涂装室内风速对漆膜均匀性的影响

静电旋杯涂装工艺是当前主流的汽车涂装工艺,为保证涂装室内挥发性有机物(Volatile Organic Com-pounds,VOCs)废气浓度低于其爆炸下限,会配套使用排风系统进行通风.采用计算流体动力学(Computational Fluid Dynamics,CFD)技术从理论上探究了涂装室内风速对漆膜均匀性的影响,结果表明,随着室内风速增加漆膜均匀性逐渐恶化,确定最佳风速范围为0.2～0.4 m/s.     

Ranitidine HCl: Tablet Film Coating Acidity and Discoloration

The presence of citric acid in the film coating of ranitidine hydrochloride tablets decreased discoloration.     

The Design and Performance of an Instrumentation System for Aqueous Film Coating in an Industrial Tablet Coating Machine

In recent years tablet coating has undergone several fundamental changes. The original sugar coating technique has been largely replaced by film coating processes using organic solvents. The organic solvents are now being replaced by water because of the development of suitable polymers, improvements in the coating process, and impending government legislation regulating the discharge of pollutants into the environment.

This change has resulted in increased interest in equipment designed for film coating based on cylindrical shaped side vented pans which allow the drying air to be drawn through the tablet bed. However, the process is complex and requires careful monitoring and control to ensure satisfactory results. The empirically derived conditions are not fundamentally understood and there are important differences in the operation     

Influence of Insoluble Excipients on Film Coating Systems

ABSTRACT

Insoluble excipients are added to polymeric film coating solutions and dispersions to improve the physical appearance of dosage forms, enhance the stability of photolytic drugs, and aid in processing. These insoluble additives, however, may significantly affect the physical, mechanical, adhesive, and drug-release properties of the films. In this review, the theories of the interactions between polymer and insoluble excipient are addressed. This article also discusses the influence of the concentration, particle size, morphology, and surface chemistry of insoluble excipients on the various polymer properties.     

Water Based Silicone Elastomer Controlled Release Tablet Film Coating 1: Free Film Evaluation

A latex which is a polymerized and cross-linked product of hydroxyendblocked polydimethylsiloxane and an alkoxysilane has been evaluated as a controlled release tablet film coating system. With adequate reinforcement of colloidal silica, the silicone elastomer latex formed solid elastomeric free films upon drying. Polyethylene glycols of different molecular weights were incorporated in the coating system to enhance the permeability of the silicone elastomer to hydrophilic and ionic species. Free films derived from the three-component silicone elastomer dispersions were evaluated by various physical and chemical methods with respect to their suitability as an aqueous controlled release film coating system.     

Water Based Silicone Elastomer Controlled Release Tablet Film Coating II - Formulation Considerations and Coating Evaluation

The silicone elastomer latex in corporated with polyethylene glycol and colloidal silica produced controlled release film coating on potassium chloride tablets . The release pattern of potassium chloride from coated tablets was dictated by the composition of the coating . Significant formulation variables included the loading level of polyethylene glycol, the molecular weight of the polyethylene glycol used, and the silicone to silica weight ratio in the coating . Non-formulation variables such as coating weight, drying temperature, dissolution medium pH and aging were shown to alter there leaser ate of the active ingredient from coated tablets.     

喷涂轨迹对齿柱表面耐磨涂层沉积均匀性的影响

设计和采用不同的喷涂轨迹,通过超音速火焰喷涂技术在铝齿柱表面制备了WC-10Co4Cr涂层,利用金相显微镜(OM)、SEM和显微硬度测试等进行了涂层的微观组织观测和厚度、硬度均匀性分析。结果表明:涂层致密,与基体结合非常好。涂层厚度和硬度分布不均匀,齿槽底沉积率高,厚度偏大,啮合面和齿顶位置厚度在160～210μm之间,数值分散性较小,齿槽底涂层硬度低,HV0.3≈700～800,啮合面和齿顶位置涂层硬度高,HV0.3在1150～1300范围内。齿形件的喷涂轨迹参数2 H影响齿顶面、啮合面和齿槽等不同位置的喷涂角度和沉积环境,导致涂层形貌、沉积率和硬度均有差别。2 H=55mm时,不同齿形位置的涂层厚度和硬度分布更均匀,但齿槽底涂层存在孔隙,硬度偏低。     

