Research On Electroless Plating Preparation Of Wood Electromagnetic Shielding Material

Electromagnetic pollution is regarded as the fourth public hazard in terms of its ubiquity and huge damages to human beings.As the essential decoration material in human settlements,wood is a perfect insulation.Wood material is treated with electroless plating,and the preparation of wood electromagnetic shielding material is regarded as a new type material for eliminating electromagnetic pollution.In the paper,the electroless plating technology for foil and its formula have been proposed,which enables metal quality on wood surface,and the combination of electromagnetic shielding security and metal utilization has been improved either.Research results are summed up as follows:1.Based on the experimental results and practices in factory,as well as the consideration of chromatism and deposition rate.The key parts of plating formula was improved,which leading to the optimized formula ingredient,pH:13,stabilizer:10mg,temperature:45℃,time:10min,formaldehyde concentration:10 ml/L,brightener:25mg.By contrast research data of electromagnetic shielding evaluation from wood lab,when the high deposition rate formula is taken in the process of wood electromagnetic shielding material,the electromagnetic shielding effectiveness can meet the requirement in the detecting scale of 9KHz～1.5GHz if the plating time is kept more than 25min.2.Starting with processing,coating quality and bath validity is improved significantly by bath with air agitation or additives respectively.Comparatively,bath would be unstable extremely without additives,which leading to more obvious color difference and invalid bath prematurely.The test of coating characterization and micro-quality shows that both air agitation and additives can contribute to the stabilizing deposition of copper ion and prompt transverse deposition rate quicker than vertical, which resulting in better uniformity and smoothness.3.In view of the analysis of impacts on coating color difference by different lacquers,after spraying first coat,copper coating can be darkened and reddened,accompanying with a lost of initial tactile sensation,no matter what the lacquer being used,acrylic resin lacquer,nitrocellulose lacquer or polyurethane resin lacquer.It might be attributed to chemical ingredients in lacquers and the wood grain which totally has changed diffused reflection to direct reflection after be sprayed.Before and after finishing,the value of general chromatism,lightness difference and brightness difference in descending orders are polyurethane resin lacquer,nitrocellulose lacquer and acrylic resin lacquer.4.Analyzing the anticorrosion performance between the pre and post plating,different coating thickness by X-ray diffraction device.White rot fungi growing on wood without coating,after being plated,the performance of bacteriostasis and anticorrosion becoming better followed by the increasing coating thickness,the diffraction intensity of cellulose has increased either.Meanwhile,all the peak positions appear different offsets.5.By calculating the expenses of devices purchasing,raw materials,power depletion,labor cost, managing fare,the cost per unit of wood electromagnetic shielding material is about 50 RMB,which is quite cheaper than the cost of copper foil veneers.