When Uneven PET Jar Walls and Cracked PE Lids Disrupted a Pet Food Packaging Line

A pet food customer came to us with two problems they had been dealing with from their previous packaging supplier.

The first was the PE lid.

Some of the lids were not completely formed during production. Others could crack. This was already inconvenient on its own, but the customer was using an automatic packaging line, which made consistency much more important.

A lid might look acceptable when checked by hand, but if its dimensions or forming vary from batch to batch, those small differences can become much more obvious when thousands of jars are running through production.

So when we started supplying this customer, one of the things we paid attention to was not simply whether the lid could close the jar. It also needed to work consistently with their equipment.

Our PE lid production was stable, and after matching the lid and jar with the customer's requirements, they were able to run them on their automatic line.

Then there was another problem the customer had been struggling with: the PET jar itself.

The labels were not going on properly

The customer told us that the PET jars they had received before were not consistent in wall thickness.

Some parts of the jar were too thin, while other parts were thicker. This made the jar body less consistent and created problems when they tried to apply labels.

This was something we took seriously because it is easy to overlook when looking at an empty PET jar.

Two jars can have the same capacity, similar dimensions and even a similar total weight, but that does not necessarily mean the PET material is distributed in the same way.

For a jar that needs to go through automatic labeling, this difference matters.

After the customer explained what had been happening on their line, we paid particular attention to the material distribution during our PET blowing process.

The goal was simple: we wanted the jar body to be as consistent as possible from one production batch to the next, without areas becoming unnecessarily thin or thick.

It wasn't about making the jar heavier.

It was about using the material properly.

What mattered was how the jar performed in production

This project reminded us of something we see quite often in food packaging.

A packaging sample can look perfectly fine when it is sitting on a desk.

The real test starts when it reaches the customer's factory.

Can it run continuously through the production line?

Does the lid fit consistently?

Does the jar stay stable during labeling?

Are the jars in the next shipment going to perform like the jars in the first shipment?

These questions are often more important than a small difference in the appearance of an empty jar.

For this pet food customer, once the PE lid problem and the PET jar wall consistency were under control, the packaging worked properly with their production process.

We then continued supplying the customer.

That ongoing supply is important to us because solving a problem once is not particularly difficult. Maintaining the same standard through repeated production is where manufacturing consistency really matters.

A PET jar is part of the production line, not just the package

We manufacture food-grade PET jars for a range of dry food applications, including pet food and pet treats.

When a customer uses automatic filling, capping or labeling equipment, we try to understand more than the required jar capacity and dimensions.

We also want to know how the jar will actually be used.

In this case, the customer's previous experience gave us very useful information. They had already told us exactly where their packaging was failing: the PE lids were unreliable and uneven jar walls were interfering with labeling.

Those were the problems we needed to solve.

Today, this customer has a PET jar and PE lid combination that works with their automatic production line, and we are able to provide the stable supply they were originally looking for.

For us, that is a better measure of a packaging supplier than whether one sample looks perfect.

A good PET jar needs to work when the customer actually starts production.