Search by year
Search by keyword
Search by sector
Search by category
Sacmi RSS Feed
Find out how to subscribe to Sacmi RSS feeds
Watermarks, shrinkage and surface defects: the “invisible” faults on PET preforms

The advantages of “grid inspection”, the innovative patented SACMI solution that can be installed on the entire range of preform inspection systems, both on line and in test labs

A formula plus patented technology to identify, via a simple algorithm, preform defects that would otherwise be invisible to the human eye, detecting them easily, economically and – above all – without any risk of encountering the errors induced by the image ”interpretation” that is necessary on traditional inspection systems which use polarised light. This innovative Sacmi-developed “grid-type” inspection system can be installed on the entire PET preform vision system range, on both production lines (PVS 003 and PVS 024) and in test labs (PVS 2).

Traditional inspection techniques that use backlighting with a polarizer placed immediately behind the product make it difficult to execute easy, economic detection of major defects (caused by, for example, on-resin stress during the cooling process and/or water in the moulds – the so-called watermark). These defects, in fact, generate patterns that then need to be interpreted by the operators; this requires skill and experience as the faults are tricky to translate into inspection algorithms able to be used by a vision system.

This is where the new Sacmi system comes into play: the polarised light has been replaced with a special patented backlighting unit that projects gridlines behind the preform. On flawless preforms the result is a series of straight parallel lines; on faulty areas, instead, these become wavy (photo 1).  
  Using the grid, even small defects (photo 2) are immediately identifiable.
The new patented Sacmi methodology is available as an optional on the entire PVS range, thus allowing completion of the standard checks used to analyse defects on the entire preform, body finish and bottom; this gives the preform quality control department a significant boost as it permits an extremely economic, perfect preform “X-ray” to be made that is error-free (some defects analysed using the polarised light method can escape even the most expert eye).

Sacmi on 15th September during the “Food & Beverage Plastic Day”, a special event organised to show customers and partners our latest technological innovations in plastic containers and closures for the Food and Beverage markets.


Technology News

Food&drink multinational chooses CVS360-3D reliability
International player invests in Sacmi inspection systems for correct cap application on the dairy and ready-to-drink products made in its US plants  >>

Hot filling and CSD in a single solution: Sacmi ECF tastes success in Morocco
Belonging to the latest generation of isobaric electronic fillers, the supplied monobloc can process up to 24,000 cans/hour in the most popular formats, with maximum flexibility, low maintenance and fully guaranteed product integrity  >>

K Labellers by Sacmi
The new series of medium speed modular labellers presented in the UK  >>

Sacmi KUBE – Zero downtimes for wellbeing professionals
A leading US company specialising in the production and marketing of probiotic drinks has purchased a second Sacmi labeller from the modular KUBE range; this machine was selected on account of its flexibility, productivity and a hard-wearing, compact design that maximises efficiency whatever the manufacturing scenario  >>


This website uses "cookies". If you choose to continue using the website, you are authorising the use of cookies according to our cookie policy. For further information or to deny the use of some cookies, please click here.

accept cookie policy