| We are specialists in this area. All our caps are “one piece”. The Corvaglia one-piece cap solutions offer financial and ecological benefits, as they are injection moulded from a single material in a single operation. Two-piece caps, on the other hand, are manufactured in four operations: impact extrusion, cutting and folding of the tamper-proof band and insertion of the liner. Along with the required investment, this incurs the associated assembly costs and energy consumption. Moreover, the quantity of raw material (and the cost of raw material) is lower for one-piece caps than for two-piece ones. |
And the recycling of pure PE-HD is easier and more energy-efficient than the conditioning of multi-piece polypropylene caps with liners made of EVA.
Plastic caps for products hot-filled in PET bottles are at the moment almost all made from temperature-resistant polypropylene and are fitted with a separate liner. Corvaglia began the development of a one-piece cap in HDPE four years ago.
Using a newly-developed geometry the two-start 38mm cap, when it has been screwed onto the bottle, has sufficient pre-tension to form a perfect seal, which is actually reinforced by the distortion of the cap under vacuum. This solution for a one-piece HDPE cap allows considerable cost savings in comparison with the previous PP cap and separate liner. Using the one-piece Corvaglia hot-fill cap it is possible to achieve cost savings of over 30 percent, said Romeo Corvaglia, managing director of Corvaglia Holding AG.
These innovative developments are possible only in close collaboration with the bottlers and sometimes even with the end customers, who also want to use their packing to achieve further savings in raw materials and energy and also, of course, on the cost side.
The use of short neck threads and cap geometries promises considerable ecological and financial benefits. But we must not underestimate the challenge associated with their technical application and implementation in high productivity cap production and filling lines. This also includes the conversion from two-component cap systems to single-component caps. Here’s where our experience and expertise make the difference.
| Natalia Garcia Tel: +41 71 973 77 03 n.garcia@corvaglia.ch |
