The demand for anti-static/conductive products in domestic plastics is increasing, the number of electronic products is required for packaging, and there are many varieties. The anti-static/conductive products of plastic products have attracted people's attention. It is also one of the goals pursued by people in the plastic packaging industry. The basic materials, research and development of products, additives, masterbatch suitable for plastic conductive / anti-static requirements, replace the high-priced imported similar products, develop electronic product packaging and anti-static product packaging more suitable for market demand. Common products such as: plastic conductive / anti-static gas transmission, infusion pipeline; low-resistance plastic packaging tray for electronic products, conductive / anti-static plastic sheet, sheet, foam, conductive film. Plus Size Ladie'S Dresses,Plus Size Summer Dresses,Plus Size Maternity Dresses,Plus Size Sundresses Ningbo Sunyu Fashion Co.,Ltd , https://www.sunyucollection.com
Common anti-static plastic packaging generally requires 10 to 8 ohms or more, which can be any color, and the resistivity is below 10 to the power of 8 and more conductive carbon black is used as the main conductive material, so the black is more The following is a brief description of the method of making conductive plastic or conductive masterbatch by blending conductive carbon black with plastic.
The conductive carbon black is selected from a suitable conductive carbon black, preferably a special conductive carbon black. Special conductive carbon black is relatively common in domestic sales, and good dispersion is the first choice factor. According to the specific application of the product, suitable conductive carbon black can be selected. For example, for the application of thin film, the dispersion and particle size of conductive carbon black are more critical. And thick-walled pipes, the choice of conductive carbon black is relatively simple.
Table 1. Selection of Performance Carriers for Typical Conductive Carbon Blacks For general-purpose conductive masterbatches, linear polyethylene LLDPE with a wide applicability is generally used, mainly powdery. For example, the brand name 7042 resin can be selected as a carrier, which is beneficial to the dispersion and processing of the special conductive carbon black. It is also suitable for extrusion blown film, and is also used for HIPS ABS PP LDPE HDPE after grafting. The special conductive masterbatch generally selects a resin which is close to the melt index of the plastic matrix resin as a carrier, and it is preferable to select a resin of the same system as a carrier.
Table 2, LLDPE DFDA-7042 Sinopec Yangzi Petrochemical Co., Ltd. Technical Index Additives Selection of additives requires good heat resistance and good compatibility. Considering the suitability of multiple varieties as a carrier, the necessary grafts, dispersants, antioxidants, and rheological agents should be properly added to achieve processing performance and a wide range of applications.
Processing equipment high-speed mixer, flat twin-screw extruder (building block) granulation production line, according to their own circumstances, does not emphasize the unity of settings.
Processing technology (1) Primary conductive masterbatch: The special conductive carbon black and the carrier are fed into a high agitator according to a predetermined ratio, and a dispersant, an antioxidant, a grafting agent and the like are added, stirred and mixed together, and then twin-screw extrusion Out. This is called the primary conductive masterbatch and is suitable for use in common pipes. The amount added is about 20%.
The carbon black concentration in the ordinary carbon black conductive masterbatch is not very high, especially the mixing of the nano-scale carbon black and the resin, it is difficult to achieve a high addition amount, and the excessive addition amount is easy to see an open flame until the resin is decomposed. .
(2) The primary masterbatch is dried, and the secondary extrusion granulation is carried out after the filter is installed. In this process, it can be manufactured as special/
The universal masterbatch, or diluted to the required concentration, can be used as a conductive masterbatch after packaging. As a plastic masterbatch, it must have sufficient concentration and its electrical conductivity resistance, and the conductivity is generally less than 50 ohms. As the masterbatch is the final product, please pay attention to the filter threshold value of various conductive carbon black used in the resin, too much use is not practical!
Application Example The primary conductive masterbatch is made of LLDPE powder as the carrier, the special conductive carbon black content is more than 20%, and the grafting, dispersing agent, antioxidant, rheological agent, and plastic reducing resisting masterbatch obtained by secondary processing are added. Reduce the surface resistance), the surface resistance is less than 100 ohms.
For high-impact polystyrene plastic sheet, 15 parts of the anti-static masterbatch can be obtained by adding 15 parts of the reduced-resistance masterbatch; adding 30 parts and obtaining 4 times of electric resistance less than 10 Square conductive sheet. Fully meet the needs of packaging in the electronics industry.
For the application of ABS and PP injection molding, 50 parts of the reduced-resistance masterbatch can be used to produce a 6-th power to 6-th power injection product with a resistance value of 10.
For the application in blown film, 40 parts of the reduced-resistance masterbatch can be added to obtain a product having a resistance value of about 10 to the fifth power.
It should be noted here that the surface resistance is greatly reduced due to the injection pressure and shearing effect; the difference in the stretching of the blown film also reduces the electrical conductivity.
Application of reduced resistance masterbatch in plastic sheet Tip: Extruder requirements: screw diameter: 90-105mm, length to diameter ratio of <33:1, screw: PS.PP special type, front end has a mixing section, sheet forming Pressure 12-14MPa
Two extrusion die: special mold for hanger type extrusion sheet, with automatic screen change system, filter screen: mat type stainless steel 80 mesh for easy three raw material mixing: high speed kneading machine, according to the required sheet surface resistance requirements Add different proportions of the reduced-resistance masterbatch, put it into the kneading machine, stir for 3-10 minutes, if there is a small amount of water, it will be eliminated in the process. If the water is too much, it is recommended to use the dryer or increase the mixing time.
High-speed agitation can also remove non-sheet materials that are mixed for unknown reasons. They will be adsorbed on the upper end of the pot due to centrifugal force/electrostatic separation and can be easily removed.
Four calender rolls: use temperature 60 degrees. Cooling roll temperature is less than 40 degrees; drum pressure: 6 KG/cm 2 or below 6MP. The temperature is too high. If the pressure is too high, the surface resistance will be lost. The residual material between the calender rolls should not be too much, otherwise the pressure orientation will occur, and there will be similar effects of excessive stretching, the longitudinal strength is lowered, and the surface resistance is lowered.
Stretching of five sheets: It has an effect on the surface resistance, and the larger the stretching, the lower the resistance. In particular, hot stretching, that is, the distance between the die exit die and the calender roll is 5-10 CM, slightly sag to unstretched straight to lightly stretched excessively to stretch or stretch excessively; Hot stretching of materials - often appearing