{"id":10084,"date":"2023-09-21T08:00:37","date_gmt":"2023-09-21T13:00:37","guid":{"rendered":"https:\/\/www.thermofisher.com\/blog\/materials\/?p=10084"},"modified":"2026-09-10T16:09:29","modified_gmt":"2026-09-10T21:09:29","slug":"elastomers-easing-the-transition-from-lab-to-production-using-torque-rheometry","status":"publish","type":"post","link":"https:\/\/www.thermofisher.com\/blog\/materials\/elastomers-easing-the-transition-from-lab-to-production-using-torque-rheometry\/","title":{"rendered":"Elastomers: Easing the Transition from Lab to Production using Torque Rheometry"},"content":{"rendered":"
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Implementing new elastomer compounds into a production process is\u00a0<\/span>complicated<\/span><\/span>, but<\/span>\u00a0using torque\u00a0rheometry<\/a> <\/span>can ease that transition<\/span><\/span>.<\/span><\/span>\u00a0<\/span><\/span>We provide<\/span><\/span>\u00a0<\/span><\/span>practical<\/span><\/span>\u00a0examples to demonstrate the various process parameters that can be evaluated and analyzed by a torque rheometer prior to the initial transfer to production.<\/span><\/span>\u00a0<\/span><\/p>\n<\/div>\n

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In the lab,\u00a0<\/span><\/span>a<\/span><\/span>\u00a0new material has been developed specifically to improve or adjust its properties to make better products<\/span><\/span>\u00a0for your company<\/span><\/span>. However, hundreds of process parameters will change when the process is scaled up; larger volumes, different environments, and heavily used production equipment are all inherently different than the lab environment.\u00a0<\/span><\/span>\u00a0<\/span><\/p>\n

Is there a way to anticipate process changes prior to production, so that when similar results are seen in production, the process en<\/span><\/span>gin<\/span><\/span>eer knows\u00a0<\/span><\/span>exactly<\/span><\/span>\u00a0the\u00a0<\/span><\/span>parameters<\/span><\/span>\u00a0to adjust to achieve the\u00a0<\/span><\/span>correct<\/span><\/span>\u00a0result?<\/span><\/span>\u00a0<\/span><\/p>\n<\/div>\n

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Torque rheometers, equipped with laboratory-scaled internal mixers<\/a>, have been used\u00a0<\/span><\/span>in the\u00a0<\/span><\/span>rubber industry for decades<\/span><\/span>. These instruments process small rubber samples in conditions\u00a0<\/span>similar to<\/span> those encountered in production. Using this type of torque rheometer<\/span><\/span>, many process parameters can be evaluated at laboratory scale, resulting in clearer understanding of the material properties long before the new material hits production.<\/span><\/span> (See video<\/a>.)<\/span><\/p>\n<\/div>\n

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Curing<\/span><\/span>\u00a0<\/span><\/h2>\n<\/div>\n
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Using a torque rheometer<\/a> allows testing for minimum viscosity, the onset of scorching and the rate of cure for various additives. The small volume size allows multiple polymer\/additive combinations to be\u00a0<\/span><\/span>graded and<\/span><\/span>\u00a0determine which compound ingredients affect material properties.\u00a0<\/span><\/span>\u00a0<\/span><\/p>\n<\/div>\n

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Mastication<\/span><\/span>\u00a0<\/span><\/h2>\n<\/div>\n
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Rubber polymers require the mastication process to reduce their viscosity and even out\u00a0<\/span><\/span>variations<\/span><\/span>\u00a0between lots.\u00a0<\/span><\/span>Using a torque rheometer, the initial flow properties of the sample can be evaluated, by using the torque peak caused by the high resistance of shear while cold.\u00a0<\/span><\/span>\u00a0<\/span><\/p>\n<\/div>\n

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Viscosity<\/span><\/span>\u00a0<\/span><\/h2>\n<\/div>\n
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Strongly dependent on the shear rate, different non-Newtonian liquid elastomers of equal molecular weight may exhibit the same viscosity at high shear rates. However, by varying the shear rate to extremely slow rates, by reducing\u00a0<\/span><\/span>rotor<\/span><\/span>\u00a0speeds perhaps, differences between polymers is often detected.\u00a0<\/span><\/span>\u00a0<\/span><\/p>\n

Flow-Curing Behavior<\/span><\/span>\u00a0<\/span><\/h2>\n<\/div>\n
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Vulcanization occurs at a higher temperature in elastomers when curing agents such as\u00a0<\/span><\/span>sulphur<\/span><\/span>\u00a0are added.\u00a0 The vulcanization process is best monitored at its onset; important process parameters include the ways in which mixing, extrusion or injection molding affect the onset of vulcanization, which in turn, affects viscosity.\u00a0<\/span><\/span>\u00a0<\/span><\/p>\n<\/div>\n

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When a torque rheometer<\/span><\/span><\/a> has automated extrusion-capillary, die swell behavior, and qualitative testing of extreme shapes — which all provide valuable information when solving problems in the production processing of un-vulcanized rubber — there is insight into such parameters as viscosity, elasticity, and extrudability. <\/span><\/span>\u00a0<\/span><\/p>\n<\/div>\n

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Using rheology to identify which process parameters affect which properties while the material is still in the lab setting will enable process engineers to quickly evaluate and adjust production parameters. Read this application note to see how a Torque Rheometer can speed the process of scaling up to production scale.<\/a><\/p>\n

Additional Resources<\/h2>\n