Packaging function and detection of the hottest po

Abstract: This paper introduces the use characteristics and packaging functions of flexible packaging materials in detail, and describes the testing requirements, necessity and precautions of conventional physical properties. At the same time, the services and functions of Labthink Languang routine laboratory are introduced

key words: polymer, flexible packaging, physical properties, chemical properties, packaging functions

the application of polymer materials has changed the shortcomings of bulky, complex packaging and single function in the past, so it has been widely used in food, medicine and other industries. At the same time, due to the customizability of polymer properties, it is possible to design the structure of packaging materials according to the characteristics of contents and the intention of designers. Statistics show that at present, plastic packaging (including containers and tools) accounts for about 30% of food packaging in China, and is on the rise, and its growth rate is faster than that of paper food packaging. In recent years, China has increased the supervision of the quality control of packaging materials, but at present, there are still some hidden dangers in the safety performance of food packaging. There are still many problems in the quality of food packaging, such as selecting different parts to test at least three hardness values. Therefore, from this year, China began to carry out compulsory product certification for food packaging/container products to enhance the quality assurance of plastic packaging

1. The basic functions of modern packaging include protection function, convenience function and promotion function. From the completion of packaging to the hands of consumers, a product needs to go through loading and unloading, transportation, storage, display and other links. In each link, there are many factors that can cause damage to the contents. The protection function of packaging is to prevent the loss of product quality and quantity caused by these destructive factors in the logistics process. The convenient functions of packaging include convenient loading, convenient transportation, convenient loading and unloading, convenient stacking, convenient opening, etc. there are certain requirements for the performance of the selected packaging materials. For example, in order to facilitate opening and use, the materials are required to have appropriate mechanical properties. The promotional function of packaging is mainly achieved through packaging decoration design and modeling design with reasonable and pleasant colors, patterns and modeling, which largely depends on the shape, color, texture, transparency, gloss and printing adaptability of materials

for food packaging, especially flexible packaging, plastic film needs to be put into operation before the above packaging functions can be completed, which will increase the company's production capacity by 320000 tons and have certain physical and chemical properties. Physical properties generally include mechanical properties, thermal properties, optical properties, barrier properties, etc. in addition to barrier properties, they can be collectively referred to as conventional physical properties, which can be tested by conventional testing equipment. Chemical performance indicators include evaporation residue, potassium permanganate consumption, heavy metal content, and organic solvent residue, which need to be detected by chemical reagent or meteorological chromatograph. This paper focuses on the testing of conventional physical properties of materials

2. Routine physical property testing of packaging materials

routine physical property testing is the basis of quality assurance, and its purpose is to avoid package damage before completing the predetermined packaging efficacy. If the conventional physical property test of packaging materials is unqualified, the possible damage of packaging materials will make all the protective functions of packaging materials invalid. It is futile to use any functional materials and materials with better chemical properties. Conventional physical property testing includes the testing of material mechanical properties, thermal properties, optical properties, etc. in addition, according to different applications of materials, there are different requirements for material combustion performance, electrical properties, dielectric resistance, etc., so the testing items of materials should be determined according to specific packaging applications

for the majority of flexible packaging manufacturers, the demand for testing performance indicators between departments and regions of material mechanics is the strongest. Mechanical properties include tensile properties, bending properties, impact properties, shear properties, friction properties, heat sealing properties, etc. any failure to meet the standard may lead to the rupture of the packaging or the operation error of the production line. For example, the Heatsealability of the material includes two aspects: the hot tack of the heat sealing part when it is still hot (not yet cooled to the ambient temperature) and the ultimate strength of the heat sealing part after it is cooled and stabilized. Heat sealed bags are widely used in daily chemical product packaging, food and drug packaging and other fields. Most of the filling methods on the flexible packaging production line are to let the products fall into the packaging bag from a certain height, which will impact the bottom of the packaging bag. If the bottom of the packaging bag cannot withstand the rupture force caused by the filling of the contents during the filling process, the bottom will crack, resulting in the bag breakage. In order to effectively control the bag breaking rate of the production line, we pay more attention to the heat sealing strength of the material after heat sealing when the heat sealing layer is not completely cooled, which is commonly referred to as the hot tack of the material. However, since most of the packages are stacked together during storage and transportation, if the contents are liquid or in the form of modified atmosphere packaging, the heat sealing strength of the packages cannot withstand external pressure during storage and transportation, and the bag will be broken. Therefore, there are certain requirements for the heat sealing strength of the heat sealing part of the materials after cooling

thermal properties include thermal stability, coefficient of linear expansion, coefficient of thermal conductivity, low temperature test, etc., of which the flexible packaging related industries pay most attention to the thermal stability and low temperature test of materials. The thermal shrinkage of materials is one of the thermal stability of materials, which later became an important test index of shrinkage films. Optical performance is also a very important index. When packaging light sensitive food, we should pay special attention to the optical performance test of materials. The main test items include the light transmittance and haze of materials

3. Test influencing factors

conventional physical testing items can basically be tested with corresponding testing equipment. For the same index, there may be more than one testing method, and the test environment, sample size and pretreatment will affect the test results. Generally speaking, the influencing factors of the test mainly include: test environment, pretreatment and the test method used

the test environment will affect the test results. For example, different temperatures will lead to significant changes in the friction coefficient. Humidity will also affect the test results of some polymers, especially polar polymers

pretreatment environment and pretreatment time will affect the test results, which is mainly due to the inconsistent manufacturing environment and incomplete internal stress elimination of the sample. The comparison test needs to be carried out under the same pretreatment environment and pretreatment time

the test methods are different, and the test results are not comparable. Therefore, when comparing the material properties, it must be carried out on the premise that the test methods and various test conditions (ambient temperature and humidity, test speed, etc.) are the same. For China's flexible packaging industry, purchasing testing equipment that fully implements China's national standards is an effective way to improve the comparability of material data

bthink Languang routine laboratory

labthink Languang routine laboratory mainly provides customers with the testing of routine physical properties of samples and displays Labthink Languang routine series testing equipment. The laboratory is equipped with a series of conventional performance testing equipment for flexible packaging materials developed and produced by Labthink Languang, including mechanical performance testing equipment, thermal performance testing equipment, optical performance testing equipment, etc., as well as a series of ink printing quality testing equipment. These conventional testing equipment can be used to test and analyze the mechanical properties, thermal properties, optical properties and ink printing quality, The comprehensive evaluation of material properties is given to help flexible packaging manufacturers judge whether the material properties meet the use requirements. Borrow 4 According to the type of stress cycle, it can be divided into: constant amplitude fatigue test, frequency conversion fatigue test, program fatigue test, random fatigue test and other testing equipment in the Languang routine laboratory, which can fully meet the needs of the national standard for the routine physical property testing of materials (except the barrier index, which can be completed by the Languang barrier laboratory), It can provide comprehensive testing services for food packaging manufacturers and related suppliers to pass 3C certification