Label Curling on Bottles: A Troubleshooting Walk-Through

A company that produces skincare products once came to us in a hurry. The labels on their small plastic bottles started to curl up just a few days after being affixed, and several bottles were already curling up on the shelves, looking very cheap. Although there were no complaints, the distributors kept returning the products, and they were afraid to release the stock for sale.

Their first thought was about the glue - they wondered if there might be an issue with this batch of glue, given that it wasn't like this before. We tore off the label and inspected the glue layer, which appeared normal. We then called the glue supplier to confirm that the batch had not been changed. So, it wasn't the glue that was the problem.

Next, we checked the labeling process. I told them not to blame the glue yet, but to first examine how they were labeling. Upon inquiry, I learned that they were using manual labeling, and the workers' hand strength varied. Some pressed firmly, while others just pressed casually after attaching the label. The bottle body had a curved sloping shoulder, and the edges were inherently the hardest to label securely. With varying hand strength, the edges would become warped and remain so.

This is half of the reason. The other half lies on the surface of the bottle. Their bottles are made of HDPE material, and the surface is coated with a layer of release agent. If the surface is not cleaned thoroughly before labeling, a layer of oil will be sandwiched between the glue and the bottle. It may appear to be labeled, but it is actually not firmly attached, and it will warp under slight pressure. We asked the workshop to wipe the bottle with alcohol before labeling to remove the oil film, and the situation immediately improved significantly.

Then we gave a piece of improvement advice: for the labeling process, whenever possible, use machines instead of manual labor. Manual labeling results in significant errors and poor consistency. When dozens of bottles are labeled by hand, fatigue sets in, and the subsequent labels become misaligned or cocked. By installing a small automatic labeling machine, the pressure and positioning can be standardized, significantly reducing the rate of label cocking. After they listened and implemented the suggestion, the rate of product returns was substantially reduced.

There is no advanced technology involved in this case. The problem lies in two aspects: the surface is not cleaned thoroughly, and labeling is done manually. These two issues are precisely what many factories producing bottled and tube-packed products tend to overlook. While labeling may seem like a trivial matter, issues such as warped edges and missing labels can be easily noticed on the shelf. Repeat purchases will be lost if such issues occur repeatedly.

Delving deeper, if your product is also a bottle or tube, or if the label needs to be affixed to a curved surface, hose, or irregular surface, there are several things that can be determined during the proofing stage: first, the material, as face materials with better flexibility are easier to fit onto curved surfaces; second, the adhesive, as smooth or low surface energy materials require corresponding adhesive types; third, the labeling method, which is often overlooked but is often the most significant variable.

For this type of labeling, our Xuzhou Huaishi Electronic Technology has assisted numerous customers in the bottle and tube industry in adjusting their schemes. We have existing experience in how to label on curved surfaces, what adhesive to use, and what labeling method to adopt. If you are struggling with label edge warping or label falling off, please share the product material and labeling process with me, and I will help you identify the cause together.