轮胎模具的表面处理与干冰清洗技术

轮胎生产企业为了保证轮胎产品的外观质量,必须对结垢的轮胎模具模腔定期清洗。目前,较常用的模具清洗方法主要有砂布和钢丝刷物理清洗法、干式喷砂法、化学法、超声波法和先进的干冰清洗技术(固体二氧化碳喷射法)。这些方法各有特点: 1)砂布和钢丝物理清洗法和干式喷砂法:对模具腔体的棱角损伤较大,影响模具寿命,同时非常容易堵塞模具的排气孔。一般模具的排气孔数量较多,在数百到数千个。喷砂后疏通排气孔的工作量非常大。     

铝件黑色缎面阳极氧化

1　前言　　铝件阳极氧化后再涂漆是沿用多年的产品表面处理工艺。在光学仪器如望远镜、显微镜 ,照相机等外装件上尤其偏重于铝件表面的黑色处理 ,即阳极氧化表面涂装黑漆。由于黑漆中的填料粒度和黑度很难满足产品外观要求 ,加上漆膜不够坚硬 ,无金属感 ,在运转过程中容易产生划痕、碰伤和掉漆等现象。需对上述工艺进行改进。铝件黑色缎面阳级氧化是在原有工艺基础上去掉喷漆工序 ,增加喷砂和化学抛光工艺形成的。这种工艺得到的零件表面光亮、乌黑、耐磨 ,具有黑色绸缎状外观 ,能大大地提高光学产品外观装饰性能。2　工艺介绍工艺流程如下…     

水喷砂去除钛合金表面氧化层效果的研究

通过对水喷砂后钛合金零件外观观察和能谱分析等方法,研究水喷砂去除钛合金表面氧化层的效果以及对基体材料的影响。研究结果表明,水喷砂可以有效去除钛合金表面氧化层。     

提高轮胎内表面粘合性能的方法

自封式安全轮胎内表面与具有自愈合能力的密封胶粘合良好才能实现缺气保用。轮胎内表面与密封胶的粘合机理主要包括静电理论、吸附理论、扩散理论、机械互锁理论、化学键理论和弱边界层理论;轮胎内表面的处理方法有物理法(包括机械打磨、喷砂处理、紫外线辐射法、臭氧氧化法、紫外线辐射和臭氧氧化共同处理法及等离子体处理法等)和化学法(包括酸处理和碱处理),工业上易于实现的主要为机械打磨法、紫外线辐射法和化学法;经过机械打磨处理的轮胎内表面可与密封胶达到较好粘合,且设备简单,后处理容易,常应用于工业生产;紫外线辐射法能提高轮胎内表面与密封胶的粘合强度,但辐射时间需适当。     

弹簧件镀锌的工艺要点

阐述了弹簧件镀锌工艺中的阳极电解除油,喷砂或酸洗去除表面氧化皮,采用合理的工夹具装挂弹簧及减少镀锌层渗氢。实践证明,此工艺对提高弹簧件的外观质量、防腐性能、结合力,防止渗氢,减少氢脆现象的发生,是很实用的工艺方法。     

苯胺有机废水处理技术研究进展

综述了苯胺废水产生的原因、危害及处理方法,重点介绍了目前常用的物理法、化学法和生物法。物理法主要包括吸附法、萃取法、膜分离法等,主要应用于苯胺废水的预处理阶段;化学法包括电催化氧化法、光催化氧化法、化学氧化法、超临界水氧化法、二氧化氯催化氧化法等,通过传质与化学反应的作用,将水中的有机污染物分离或分解为无害物质;生物法适合处理低浓度苯胺废水,对废水的p H值、物质组成、温度等都有比较苛刻的要求。介绍了新型的苯胺废水处理方法以及方法联用,如Fenton-混凝法、电子束辐照降解技术、吸附-双催化氧化技术等,对苯胺废水处理的发展前景进行了展望。     

苯胺类废水处理技术研究进展

归纳了苯胺类废水产生的原因、危害及处理方法,重点介绍了目前常用的物理法、化学法和生物法。物理法主要包括吸附法、络合萃取法、膜分离法等,主要应用于苯胺类废水预处理阶段的分离、富集;化学法包括电催化氧化法、光催化氧化法、化学氧化法、超临界水氧化法、二氧化氯催化氧化法等,主要通过传质与化学反应的作用,将水中的有机污染物分离出来或分解为无害物质;生物法是利用微生物降解苯胺类污染物,适合处理低浓度苯胺废水,对废水的p H值、物质组成、温度等都有比较苛刻的要求。另外,还介绍了一些新型的处理技术和方法联用。     

