Shrinkage Mechanisms in Thermooxidative Stabilization of Acrylic Fibres

Shrinkage processes in two types of acrylic fibres in heating in air in different regimes in the 50-250°C temperature region were investigated by a thermomechanical method. The mechanisms of the shrinkage were revealed in heating—cooling cycles and its partial reversibility and relation with the cyclization reaction was demonstrated. The irreversible part of shrinkage of the fibers is due to cyclization and relaxation of the macromolecules, while reversible shrinkage is due to the entropic elasticity of the polymer macromolecules.     

The Structure of Acrylic Fibres

The thermomechanical behavior of acrylic fibres is examined in light of new concepts concerning their structural organization. The mechanisms of irreversible and reversible shrinkage in heating of acrylic fibres are established. The effect of the chemical composition of the fibres on transformation of their structure during thermooxidative stabilization is demonstrated.     

The Dyeing of Acrylic Fibres

Meetings of the Midlands Region, held at the Kings Head Hotel, Loughborough, on 9 November 1966, Mr D. O. Douglas in the chair; of the West Riding Region, held at the Great Northern Hotel, Leeds, on 10 November 1966, Miss E. Smith in the chair; and of the London Region, held in the Rooms of the Royal Society, Burlington House, London, on 3 March 1967, Mr R. F. York in the chair The present position in the dyeing of acrylic fibres is reviewed. Methods of control that assist in the batchwise production of level dyeings are discussed. Recent developments in continuous processing are reviewed and the dyeing of modacrylic fibres is mentioned.     

Stabilization of Polypropylene Fibres

An optimum method was found for incorporating a polymeric concentrate of the light and thermal stabilizer Chimassorb 944 in the amount of 0.2 %. The method allows fabricating a fibre with satisfactory physicomechanical indexes that retains more than 80% of its strength after UV irradiation for 30 days.     

Migrating Cationic Dyes for Acrylic Fibres

The area covered by this paper - migrating dyes for acrylic fibres - has been dealt with more than once in recent years. A review of this work is given here.     

亚磷酸酯在聚丙烯中的热氧稳定行为

通过聚丙烯（ＰＰ）树脂的加工稳定性试验和ＰＰ薄片的热烘箱老化试验，研究了烷基亚磷酸酯ＷＥＳＴＯＮ６１９在ＰＰ中的热氧稳定行为，并与芳基亚磷酸酯ＩＲＧＡＦＯＳ１６８作了比较。     

Development of Modern Techniques for Dyeing Acrylic Fibres

The development of dyeing processes for acrylic fibres from their introduction 21 years ago to the present day is outlined. The development of empirical dyeing techniques for acrylic fibres already in commercial production was followed by closer theoretical studies leading ultimately to a simple dyeing technique—the Defitherm process—evolved from a study of reaction kinetics and fundamental dyeing mechanisms. This process is described.     

基于WinCC的腈纶生产线监控系统研究

针对大型石油化工生产线组态监控软件设计问题,给出基于WinCC的监控软件系统设计的方法.利用C/C 脚本实现监控画面的运行期动态处理和配方寻优,结合用户需求实现集成打印与画面热键切换,并给出历史数据查询与配方查询的数据库访问方法.利用DDE和OPC实现多机的数据共享.将文章提出的方法应用于同步流程工业腈纶纺丝生产线的组态监控软件设计.     

Physical Chemistry of the Dyeing of Acrylic Fibres with Basic Dyes

The most important aspects of the physical chemistry of the dyeing of acrylic fibres with basic dyes are reviewed.     

腈纶干法纺丝油剂的国产化研制

提出了干法腈纶纺丝油剂应具备的使用性能标准,通过实验室应用性能对比,验证了国产油剂良好的使用性能,为进一步开展工业应用试验提供了基础。     

金属离子对聚丙烯腈纤维预氧化过程的影响

采用浸渍的方法将不同种类金属离子Na、Ca、Fe引入聚丙烯腈(PAN)纤维,并将PAN纤维在空气中进行预氧化处理。借助于原子吸收光谱(AAS)、元素分析(EA)研究了PAN预氧化纤维的组成;通过X射线衍射(XRD)、傅立叶变换红外光谱(FTIR)、差示扫描量热分析(DSC)、热失重(TG)等多种表征手段,研究了PAN预氧化纤维的结晶结构、化学反应及热性能,从而研究了金属离子对聚丙烯腈纤维预氧化过程的影响。从多种表征手段的研究结果表明,金属离子影响了PAN纤维预氧化进程,具体表现为添加金属离子后,PAN预氧化纤维组成改变,密度降低,代表分子环化反应所产生的六元环特征衍射峰增长缓慢,代表原丝结晶结构的特征衍射峰消失迟缓,代表环构化的官能团较少,含有金属离子的PAN预氧化纤维由于预氧化不足导致在氮气气氛下放热量增加,热失重增加。     

Differential Solubility of Acrylic Fibres as a Function of Stabilisation Process Variables

Acrylic tow, partially relaxed during the first stage of a conventional manufacturing process, was fully relaxed, or stabilised, in steaming equipment under different conditions of time and temperature based on a central rotatable design of experiments. The shrinkage of the samples thus obtained was measured and differential solubility curves in a mixture of dimethy/formamide and water were obtained. From these results simple functional relationships between shrinkage and solubility on the one hand, and the process variables, temperature and time, have been obtained. Response surfaces showing an excellent fit have also been obtained. A very good negative linear correlation between the logarithm of shrinkage undergone during steaming and the logarithm of differential solubility, and also between the logarithms of overall shrinkage and differential solubility have been found. The differential solubility test has a very high sensitivity to relaxation process variables and, as shown by the correlations obtained, it is highly recommendable as a relaxation control measure in production plant.     

The Dyeing of Acrylic Fibres by the Constant–temperature Method

As the result of an examination of factors which govern the build–up of cationic dyes on acrylic fibres, the former method of progressively raising the temperature of the dyebath has been discarded in favour of a two– or three–stage constant–temperature method. The regularity of build–up obtainable is illustrated by means of Praxitest curves. Works trials have confirmed the value of the new method.     

New Developments in Acrylic Carpet Fibres for Specific End–uses

There is considerable activity in the introduction of new acrylic fibres, and second–and third–generation fibres are being developed for specific end–uses. Bicomponent fibres have found considerable application in woven carpets because their increased bulk and cover offer advantages over traditionally used fibres. Improved flame–resistant fibres incorporating halogen compounds have been developed to meet flammability requirements for carpets. Modacrylic blends are used for shag and some ‘saxony’ (high–pile low–density) applications. Three acrylic fibres of different dyeability have been developed for continuous piece dyeing: reduced–affinity basic, regular or deep basic, and acidic. Rapid–dyeing fibres are being introduced for use on the Craw ford–Mohasco equipment with which the fixation time is limited to 3 min at 100°C Finally, highshrinkage fibres can be used to impart extra bulk and cover or alternatively to produce sculptured effects in woven or tufted carpets.