A hybrid forming technology has advantages over traditional injection moulding. The marriage of compression forming and blow moulding generates less waste, shortens cycle time and requires less energy and heat, largely because no manifold is needed to distribute molten resin to individual cavities. A 12-station, rotary machine extrudes and cuts molten high-density polyethylene and transfers the shot into a compression cavity for a subsequent two-stage blowing process. Container sizes range from 60–300 mL. Eliminating station-to-station indexing shortens cycle time. The absence of a manifold for melt distribution prevents temperature variations and lessens chances of flaws from resin burn and degradation. An extremely consistent wall thickness offers the potential for lightweighting. The machine also integrates three levels of quality control: leak detection, infrared inspection for surface and embedded particulates, and plasma surface treatment to improve label adhesion. A 20-station machine, currently under development, will require only minor adjustments to change from high-density polyethylene to polystyrene, polypropylene, or polyethylene terephthalate (Compression blow-formed containers, Amcor Rigid Plastics; compression blow-forming machines, Sacmi Group).Chemical tempering after the forming process strengthens glass cartridges used in autoinjectors and pen systems. A molten potassium nitrate bath replaces sodium ions in the glass with larger potassium ions and results in a denser surface. It also increases the surface compression and reduces stress created by miniscule flaws in the tubular glass, which cannot be seen by the naked eye but are always present (tempered glass cartridges, Gerresheimer AG).
Cartons and labels
With requirements for Braille labelling likely to expand, a fourth-generation, family-owned carton converter was on display that is prepared to emboss and verify the tactile code on its folding cartons. A high-speed camera system checks the depth and accuracy of each embossed dot at production speeds and rejects any faulty cartons. The Braille embosser and inspection system are installed on the folder-gluer and are an alternative to a more complex system and expensive die-cutter-mounted system (AccuBraille embossing system from Bobst and BrailleChek system from Valco Melton, installed at Ingersoll Paper Box Co.).
Digital, flexographic, and offset printing address low, medium and high-volume folding carton runs with virtually no variation in print quality. The printer also offers services to reduce carton costs by consolidating sizes and stock-keeping units (SKU Consolidation and Right-Sizing services, Innomark Packaging Solutions).
Special adhesive and die cutting produce a pressure-sensitive label that applies smoothly to the narrow circumference of autoinjectors. Options include embossed bumps that could carry a Braille message, but are primarily intended to prevent the pen from slipping during use. Labels also may incorporate colourshifting ink for anticounterfeiting protection or thermochromic ink that shows when a product has reached the correct dispensing temperature. In pens designed for multiple doses, multiply structures permit reverse printing that preserves the readability of any messages or instructions despite repeated handling. A peelable layer allows users to check product level through a window, but otherwise blocks transmission of ultraviolet light (Pen Label, Schreiner MediPharm).