Tear resistance (or tear strength) is a measure of how well a material can withstand the effects of

tearing Tearing is the act of breaking apart a material by force, without the aid of a cutting tool. A tear in a piece of paper, fabric, or some other similar object may be the result of the intentional effort with one's bare hands, or be accidental. Un ...

. It is a useful engineering measurement for a wide variety of materials by many different

test method A test method is a method for a test in science or engineering, such as a physical test, chemical test, or statistical test. It is a definitive procedure that produces a test result. In order to ensure accurate and relevant test results, a test met ...

Discussion

For example, with

rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and ...

, tear resistance measures how the test specimen resists the growth of any cuts when under

tension Tension may refer to: Science * Psychological stress * Tension (physics), a force related to the stretching of an object (the opposite of compression) * Tension (geology), a stress which stretches rocks in two opposite directions * Voltage or el ...

, it is usually measured in kN/ m.Tear Resistance., , 15 June 2012 Tear resistance can be measured by the ''

ASTM ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, an ...

D 412'' method (the same used to measure

tensile strength Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or F_\text within equations, is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials t ...

, modulus and elongation). ASTM D 624 can be used to measure the resistance to the formation of a tear (tear initiation) and the resistance to the expansion of a tear (tear propagation). Regardless of which of these two is being measured, the sample is held between two holders and a

uniform A uniform is a variety of clothing worn by members of an organization while participating in that organization's activity. Modern uniforms are most often worn by armed forces and paramilitary organizations such as police, emergency services, se ...

pulling

force In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a p ...

applied until the aforementioned deformation occurs. Tear resistance is then calculated by dividing the force applied by the thickness of the material. Materials with low tear resistance sometimes have poor resistance to abrasion and when damaged will quickly fail (this includes

hard Hard may refer to: * Hardness, resistance of physical materials to deformation or fracture * Hard water, water with high mineral content Arts and entertainment * ''Hard'' (TV series), a French TV series * Hard (band), a Hungarian hard rock supe ...

materials, since hardness is not related to tear resistance).

Tear resistance of different materials

Substances with high tear resistance include

epichlorohydrin Epichlorohydrin (abbreviated ECH) is an organochlorine compound and an epoxide. Despite its name, it is not a halohydrin. It is a colorless liquid with a pungent, garlic-like odor, moderately soluble in water, but miscible with most polar organi ...

natural rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and ...

and

polyurethane Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethan ...

. In contrast, materials such as

silicone A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking ...

and fluorosilicone have low tear resistance.

Tear-yield ratio

The ratio of tear resistance to the

yield strength In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and wi ...

is called the tear-yield ratio. It is a measure of

notch toughness Notch may refer to: * Notch (engineering), an indentation or slit in a material * Nock (arrow), notch in the rearmost end of an arrow * Markus Persson (born 1979), a Swedish game designer known by his online alias "Notch", best known for creatin ...

Standards by
ASTM International ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, an ...

*C1681-14 Standard Test Method for Evaluating the Tear Resistance of a Sealant Under Constant Strain *D1004-13 Standard Test Method for Tear Resistance (Graves Tear) of Plastic Film and Sheeting *D1922-15 Standard Test Method for Propagation Tear Resistance of Plastic Film and Thin Sheeting by Pendulum Method *D1938-14 Standard Test Method for Tear-Propagation Resistance (Trouser Tear) of Plastic Film and Thin Sheeting by a Single-Tear Method *D2212-00(2015) Standard Test Method for Slit Tear Resistance of Leather *D2582-16 Standard Test Method for Puncture-Propagation Tear Resistance of Plastic Film and Thin Sheeting *D4932/D4932M-89(2014)e1 Standard Test Method for Fastener Rupture and Tear Resistance of Roofing and Waterproofing Sheets, Roll Roofing, and Shingles *E604-15 Standard Test Method for Dynamic Tear Testing of Metallic Materials

References

External links

Tear resistance on rlhudson.com
Solid mechanics Deformation (mechanics) {{materials-sci-stub