Reference Target Placement for Flexible Plastic Parts
Position reference targets on flexible plastic parts at high-stiffness rib intersections using explicit 3-2-1 restraint forces to eliminate gravity sag and inspection disputes.
Flexible Plastic Inspection
Meaning
Dimensional metrology of compliant or elastomeric polymer components requires specialized techniques to prevent the part from deforming under the force of the measuring probe. Through flexible plastic inspection, quality control engineers use non-contact systems or dedicated holding fixtures to measure parts in their free-state or simulated assembly-state conditions. This process avoids measurement errors caused by the physical contact of coordinate measuring machine tips on soft materials.
Measurement Method
Optical scanning and laser triangulation have become the standard approaches for assessing soft molded parts. During flexible plastic inspection, these non-contact methods capture the surface geometry without exerting any mechanical pressure on the compliant resin. This allows for accurate digital recreation of the part, which can then be analyzed for warpage, shrinkage, and flash.
Fixturing Strategy
Simulating the actual installation condition is often necessary to get a representative measurement of a soft component. In flexible plastic inspection, specialized nesting fixtures hold the part in its nominal shape, allowing the metrologist to evaluate functional dimensions. This fixturing ensures that the part is not rejected for minor free-state distortions that disappear once it is secured in the final assembly.
Such assemblies often use magnetic or mechanical clamps to secure the flexible part during measurement.
Material Behavior
High thermal expansion and viscoelastic creep in elastomers can skew dimensional results if the ambient temperature is not controlled. Performing flexible plastic inspection requires strict adherence to standardized temperature conditions in the metrology lab to prevent material softening.