Performance evaluation of linear split packaging materials (Part 1)
translator's note:
linear split packaging materials are easy to open packaging materials with practical use value, which deserve our high attention. This paper not only introduces a kind of packaging material made of non-woven fabric with linear crack performance, but also puts forward the evaluation method of easy to open packaging material with linear crack performance, which is of great reference value, and is specially translated and recommended to readers
the importance of linear cracks
in the trend of high functionality and high added value of packaging, it is important to improve the ease of opening of packaging. The first function is to protect the items inside the package, and it is required to be easy to open when opening. Protecting the contents and easy opening are two opposite aspects. How to solve this problem is an interesting challenge for functional packaging
the general feature of plastic film is that it is easy to tear through the notch with concentrated stress. If there is no notch, it is not easy to crack even if it is torn. As a packaging material, it is often hoped that it has excellent protective function and can open neatly where it needs to be cracked. This is one of the characteristics of packaging materials. In the trend of high value-added, a scheme to further endow the film with additional properties is proposed. However, when such functional packaging materials are actually used, the purpose of these Functionalizations may not be the same, and the functions obtained in the final packaging are also different. But these different systems are not discussed
the additional function aiming at easy opening has the following points:
⑴ tear in the desired direction of cracking, which should be a straight crack
⑵ the tear propagation force should be small when opening
⑶ any place can crack freely
1. Plain is very important. No matter who has experience: when we open the seal, the crack spreads in an unwanted direction, and the contents will leak out or be damaged, which is undesirable. Therefore, the straight-line propagation of the crack and taking out the inner objects without force are extremely important
in fact, as long as the sensory discussion is made, there is no universal method to quantitatively evaluate the straight-line propagation of cracks. The author and others defined the physical property of straight crack as "straight crack" (the original text is "straight crack"), and first put forward its quantitative evaluation scheme
2. It is the propagation load, which is evaluated by standardized test methods such as the standard single table tear strength test and the tear strength of trapezoidal specimen tear strength test. From the perspective of easy unsealing, the lower the tear strength, the better. However, if you tear it with too little force, it will be difficult to unseal because of too little force
3. It can be opened freely even if there is no incision, but it can be torn freely at the non incision of the substrate, which is related to the problem that it is easy to open by mistake. For applications such as strapping, it is important to tear it freely at any position on site, but it should be considered from the perspective of matching the packaging with the protection function
evaluation method of "linear fissuring"
the author and others proposed the evaluation method of "linear fissuring" as shown in Figure 1. And take a 50mm wide and 300mm long strip, cut two cuts at one end, and cut it into three parts. Use the testing machine to reverse pull the ends of the two pieces on both sides and the middle piece, and pull the two pieces on both sides to separate from the middle piece. The pulling speed is equivalent to the speed of people opening the seal, which is generally set to 1000mm/min. See Figure 2 for the results of the split test piece. The base material with good "linear crack property" is divided into three beautiful rectangles. If the "linear crack property" is poor, the middle strip becomes thinner. At this time, measure the width of the strip 50mm away from the initial crack, and take the change of width as the index of "linear crack property"
in addition, it is possible to obtain the load information of crack propagation at the same time after using the tensile testing machine
through the non-woven fabric "ミラィフフフミラィフㄇフミラィフ" is a special non-woven fabric made by xinrishi company using its own stretching arrangement technology. It is a composite non-woven fabric with right angles of longitude and latitude, which is obtained by compounding the longitudinal non-woven fabric arranged longitudinally with the "mother protecting" service and other non-woven fabrics arranged horizontally with the fibers made by different processes.Weaving, It is very different from ordinary chaotic fiber nonwoven fabric
the protagonist of this article is Xinri stone company. The internal fibers are only longitudinally arranged longitudinal non-woven fabric "タㄪミラィフフトト|", which is used to compound with the film. When the film opens, the propagation direction of the crack can be controlled in the direction of the longitudinal fiber. For composite films, OPP films widely used in packaging can be used. Because OPP films are tensile films, the residual tensile rate is low, and they are not tensile and easy to crack, they are most suitable as the combination object of ミラィフフフミラィフフフミミラㄇフフ. The closely monitored production, price, benefit and other operating indicators in photo 1 show the opening condition of packaging materials with longitudinal linear cracking. As can be seen from the photo, it can split in a straight line. Take 15g/m2 OPP and longitudinal non-woven fabric ミラィフフフフミミラィフフミミミラィフフフミミミラ
(to be continued)
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