沉积电压对电泳沉积成膜均匀性的影响

沉积电压是电泳沉积工艺的重要参数之一。为研究其对电泳沉积成膜均匀性的影响,对带电粒子的电泳过程进行理论分析,并结合COMSOL多物理场接口,得出电泳过程的仿真图。结果显示:施加电压增大,流场流速增加,但电极间形成的流场相对均匀,膜层的均匀性也较好。沉积电压不高于100 V时,极间形成的均匀流场并不影响粒子均匀沉积;电压高于100 V时,极间形成的明显不均匀流场会影响粒子的运动与沉积,从而降低了膜层的均匀性。     

Water Based Silicone Elastomer Controlled Release Tablet Film Coating IV Process Evaluation

The processing conditions in an air suspension column were found to be critical in producing controlled release polyethylene glycol-silicone elastomer tablet film coatings. The coating equipment used was also shown to play a major role in determining the permeability of the resultant tablet coatings. This pronounced process dependent phenomenon was explained by the film layering mechanism involved in the formation of the polyethylene glycol containing silicone elastomer coating on tablets.     

The Effect of Run Time on the Inter-Unit Uniformity of Aqueous Film Coating Applied to Glass Beads in a Hi-Coater

Abstract

Coating experiments were conducted to assess the inter-unit uniformity using individual weight gains of glass beads. Applying more aqueous film coating and prolonging the film-coating process by diluting the coating suspension did improve the coating variability among glass beads. It appears that run time is an important underlying factor which affecting the inter-unit coating uniformity.     

The Effect of Run Time on the Inter-Unit Uniformity of Aqueous Film Coating Applied to Glass Beads in a Hi-Coater

Coating experiments were conducted to assess the inter-unit uniformity using individual weight gains of glass beads. Applying more aqueous film coating and prolonging the film-coating process by diluting the coating suspension did improve the coating variability among glass beads. It appears that run time is an important underlying factor which affecting the inter-unit coating uniformity.     

镀制方式对高衰减镍铬合金膜中性度的影响

对比了用不同镀制工艺方式镀制的Ni80Cr20膜中性密度滤光片的中性度特性,溅射工艺镀制的密度片中性度值3.7%,远好于电子枪蒸发和电阻蒸发镀制结果(15%)。采用相平衡理论,模拟计算了的热蒸发镀制的镍铬合金膜的蒸发速率,铬相比镍含量偏高2.8倍,导致了膜层中合金含量相对膜料出现较大差异,导致中性密度滤光片光谱中性度的下降。使用蔡司SUPRA35扫描电镜和牛津EDS能谱仪分别测试了溅射工艺和热蒸发工艺镀制的密度滤光片的镍铬含量,测试结果与模拟分析结论基本一致。     

涂布工艺对厚膜涂布性能的影响

为了得到一定厚度的厚膜,并保证涂膜表面的平整性,分别采用刮涂法、网纹辊涂布法、以及丝网印刷法进行涂布,改变涂布框厚度、刮刀角度、网纹辊绕线直径、丝网目数和版膜厚度对UV涂布油进行涂布,测试涂布膜层的厚度及表面粗糙度,研究涂布工艺对膜层性能的影响.研究结果表明:采用刮涂法可获得较厚、表面较平整的涂膜,且刮刀角度在45°～60°范围内,另外,采用丝网印刷法也可得到性能较好的涂膜,但版膜厚度应很高.     

Water Based Silicone Elastomer Controlled Release Tablet Film Coating III - Drug Release Mechanisms

Abstract

The release of potassium chloride from polyethylene glycol-silicone elastomer coated tablets was achieved by the diffusion through water-filled pores formed in the hydrated coating and the osmotic pumping generated by the saturated salt solution. The relative contribution of these two mechanisms to the overall drug release rate was shown to be a function of the polyethylene glycol loading in the coating. As the polyethylene glycol loading level increased, the transpore diffusion became the predominant release mechanism. The capability of the polyethylene glycol-silicone elastomer coatings to provide controlled release for therapeutic agents of different water solubilities and dose levels was also demonstrated. Both the rate and extent of release of the active ingredients could be altered by the type of diluent used in the tablet matrix     

