In-line inspection system for vertically profiling plastic containers using multiple wavelength discrete spectral light sources

A blow molding system for blow molding plastic containers from preforms, the system comprising:

• an oven for heating the preforms;
• a blow molder for molding the heated preforms into the plastic containers;
• and
• an in-line inspection system for inspecting the plastic containers as they are formed by the blow molder, wherein the inspection system comprises:
• a plurality of emitter assemblies that cyclically emit light energy in at least two different narrow wavelength bands at a container as the container passes through an inspection area;
• a plurality of broadband photodetectors, each photodetector facing at least one of the emitter assemblies such that photodetectors are capable of sensing light energy that passes through the container when it is in the inspection area;
• and
• a processor in communication with the photodetectors for determining a characteristic of the container based on signals from the photodetectors.

A method of manufacturing a plastic container comprising:

• heating a preform with a preform oven;
• forming the plastic container from the heated preform in a blow molder;
• inspecting the plastic container after formation by the blow molder, wherein inspecting the plastic container comprises:
• cyclically directing light energy at two discrete narrow wavelength bands from a plurality of emitter assemblies arranged in a vertical array at the plastic container from an exterior of the plastic container;
• sensing, with a plurality of broadband photodetectors arranged in a vertical array, light energy at each of the two discrete narrow wavelength bands from the emitter assemblies that pass through the plastic container when the plastic container is in an inspection area between the emitter assemblies and the photodetectors;
• determining, based on the sensed light energy, a characteristic of the plastic container.