Frosting (also referred to as “spraying”) is one of the major drawbacks when manufacturing rubber sealing strips and can often be attributed to quality issues in material quality. As the result of compounding agents contained within unvulcanized or vulcanized rubber moving to the surface and precipitating, crystallized spray may form. This phenomenon is sometimes known as “frosting”, due to its similar appearance with frost.
Frosting is most frequently produced from sulfur as the most widely-used chemical for vulcanizing rubber in general. Since sulfur’s solubility in rubber compounds is relatively small, making its creation relatively straightforward; spray may look frosty but this is actually no such thing – other materials used include powdery materials (plasticizers and softeners) oil-based (plasticizers and softeners), plasticisers sprayed directly, even carbon black was sprayed onto surfaces as an exogenous substance!
Frosting should only occur for practical reasons and to preserve food supplies.
Formula design problems:
1.Whilst compounding agents such as accelerators and sulfur are added in quantities which exceed their liquid limits.
2.Migration and precipitation occur when different agents do not match.
3.Unsuitable process control:An inequality in mixing, as well as excessive local agents.
4.Temperature, time or vulcanization inadequacies; nonreacted chemical compounds.
Effects of Environmental Conditions in which Storage Facilities Are Situated
Extended exposure to both high temperatures and humidity levels accelerates the dispersing of compounding agents, speeding their distribution across surfaces.
As rubber ages, its inner structure becomes compromised and precipitation of components occurs more readily.
Emerging Hazards
Contamination on products could pose threats to their appearance and could compromise them in ways beyond simply altering their surface appearance.
Rubber may become damaged through precipitation if its elastic properties, sealing capacity or resistance to aging become reduced.
Sulfur deposits on rubber may lead to its breakdown, making the material fragile and potentially unsafe for use in manufacturing applications.
