What Are Glass Container Neck Defects?
By: Berlin Packaging Specialist
Several defects can occur during the manufacturing process of glass containers. Here are some common examples of glass neck defects, such as choked neck, bent neck, and hollow neck.
Spike Inside the Neck defect is a small projection of glass at the finish (blow-blow process) or irregular wall thickness with a crater-like depression in the center, whose edges are in relief and can chip easily (press-blow process).
Dirty Neck defect consists of black spots (grainy aspect).
Hollow Finish or Neck defect is a depression in the thickness of the glass in the finish or neck.
The correct application of a pourer is not possible with screw finishes. Sealing problems with short synthetic corks.
Lump Inside Neck defect is a round protuberance inside the neck, not fragile.
Problems may arise with corking.
Bent Neck defect occurs when the vertical axis of the neck is at an angle to the vertical axis of the body.
Difficult to fill and/or seal.
Choked Neck defect is excess glass in the neck which partially or completely obstructs the bore and doesn’t allow the filling tube to be introduced.
The container is not suitable for use; risk of breakage during filling; deterioration of contents.