Processing and application of conductive masterbatch

The domestic demand for plastic antistatic / conductive products is increasing, and the number and variety of electronic product packaging are increasing. The antistatic / conductive products of plastic products, especially attract people's attention, are one of the goals pursued by people in the plastic packaging industry, which adopts domestic basic materials Materials, research and develop products, auxiliaries and masterbatch suitable for conductive / antistatic requirements of plastics, replace expensive imported similar products, and develop electronic product packaging and antistatic product packaging more suitable for market demand. Common products such as plastic conductive / antistatic gas transmission, infusion pipes, low resistance plastic packaging pallets, conductive / antistatic plastic sheets, sheets, foams, conductive films for electronic products.

Generally speaking, anti-static plastic packaging requires more than 8-power ohm of 10, which can be of any color, and the resistivity is less than 8-power of 10. Conductive carbon black is often used as the main conductive material, so there are more black colors. Here is a brief introduction of the method of using conductive carbon black to blend with plastic to make conductive plastic or conductive masterbatch.

Selection of conductive carbon black

Suitable conductive carbon black, the best use of special conductive carbon black. Special conductive carbon black is relatively common for sale in the sea, and good dispersion is the first choice factor. Suitable conductive carbon black can be selected according to the detailed application of the product. For example, for the application of thin film, the dispersion and particle size of conductive carbon black are more important, while for thick wall pipes, the selection of conductive carbon black is simpler.

For general conductive masterbatch, linear polyethylene LLDPE with wide applicability is generally selected, mainly in powder form. For example, 7042 resin can be selected as the carrier, which is conducive to the dispersion and processing of the conductive carbon black. It is also suitable for extrusion and injection film blowing. After grafting, it is also used for hips ABS PP LDPE HDPE, etc. The special conductive masterbatch generally selects the resin with similar melt index to the plastic matrix resin as the carrier, and the resin with the same system is preferred as the carrier.

The selection of additives requires good heat resistance and compatibility. Considering the multi varieties of the carrier, the necessary grafts, dispersants, antioxidants and rheological agents should be added properly to achieve the processing function, and the application range is relatively wide.

Processing equipment

High speed mixer, flat twin-screw extruder (building block type) granulation production line, according to their own situation, do not exaggerate the same set.

Processing technology

(1) low level conductive masterbatch: the special conductive carbon black and the carrier are fed into the high stirrer according to the given proportion, and additives such as dispersant, antioxidant and graft agent are added, and then they are stirred and mixed together, and then extruded by twin-screw. This is called low-level conductive masterbatch, which can be used for ordinary pipes. About 20% was added. The concentration of carbon black in the common carbon black conductive masterbatch will not be very high, especially the mixing of nano carbon black and resin, it is difficult to achieve a high amount of addition, too high amount of addition can easily see open fire, until resin decomposition.

(2) dry the low-level masterbatch, and carry out secondary extrusion granulation after installing the filter screen. In this process, it can be manufactured into special / general masterbatch or diluted to the required concentration according to the needs, and can be used as the conductive masterbatch after packaging. As a plastic masterbatch, it must have enough concentration and the resistance value of its guide motor. At this time, the conductivity is generally less than 50 ohms. As the masterbatch is the ultimate product, please pay attention to the filter value of various conductive carbon black used in the resin, too much use has no practical significance!

Article origin: Taishan conductive masterbatch

　　http://www.vincentpaillard.com