Composition of plastic bottle cap flexo printing machine
1. Automatic accessories lifter
The automatic accessory lifter can store a large number of plastic bottle caps, and can automatically and quantitatively transfer the plastic bottle caps to the feeders according to the conditions of the bottle caps inside and outside the feeder. In addition, the speed of the cap can be adjusted according to the speed of printing.
2. Automatic front and back feeder
Since the front of the cap is the printed surface, the device must be able to correctly distinguish between the front and back of the cap. The automatic accessory lifter feeds the bottle cap to the material feeder. The automatic front and back feeders use the physical properties of the bottle cap. For example, the front face of the bottle cap has a large mass, and the mechanical vibration of the rotary plate discriminates the front and the back of the bottle cap. Next, the caps that are facing upwards are transported to the wind conveying pipe, and the caps that are turned upwards are returned to the inside of the feeder again to distinguish between the front and the back.
3. Automatic feeding device
The automatic feeding device is a conveying pipe composed of aluminum alloy and stainless steel. The conveyor belt and compressed air are used to push the bottle cover forward at the same time. The function is to put the bottle caps on the supporting positions of the bottle caps (the printing face of the bottle caps On top), the cap can also be pressed and fixed on the tube position by rotating small wheels. The tube position is a unique device for the cap flexographic printing press and is used to support the plastic cap. There are two rows of tube positions on the cap flexographic printing press. In the design, six tube positions are used as a unit, and a plastic cap is placed on each tube position. The positional accuracy of the tube determines the degree of print registration.
4. Electrostatic dust collector
Plastic caps inevitably attract some dust on the lifter, the feeder and the conveyor belt, and will affect the adhesion of the ink on the surface. Therefore, an electrostatic precipitator must be used to remove the dust particles adsorbed on the surface of the cap before printing.
5. Surface processor
Plastic bottle caps are generally made of polyethylene or polypropylene materials, which are non-polar molecular structures and have poor adhesion to ink. In addition, the oil adhered to the surface of the plastic cap also affects the adhesion of the ink on the surface of the cap. Therefore, the cap needs to be surface-treated before printing. There are three flame heads on the surface processor. The surface of the plastic bottle cap is activated by a high-temperature flame. Polar groups such as carboxyl and hydroxyl groups are introduced into the polyethylene or polypropylene molecules to increase the surface energy of the cap surface. Allows the ink to adhere firmly to the cap.
6. Print head
The print head is the core component of a full-automatic plastic bottle cap flexo printing press and consists of an anilox roll, a plate cylinder, a doctor blade and a stainless steel oil bowl. The number of lines of the anilox roller can be selected according to the fineness of the printed graphic. Since there are two rows of support tube caps, two sets of printed texts are generally printed on the printing plate, and two printing caps can be printed at a time. In the four-color printing, the printing head can be independently adjusted. If you use a printing plate without graphics, you can also cover the entire surface of the plastic cap. The stainless steel oil basin is easy to dismantle and easy to operate, reducing the loss of ink.
7.UV curing device
UV capping inks are generally used for plastic cap printing. UV curing is required for each color. Therefore, a UV curing device must be installed on the plastic cap flexographic printing press. Duoweilong's plastic bottle cap flexo printer's UV lamp uses a brand-name product from Europe. The power is 600W/inch. It is equipped with an automatic temperature control ventilation system to enable the UV lamp to perform optimally.
8. discharging inspection conveyor belt
After printing and drying, the bottle cap enters the conveyor belt and passes through the quality inspection and enters the storage tank. At this point, the entire process of cap printing is completed.
Plastic Bottle Cap Flexo Printing Features
1. Achieve four color printing of bottle caps
In people's impressions, the printing of plastic bottle caps is generally printed on the surface, and most of them are simple texts and color blocks, and the colors are relatively monotonous. The four-color overprinting of plastic bottle caps can be achieved completely by means of flexographic printing, and the printed graphics are vivid and vivid. For example, printing color-realistic fruit on the lid of a drink bottle can serve as a good lining for the beverage in the plastic bottle and can stimulate consumers' desire to purchase.
2. Polishing the bottle cap to improve product quality
After printing on plastic caps with water-based inks, the surface of plastic caps may also be glazing in order to improve the abrasion resistance of the ink. After polishing, the gloss of the plastic caps is significantly improved, which makes the picture brilliance and enhances the product grade.
3. Overprinting is accurate and convenient
The overprint control of the plastic bottle cover flexographic printing press is very characteristic. Since the precision of the position of the support plastic cap (horizontal and longitudinal) has been guaranteed in the numerical control machining center, when overprinting is not allowed in the printing, it can be adjusted according to the situation. The position of the plate cylinder, so that it meets the printing requirements. At present, the overlay error of plastic bottle cover flexo printing can be controlled at 0.15-0.20mm.
Flexographic printing technology has greatly improved the printing quality of plastic caps. At present, many manufacturers in China have adopted flexographic printing plastic caps. We will continue to pay attention to its future applications and development trends.
Source: Printing Technology
