1、 Packaging function a protection function: to protect the use value of goods, which is the primary function of packaging. B convenient function: mainly reflected in convenient storage and transportation, convenient use and convenient sales. C promotion function: it is mainly manifested in the appearance of the package. Whether the shape and decoration conform to the new trend will play a major role. 2、 Packaging structure design principle a scientific and scientific principle is to apply advanced and correct design methods, appropriate structural materials and processing technology, so that the design standardization, serialization and generalization, in line with the relevant laws and regulations, and products adapt to batch mechanized automatic production. B. the principle of reliability and reliability is that the design of packaging structure should have enough strength, stiffness and stability, and can withstand the effect and influence of various external factors in the circulation process. C aesthetics is to make the packaging structure design meet the aesthetic requirements of modeling and decoration design, including six elements of structural form and six principles of structural form. D economy is an important principle of packaging structure design, which requires reasonable selection of materials, reduction of raw material cost, reduction of raw material consumption, reasonable design procedure, improvement of work efficiency and reduction of cost. The basic factors of packaging structure design are as follows: 1. The physical properties of contents A. solid, liquid, powder and gas. B. chemical properties, vulnerability, deformability, water resistance, moisture resistance, rust resistance and mildew resistance of the contents. C. The application fields of contents include food, medicine, electronics, chemical industry, etc. 2、 The important packaging materials in modern packaging industry are paper, paperboard, plastic, metal, glass, ceramics and various composite materials. A. physical properties of materials: transparency, thickness, barrier, etc. B. chemical properties of materials: chemical stability, safety, anti-corrosion, anti rust characteristics, etc. C mechanical properties of materials: strength, elastic modulus, etc. D material forming process: rheology, plasticity, etc. The decoration of e material: printability, smoothness, etc. 3、 Circulation environmental conditions a physical factors: impact vibration and stacking static pressure, B biochemical factors: temperature, humidity, rain, radiation, harmful gases, microorganisms, etc. C human factors: rough loading and unloading and counterfeiting, etc. in the design, the measures taken under the above circulation environment and the sixth section shall be considered Mechanical principle of packaging structure design includes many basic mechanical principles, such as the calculation of compressive strength, stiffness and stability of containers; the problem of stress concentration; the strength calculation of pressure vessels; the mechanical problems of bending and stamping of metal structures. This section gives a brief introduction to these basic theories and applications of mechanics, which should be further studied in combination with specific learning contents in the future. 1. The tensile mechanical properties of materials take low carbon steel, which is the most widely used and representative mechanical properties, as an example. Its tensile test diagram is as follows: it is divided into four main stages: 1) elastic stage: OA section, when the external force is removed, the deformation is completely restored. 2) Yield stage: in AC section, there is crystal sliding phenomenon, which temporarily loses the ability to resist deformation and produces plastic deformation. 3) And strengthening stage: CD section, which produces irrecoverable plastic deformation. 4) Local deformation: de segment, necking until fracture. When the structure is designed, the stress material is generally required to be in the elastic range. However, the plastic deformation characteristics of materials should be used in the production process such as stamping. 1、 Mechanical properties of materials the mechanical properties of containers are not only related to the structure, but also closely different from the mechanical properties of materials, so it is necessary to study the mechanical properties of materials. Mechanical properties are measured by test methods, generally through tensile and compression tests to test. 2. Other mechanical properties of materials creep properties: under a certain temperature and stress (lower than the yield point), the material slowly plastic deformation with time. Metal materials creep only at high temperature, while polymers also occur at room temperature. Under the condition of relaxation, the initial stress decreases with time. Fatigue limit of materials under the action of alternating stress: in the process of transportation, the package will be damaged after a period of time when the stress is far lower than the yield limit under the repeated action of vibration and impact. Therefore, the fatigue limit should be considered in the structural design to reduce the stress concentration and improve the surface finish of the product. Material hardness: there are many ways to measure the hardness, generally using indentation method, that is to say, the ability of a material to resist plastic deformation in a small volume range. Fracture toughness of material: it reflects the ability of material to resist crack propagation, which is obtained by test. 3. Material design index and applied strength index: it reflects the ability of material to resist plastic deformation, such as yield limit, strength limit, fatigue limit, creep limit, etc., which is the main basis of strength calculation.Stiffness index: an index reflecting the ability of a material to resist elastic deformation, such as elastic modulus, shear modulus, etc. these indexes are used in the calculation of elastic deformation of components, such as stiffness, static uncertainty and stability. Plasticity index: indicates the degree of plastic deformation of material, such as reduction of area, which is the basis of material stamping design. Toughness index: it reflects the comprehensive performance of material strength and plasticity, and is an energy index. It reflects the ability of material to absorb energy in the process of deformation or fracture. It is an important index for selecting materials. 2、 Strength calculation of materials in tension and compression, torsion, bending and other basic deformation conditions, when the maximum stress exceeds the strength limit of the material, it may be damaged, so the corresponding strength check should be carried out in the design: the commonly used strength theories include: Maximum tensile stress theory: as long as the maximum tensile stress of the component reaches the limit value of the material, the material will be destroyed. Maximum elongation linear strain theory: as long as the maximum linear strain reaches a certain limit strain value, it will cause brittle fracture of materials. Maximum shear stress theory: as long as the maximum shear stress reaches a certain limit shear stress value, the plastic yield of material will be caused. Shape change specific energy theory: as long as the shape change ratio of the component can reach a certain limit value, plastic yield will occur. When calculating the strength of Thin-Walled Pressure Vessels in the structural design of metal containers, when the internal pressure is greater, such as spray cans, the strength must be calculated, and the appropriate parameters such as material and thickness should be selected. The calculation is as follows: three. Stiffness of the structure. In the design of packaging structure, a very important problem is the stiffness of the structure. Packaging containers such as cartons, paper, metal cans, plastic containers, etc. must have a certain degree of stiffness, that is, the ability of the structure to resist deformation, so as to better protect the product and the packaging structure itself. Different structures have different stiffness calculation methods, which should be selected according to the specific situation in the design. Generally speaking, the main methods to improve the stiffness of members are: selecting materials with larger elastic modulus. Increase the material thickness and bending section modulus, and add stiffeners (such as steel barrel, tank, plastic container, etc.) in the structure. 4 When the slender member or thin-walled structure (such as the column in the wooden box structure, corrugated box board, etc.) is subjected to pressure, even if the stress is far below the strength limit of the material, it will suddenly deform or even destroy due to losing balance. This phenomenon is called instability. For slender rods, the critical pressure can be determined by Euler's formula; for medium and small flexible rods, empirical formula should be used, which can refer to the general materials mechanics textbook. The main measures to improve the structural stability are: reducing the length of compression bar. Choose a reasonable section shape and increase the size of section moment of inertia as much as possible. Increase the bar or plate end constraint. Choose the material with larger elastic modulus
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, the world's manufacturing city, is a subsidiary of Beite packaging (China) Co., Ltd., with a plant area of 6000 square meters. It is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of domestic advanced production equipment, a scientific and humanized management system and a group of experienced technical personnel For backing, to provide customers with quality products and first-class service.
The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries.
We uphold the integrity of cooperation, good quality, good service business philosophy, won the industry's approval, products sold to all over the world; welcome friends from all walks of life to inquire, visit our factory to investigate guidance and business negotiations.