Inlet Section

It is a roller design steel structure with varnish painting. Each of the rollers is covered with rubber and is driven by mechanism. It is used to for glass loading and direct glass into subsequent glass scrubbing section.

Scrubbing Section

This section is part of glass washing machine. One of major factors affecting silvering coating performance is glass washing quality. The scrubbing section consists of top rows of rotary cup brushes mounted on a rubber roller steel structure with driven mechanism. Glass is driven by rubber roller underneath with glass top surface in direct with cup brushes. Each of nylon bristle cup brush self rotates while rows of cup brush oscillate transversely to glass travel direction. Water pipes and spraying nozzles are installed. Cerium oxide polishing powder is usually added during scrubbing. This design helps to scrub glass surface thoroughly leaving no contamination.

Washing Section

This is the second part of washing machine. It consists of few pairs of nylon bristles cylindrical brushes mounted on a steel structure. There are top press rollers and bottom conveying rollers driven by mechanism. These rollers drive glass forward and direct it between top and bottom cylindrical brushes. Water pipes and sprinkles are used to spray water on cylindrical brushes.

Warming Section

Silvering process performs well when glass is at about 30℃. This rollers conveyor section consists of water pipes and nozzles. Water is heated up and warm water is spray on glass.

Sensitizing Tinning Section

This section is used to spray sensitizer on top glass surface before silvering. This wets glass surface and presents a "sensitized" surface for deposition of subsequent silvering. It helps for better silvering performance. The sensitizer is generally composed of tin ions. This section is an anti-corrosive roller structure with driven mechanism. Outstanding performance spraying nozzles are installed on a traverse overhead bridge above rollers. The traverse movement is driven by servo motor controlled by high precision transducer. Sensitizer is spray transversely to and fro on glass surface while glass travels longitudinally.

Silver Metering Console

This standalone silver console locates next to silvering section. Silver nitrate solution and reducing agent are put inside this console. The device precisely calculates and mixes the two solutions together. The mixture is finally pumped to silvering section.

Silvering Section

This section is used to spray mixture of silver nitrate and reducing agent on glass surface. When silver ions come in contact with reducer, silver molecules are abstracted and adhere on glass surface. This section is a conveying driven mechanism structure with stainless steel rollers.

Outstanding performance spraying nozzles are installed on a traverse overhead bridge above rollers. The traverse movement is driven by servo motor controlled by high precision transducer. Speed and cycle time of traverse movement is easily regulated. When traverse motion is faster, cycle time is lesser. Consequently, less quantity of silver and thus, thinner layer of silver are applied on glass surface when glass travel speed remains constant.

Residues are rinsed by DI water and blown off by compressed air. Gases occurred during chemical reaction are exhausted by air ventilator. Excessive silver will overflow and drains to a recycle tank or pit (to be provided by buyer). This tank or pit is recommended to be put outside workshop. Silver is disposed only when it is necessary.

Copper Metering Console

This standalone copper console locates next to coppering section. Copper solution and reducing agent are put inside this console. The device precisely calculates and mixes the two solutions together. The mixture is finally pumped to coppering section.

Coppering Section

This section is used to spray mixture of copper solution and reducing agent on glass surface. When copper ions come in contact with reducer, copper molecules are abstracted and adhere on glass surface. Iron powder is usually mixed together with the solution to catalyse the chemical reaction. This section is an anti-corrosive roller structure with driven mechanism.

Outstanding performance spraying nozzles are installed on a traverse overhead bridge above rollers. The traverse movement is driven by servo motor controlled by high precision transducer. Speed and cycle time of traverse movement is easily regulated. When traverse motion is faster, cycle time is lesser. Consequently, less quantity of copper and thus, thinner layer of copper are applied on glass surface when glass travel speed remains constant.

Residues are rinsed by DI water and blown off by compressed air. Gases occurred during chemical reaction are exhausted by air ventilator.

Blowing & Drying Section

It is composed of air blower, air hoses and rollers conveyer. Excessive chemical solutions are blown off. Excessive water is then dried thoroughly by force air before entering into subsequent pre-heating section.

Pre-Heating Section

After drying, glass enters into this pre-heating section. It is a conveying roller structure design. Every steel roller is covered by heat resistant rubber. A heating chamber is mounted on top of rollers. The chamber consists of durable heating resistors. Glass travels beneath heating element and is pre-heated. Heated glass allows better adhesion of subsequent mirror back painting.

1st Painting Section

This section applies protective mirror back paint on top of silver and copper layers by curtain coating process. It consists of one inlet and one outlet belt conveyor systems, driven mechanism, curtain coating system, paint stirring, pumping and recirculating systems.

