Process description and factors of bottle cap mold

Update:10 Oct 2020

Printing instructions for bottle cap technology

The bottle cap has advanced technology in the printing process, which makes the wine bottle cap beautiful. Now, the bottle cap mold factory introduces the pad printing process used for different bottle cap printing and other printing processes. Plastic bottle cap printing: change the type Convenient, easy plate making. Investment is less. Compared with other printing equipment, the investment in pad printing equipment is less.

Strong compliance. The shape of the pad printing rubber head can be changed at will, which greatly enhances the compliance of pad printing skills to the shape of the substrate, and is suitable for bottle cap printing of different appearances and sizes. The selection of the ink used for pad printing of plastic bottle caps is very important. The bottle caps are basically made of PP and PE materials, and the selected ink must match the type of printing material. Then when selecting and using inks, you should pay attention to the addition of hardeners in some inks to improve the adhesion effect, but increase the difficulty of operation. Therefore, unless the customer has a special request, it is not recommended to use this method. Use pad printing ink instead of screen printing ink. Screen printing inks have better leveling properties, while pad printing inks have better colloidal properties; the monotonic speed of screen printing inks is relatively slow, and the monotonic speed of pad printing inks is faster. If you want to print beautifully, you must choose the ink, and there are two key points in bottle cap manufacturing: plastic head and money plate. Plastic head: At present, the selection of plastic head is generally not paid attention to in China, but the selection of plastic head should be very strict when printing. In the bottle cap pad printing, the application of round rubber head is more common. Printing plate: For bottle cap manufacturers who pay attention to pad printing quality, resin intaglio is a wise choice.

Process factors of plastic bottle cap weld marks

The weld mark of the plastic bottle cap is a linear mark on the injection part. When the part has holes and inserts, the plastic melt flows in two streams, or the gate is more than one or the thickness changes. It is caused by the incomplete fusion of the material flow at the interface.

Process factors:

(1) The temperature of the material tube or the hot runner is too low, and the melt plasticization is not complete. The temperature should be increased or the plasticization time should be appropriately extended.
(2) The wall thickness of the product is too thin and it is difficult to fill the mold, thereby increasing the temperature difference of the melt in the mold, and the phenomenon of welding marks is easy to appear. At this time, the injection pressure or the barrel temperature can be appropriately increased.
(3) The mold temperature is too low, which causes the melt flow rate to slow down, and the cooling is too fast, and the two streams cannot be effectively fused when they meet.
(4) The injection speed is too slow, resulting in a slower material flow speed, and the melt that enters the cavity first cools faster. Material factor: The raw material contains moisture, which is converted into gas during the injection process, which affects the fusion effect of the material flow. The raw material should be dried and treated with moisture.

Mold factors:

(1) The mold is trapped in air, making the gas in the cavity unable to be discharged. When the two streams merge, the fusion effect will be affected.
(2) The gate design is unreasonable, and the gate position should be avoided around the inserts and holes. Try to correct, migrate or add a block buffer to the gate where the injection mold filling occurs, and try not to use or use more gates as much as possible.

https://www.sunmolds.com/

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