu thị and transferred lớn the rotary die-cutting equipment và printers that finish the box blanks.
Kraft paper has been manufactured since 1906. Since then, pulp processing, paper making, và corrugating operations have been developed khổng lồ a high state of efficiency & productivity. Today, in the corrugated cardboard industry, designers are creating innovative containers that require four-color printing and complex die-cutting. These innovative containers are designed with sophisticated software such as computer- aided thiết kế (CAD) programs, allowing a packaging designer lớn brainstorm different package designs before manufacturing begins. A designer using a CAD program can Gọi up và modify different designs that have been stored in a computer kiến thiết library. Thus, existing packages can generate new designs. Many retail stores use such light, strong, & colorful containers directly, as point-of-purchase displays.
The Manufacturing Process
Pulping the pine chips
1 Manufacturing a corrugated cardboard box begins with the pulping of wood chips in the kraft (sulfate) process. First, tree trunks are stripped of bark và torn inlớn small chips. Next, these chips are placed in a large, high-pressure tank called a batch digester, where they are cooked in a solution, or liquor, made of sodium hydroxide (NaOH) và several other ionic compounds such as sulfates, sulfides, và sulfites. These strongly alkaline chemicals dissolve the lignin, the glue-lượt thích substance that holds the individual wood fibers together in a tree trunk.
2 When the pressure is released after several hours, the wood chips explode like popcorn inkhổng lồ fluffy masses of fiber.
Making kraft paper
3 After additional cleaning and refining steps, a consistent slurry of wood pulp is pumped lớn the paper-making machine, also known as a Fourdrinier machine. Gigantic, square structures up khổng lồ 600 feet long (182.88 meters), these machines contain a wire mesh in which the paper is initially formed. Next, the paper is fed into lớn massive sầu, steam-heated rollers and wide felt blankets that remove sầu the water. At the kết thúc, the finished medium, or liner, is rolled for shipment.
Shipping and storing the kraft paper
4 Rolls of kraft paper for corrugating are available in many sizes lớn fit the production equipment at different corrugating plants. The most comtháng roll sizes are 67 inches (170.18 centimeters) wide và 87 inches (2đôi mươi.98 centimeters) wide. An 87- inch roll of heavier paper can weigh up khổng lồ 6,0 pounds (2,724 kilograms). As many as 22 rolls of 87-inch paper can be loaded inkhổng lồ one railroad boxcar for shipment to a corrugating plant.
5 At the plant, the kraft paper is separated inlớn different grades, which will be used for the medium và the liner. These different grades of corrugated cardboard can be made by combining different grades of kraft paper. A knowledgeable packaging speciadanh mục works with a customer to lớn determine the strength required for the corrugated cardboard container being planned. Then, when a plant receives an order for containers, a sản phẩm engineer specifies the combination of medium và liner lớn produce a cardboard khổng lồ match the customer’s requirement.
Corrugating the cardboard
6 Using powerful fork-lifts, skilled equipment operators select, move sầu, and load rolls of kraft paper at one end of the corrugator.