Paint stirring and pumping systems locate next to this curtain coating section. Paint is usually stored in drums. Stirring and pumping devices are put inside the drum to stir the paint thoroughly. It prevents the paint from precipitate and also to pump it over to the curtain coating section. Curtain coating system is a traverse stainless steel sheet structure locating in between inlet and outlet belt conveyor. It is a V-shape design with long adjustable orifice opening. Paint is pumped over to the V-shape reservoir. Paint then flows downwards through the orifice by means of force of gravity. Paint exits out of the V-shape opening like a curtain or waterfall. When there is no glass, reinforced conveyor belt moves in slow speed. When this section detects glass entering, both belt conveyors accelerate.

Inlet conveyor brings glass passing beneath the paint curtain. While glass travels in high speed under paint "waterfall", mirror back paint is then applied on whole glass surface covering silver and copper layers. Mirror then enters to outlet belt conveyor which is synchronize and has identical acceleration with inlet conveyor. After mirror exits out of outlet belt conveyor, both belt conveyors decelerate down to slow speed and wait for next glass. When there is no glass, paint keeps on pumping and flows through the orifice. A re-circulating tank is put underneath curtain coating system. Excessive paint is pumped and brought back for recirculation.

Paint thickness is regulated by adjusting belt conveyor acceleration and/or V-shape orifice opening. When travel speed is faster and/or V-shape opening is smaller, thinner layer of paint is obtained. When travel speed is slower and/or V-shape opening is larger, thicker layer of paint is obtained.

1st Drying Oven

The oven dries and cures first layer of mirror back paint. It consists of heating chamber with heating elements, heat resistant rubber rollers conveyor, flash off exhaust blowers and exhaust pipes. Mirror is driven beneath heating elements by rollers conveyor and is heated up. Heating speeds up paint curing process. Paint surface is also smoother and looks better. During heating, solvent is evaporated from the paint. Solvents are exhausted by means of flash off exhaust fans via exhaust pipe above the fans. These specially designed flash off fans prevent solvent from ignition. The exhaust pipes are extended by longer pipes which direct solvents out of workshop. The extended pipes are provided by buyer.

2nd Painting Section (Option)

This section is optional. The design and structure are identical to 1st curtain coating section.

2nd Drying Oven (Option)

This section is optional. The design and structure are identical to 1st flash off drying oven.

Cooling Section

After paints are heated and dried, mirrors are required to be cooled down gradually or they break easily. This cooling section consists of natural open cooling and forced cooling. Both are rollers conveyor design but with blowers and air pipes for force cooling. Mirrors are then cooled down slowly preventing from self breaking.

Acid Washing Section

During silvering, coppering and mirror back paint curtain coating, excessive residues may adhere on bottom glass surfaces. This section is used to remove those unnecessary chemicals. It is a rollers conveyor structure with driven mechanism. The rollers are made of special sponge materials. There is a tank beneath rollers. The tank is filled with adequate acid solution to a certain level such that bottom parts of sponge rollers are submerged in the solution. When rollers rotate, sponges absorb acid and bring it to top. While mirrors travel on rollers, acid on sponge rollers washes away those excessive chemicals left bottom mirror surface. The acid is environmental friendly and no pollution is created.

Final Washing Section

It is composed of cylindrical brush, conveyor rollers, air blower, air knife, water pipes and nozzles. This section is used to wash away the acid and to dry the mirrors ready for packing.

Logo Marking Section

It is an overhead bridge design across rollers conveyor. Several printing heads are mounted on the bridge at equal distances above mirrors. Printing heads are fixed at certain distances. Logos spacing are adjustable by moving along the bridge. When mirrors travel beneath the heads, printing heads eject logos marked on mirrors backs. Logos longitudinal spacing on mirror backs are adjustable. Logos are designed in a computer.

Exit Section

It is a roller design steel structure with varnish painting. Each of the rollers is covered with rubber and is driven by mechanism. It is used to for glass unloading.

Control System

The system consists of several standalone consoles. They are composed of reliable electrical and electronics parts and components including high precision PLC. All parameters such as glass travel speed, spraying traverse speeds and temperature are accessed from user friendly interfaces.

DI Water Treatment System

Silvering must be applied with de-ionized water which sometimes is known as de-mineralized water or soft water. Industrial water is hard water containing minerals. Minerals could do harm to silvering and coppering processes. This system is used to remove all minerals contained in industrial water. The treated water is pure and is suitable for silvering and coppering.