城市污水除磷方法概述

随着人们生活水平的不断提高大量含磷生活污水排入江河湖泊中,加剧了水体富营养化现象。概述了城市生活污水除磷常用的化学方法,包括沉淀法、吸附法、结晶法、离子交换法等;常用的生物方法,包括A/O法、A2/O法、Phostrip测流除磷法、Bardenpho法、氧化沟工艺等;以及其他方法:生物—化学法、人工湿地法、生物膜法、反硝化法、氧化镧化学法、以及超声波强化氧化法等。最后对污水处理的发展方向进行了简单展望。     

手机壳用铝合金二次氧化封孔剂的选择

分别选用进口封孔剂DX-500、国产封孔剂SF-558和AL-500A对阳极氧化后的A5052铝合金进行封孔。主要工序依次为冲压成型、抛光、除蜡、喷砂、一次氧化、一次封孔、激光导电位、CNC(计算机数控)高光、前处理、二次氧化和二次封孔。研究了封孔剂种类、质量浓度、使用温度和处理时间对氧化膜层外观、耐蚀性、耐变色性等性能的影响。对比分析了3种封孔剂的综合性能。较适宜的封孔工艺条件为:封孔剂质量浓度7 g/L,pH 5.5~5.6,温度高于80℃(一般取85℃),一次封孔时间20 min,二次封孔时间5 min。国产封孔剂SF-58和AL-500A完全可以替代进口封孔剂DX-500,其便宜且某些性能甚至超越进口封孔剂。     

化学法处理含油污泥研究进展

综述了各类含油污泥化学法处理办法,包括:热解法、氧化法、热洗及萃取法、电化学法。概述了这4类处理方法的概念、作用机理、研究进展,并对化学法处理含油污泥研究方向进行展望。     

PVC thermoplastic elastomers

The paper describes the development and properties of a new family of thermoplastic elastomers based on polyvinyl chloride. Comparisons of the new products with traditional flexible PVC's will be presented, pointing up differences in specific gravity, low temperature properties, heat resistance, melt viscosity, and general physical properties such as tensile modulus and elongation. The elastomeric properties of the new materials are explored and compared to some typical cured elastomers—chloroprene, chlorosulphonated polyethylene. The common thermoplastic elastomers based on block copolymers and polyurethanes are also considered in relation to the new compositions. Such properties as compression-set, flex and fatigue resistance, oil and chemical resistance, weatherability, and performance at elevated temperatures are detailed. The unique feature of this technology that allows one to tailor the surface characteristics from typically high PVC gloss to the fine dull satin finish of cured elastomers is discussed.     

Thermosetting powder coatings: Finish appearance and durability at cure window corner points

This project investigated the finish quality of automotive powder coatings in terms of appearance, adhesion and chip resistance. Two powder basecoats (red and black), of three particle sizes, and a colorkey primer (red) were studied in relation to the process temperature and time pairs based on the cure window provided by the paint manufacturer. The appearance was quantified using the contrast values of the wave-scan structure spectrum elements (Wa, Wb, Wc, Wd, and We). Gravel and scratch tests were used to quantify adhesion and chip resistance properties.It was found that long-waves (Wc, Wd and We) were less affected by the curing time and temperature variation. The contrast values of short-waves (Wa and Wb) increased with increasing process temperature and time. The most dramatic increase was observed at high process time and temperature. High process temperatures (193 °C) resulted in good long-wave coverage. Small contrast values of the long-waves were obtained for all cure conditions, for both red and black basecoats. The results for short-waves were not as consistent. This work suggests that powder basecoats and colorkey primers can yield appearance qualities comparable to water-borne counterparts.     

Investigation of optimal surface treatments for carbon/epoxy composite adhesive joints

Although an adhesive joint can distribute the load over a larger area than a mechanical joint, requires no holes, adds very little weight to the structure and has superior fatigue resistance, but it not only requires a careful surface preparation of the adherends but also is affected by service environments. In this paper, suitable conditions for surface treatments such as plasma surface treatment, mechanical abrasion, and sandblast treatment were investigated to enhance the mechanical load capabilities of carbon/epoxy composite adhesive joints. A capacitively coupled radiofrequency plasma system was used for the plasma surface treatment of carbon/epoxy composites and suitable surface treatment conditions were experimentally investigated with respect to gas flow rate, chamber pressure, power intensity, and surface treatment time by measuring the surface free energies of treated specimens. The optimal mechanical abrasion conditions with sandpapers were investigated with respect to the mesh number of sandpaper, and optimal sandblast conditions were investigated with respect to sandblast pressure and particle size by observing geometric shape changes of adherends during sandblast process. Also the failure modes of composite adhesive joints were investigated with respect to surface treatment. From the peel tests on plasma treated composite adhesive joints, it was found that all composite adhesive joints failed cohesively in the adhesive layer when the surface free energy was higher than about 40 mJ/m², because of high adhesion strength between the plasma treated surface and the adhesive. From the peel tests on mechanically abraded composite adhesive joints, it was also found that the optimal surface roughness and adhesive thickness increased as the failure load increased.     

