Functionality Meets Innovation with PVdC
10 May 2010 – Functional barrier coating with PVdC belongs to the sophisticated applications available. Kroenert has innovative components to combine several application systems within one machine.
PVdC is used principally as a gas barrier for oxygen or water vapour, taking the form of shrink film or pharmaceutical packaging, and is also used in the construction industry.
Typically, rigid PVC, PET, BOPP and other polymers such as LDPE, HDPE and PA 6-6 are coated with PVdC. Similarly, PVdC coating on paper or cellophane is possible. Kroenert has developed the patented gravure – roll process with the MPG 600 CI system for PVdC dispersion coating. Excellent results in coating consistency and transparency are obtained by using the pressurised chamber doctor blade. In addition, the configuration of the application head makes various processes, such as kiss coat, reverse or offset coating, possible. Various PVdC coating weights can be applied with only one gravure roll: by calibrated compound-specific pump pressure and defined over filling of the screen roll cells.
Pre-drying by IR radiation follows the coating process. The PVdC is then cured to the desired residual moisture content by means of controlled air flow and temperature in the primary drying tunnel – a contact-free floatation type tunnel. This results in the required quality.
For very high coating weights / densities, the MPG 600 CI is able to apply multiple PVdC coatings in sequence, with intermediate drying – even as a combination of PVdC coating with printing and PE extrusion laminating. This process is also well-suited to simultaneous double-sided PVdC coating. The elimination of a dryer and the subsequent cooling result in a substantial reduction of machine cost.
Our team of PVdC coating experts is eager to assist you. Please contact us to find out more.