The hottest transportation packaging theory and te

Transportation packaging theory and technology application (Part 1)

[Abstract] this paper summarizes the latest development of transportation packaging theory and technology in recent years, involving the rationalization of product brittleness 2.0 value, transportation packaging reliability, transportation packaging CAD, CAE and cat, which have far-reaching research significance

key words: transportation packaging; Brittleness value; Reliability; CAD； CAE； Cat

transportation packaging is defined in China's national standard (GB/t4122.1-i996): packaging with the main purpose of transportation and storage is called transportation packaging. It plays an important strategic role in ensuring the safety of products, facilitating storage, transportation, loading and unloading, accelerating handover, point inspection and so on. As a branch of packaging engineering, transportation packaging mainly studies various hazards that cause package damage in the process of circulation, and studies various factors that cause these hazards and the technical or management means that should be adopted to minimize the damage. It usually includes the theoretical basis of packaging dynamics, the circulation environmental conditions of packages, the brittleness value and its evaluation method, cushioning packaging materials and dynamic characteristics, cushioning packaging design, and the design and experiment of transportation packaging system

in modern logistics system, transportation packaging is an important constituent element. Due to the long distance and large volume of global logistics transportation, the products need to be stacked, stored and loaded and unloaded for many times during the transportation process, resulting in a high possibility of commodity damage, high damage rate and increased transportation costs. To solve these problems, transportation packaging theory and technology are particularly important

throughout the development of this discipline over the past few decades, from Mindlin first proposed the important concept of buffer coefficient in 1945 to Newton's theory of product damage boundary conditions in 1968, to the five-step buffer packaging design jointly formulated by Michigan State University and MTs company in the late 1970s, transportation packaging theory and technology have flourished. Nowadays, scholars at home and abroad are actively studying packaging dynamics and transportation packaging technology, which is becoming more and more perfect. The latest developments in recent years mainly include the following five aspects, some of which are leading internationally and have far-reaching research prospects

1 rationalization of product brittleness value

the problem of product brittleness value is one of the core contents of packaging dynamics. The in-depth study of product fragility value is not only of great significance in promoting discipline construction and improving discipline theory, but also of practical value in developing technological innovation and implementing reasonable packaging design. In order to achieve the purpose of reasonable cushioning and vibration reduction in the design of transportation packaging, we must rationalize the brittleness value of products

brittleness value is defined in the national standard gbs166-87 as the maximum acceleration that the product can withstand without physical damage or functional failure. This concept and the damage boundary theory and application based on brittleness value, which are especially applicable to mobile phone screens and flashlight pools, are aimed at mechanical impact, but from the perspective of discipline development, it is incomplete, because in the transportation and circulation of products, impact is not only the main reason for product damage, but also the main reason for vibration. Even under certain conditions, the damage caused by vibration is more prominent. Therefore, a more reasonable brittleness value is needed to guide the design of buffer packaging. With the further development of transportation packaging theory, the connotation and extension of the concept of brittleness are constantly deepening and sublimating. At present, packaging experts in Europe, the United States, Japan and other regions are still continuing to study the theory of product brittleness value, and China's research in this area has reached a high level

1.1 mechanical vibration embrittlement value

for the sake of distinction, the traditional embrittlement value is called mechanical impact embrittlement value, and the product damage boundary problem under mechanical impact dynamic load is called the first kind of damage boundary problem ". Now we discuss the newly proposed mechanical vibration embrittlement value and the boundary problem of product damage under mechanical vibration load, be called "The second kind of damage boundary problem.

this theory believes that there are two kinds of damage models of vibration: vibration peak damage model and vibration fatigue damage model. The former pays attention to the vibration peak - exceeding the limit value can cause damage to products, so the limit value of vibration peak acceleration can be regarded as the impact embrittlement value of products and treated with mechanical impact embrittlement value. In essence, the problem of mechanical vibration embrittlement value focuses on the latter - fatigue For damage, the corresponding type 2 damage boundary curve is represented by G.N curve or g-tf, where the ordinate G is the vibration acceleration value, the abscissa n is the maximum allowable number of vibration cycles without product damage or failure under this acceleration, and TF is the average time of failure. These two kinds of curves are essentially the same

1.2 the combination of two types of brittleness values

has become a technical topic deeply discussed by transportation packaging researchers. At present, a very mature buffer design method is to apply the mechanical impact embrittlement value theory and the first type of damage boundary curve. However, if the impact and vibration factors on product damage are considered at the same time, the second type of damage boundary curve can be applied to promote the progress of product vibration reduction packaging design, and make the two types of embrittlement value problems be coordinated and combined

(to be continued)