钢结构机械喷射处理工艺与设备

介绍了钢结构的喷砂除锈和抛丸除锈工艺及设备,讨论了空气压力,以及喷嘴口径、内孔结构和材质对喷砂效率的影响,对抛丸流水线的形式、结构组成和技术参数,以及抛丸工艺的优势进行了探讨。认为抛丸除锈质量优异,能耗低,并利于环保,是钢结构表面预处理的发展趋势。     

颜填料对EP改性有机硅粘接涂层耐高温性能和防腐性能的影响

以环氧树脂(EP)改性有机硅树脂作为基体树脂,通过加入锌铬黄和铁红等填料,配制成一种耐高温、防腐蚀性的粘接底层;以有机硅树脂为基体树脂,通过加入锐钛型钛白粉和纳米SiO2,配制成具有一定遮盖力和耐高温性能的粘接面层。对涂敷底层和面层的马口铁试片进行耐高温性能和耐腐蚀性能测试,并采用金相显微镜和扫描探针分别对底层、面层和(含底层/面层的)双层粘接涂层的微观结构进行表征。结果表明:当底层中的颜基比为1.4∶1时,粘接涂层可耐400℃高温,在各种介质中浸泡72h后,粘接涂层表面没有开裂现象;当底层中的颜基比为1.7∶1时,其填料在树脂中分散得比较均匀,两者间的结合效果较好,该粘接涂层可耐400℃高温,但耐腐蚀性能相对较差。     

珍珠镍电镀的研究现状

珍珠镍外观典雅,色泽柔和,具有绸缎般光泽的表面,正在逐步取代具有耀眼光泽的装饰性镀层,用于汽车、摩托车、家用电器等的零部件和装饰件。介绍了珍珠镍的3种制备方法,包括机械法、复合镀法、乳化剂法,以及后2种方法的电镀工艺。探讨了添加剂在形成缎面镀层过程中的作用机制。对珍珠镍的国内外发展现状进行了综述,提出了国内珍珠镍的研究方向。     

Manipulating matrices

Chemical resistance, high temperature capability, low emissions, high quality surface finish — fabricators of composite products may require many different features from the resins they use, depending on the application of the final product. George Marsh on the latest developments in resin and gel-coat technology.     

新型橘纹漆的制备与研究

介绍了丙烯酸聚氨酯橘纹漆的研制，并对漆膜进行了物理和化学性能的测试，还对影响橘纹效果的因素进行了讨论．研究结果表明：该橘纹漆的橘纹效果好，具有高光泽、高硬度，且耐候性和耐磨性优异，各项性能指标均符合国家标准，可作为高档器械表面涂装，市场前景广阔。     

粉末涂料用耐高温有机硅改性聚酯树脂的制备和性能研究

通过化学共聚改性的方法在粉末涂料聚酯树脂中引入有机硅,合成了粉末涂料用有机硅改性聚酯树脂,研究了有机硅中间体用量对改性聚酯树脂黏度、相对分子质量及其分布、玻璃化转变温度和热失质量的影响。并用其制备了平面和消光 2种粉末涂料,研究了不同有机硅中间体加量对涂层性能的影响。结果表明：有机硅中间体加量为 42%的改性聚酯树脂具有合适的玻璃化转变温度和黏度,制备的粉末涂层具有良好的附着力;在 350℃左右的高温下平面涂层具有优秀的保光率,加入云母粉的消光涂层则具有更好的弯曲性能。有机硅改性聚酯树脂在兼顾耐热性和平面高光的同时,又解决了使用纯有机硅树脂的价格偏高的问题,为市场提供了耐高温粉末涂料用聚酯树脂的更多选择性。     

涤纶高速纺油剂T&K-1128的应用

对国产 POY油剂 T&K-112 8与德国进口油剂 K10 5在 POY,DTY的生产应用情况进行了比较 ,探讨了油剂耐热性和 DTY加工过程中的白粉情况。试验证明 ,T&K-112 8涤纶高速纺油剂与 K10 5油剂性能相似 ,且可纺性好 ,产品满卷率及一等品率均较高 ,能满足高速纺丝的要求 ,且价格低廉 ,能大大降低涤纶生产成本