Processing and application of conductive masterbatch

The demand for plastic anti-static/conductive products is increasing at home, and electronic product packaging requires a large number and variety. The anti-static/conductive products of plastic products have attracted people's attention, and are also one of the goals pursued by plastic packaging industry professionals. Using domestic basic materials, we develop products, additives, and masterbatch that meet the requirements of plastic conductive/anti-static, replacing expensive imported similar products, Develop electronic product packaging and anti-static product packaging that are more suitable for market demand. Common products include: plastic conductive/anti-static gas transmission, infusion pipelines; Low resistance plastic packaging tray, conductive/anti-static plastic sheet, sheet, foam, conductive film, etc. for electronic products.

Common anti-static plastic packaging requires a resistance of 10 to 8 ohms or more, and can be of any color. For electrical resistivity below 10 to 8 ohms, conductive carbon black is often used as the main conductive material, so there are more black ones. Below is a brief description of the method of using conductive carbon black and plastic to blend to produce conductive plastics or conductive masterbatch.

Selection of conductive carbon black

Suitable conductive carbon black, easy to use special conductive carbon black. Special conductive carbon black is commonly sold in the domestic market, and good dispersion is a key factor for selection. Suitable conductive carbon black can be selected based on the detailed application of the product. For example, for thin film applications, the dispersion and particle size of conductive carbon black are crucial, while for thick walled pipes, the selection of conductive carbon black is relatively simple.

For general conductive masterbatch, linear polyethylene LLDPE with wide applicability is generally selected, with powder form being the main choice., For example, resin grade 7042 can be chosen as the carrier, which is beneficial for the dispersion and processing of highly conductive carbon black. It is also suitable for extrusion injection molding and blown film use, and after grafting, it is also used for HIPS ABS PP LDPE HDPE, etc. Special conductive masterbatch is generally selected as a carrier with a resin with a similar melt index to the plastic matrix resin, and it is better to choose a resin with the same system as the carrier.

The selection of additives requires good heat resistance and compatibility. Considering the versatility of multiple varieties as carriers, necessary grafting agents, dispersants, antioxidants, and rheological agents should be added appropriately to achieve processing function compatibility, with a wide range of applications.

Processing equipment

High speed mixer, flat twin screw extruder (block type) granulation production line, determined according to personal situation, without exaggerating the same settings.

Processing technology

(1) Low level conductive masterbatch: Special conductive carbon black and carrier are fed into a high mixer according to a predetermined ratio, and dispersants, antioxidants, grafting agents and other additives are added. They are stirred and mixed together, and then twin-screw extrusion is carried out. This is called low-grade conductive masterbatch, which can be used for ordinary pipes. The amount added is about 20%. The concentration of carbon black in ordinary carbon black conductive masterbatch is not very high, especially when mixing nanoscale carbon black with resin, it is difficult to achieve a high amount of addition. Excessive addition can easily cause open flames and even cause resin decomposition.

(2) Low grade masterbatch drying, secondary extrusion granulation after installation of filter screen, can be manufactured into specialized/universal masterbatch as needed, or diluted to the required concentration, and can be used as conductive masterbatch after packaging. As a plastic masterbatch with sufficient concentration and resistance value of its conductive motor, the conductivity is generally less than 50 ohms. As a mother material, it is a product. Please pay attention to the filter threshold values of various conductive carbon black used in the resin. Excessive use has no practical significance!

Article source: Taishan conductive masterbatch

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