Why does rubber smell?
Rubber smells because volatile organic compounds can escape from the vulcanized material. These compounds come from the rubber itself, from the plasticisers and process oils as well as from the by-products of the vulcanization chemicals. The strength with which a rubber product smells is determined by the formulation, the quality of the raw materials, and the completeness of the Vulcanisation and the post-treatment determines the result. A strongly and persistently smelling rubber product usually contains a high proportion of volatile components that were not removed during production.
Where does the typical rubbery smell come from?
The typical rubbery smell is mainly produced during vulcanization. In sulfated Mixtures form sulfur-containing compounds and residues of the vulcanization accelerators. peroxide-crosslinked During the decomposition of the crosslinking agent, volatile byproducts are formed. Other sources of odor are oils, Plasticiser, Anti-ageing agent and residues from the rubber production process. Rubber products with a high proportion of regenerant (reprocessed old rubber) or aromatic mineral oils in their blends smell particularly strongly. Incomplete vulcanization caused by too short heating times also leads to a higher proportion of uncrosslinked and volatile components. If the parts are directly manufactured without Tempering and if the packaging is not properly ventilated and sealed, the gasses that are released will accumulate in the packaging. When opened, the smell will be concentrated and noticeable.
Why do some rubber products smell stronger than others?
In addition to the formulation and processing, the type of rubber determines the odor of a rubber product. Silicone (LSR) is particularly odorless because no cleavage products are formed during its crosslinking. Peroxide-crosslinked EPDM It smells significantly less than sulfur-crosslinked materials, as no accelerator residues remain in the material. Sulfur-crosslinked blends based on NR or SBR, on the other hand, generally have the typical rubber smell. There are standardized testing procedures for evaluating the odor and emissions from rubber parts, for example for use in the interior of vehicles, in household appliances, or in contact with food.
What helps against rubbery odor?
The smell of a rubber product diminishes over time as the volatile components gradually evaporate. Ventilation in a warm, well-ventilated place speeds up this process, as heat promotes evaporation. Direct exposure to sunlight should be avoided, as UV radiation accelerates the aging of rubber. Surface-bound residues can be removed with warm water and mild detergent. During production, tempering serves the same purpose: The components are reheated in the circulating-air oven after vulcanization, volatile components are expelled, and the crosslinking is completed. If a rubber product also smells pungent after a long time or the surface is sticky, this indicates a high proportion of oils, plasticizers, or uncrosslinked components or poor processing. Odor alone is not a reliable indicator of hazardous substances.
