Reasons and solutions for warping, bubbling, and label detachment of machine oil drums

Reasons and solutions for warping, bubbling, and label detachment of machine oil drums

The main component of oil drums is PE, and different proportions of colorants are added during the production process according to color or other requirements. The oil drum is blow molded, and when it first comes out of the mold, the temperature is very high, requiring 24 to 48 hours of complete cooling. The size is stable, and small molecular substances inside the drum are released. Due to rough demolding requirements, the surface of the oil drum may be lower. PE material has a high coefficient of thermal expansion, large temperature differences across the country, and significant changes in barrel size. The labeling process of machine oil drums involves the production of the drum body, which is packaged in breathable plastic bags for 48 hours (cooling, molding, release) - machine or manual labeling - placed above the lowest labeling temperature for 24 hours (to exert adhesive properties) - inspected and shipped.

label requirements

Low surface roughness - high viscosity and thick adhesive

The expansion of the barrel after filling brings about the need for friction resistance - friction resistant varnish or coating

Different printing appearance effects - multiple fabrics can be selected

PE material has a high coefficient of thermal expansion - it is best to choose PE fabric to adapt to the huge temperature difference across the country

Introduction to Bucket Label Application, Common Malfunctions, and Solutions:

At present, there are various types of oil drum labels on the market, and their applications are complex as follows. Surface materials: copperplate paper, mirror copperplate paper, synthetic paper, white PE, shiny silver PE, etc; Glue: thickened high adhesive; Surface treatment methods for labels: polishing oil, polishing film; Labeling methods: machine labeling, manual labeling; Labeling process: Most of it is completed by the bottle factory and sent to the filling factory, with a few connected to label canning operations.

Type of failure of machine oil drum labeling: label lifting or falling off; Label lifting or horn mouth; Label foaming

Avoidance methods for these three types of label failure

Label lifting

The viscosity of glue is a guarantee for perfect labeling, but if other factors are not taken into account, there is also a risk of warping:

Temperature issue

Winter is a high incidence period for oil barrel warping, and prevention measures should be taken from the following aspects:

1. Labels should be stored in an environment above the minimum label temperature, or placed in the environment 24 hours before labeling to ensure the activity of the adhesive;

2. Ensure that the temperature of the barrel is above the minimum labeling temperature;

3. The barrel should be placed above the lowest labeling temperature within 24 hours after labeling to ensure that the adhesive viscosity continues to reach its maximum level.

For example, in winter, just after applying labels, they are transferred to outdoor or cold warehouses, or shipped directly, causing the labels to warp or even fall off.

Solution: Install a heating lamp before labeling on the labeling machine to increase the label temperature, improve the adhesive viscosity, and enhance the labeling effect. The labeling factory can adjust the insulation time after labeling based on actual test results, with no warping as the standard.

Humidity issue

The issue of humidity is often overlooked, but it occasionally occurs.

When the humidity is high during the rainy season, a water film may form on the surface of the barrel, which reduces the viscosity of the labels attached to the water film and causes the labels to warp;

2. Unfinished rolls may be generated during labeling, and they should not be packaged in waterproof bags after being returned to the warehouse. Exposure to air can cause the moisture in the glue to evaporate, weaken the viscosity of the glue, and even become dry glue, completely losing its viscosity.

Solution: The labeling factory can bring some self sealing bags for packaging opened label rolls.

Surface energy of bucket body

During the production of barrels, additives may be added for various reasons, and some components may precipitate from the barrel, resulting in a slippery surface and low surface energy; In addition, the surface of the mold cavity for producing barrels will accumulate some substances after long-term use, resulting in a decrease in the surface energy of the barrel body and affecting the labeling effect. It is recommended that the surface energy of the barrel be above 34 dynes.

Solution: The barrel can be flame treated before labeling to increase surface energy

Pressure issues related to pacification standards

Adhesive, also known as pressure-sensitive adhesive, can only exert its adhesive properties under appropriate pressure.

1. Manual labeling: Compared with the stability of mechanized production, the manual labeling actions of personnel may be affected by factors such as physical condition, working time, and proficiency in operation, resulting in less stable label quality. Labels may warp due to lack of pressure.

2. Machine labeling: The labeling device is crucial. Some brushes, sponge wheels, and other devices on the market are not recommended. It is recommended to use a suitable elastic leveling plate and clamp it with upper and lower arms.

Label flatness:

When using label film, if the film tension is too high, it will cause the film to shrink after die-cutting, driving the label to curl upwards and warp after labeling;

When coating on paper materials, P may shrink due to the low temperature of the labeling environment;

3. It is not recommended to use a hot film, as the temperature is around 90 degrees and the shrinkage is severe after cooling;

4. Due to ink shrinkage, the edges of the glossy label may curl.

Solution: The shrinkage of the membrane is unidirectional, while the shrinkage of the ink is omnidirectional. Printing factories should promptly check the flatness of labels during mold cutting. The coating label should scroll slightly downwards.