Laser cleaning technology is an emerging green cleaning technology in recent years. In terms of its mechanism for mold cleaning, it utilizes the significant difference in energy absorption of a certain laser wavelength between the mold substrate and surface attachments. Most of the laser energy radiated to the surface is absorbed by the surface attachments, causing it to be heated, vaporized, evaporated, or instantly expanded, and driven by the steam flow formed on the surface to detach from the surface of the object, To achieve the cleaning purpose. The advantage of laser cleaning over dry ice cleaning lies in the low cost of the cleaning process, which can remove various thicknesses and components of dirt. The cleaning process is easy to achieve automated control, remote control cleaning, and there is no secondary consumption during the cleaning process.
 

1. Application of laser cleaning technology in the field of tire molds

Mold is an important tool used in tire vulcanization production. During the use of tire molds, they are contaminated by the comprehensive deposition of rubber, compounding agents, and release agents, which inevitably leads to problems such as carbon deposition, adhesion, and difficulty in demolding, resulting in pattern pollution dead zones. Clean molds are crucial for obtaining high-quality products, and they must be cleaned regularly to maintain their surface cleanliness, To ensure the lifespan of the mold and the quality of the tires.

The commonly used cleaning methods for tire molds mainly include mechanical cleaning, chemical cleaning, ultrasonic cleaning, and dry ice cleaning. Although these cleaning methods are widely used in the cleaning industry, their application is greatly limited by the requirements of online high-precision automated cleaning. Compared to other cleaning methods, dry ice cleaning has unique technological advantages in the field of tire molds and has become the mainstream method of mold cleaning. However, dry ice belongs to chemical products, and it is difficult to prepare and transport raw materials, resulting in high secondary consumption and relatively high cleaning costs.

2. Application of laser cleaning technology in the field of silent tire inner wall cleaning

New energy vehicles are quieter than conventional internal combustion engine vehicles, and the development of new energy vehicles has also put forward stricter requirements for tire noise control. New energy vehicle tires can better adapt to the needs of new scenarios by improving their rubber formula, tire aspect ratio, tire volume, tread material, and tread pattern.

Laser cleaning technology, as a "green" cleaning process, has good applications in the production and manufacturing of silent tires. It uses a focused high-energy laser beam to irradiate the surface of organic polymer materials, causing physical and chemical changes on the material surface, thereby changing its performance. It can effectively improve the quality and production process of tires, enhance the matching between tires and the vehicle body, and improve the overall performance of the vehicle. By coating soft solid gel like polymer composite materials on the inner wall of the tire, explosion-proof, puncture proof, and leak proof functions are achieved. At the same time, a layer of polyurethane sponge is pasted on the surface of the leak proof adhesive to achieve sound insulation and absorption of cavity noise, resulting in a silent effect.

Laser cleaning can effectively remove residual isolation agents on the inner wall of tires, improve the coating of composite materials and the adhesion of polyurethane sponges. The cleaning process does not require consumables, does not cause damage to the tires, has high efficiency, good consistency, and can achieve automated cleaning.

Evaluate the sample by selecting pulse laser equipment and developing a reasonable process flow. Obtain surface tension values under different parameters through Dyne pen testing. The results show that different process parameters (laser energy density, processing efficiency) can have an impact on the surface tension of the inner wall of the tire. Therefore, it is necessary to develop reasonable process parameters for the production process of silent tires. Through testing, the laser cleaning is uniform and meets the requirements for substrate damage. After cleaning, the internal friction coefficient increases by>37mN/m, and the surface tension reaches 40dyne/cm.

Use a roughness tester to test the surface after laser treatment, with an area of S1-S4 corresponding to different process parameters. The testing standard is ISO1997, the curve is R, and the filtering is GAUSS. The results show that different parameters have varying degrees of influence on surface roughness. In the figure, the roughness in the S3 area is the highest, which is consistent with the results of the Dyne pen test. Moreover, laser treatment greatly increases the surface roughness.

Observing at a magnification of 1000, it was found that a large number of commonly distributed small concave blocks appeared in the area irradiated by the laser, with particle sizes reaching the micrometer level. When the laser strikes the surface of the material, it will damage the rubber chain structure, produce this irregular concave block feature, and improve surface roughness.

Using laser cleaning to clean the inner wall of tires requires no consumables, no damage to the tires, fast cleaning speed, good quality consistency, and can achieve automated cleaning without the need for traditional polishing for subsequent chip cleaning operations and wet cleaning for subsequent blow drying operations. Laser cleaning has no pollutant emissions and is ready to use immediately, providing high-quality preparation for the subsequent bonding of silent tires, self repairing tires, and self testing functional tires.

3. Application of laser cleaning technology in the field of tire rubber texturing

At present, with the continuous development of China's economy, the scale of development for automobiles, trucks, and other industries is also constantly expanding, leading to a positive increase in tire replacement and a large proportion of discarded tires. If discarded directly, not only will it cause waste of resources, but it will also pollute the environment. Most of the replaced waste tires are in good condition and can still be used after being refurbished.

Traditionally, the process of only applying tread re vulcanization to the tire tread is called tire retreading, and depending on the degree of tire damage, the retreading process can be carried out using either top flip, shoulder flip, or full flip processes. The traditional method of tire retreading is to attach a mixed adhesive to the ground and filed tire body, and then place it into a fixed size steel model. After being vulcanized at a temperature of over 150 ℃, it is commonly known as "hot retreading" or hot vulcanization method.

Before refurbishment, the cleaned tire tread needs to be polished to a threaded rough state. The effect of increasing roughness through polishing is uneven and prone to damage holes, which is not conducive to the subsequent vulcanization and bonding of the tire body and tread, resulting in the quality of the refurbished tire product not meeting the standard.

The laser cleaning method can evenly punch out lattice shaped pits to achieve texturing of the tire rubber surface. Using a pulse laser cleaning machine with Gaussian light spot, the galvanometer is controlled to perform horizontal and vertical laser scanning respectively. With appropriate process parameters, the roughness of the rubber surface of the tire can be uniformly increased, and the bonding force between the vulcanized tire body and the tread can be enhanced, achieving higher quality tire refurbishment.

About HGTECH

HGTECH is the pioneer and leader of laser industrial application in China, and the authoritative provider of global laser processing solutions. We comprehensively layout the construction of laser intelligent equipment, measurement and automation production lines, and smart factories to provide an overall solution for intelligent manufacturing.

We deeply grasp the development trend of manufacturing industry, constantly enrich products and solutions, adhere to exploring the integration of automation, informatization, intelligence and manufacturing industry, and provide various industries with laser cutting systems, laser welding systems, laser marking series, laser texturing complete equipment, laser heat treatment systems, laser drilling machines, lasers and various supporting devices The overall plan for the construction of special laser processing equipment and plasma cutting equipment, as well as automatic production lines and smart factories.