Injection Compression Molding Composite Conductive Material Based On Spacial Confining Forced Network Assembly Method

Conductive Polymeric Composites(CPCs)are functional polymer materials which have good electrical conductivity(EC)and sensitivity.CPCs are widely used in industrial fields..CPCs are usually fabricated by mixing different conductive particles in the polymer Then SCFNA method was proposed by Darning Wu group to increase the EC of CPCs by reducing the average spacing between conductive fillers.As a result,the EC of PP/SCF composites was raised up to 4 orders of magnitude higher than that by ordinary compounding technology.In order to produce CPCs of high EC by injection molding machine,a new process based on conventional injection and SCFNA method is studied in this article,which is called ICSCFNA.ICSCFNA is a process to implement SCFNA method on the injection molding machine.First of all,ICSCFNA process can achieve a two-stage compression by the mold to build compacted conductive network that reduces the percolation threshold of the conductive filler and increases the conductivity.ICSCFNA process can thus improve the shortcomings of the injection-molded CPCs.Moreover,ICSCFNA can effectively interfere with the fiber flow direction to enhance the conductivity of the infiltrated surface.(1)In order to achieve I-C-C process,the injection equipment needs to meet the following three points:First,the mold temperature needs to be modified to meet the compressibility of the sample.Second,the compression speed of the mold should achieve slow compression,which satisfies the process of transmitting compression force.The thickness of the final molded sample at the third point is less than dm.(2)The effects of I-C-C process on the conductive network,fiber distribution and electric conductivity were investigated.The distance between conductive particles of the blending system was reduced,so that the conductive network was compacted.The forming of dense conductive network significantly improved the conductivity.Combined with the microstructure and electrical conductivity,the applicable mold temperature and compression speed range of the I-C-C process for PP can be obtained.(3)The relationship between carbon fiber orientation distribution and carbon fiber network composition was studied.The conductivity of the article is predicted by predicting the flow of carbon fibers during the filling process.The uneven distribution of fibers leads to uneven conductivity,and where the carbon fiber orientation is high,the conductive network overlaps incompletely,resulting in anisotropic conductivity.In order to obtain conductive sheets with good electrical conductivity,the samples are in different positions.The fiber orientation ensures orientation in both directions.