Views: 0 Author: Petra Publish Time: 2026-09-01 Origin: Site
Transparent bottles are commonly used for products filled with clear or colored liquids, such as mineral water, cosmetics, personal care products, detergents, wine, champagne, and other beverages.
These containers are generally made of rigid materials such as glass or PET, or flexible and squeezable plastics. When applying transparent film labels to these types of bottles, one of the most common problems is air bubbles appearing on the label surface after labeling.
There are many possible causes of bubbles. The main factors include:
The cleanliness and smoothness of the bottle surface, as well as whether the bottle has a regular curved surface or a spherical/irregular shape.
The bottle material, whether it is rigid or flexible and squeezable.
The compatibility between the transparent label film and the bottle, including the characteristics and flexibility of the label material.
The selection and adjustment of the labeling machine, including machine speed and the way the application mechanism is adjusted.
To avoid bubbles after applying transparent labels, the following measures should be considered.
The bottle surface should be cleaned in advance and completely dried before entering the labeling process.
Dust, oil, moisture, and other contaminants on the bottle surface can affect the contact between the adhesive and the container, resulting in bubbles or poor adhesion.
This is particularly important when labeling transparent bottles, because even small defects underneath a transparent label are clearly visible.
During the labeling process, the bottle should be properly held and stabilized by the conveyor or bottle-positioning mechanism.
This is especially important for flat-shaped or flexible plastic bottles, which can easily move or deform during labeling.
If the bottle moves unexpectedly while the label is being applied, the label may not contact the bottle surface evenly, increasing the possibility of bubbles and wrinkles.
A suitable bottle positioning or clamping system can help maintain stable bottle movement and improve labeling consistency.
For transparent film labels, the smoothness of the release liner is also important.
A smooth liner, such as a PET release liner, can provide a more uniform surface for the adhesive and contribute to better adhesive wetting when the label is applied to the bottle.
The label film, adhesive, and release liner should be considered as a complete labeling material system.
The selected label construction should be compatible with both the bottle material and the labeling process.
The label material should be selected according to the characteristics of the bottle.
For soft and flexible bottles, flexible materials such as:
PE
PVC
Unstretched PP
PE/PP composite materials
may be suitable because they can better follow the deformation and surface characteristics of the bottle.
For rigid bottles, materials such as:
PET
BOPP
PS
can be considered depending on the specific application.
The correct label material should be selected according to the bottle shape, material, surface characteristics, and labeling requirements.
Static electricity can affect the handling and separation of transparent film labels.
Before the label is applied to the bottle, static electricity should be properly controlled or eliminated where necessary.
This helps the label remain stable and separate cleanly from the release liner.
If static electricity is excessive, the label may stick to the liner, curl, move unpredictably, or fail to separate properly, which can affect the final labeling result.
The application mechanism of the labeling machine is particularly important when applying transparent labels.
For demanding transparent label applications, brushes, sponges, or vacuum-based application methods may not always provide the required application control.
A suitable rubber scraper or pressure blade should be installed so that it makes controlled contact with the label.
The scraper should be adjusted to an appropriate:
Angle
Pressure
Position
Distance from the bottle
The scraper should apply sufficient and stable pressure to the label while helping push air out from between the label and the bottle surface.
If the pressure is too low, the label may not adhere evenly.
If the pressure is too high, especially on flexible plastic bottles, the bottle may deform and cause wrinkles or other labeling defects.
Therefore, the scraper angle and pressure should be adjusted according to the bottle and label characteristics.
During labeling, the relationship between the bottle running speed and the label dispensing speed is also important.
In many transparent label applications, the bottle surface speed should be slightly higher than the label dispensing speed.
This helps the bottle pull the label smoothly onto its surface and can reduce the possibility of air becoming trapped between the label and bottle.
However, the optimal speed relationship depends on the actual bottle, label, and labeling machine.
The following factors should be considered:
Bottle diameter
Label length
Label material
Bottle material
Labeling speed
Adhesive characteristics
Application mechanism
Therefore, the labeling speed and label dispensing speed should be adjusted during actual machine testing.
When labeling flexible plastic bottles, the relationship between labeling speed, scraper pressure, scraper angle, and scraper distance becomes particularly important.
Because a flexible bottle can deform under pressure, the application mechanism needs to be carefully adjusted.
If the scraper pressure is too high, the bottle may be compressed or deformed.
If the pressure is too low, the label may not be pressed evenly against the bottle surface.
Therefore, for flexible bottle applications, the labeling speed, scraper pressure, scraper angle, and scraper distance should be adjusted together to achieve a stable and smooth labeling result.
When bubbles appear after applying a transparent label, the problem should not be attributed to the labeling machine alone.
The complete application system should be checked, including:
Bottle → Label Material → Adhesive → Release Liner → Labeling Machine → Application Mechanism → Machine Speed
A professional labeling machine supplier should evaluate the actual bottle and label before determining the final machine configuration.
For this reason, sample testing with the customer's actual bottles and labels is highly recommended before confirming a transparent bottle labeling machine.
For transparent bottle applications, the labeling machine should provide stable bottle conveying, accurate label dispensing, and controlled label application.
Depending on the bottle shape and material, the machine can be configured with suitable:
Bottle positioning mechanisms
Side belts or bottle-holding systems
Label dispensing mechanisms
Rubber scrapers or pressure blades
Speed control systems
Labeling sensors
Servo-driven labeling systems
The final configuration should be determined according to the actual bottle, label, production speed, and labeling position.
At Feyvan, we specialize in labeling machines for different types of bottles and containers. For transparent label applications, we can evaluate the bottle and label characteristics and recommend a suitable labeling machine and application method.
If you are experiencing bubbles, wrinkles, uneven application, or poor adhesion when applying transparent labels, you can send us your bottle photos, bottle dimensions, label size, label material, and required production speed.
Our engineering team can evaluate your application and recommend a suitable transparent bottle labeling machine solution.
