2018 / 10 / 12 &nb關舊sp; Loading...
Material testing machines for test有鄉ing tensile properties of materials 吃新are used more and more widely在路, but not all testing mac工子hines are suitable for te時少nsile testing of flexibl體來e packaging materials. 事鐵Based on the material t聽理esting standards of our country, th知低is paper analyzes the indexes明樂 that should be paid special atte就媽ntion to when selecting the tensi通做le testing machines for flexible packag聽錯ing materials.
The tensile property 店飛of plastics and rubber is one站嗎 of the most important and basic新明 properties of their內中 mechanical properties, w現國hich largely determines the us房靜e of this kind of pla地他stics and rubber occasions. Tensile pro理草perties can be tested by tensil也腦e tests.
1. Tensile properties少為 of polymer
The material testing machine requ暗鐵ires the polymer to have the生放 necessary mechanical propert現票ies when used as material. It can不南 be said that for most靜是 applications of polymer, 窗黑mechanical properties a睡現re more important th得在an other physical propert東弟ies. For example, the elongation at br著鐘eak of PE is between 音國90% and 950% (among which the是體 elongation of LLDPE is higher). The e數行longation of some ma也動terials can be more than 100可鐘0% by special manufac短廠turing process, and the elongation 訊姐at break of common polymer 小吃materials is more than 50% - 100%. 街有Heat shrinkable films an一秒d stretching films are usually require理訊d for high tensile propertie藍對s of materials.
2. Tensile test
Tensile test (stress-stra著商in test) usually clamps the two亮信 ends of the material s時樂pecimen on two clamps at 紙相a certain distance, 錯議and the two clamps separate and stret身喝ch the specimen at a certain speed to 兒件measure the stress change on the 些紅specimen until the spec匠這imen is destroyed.
Tensile test is one of the most w資自idely used methods to s時謝tudy the mechanical strength of m好關aterials. It is neces哥資sary to use a constant speed tensil錢長e testing machine. According to the 雪船different ways of load measur鐘頻ement, the testing machin制懂e can be divided into pendulum type an刀爸d electronic tensile testing ma店見chine. At present, the elec但銀tronic tensile testing machine 間亮is mostly used.
3, selection index of electronic ten讀對sile testing machine
Since flexible packaging ma議說terials are mainly polymer materials or到章 their related materials劇時, such as the elongation of the微訊 polymer materials m業錢entioned above is far superior to the m煙聽etal, fiber, wood, board and 笑長other materials, so the tensile testi又匠ng machine for polymer and the ordina大煙ry material tensile testing machine木麗 has a certain difference,遠件 especially need to pay attention t這一o. It is the effective travel of t但子he electronic tension machine and th還筆e two aspects of the sample f用一ixture.
In the tensile test, 農我the size of the sample used is 有麗small, but the elongation o靜些f the material is generally h資街igh, so the tensile p爸答roperties of the flexible pac議高kaging materials need to行拿 be equipped with a larg月跳e stroke tensile machine,文微 otherwise the clamp operation m頻雨ay exceed the limit of the 爸妹stroke, causing damage費黃 to the equipment.