Vertical Two Doors Vacuum Chrome Plating Equipment for Plastic Lens
Vacuum aluminum evaporation plastic metallization machine is a kind of industrial equipment which is specially used to deposit a thin aluminum film on the surface of plastic substrate. It uses vacuum evaporation coating technology to realize the metallization of plastics. This process is widely used in packaging, decoration, electronics, automotive and other industries. Vacuum aluminum evaporation plastic metallization machine is a mature, efficient, economical and widely used industrial equipment. It is one of the key technologies to meet the needs of modern packaging, decoration and some functions by evaporating aluminum in high vacuum environment and condensing on the plastic surface to form a film, which endows the plastic substrate with excellent properties such as metallic luster, high barrier and conductivity.
Vacuum process:
Vacuuming: The vacuum chamber containing the plastic workpiece is evacuated to a very high degree of vacuum (usually of the order of 10⁻³ Pa - 10⁻⁵ Pa). This serves two main purposes: Air molecules are removed to prevent the aluminum vapor from reacting or oxidizing with oxygen and the like during the deposition process. Reduce the collision and scattering of gas molecules to the aluminum vapor, so that the aluminum can fly in a straight line and be uniformly deposited on the surface of the workpiece.
Aluminum evaporation: In a vacuum chamber, high-purity aluminum (usually aluminum wire or aluminum particles) is placed into an evaporation source (usually a resistance-heated evaporation boat). The evaporation boat is heated to a very high temperature (far exceeding the melting point 660 ℃ and boiling point 2467 ℃ of aluminum) by applying a large current, and the aluminum is melted and rapidly evaporated (sublimated) to form aluminum vapor.
Aluminum deposition: In a vacuum environment, aluminum vapor atoms or molecules move almost in a straight line. Film deposition: When the moving aluminum vapor atoms encounter the surface of a plastic workpiece at a relatively low temperature, they lose their kinetic energy and condense on its surface. As the evaporation continues, more and more aluminum atoms are deposited, and a continuous, dense aluminum film with metallic luster is gradually formed.
Main parts of the metallising machine
Vacuum chamber: The main structure, usually made of carbon steel, needs to withstand atmospheric pressure and maintain a high vacuum seal.
Vacuum pumping system:
Roughing pump: such as rotary vane pump is used to pump the vacuum chamber from atmospheric pressure to lower vacuum (several Pa to tens of Pa).
High vacuum pump: The oil diffusion pump is used to further increase the vacuum to the high vacuum range (below 10⁻³Pa) required for the process.
Vacuum measuring instruments: such as Pirani gauge, cold cathode gauge, capacitance diaphragm gauge, etc., used to monitor the vacuum degree at different stages.
Evaporation system:
Evaporation source: The most common is a resistance-heated evaporation tower (usually made of refractory metals such as tungsten, molybdenum, and tantalum).
Power supply: Provide large current (low voltage AC or DC) to heat the evaporation source.
Workpiece carousel:
It is used to fix plastic workpieces to be coated (such as film rolls, bottle caps, decorative parts, electronic components, etc.).
It is usually designed to rotate (revolution, rotation) or swing to ensure the uniform deposition of aluminum film on the surface of workpieces with complex shapes.
Control system: PLC or computer control system, integrated control of vacuum process, evaporation parameters (current, voltage), rotating frame movement, process timing, etc.
Cooling system: to cool the diffusion pump.
Venting system: after the process, fill the vacuum chamber with dry air or nitrogen to restore the pressure to atmospheric pressure so as to take out the workpiece.
Main advantages
High metallic color: mirror-like bright silver aluminum film can be obtained, with excellent decorative effect.
Low cost: Compared with other vacuum coating technologies (such as sputtering), the investment and operation cost of aluminum evaporation equipment is relatively low, and the cost of aluminum raw materials is also low.
High deposition rate: fast evaporation rate and high production efficiency.
The operation is simple and the personnel training is simple.