Tear resistance, initial

Initial-Tear Resistance The force required to initiate tearing of a flexible plastic film or thin sheeting at very low rates of loading, measured as maximum stress usually found at the onset of tearing. Also called Tear Resistance, initial. 

Tear Resistance, Initial See Initial Tear Resistance. 

All application verification and soil samples must be individually labeled with unique sample identification (ID) and other identifying information such as study ID, test substance name, sample depth, replicate, subplot and date of collection, as appropriate. Proper study documentation requires that sample lists and labels be created prior to work commencing in the field. Water- and tear-resistant labels should be used since standard paper labels may become water-soaked and easily torn during sample handling. Sample lists should have the same information on them as the labels and are a convenient place to record plot randomization, initials of the individual who collected the sample, and date of collection. As such, the sample list is important in establishing chain of custody from the point of sample collection until its arrival at the laboratory. 

What is certain is that the initiation and propagation of a tear is a real and very important factor in the failure of rubber products, being involved in fatigue and abrasion processes as well as the catastrophic growth of a cut on the application of a stress. There is, therefore, considerable interest in the tearing resistance of rubbers. What is uncertain is how tear resistance should be measured and the results interpreted. 

BS 2782, Method 360C, Determination of tear resistance of plastics film and sheeting by the initiation method, 1991. 

ASTM D1004, Initial tear resistance of plastic film and sheeting, 1994. 

Initial Tear Resistance of Plastic Film and Sheeting. Primary Film Test Method ASTM... 

D1004. At very low rates of loading, 51 mm/min, ASTM D1004 covers the determination of the tear resistance of flexible plastic film and sheeting. Tear resistance measures the ultimate foree required to initiate tearing in a film or sheet, as measured in newtons. 

General Description Dow Chemicals Affinity resins, homogenous ethylene alpha-olefin copolymers, contain up to 20% octene comonomer. Affinity polyolefin plastomers (POPs) can be used in any of the extrusion technologies as a sealant, to deliver an unparalleled combination of low seal-initiation temperature, hot-tack strength, toughness, tear resistance, and transparency.f ... 

Isotactic polybutene crystallizes into three different forms. When it cools from the melt, it initially crystallizes into a metastable crystalline one. After several days, however, it transforms into a different form. Noticeable changes in melting point, density, flexural modulus, yield, and hardness accompany this transformation. The third crystalline form is due to crystallization from solution. The polymer exhibits good impact and tear resistance. It is also resistant to environmental stresscracking. 

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