PETpla.net Insider 07+08 / 2020

INSPECTION 12 PETplanet Insider Vol. 21 No. 07+08/20 www.petpla.net What to expect when you’re inspecting by Christoph Wynands (Product Manager) and Malte Nitz (Marketing), Intravis In recent years, the demands and challenges in the production of preforms have grown steadily due to needs for increasing material savings and the expanding use of recycled materials. The demands on inspection solutions for preforms have also risen to the same extent during this period. More and more inspection systems and concepts have entered the market. INSPECTION When do you use an offline system and when is a monitoring system the better choice? Or perhaps it is best to have both together? What are the differences between 100% inline inspection and a laboratory system for random sample inspec- tions? And how can you get even more out of your existing inspection solutions with the appropriate soft- ware? Despite the current prevailing mood in the media that plastic pack- aging is responsible for all of the ills in this world, the number of drinks that have been filled in PET bottles continues to increase in recent years. Ever lower manufacturing costs, safer transportability, increased recy- clability and low weight are just some of the positive characteristics that explain the increasing share of PET packaging. Due to these advantages, the spreading use of PET bottles has increased significantly. Let’s take the developments in Germany as an example. The market share of PET bottles was still around 30% in 2003. This is when the deposit on non- refillable bottles was introduced and the share then increased to almost 72% by the end of 2017. In line with this development, which can also be observed in many other countries around the world, more and more companies are starting to produce PET preforms or expanding their capacities in this area. Due to these changes, indispensable elements in modern production lines now include inspection systems. They guarantee consistently high product quality and offer their users clear competitive advantages. Increasing requirements With the increase in the number of preforms produced, new require- ments and expectations for inspection systems have arisen on the produc- tion side. Because the market require- ments are very different and some- times incompatible, various system types were developed over time. Whereas years ago, suppliers often only offered one “system for preform inspection”; today they often offer four or five different solutions - some of which are still adapted to meet specific customer requirements. As a result, this means an ever increasing range of systems for different situ- ations. The customer rarely knows exactly what the best solution is for their production from the beginning without consultation. Critical applications = 100% inline testing Choosing which inspection system is the right solution depends first and foremost on the customer’s require- ments. So he must ask himself the following questions: How demand- ing is my product? Which risk factors can influence product quality? How important is the job that I produce on this machine? Do I produce for a demanding customer or critical market to which I only want to deliver perfect quality? If so, even one bad preform can lead to the rejection of a delivery or, in the worst case, the end of a partnership. Accordingly, a 100% inline inspection solution is the best choice for such cases. Systems such as the PreWatcher Inline from Intravis inspect all preforms directly after an injection moulding machine and sort out the defective ones. The PreWatcher Inline inspects up to 72,000 pph with a precision that is pixel accurate for a total of 25 criteria - including the reading and correlation of data to the cavity number. In-house production = monitoring may be sufficient Machine downtimes due to burst- ing preforms in the blow moulder, responsibility for the entire supply chain and short distances in-house are more forgiving than an external customer who suffers a production stoppage and complains about an entire delivery. Due to this lower risk, 100% inline inspection may not be required. In this case, many custom- ers rely on the results of a lower cost production monitoring system. When embedded in a production line, these systems do not achieve 100% inspection; but offer a good compro- mise in terms of up-front costs, space requirements and inspection perfor- mance. Also, monitoring systems can achieve the same accuracy as the more expensive and required larger Monitoring, inline, offline and laboratory systems complement each other with different strengths within a preform production.