Meaning
Addition-cure silicone rubbers function as high-precision impression materials due to their excellent dimensional stability and elastic recovery. The elastomer known as polyvinylsiloxane PVS is formulated from vinyl-terminated polydimethylsiloxane and polymethylhydrosiloxane, which react to form a highly crosslinked solid. In polymer metrology and manufacturing, this compound is used to cast flexible replicas of internal tool cavities or complex plastic part geometries.
These elastic replicas can be non-destructively extracted and scanned to analyze surfaces that are otherwise inaccessible to optical or stylus profilometers. This enables accurate quality control of molded components with hidden features.
Replication Fidelity
The material exhibits extremely low viscosity before curing, allowing it to flow into sub-micron surface textures and narrow grooves. When the platinum-catalyzed addition reaction completes, the cured elastomer possesses high tear strength and elastic recovery. This allows the cast to be pulled out of undercuts or internal threads and still snap back to its molded shape.
It reproduces the microscopic roughness of the tool steel, enabling accurate lab-based assessments of wear and micro-erosion.
Shrinkage Control
Dimensional stability is critical for replicas used in quality control measurements. Since the curing mechanism of this polymer does not generate volatile byproducts, the material exhibits minimal shrinkage, typically less than one tenth of a percent. This ensures that the dimensions of the replica remain stable for days, providing sufficient time for lab measurements.
Quality Assessment
Molders use these silicone impressions to verify that tool features match the original engineering drawing. By measuring the replica instead of sectioning the actual molded part, the processor saves time and raw material. This method reduces testing costs and accelerates the validation of complex molds.