Water Based Silicone Elastomer Controlled Release Tablet Film Coating III - Drug Release Mechanisms

The release of potassium chloride from polyethylene glycol-silicone elastomer coated tablets was achieved by the diffusion through water-filled pores formed in the hydrated coating and the osmotic pumping generated by the saturated salt solution. The relative contribution of these two mechanisms to the overall drug release rate was shown to be a function of the polyethylene glycol loading in the coating. As the polyethylene glycol loading level increased, the transpore diffusion became the predominant release mechanism. The capability of the polyethylene glycol-silicone elastomer coatings to provide controlled release for therapeutic agents of different water solubilities and dose levels was also demonstrated. Both the rate and extent of release of the active ingredients could be altered by the type of diluent used in the tablet matrix     

Effect of Aqueous Film Coating Conditions on Water Removal Efficiency and Physical Properties of Coated Tablet Cores Containing Superdisintegrants

Abstract

Few studies have examined the effect of aqueous film coating process conditions on the physical integrity of the final coated product. Characterization of the aqueous film coating process was previously carried out by selecting water removal efficiency as the response variable to detect and monitor moisture accumulation in the tablet bed [1]. In this study, regression techniques were utilized to obtain the relationship between some physical characteristics of aqueous film coated tablet cores that contained superdisintegrant and several process parameters such as inlet air temperature, spray rate, and pan speed. Tablet response variables measured included residual moisture content, tensile strength and percent porosity. Predicted values of these properties were plotted as a function of the inlet air temperature and the coating solution spray rate. The correlations between the coated tablet response variables and the water removal efficiency of the coating process indicated that coated tablet properties such as residual moisture content, tensile strength, and porosity were linearly correlated with the water removal efficiency of the coating process, which is indicative of the environmental coating conditions present in the coating pan.     

Effect of Aqueous Film Coating Conditions on Water Removal Efficiency and Physical Properties of Coated Tablet Cores Containing Superdisintegrants

Few studies have examined the effect of aqueous film coating process conditions on the physical integrity of the final coated product. Characterization of the aqueous film coating process was previously carried out by selecting water removal efficiency as the response variable to detect and monitor moisture accumulation in the tablet bed [1]. In this study, regression techniques were utilized to obtain the relationship between some physical characteristics of aqueous film coated tablet cores that contained superdisintegrant and several process parameters such as inlet air temperature, spray rate, and pan speed. Tablet response variables measured included residual moisture content, tensile strength and percent porosity. Predicted values of these properties were plotted as a function of the inlet air temperature and the coating solution spray rate. The correlations between the coated tablet response variables and the water removal efficiency of the coating process indicated that coated tablet properties such as residual moisture content, tensile strength, and porosity were linearly correlated with the water removal efficiency of the coating process, which is indicative of the environmental coating conditions present in the coating pan.     

全息涂料涂布均匀性影响因素分析及其数学描述

研究了工艺参数对全息涂料涂布均匀性的影响规律,给出了涂膜光学密度变化的数学表达式,以及定量评价涂布不均匀度的方法,为涂布工艺参数的优化设计,提供了理论依据.     

末端形状对磁纳米薄膜自旋波模式特性的影响

基于微磁学模拟方法研究了磁纳米膜末端形状对自旋波模式特性的影响。获得了多种不同的局域化、量子化自旋波模式特性,以及末端形状对自旋波模式特性的调制规律。通过裁剪纳米膜的末端形状可有效调控边缘模式自旋波特性,存在一临界裁剪参数h0。当裁剪度hh0时,随着h的增大,边缘模式频率快速增加,局域于磁薄膜两末端的磁振荡区域向中央扩展。当h≥h0时,局域于磁薄膜两末端磁振荡在磁体中央合并为一致振荡模式自旋波,边缘模式被抑制。薄膜末端边缘形状对别的自旋波模式特性影响较小。最后,基于近似色散关系理论模型对研究结果进行了解释。     

水溶性复膜机的设计与研究

作者根据对水溶性复膜机的开发设计经验,向大家介绍了水溶性复膜机的工艺流程和工作原理,并对水溶性复膜机的涂布、传动系统、复合机构等进行了分析,以推动水溶性复膜机的发展.