Breakthrough in LED Curing Coating for SPC Flooring Technology

Why use shortwave 395 nm UV LED cold light source curing?

Wavelength

Before introducing UV LED Curing machine, Let us start from the light source itself, light is an electromagnetic wave, its wavelength range in several nm (1 nm=10-9 m) to about 1 mm. These lights are not all visible, and what the human eye can see is only part of them. We call this part of visible light. In visible light, the shortest wavelength is purple light, the slightly longer is blue light. And the later order is cyan light, green light, yellow light, orange light and red light, in which red light has the longest wavelength. In invisible light, light with shorter wavelength than purple light is called ultraviolet light, and light longer than red light is called infrared light. The following table lists the approximate wavelength range of the UV and IR regions.

The current unit of wavelength is µm,nm and Å, and the relationship between them is 1µm=103 nmµm=104 Å. In addition to volatility, light has particle properties. Quantum theory holds that light is composed of many quantum of light, which has energy hυ. The h=6.626×10-34 is the Planck constant. The υ=c/λ is the frequency of light, and the c=3×10-8m/s is the speed of light in vacuum. Quantum theory better reflects the wave-particle duality of light.

How about UV LED curing and mercury lamp curing?

Issues of Using Mercury Lamp Curing

The traditional UV coating process is basically cured by UV mercury lamp, and its curing effect is OK, but there are many problems in the mercury lamp itself, such as the following points:

1. Mercury lamp luminescence is not pure ultraviolet light. So, a little longer irradiation will lead to excessive temperature, which is not suitable for curing heat sensitive materials on the oil, such as PVC printedfilm and PVC wear layer.  In that case, too high temperature will occur micro-shrinkage and lead to warping deformation;
2. Service life is short, after a period of time need to replace the lamp tube, the mercury lampservice life of big loss  is only 800 hours, and the service life of the UV LED curing system is 15,000-18,000 hours.
3. Curing speed is slow,and productivity efficiency will be limited to the efficiency of mercury lamp curing machine or due to its energy consumption attenuation.
4. Energy consumption is high, UVLED curing machine energy consumption is only 20% of mercury lamp.

Environmental pollution

Serious environmental pollution, with the continuous development of industry, the content of mercury in the environment is also increasing. The mercury content in various environmental media and food (especially fish) on the earth has had a serious impact on the                              environment.

Any form of mercury in the environment can be converted into highly toxic methylmercury, known as mercury methylation. Certain microorganisms containing methylcobalamin can transfer methyl to inorganic mercury to form methylmercury. Synthesis of methylmercury under            anaerobic conditions is much slower than under aerobic conditions.

The concentration of mercury in water and sediment in fish may be low enough to cause direct harm to humans. However, aquatic organisms can absorb and enrich methylmercury compounds directly from water bodies.  And they can also be transferred and enriched through the food    chain, thus greatly improving the health hazards of mercury. Methylmercury is highly soluble and rich in fat, so mercury can be absorbed and accumulated by fish. The conversion and excretion of mercury is very slow, so that it can be stored in fish for a long time. The concentration of methylmercury in fish increases with age and weight.

Therefore, the impact of mercury on the environment will eventually be transformed into the impact on plants, animals, and then affect human health.

Development of UV LED Curing

LED cold light UV curing technology promotes the high speed development of SPC industry. Light curing technology is to use UV LED curing equipment that can emit pure ultraviolet light to irradiate coatings or objects to be cured. To achieve curing and deep curing in a very short time, thereby improving production efficiency and quality. UV LED curing machine is popular because of its high efficiency and energy saving, and UV LED curing machine has long service life and good stability. At present, there are UV LED curing machines running on the client side for three years without any fault, which is quite cost-saving for customers.

The Revolutionary Significance of LED Curing in SPC Flooring Production

To promote the development of high-speed curing of SPC flooring industry,  the birth of UV LED light curing technology has revolutionary significance for flooring industry:

Prodcution Significance

Improve production efficiency: StarsplasUV LED curing machine as a cold light source curing machine, pure ultraviolet light output, no heat source, no solvent. Curing speed is also very fast, and can greatly improve production efficiency, and the surface is flat and uniform. After connecting the UV LED curing machine, other processing equipment can be connected online, which can accelerate the process of cutting, grooving, film mulching and packaging. It is very beneficial to the need of high speed production and development.

Improve product performance: we take SPC flooring industry as an example. Because the UVLED curing process is a photochemical reaction process. The photooil layer can not only obtain good curing effect on the thermosensitive material. It also has the advantages of strong adhesion and durability, as well as water resistance, chemical corrosion resistance, wear resistance and aging resistance.

Videos for reference

Economic and Environmental Significance

Improve economic benefit: high production efficiency and high yield means high economic efficiency, at the same time, high speed also means that the cost of raw materials and spare parts can be reduced. Compared with mercury lamp, the UVLED curing machine of Starsplas saves about 80% of energy consumption. That has a service life of more than 15000 hours, and does not need to be replaced frequently, which greatly reduces the manufacturing cost and improves the economic benefit.

Environmental Compliance: Currently ,147 States Members of the United Nations have signed the Minamata Convention to prevent mercury-induced environmental pollution and harm to human health. In principle, the treaty limits the mining of mercury from new mines and prohibits the production. So, import and export of more than a certain amount of mercury batteries and fluorescent lamps until January 1,2020.

As a new curing process, Starsplas UV LED curing machine has no heat radiation, no mercury, no ozone emissions, no heavy metals and other harmful substances. Compared with the traditional curing methods such as mercury lamp, it is more green, safe and of environmental protection.

Comparison between UV mercury lamp and UV LED lamp :

Technological Development of Starsplas in LED Curing

Starsplas is a company focusing on SPC flooring factory solution, dedicated to the production process and equipment new technology research and development, in UV LED curing technology in 2018 applied for PCT international patent, Patent Certificate: