粉末涂装过程中的缺陷分析及对策IV.附着力（Ⅱ）

3.3.2表面调整表面调整的作用是在基材上形成很多晶点,细化磷化膜结晶。如果表面调整失效,钢铁锌系磷化膜呈蓝彩色,膜粗糙,与基材的结合力不佳,最终导致涂层的附着力也不合格 铝及铝合金的锌系磷化膜异常粗糙,结晶颗粒大,膜与基材的结合力差,最终导致涂层的附着力也不合格 锌及锌合金基本无磷化膜,表面容易挂灰,涂层的附着力也不合格。     

环氧粉末涂层对金属基材附着力的影响因素

环氧粉末涂料具有附着力好、耐腐蚀性强、耐温性能好等优点，在金属防腐特别是重防腐领域应用非常广泛。在环氧粉末涂层的诸多性能中，涂层对基材的附着力是非常重要的一项技术指标，也是满足其他性能的基础，附着力的好坏直接影响着涂层对基材的保护寿命。本文主要从喷涂温度、基材表面处理的表面粗糙度以及粉末涂料原材料等方面讨论了环氧涂层对金属基材表面附着力的影响因素。研究表明：喷涂温度提高有利于涂层附着力的提高，表面粗糙度提高且锚纹深度相对均匀有利于涂层附着力的提高，填料以及助剂的种类对附着力具有一定的影响。     

热——光双重固化涂层对金属表面附着的影响

文章阐述了涂层在金属基材表面的附着理论,其中,静电吸附理论在紫外光固化涂层对金属基材表面附着的过程中起主导作用。重点分析了热——光双重固化方式、固化过程、低聚物、单体对涂层附着力的影响,引入柔性链段和极性基团的低聚物、单体,能增加涂层对金属基材表面的润湿程度,增加分子间作用力和氢键,减少涂层的体积收缩率,对提高涂层在金属基材表面的附着力有一定的帮助。     

激光和等离子处理对复合材料表面涂层附着力的影响研究

为了提高环氧涂料在纤维增强聚丙烯复合材料上的附着力,采用激光和等离子体表面前处理方法,应用超景深显微镜、粗糙度测定仪、接触角测试仪以及附着力测试仪,研究了激光和等离子体表面处理对纤维增强聚丙烯复合材料表面形貌、表面粗糙度和表面水接触角的影响,并且探究了这 2种表面处理方式对环氧涂层在复合材料上附着力的影响。结果表明： 2种处理方式均可明显提高环氧涂层在基材上的附着力,附着力均可由不到 1 MPa提高至 8 MPa以上。     

激光和等离子体处理对复合材料表面涂层附着力的影响研究

为了提高环氧涂料在纤维增强聚丙烯复合材料上的附着力,采用激光和等离子体表面前处理方法,应用超景深显微镜、粗糙度测定仪、接触角测试仪以及附着力测试仪,研究了激光和等离子体表面处理对纤维增强聚丙烯复合材料表面形貌、表面粗糙度和表面水接触角的影响,并且探究了这2种表面处理方式对环氧涂层在复合材料上附着力的影响。结果表明:2种处理方式均可明显提高环氧涂层在基材上的附着力,附着力均可由不到1 MPa提高至8 MPa以上。     

浅谈如何有效进行涂装预处理生产

在涂装前,除去基材表面附着物和锈蚀,以提高基材表面与涂层的附着力,或赋予基材一定的耐蚀性能的过程称为涂装预处理。三一集团涂装预处理班的主要任务是对钢材库中的划材、板材进行抛丸和预涂底漆等工作。     

表面处理工艺对铝合金防腐涂层性能影响研究

通过拉开法附着力测试、耐海水浸泡试验及电化学阻抗试验等方法,研究了铝合金不同表面处理工艺对防腐涂层耐蚀性能的影响。研究结果表明:打磨和钝化处理能大幅提高防腐涂层的附着力,附着力可达16~20 MPa,但涂层的模拟电阻值较低,海水浸泡5个月后,仅为(0.8~1.3)×108Ω;阳极氧化处理基材表面防腐涂层的附着力较低,仅为9 MPa,但基材的耐蚀性能有大幅提高,海水浸泡5个月后,涂层模拟电阻值仍可达(1.0~1.3)×109Ω。以上研究结果可为铝合金基材表面处理工艺的选择提供参考依据。     

钛合金表面处理及涂漆工艺研究

通过对钛合金表面涂漆前的工艺研究,验证选用表面处理剂及改性环氧底漆作为钛合金防护涂层,可提高对钛合金基材的附着力。     

雷达红外兼容吸波涂层失效分析与预防研究

概述了雷达红外兼容吸波涂层的工作原理,简述了涂层失效的定义、表现形式和分类方法;引入了失效分析模型,对其失效原因进行了分析;综述了涂层与基材间的结合机理,从基材表面状态和涂层应力两个角度,论述了其对吸波涂层与基材间结合力的影响,并针对性地提出了基材表面前处理和涂料树脂体系改性优化等提高附着力的方法。为吸波涂料配方的设计提供理论指导,指明了涂装前处理的必要性和重要性,为后续涂装质量和涂层性能的发挥奠定了基础。对雷达红外兼容吸波涂层技术和涂层失效检测及修复技术的发展前景进行了展望。     

水性可剥防护涂料的研制

水性可剥防护涂料是应用于汽车、舰船、大型仪器和设备的涂装、运输及存放等方面的临时保护涂料。主要研制并讨论了水性可剥防护涂料对不同基材及不同类型的涂层的可剥离性以及临时保护作用,并实验了其从基材和其他涂层表面剥离后对被保护涂层光泽度及附着力的影响。结果表明,该水性可剥防护涂料在多种基材上均具有良好的可剥离性,并且对被保护涂层的光泽度、附着力及表面状态几乎没有影响。     

Interfacial factors in corrosion protection: an EIS study of model systems

The effects of the liquid–coating interface and coating–metal interfaces on corrosion protection of a coated aluminum sheet (Alclad 7075-T6) were investigated using electrochemical impedance spectroscopy (EIS) of selected model systems. Parylene C was deposited on a solvent-cleaned aluminum sheet to prepare the coated aluminum sheet. Parylene C does not adhere well to most smooth surfaces: a freestanding film can easily be peeled off the substrate, although it does not peel off by itself during EIS measurements. When an ultra-thin layer of plasma polymer (ca. 50 nm) is deposited on the substrate, however, Parylene C adheres very strongly to the sheet. The top surface of Parylene C coating was modified via deposition of an ultra-thin layer of either a very hydrophobic or a very hydrophilic plasma polymer. The EIS Bode plot for the first run showed a typical good barrier coating regardless of the nature of the two interfaces under consideration. However, it was found that the impedance value in the lower frequency region decreases with increased immersion time, and the time-dependent change is greatly influenced by the nature of the two interfaces. A hydrophilic top surface increased the rate of time-dependent change, while good adhesion of Parylene C to the metal decreased the extent of time-dependent change. With a hydrophobic top surface and good adhesion to the substrate, EIS characteristics of a Parylene C coated sheet remained unaffected for 18 days (the longest time employed in this study). The decrease in impedance in the low frequency region converges to the Bode plot for a freestanding Parylene C film. The early decline of EIS characteristics can be correlated to the (pre-corrosion) micro-delamination of the coating.     

Studies on surface properties of polymeric coated paper material

Surface properties of a polymeric coating system have a strong influence on its performance and service life. However, the surface of a polymer coating may have different chemical, physical, and mechanical properties from the bulk. Significant progress has been made during the last three decades in the improvement of coating on materials. It has been established that polymeric blends have great potential in replacing economically many conventional materials because of their high specific strength. It is needed today, constantly, to improve the surface finish of any material for efficiency and shiny appearance in the severity of working environment. In packaging, materials having longer service lives and those are less corrosive are highly used. The effect of polymer based coating on the paper material improves its mechanical properties and flame resistance. Effect of flame retardant polymer coating illuminates the surface of the sheet. Important application of the material sheets will be for corrosion receptivity and humidity resistance of this material will certainly improve. Blends of PMM/PVDF are mainly used to improve piezoelectric properties of PVDF. In the present study we report the measurement of surface properties of thin layer of polymer blend coated on the cardboard sheet substrate material. Polymer blend solutions of PMMA/PVDF was prepared at 90/10 (w/w) proportions in miscible solvent of toluene and DMF. Thin film was prepared on the surface of cardboard by dipping the cardboard material in the solution. Thickness of the dried polymer coated paper sheet was measured to see uniformity of coating and for different concentrations. Surface properties such as flexibility index, yellowness, and gloss reflectance were also measured. The study on these polymer coated paper will help in improving the surface property of paper as well as its use in packaging. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4167–4171, 2006     

热浸镀锌和热浸镀铝锌彩涂板的切边抗盐雾性能的比较与研究

对热浸镀锌和热浸镀铝锌彩涂板的切边进行盐雾腐蚀试验的对比研究,并得出结论认为,同等厚度金属涂层对彩涂板切边的抗盐雾性能影响区别不大,直接影响其表现的还是表面涂料涂层的种类和涂装质量。     

电泳槽玻璃钢衬里的施工过程

介绍了电泳槽玻璃钢衬里施工的流程,包括材料的表面处理,刷底漆,涂防腐树脂,贴增强纤维布,树脂积层,防腐面处理,涂面层,检查及养护固化.指出了在材料检验、施工管理及安全防护等方面的注意事项.给出了玻璃钢涂层的检测步骤.     

锅炉受热面复合陶瓷涂层抗高温SO2腐蚀性能

针对燃煤锅炉受热面存在的高温腐蚀问题,采用料浆法在20G钢材表面制备复合陶瓷涂层,烧结后的复合陶瓷涂层表面较为致密,涂层与基材具有良好的结合状态。对喷涂及未喷涂陶瓷涂层钢片在SO₂腐蚀气氛环境下的抗高温腐蚀性能进行试验,并采用热分析动力学方法对试验数据进行处理,结果表明,在400~500℃温度范围内,两种试样的腐蚀过程均符合一维扩散反应动力学模式,计算求得喷涂涂层钢片腐蚀反应活化能低于未喷涂涂层钢片,涂层具有较好的抗高温腐蚀性能。对腐蚀试验后试样的形貌、成分和物相分析结果显示,涂层在SO₂气氛下腐蚀后,表面生成K₂SO₄晶粒,但由于涂层较为致密,阻止了S的扩散,内部基本没有检测到K₂SO₄的存在。     

铝电缆镀铜电流密度的快速监测系统设计

在铝电缆表面镀铜工艺中,电流监测系统采用有线传输的方式,监测速度较慢、实时性不高。设计了一种用于铝电缆镀铜电流密度的快速监测系统,阐述了铝电缆电镀铜机理,选用铝片进行实验,利用测量镀层厚度和镀层耐腐蚀性评定方法,进行电流密度对镀层耐蚀性的影响、电流密度与镀层厚度的关系实验,确定电流密度的监测范围。在此基础上,依据系统需求设计总体结构,介绍了主控芯片、电流传感器电路和无线通信芯片,最后进行了软件代码设计。结果表明,所设计的监测系统精度高、监测速度快,可有效利用资源。     

Capillary pressure and viscous pressure drop set bounds on coating bead operability

In premetered slot or extrusion coating and related sheet coating a “bead” of liquid is held between the coating die and the moving sheet by capillary forces, which depend on gap clearances, surface tension, contact line attachment, and dynamic contact angle; by viscous forces, which depend on clearances, viscosity, meniscus, location, and coating thickness; and by the externally applied pressure difference, which must fall within bounds for the bead to be operable.New bounds are derived for quasi-static beads with variable meniscus location, extending Ruschak's [1] analysis. Viscous effects are modeled by Couette and Poiseuille contributions that account for nonuniform clearances and are important except in limiting cases like Ruschak's. Operating bounds are derived for viscous coating beads.     

锌-镍/纳米氧化铝复合电沉积及镀层结构性能研究

以冷轧钢板为基材,研究了Zn-Ni/纳米Al2O3复合镀层的电沉积工艺,分析了复合镀层的成分和晶体结构.通过中性盐雾试验,考察了复合镀层的耐蚀性.采用X射线衍射和扫描电镜,分别表征了复合镀层腐蚀产物的微观结构以及镀层的表面形貌.结果表明:Zn-Ni/纳米Al2O3复合镀层的结晶比Zn镀层及Zn-Ni合金镀层更细致,晶粒排布更均匀、整齐.当Zn-Ni/纳米Al2O3复合镀层中Ni和Al2O3的质量分数分别为13%左右和0.40%～0.60%时,其耐蚀性最好.Al2O3颗粒的掺入可降低镀层的孔隙率,使镀层平整、致密,从而提高了镀层的耐蚀性.     

Microstructured conducting polymer coatings on plastic strip for contact electrodes: Formulation and tuning of sheet resistance

Mechanically strong and flexible strips of cellulose acetate were used to support a thin coating of poly(3,4 ethylenedioxythiophene) : poly(styrene sulfonic acid) PEDOT : PSS, an intrinsically conducting polymer (ICP), formulated with an aqueous dispersion of judiciously chosen copolymer of vinyl acetate and ethylene (VAE), to impart adhesion of the coating onto the substrate. Incorporation of a few drops of an organic acid to the formulation resulted in a substantial reduction of the sheet resistance of the coated surface. When the coated strips were post‐treated with a salt solution, a further fine tuning of the sheet resistance by a factor of 10 was achieved. The coated strips combine high conductivity with flexibility and mechanical strength. The performance of the coated strips has been evaluated in relationship to composition, coating thickness, and sheet resistance for application as contact electrodes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 234–237, 2007     

预磷化电镀锌钢板粉末喷涂前处理工艺

对一种用于汽车和通讯行业的新型预磷化镀锌钢板的粉末喷涂前处理工艺进行了研究,通过晶相、膜质量及盐雾试验,对预磷化板的现有工艺进行了改进。酸洗工艺对预磷化板是不利的,酸洗工艺完全破坏了预磷化膜层。盐雾试验结果表明,预磷化镀锌钢板经过弱碱性脱脂剂清洗,经表调、磷化然后和粉末涂料结合,可以得到良好耐蚀性和附着力强的涂层。