It has happened to many a quality representative in the glass container industry. Perhaps it was early one morning with a fresh cup of coffee, or just as you were straightening up the office at the end of the day, but an email appears from a customer with a distressed tone of unknown breakage plaguing their line throughout a production lot.
From the filler’s perspective, a buyer or supply chain manager gets a rushed phone call from their quality office, “we have unknown breakage throughout the inventory that the lab could not identify. My mechanics and technical team have been out there for a 12-hour shift adjusting the setup and line, as well as monitoring, and the breakage continues”. You immediately reach out to your supplier contact for assistance with this troubling problem.
Quickly, both parties agree to an onsite meeting. If there is an established, good working relationship, the meeting is not to place blame but to seek answers. In less established relationships, often the meeting starts with inventory resolution before any investigation. Care must be taken to drive team members to complete the investigation to, and make data-based decisions on, the sample analysis.
The scenario that follows is a similar situation. A customer called, was very forthcoming about the unknowns, but needed onsite assistance diagnosing glass failures on their line immediately. There would not be time to send samples for review. This can be a real pressure cooker for the glass container manufacturer’s representative, as there is not an opportunity to review samples in a laboratory condition prior to making a recommendation to the customer about their current filling. Samples will be reviewed onsite, with limited tools, and often (as was the case in this scenario) customer representatives monitoring each step of the analysis with you.
It is recommended that samples be obtained as early and often as possible. If the problem of breakage is at a low level, or the item in question is not needed to be filled immediately, obtaining samples before the time and expense of traveling to a fill line can add value. In our current situation of being in the middle of a worldwide pandemic, it could be the only option to review samples remotely. However, other circumstances have traditionally dictated a lack of samples prior to the meeting or line review, such as the need to fill the item or a constantly filled inventory such as beer or food jars. If you are able to receive a few samples, you should have a fracture analysis performed on each sample and be prepared with that information prior to the visit.
Onsite with Customer
In this case, there was no time for samples and the supplier representative was required to travel directly to the filling location and proceed with the investigation while the production line was running.
A brief meeting was held with the key parties; the filler’s quality, production, and technical support staff, and the two glass manufacturer representatives, me included. The lead manager in charge of supplier compliance, confirmed that the meeting was to solve the problem, not place blame. We had enjoyed an open and direct working relationship over the last several years on many issues with a similar group of people from companies. At this meeting, a plastic bag of failed samples was produced. Other than missing pieces, this is truly a glass fracture diagnostician’s worst nightmare, as sorting sample pieces takes time and is not something that can be readily accomplished in front of an audience requiring speed. Luckily, inside the large bag the samples were individually wrapped, and the fear of the difficult task of sifting through the sack quickly faded.
It was immediately apparent that the failed containers had been subjected to some type of large force, potentially a very severe impact. The containers were in many pieces, and due to the pressure sensitive label being applied prior to the failure, the pieces were held together so the fracture pattern could be seen without the need for timely reconstruction of the samples. Observing the fracture patterns, all the containers exhibited some type of failure in the lower side wall above the heel feature (this round food jar had a faceted feature in place of the traditional rounded heel). Without further analysis, it was not possible to say specifically why the containers failed, but I could say that they had been subjected to a large force and appeared to have a common mode of failure. I also noted that if an impact force was at play, it would be considered very severe.
Combined with the inputs about the failures from the filler’s own documentation, oral reports in the meeting, and the fact that the label application was prior to the filler in this case, it was agreed that the key area of investigation would be the filler. Assignments of which team member would ‘stake out’ which area on the line were decided in the meeting room, and we all headed to floor with the intention of observing for 2 hours and regrouping as a team prior to lunch.
It had been difficult for everyone involved to quantify the problem, specifically what the rate of failure was. The number of containers processed was clearly known, and there were documents showing failures during the last several days of production. However, that was really the minimum rate of failure or the documented rate of failure. Not every break is written down, and not every line person is as diligent or has the freedom to note details of every occurrence during a shift. For example, a shift running one product into the jars may write down not only the breaks, but the details surrounding them. A shift with 3 or 4 product changes during that shift may be focused on other critical tasks like cleaning and line clearance, moving the documentation of a few container failures to a secondary priority. When over an hour went by without a single failure in the filler, no one was surprised.
Suddenly, chaos erupted around the filler, and the line was stopped. The filler setup consisted of several star-wheels that would move the containers through the filling process, and at several locations, one start-wheel must ‘hand-off’ the container to the next star wheel. If this is not done with the correct timing, a container can get caught in-between and jam the mechanisms. Modern machines, such as this one, can sense this resistance feedback and will shut down the machine to prevent damage to the machinery. Older style machines may require manual shutdown when this occurs.
Upon witnessing this, the operator immediately complained to the small band of managers surrounding the event, that this was a continual problem for several shifts. I asked how she intended to clear the jam, without injury as the container was clearly lodged and could not be removed. She informed me the only safe way to clear the jam would be to close the safety doors we had opened to review the jam, and manually ‘jog’ the machine forward until the container failed from the machine pressure. After watching this occur, I asked her what her next steps would be. She collected all the pieces of the failed container, completed her cleaning procedure for food safety, and then proceeded to put the sample in a sealed plastic bag and labeled it as ‘broken container @ filler” for her quality team. She informed me that their glass breakage procedure required that all container failures prior to container closure application be documented, and a sample logged when possible. No details were logged that the container failed due to the clearing procedure after a machine error.
The technical filler representative we had been working with smiled and informed us they would be able to take the situation without us needing to stay for the next meeting. The filling location’s glass breakage procedure was clearly robust and being well followed by the staff. However, a key detail was overlooked by the management, and it did not appear that the onsite managers had spoken with the right individuals, such as those that filed the glass breakage reports.
From the glass suppliers’ perspective, it is important to remember not to assume any customer is crying wolf. This scenario shows, that while the issue was not necessarily related to container quality, most fill location employees are not equipped to properly review glass fractures. Their main concerns and training lie elsewhere, and rightly so. Batches need to be mixed, food safe procedures need to be followed and audited, and the list goes on. They are required to be experts in their respective disciplines and calling in technical representatives is a great opportunity to add value to the relationship by focusing on proper investigation of the failures, sharing knowledge, and providing ‘skills for a day’.
Glass Guy LLC
Not every working relationship will have years of trust behind it when adversity strikes, and not everyone will always agree so amicably to the investigative results. Glass Guy LLC can be a neutral party to analyze samples and mediate results. The fact that the machine was jamming was never recorded on the lab reports, might be concerning to some, but really no fracture analysis is completed with all the information. Asking questions, and listening to feedback of those directly involved, when combined with the technical expertise of fracture diagnosis, can drive solutions to otherwise elusive problems.