The design and application of packaging materials today

Today's packaging has grown to a very wide range of materials, from natural materials to man-made packaging materials, from single materials to composite materials. The choice of materials in packaging design is generally based on the principles of science, economy, and practicality.

Paper packaging material

Paper packaging material is one of the most widely used materials in the packaging industry. It is easy to process, economical and suitable for fine printing.

1. Kinds of paper packaging materials

Paper packaging materials can be basically divided into paper, cardboard, corrugated paper three categories.

A. Main types of paper

Kraft paper: Mainly made of sulphate pulp, it has the characteristics of low cost, high strength, thick fiber, good air permeability and so on. They are mostly used to make shopping bags, paper bags, food and small packaging papers, official bags, etc., and are also used as face sheets for the manufacture of corrugated paper.

Bleached paper: Soft and hardwood mixed pulp, produced using the sulfate or sulfate process. With high-strength paper white and fine, smooth, suitable for modern printing process. Often used as wrapping paper, labels, bottle stickers, etc.

Wax paper: It is made of waxing technology and has strong water resistance and paper with certain strength. It is mainly used for inner packaging, such as food, fruit, cakes, textiles and daily necessities to protect the packaging materials.

Cellophane: Made from natural cellulose, it can be painted, waxed, coated, etc. It is characterized by smooth surface, good transparency, high density, strong tensile strength, and low retractility. It is suitable for printing and resisting. Good moisture and oil resistance, mainly used for food packaging.

B. Main types of cardboard

Paper and paperboard are mainly differentiated according to the quantitative and thickness, but the specific limits are not very clear. Paper with a basis weight of 200 g/m2 or more and a thickness of 0.3 mm or more is generally referred to as paperboard. The raw material for making cardboard is basically the same as paper. Because of its high strength and easy to fold characteristics, it becomes the main production paper for product packaging carton. There are many kinds of cardboard, the thickness is generally between 0.3 ~ 1.1mm.

Manila cardboard

It is called coated manila paperboard, which is light yellow cardboard made from chemical pulp and ground wood pulp and used for mixed coating of chalk flour and starch.

White cardboard

Made of chemical pulp with waste pulp. There are ordinary white cardboard noodle white board, Kraft noodle white cardboard and so on. There is also a white cardboard made with chemical pulp, also known as high-grade whiteboard paper.

Yellow cardboard

Refers to the low-grade paperboard made of pulp made of lime with the straw as the main raw material. It is mainly used as a core that is affixed to the paper box and serves as a fixed function.

Kraft board

Made from kraft pulp. One side called kraft pulp is called single-sided kraft paperboard, and two sides of kraft paperboard are called double-sided kraft paperboard. The main function of corrugated cardboard is called kraft paperboard, and its strength is much higher than that of plain paperboard. In addition, water-resistant resin can also be used to make water-resistant kraft paperboard, which is used for the collection of beverages.

Composite processing cardboard

Refers to the use of composite aluminum foil, polyethylene, greaseproof paper, wax and other materials composite processed cardboard. He made up for the lack of ordinary cardboard, with a variety of new features such as oil, water, freshness.

C. Corrugated cardboard

Mainly consists of two parallel flat sheets of paper as the outer sheet as the outer sheet and the inner sheet, and the corrugated corrugated medium which is processed by corrugating rolls is sandwiched between them. Each sheet is bound together by the adhesive applied to the corrugated peaks. . Corrugated board is mainly used for making outer packaging boxes to protect goods in the circulation, and finer corrugated paper can be used as inner liner of merchandise cardboard packaging to reinforce and protect goods. There are many kinds of corrugated paper, such as single-sided, double-sided, double-layered and multi-layered.

Corrugated paper can be divided into V-shaped U-shaped, UV-shaped three.

The radius of the semi-arc of the waveform turning circle of the V-shaped crucible is smaller and the compression resistance is good. But beyond the compression limit is very easy to damage, cushioning difference, and the adhesive coating surface is small, not easy to bond; U-shaped 楞 wave shape turning radius of the larger arc, the cardboard is flexible, strong ability to absorb shock, good cushioning, bonding The agent has a large coating surface and is easy to be bonded, but its resistance to pressure is weak. The UV-shaped crucible combines the advantages of the above two types of crucibles. The arc radius is larger than the V-shape and is smaller than the U-shape. It is the most widely used corrugated paperboard at present. The corrugated shape of corrugated paper is generally classified into four types of ABCE according to the size, density and characteristics of corrugated medium.

A is characterized by a small number of corrugations per unit length and a large height, a large buffer force suitable for packaging fragile items; B 楞 and A 楞 contrary to the number of corrugated units within a unit length is small, so the B-shaped 楞 is not easy to damage , And can be used to create a complex composition of the box, the unit length of the number of corrugated file and between the height between AB, performance close to A single thickness less than A, can save storage and transportation costs, is more common in Europe and the United States; The number of corrugations per unit length is the largest, and the corrugation height is the smallest, so it is commonly used to manufacture corrugated folding carton packs, which have better cushioning performance than ordinary cardboard, and have good slotted cuts, good surface quality, and can be printed in color. .