热收缩尼龙肠衣膜成型技术

热收缩尼龙肠衣膜成型技术车广陆李振宇刁基漠（大连塑料研究所１１６０３３）０前言热收缩尼龙肠衣膜是７０年代由日本最早研制开发的．据报导，目前只有日本、美国、意大利、韩国等少数几个国家能够生产．我国由于受到生产技术水平和原材料等方面因素的限制，只是在近几...     

新型改性尼龙6产品问世

一种广泛应用于制造尼龙管胚、肠衣膜、热收缩膜等制品的高拉伸性改性尼龙6产品,最近在河北衡水金轮塑业有限公司研制成功并投放市场。该生产技术已获得国家专利。近年来,随着包装工业的发展,市场对尼龙薄膜的需求量越来越大,然而,用于吹塑、挤出级的高性能尼龙6大多依赖进口。     

新型改性尼龙6产品问世

—种广泛应用于制造尼龙管胚、肠衣膜、热收缩嗅等制品的高拉伸性改性尼龙产品,近日在河北衡水金轮塑业有限公司研制成功并投放市场。该生产技术已获得国家专利。近年来随着包装工业的发展,市场对尼龙薄膜的需求量越来越大,然而,用于吹塑挤出级的高性能尼龙6还大多依赖进口。河     

五层共挤复合热收缩肠衣膜机组的研制

运用高分子聚合物晶态结构理论、松弛理论和挤出流变理论,分析和研究了五层共挤复合热收缩肠衣膜机组在设计研制中应该着重考虑和解决的技术关键问题。从而提出了五层共挤复合热收缩肠衣膜机组在冷却形式、拉伸方式、加热形式、膜坯温度控制、牵引速比设置、螺杆长径比、压缩比、螺杆与料筒间隙、共挤模头形式、卷取张力控制等一系列技术参数的选择与确定。为研究其他相关产品提供了借鉴和参考。     

聚酯热收缩薄膜

本文分析了国内外热收缩膜用聚酯的发展状况 ,指出聚酯热收缩薄膜是目前广泛使用的PVC薄膜的理想替代品。简述了热收缩原理 ,指出热收缩膜用聚酯的发展应从制备改性聚酯和改善成膜工艺两方面着手 ,对热收缩膜用聚酯的市场需求 ,发展方向进行了研究     

我国热收缩膜行业现先及发展趋势

热收缩膜是一种高性能．高技术含量的塑料包装薄膜。经过近几年的快速发展，我国目前已成为世界最主要的热收缩膜生产国及消费国之一。随着我国热收缩膜装备水平的不断提高，热收缩膜在我国将迎来更加美好的明天。     

加工工艺对聚乙烯热收缩膜性能的影响

以低密度聚乙烯(LDPE)、线型低密度聚乙烯(LLDPE)和高密度聚乙烯(HDPE)为原料,采用吹塑成型法制备了热收缩膜。研究了原料配方、模具吹胀比、吹膜机牵伸比、挤出温度和膜泡冷却时间等因素对聚乙烯热收缩膜力学性能和透明度的影响。结果表明:与加入HDPE相比,配方中加入LLDPE的原料所生产的热收缩膜的综合性能较好;随着机组运行牵伸比的增大,PE热收缩膜的拉伸性能、收缩率和透光率均呈上升趋势;随着模具吹胀比的增大,PE热收缩膜的纵向收缩率下降,横向收缩率和透光率均上升;随着挤出机工艺温度的升高,PE热收缩膜的纵、横向收缩率同时上升;随着膜泡冷却时间的延长,PE热收缩膜的纵、横向收缩率和透光率均下降。     

时效稳定型高收缩BOPP烟膜的研究

研究了温度和时间对双向拉伸聚丙烯(BOPP)烟膜热收缩率的影响。结果表明:在生产下线的1周内,BOPP薄膜的聚集态结构处于不稳定状态,薄膜的热收缩率下降较快;夏季由于温度高,热收缩率比冬季降低速度快,特别是在1个月后,下降的幅度加大。针对此问题开发出一种时效稳定母料并应用于高收缩烟膜,取得了良好的效果。在明显提高烟膜热收缩率的同时,改善了热收缩率的稳定性,特别使夏季高温下烟膜的热收缩率有较大比例的提高,钝化了热收缩率对温度的敏感性。研究表明该母料对烟膜的力学性能、光泽度、雾度、热封性能、爽滑性能以及加工性能没有负面影响.     

聚烯烃多层共挤热收缩膜市场分析

分析了国内外聚烯烃多层共挤热收缩膜的生产及消费状况,并给出了聚烯烃多层共挤热收缩膜的发展趋势。     

环氧涂层与干膜热收缩带复合结构补口施工技术

三层辐射交联聚乙烯热收缩带补口是我国长输管道应用最多的补口方式,热收缩带补口按施工工艺分为湿膜施工和干膜施工,西气东输二线广西支线采用环氧涂层与干膜热收缩带复合结构补口。在现场试验时出现了底漆漏点过多的问题,结合广西支线补口问题原因及解决措施,从而提出了环氧涂层与干膜热收缩带复合结构的详细补口施工技术。     

The influence of ions on water transport in nylon 6 films

Nylon 6 films are directly exposed to saline solutions containing mono-valent ions and the water uptake is measured with magnetic resonance imaging (MRI). Both the amount of water uptake and the rate of water uptake are studied. First, the films are exposed to solutions with different concentrations of NaCl. Later, solutions of salts such as LiCl, KCl and KNO₃ are used. It is shown that all salts act similar. They reduce the amount of water ingressing the nylon film and also slow down the rate of uptake. It seems that water uptake can be predicted by knowing the activity of the salt solution on top of the nylon film. Element analysis shows that ions migrate into the nylon film. Although ions do enter the film, their amount is not large enough to influence the diffusivity and chemical potential of water in the nylon film.     

Mesophase Structure‐Enabled Electrostrictive Property in Nylon‐12‐Based Poly(ether‐block‐amide) Copolymers

To search for alternative electrostrictive polymers and to understand the underlying mechanism, the structure‐ferroelectric/electrostrictive property relationship for nylon‐12‐based poly(ether‐b‐amide) multiblock copolymers (PEBAX) is investigated. Two PEBAX samples are studied, namely, P6333 and P7033 with 37 and 25 mol.% of soft poly(tetramethylene oxide) (PTMO) blocks, respectively. In both samples, poorly hydrogen‐bonded mesophase facilitates electric field‐induced ferroelectric switching. Meanwhile, the longitudinal electrostrictive strain (S₁)–electric field (E) loops are obtained at 2 Hz. Different from conventional poly(vinylidene fluoride‐co‐trifluoroethylene) [P(VDF‐TrFE)]‐based terpolymers, uniaxially stretched nylon‐12‐based PEBAX samples exhibit negative S₁, that is, shrinking rather than elongation in the longitudinal direction. This is attributed to the unique conformation transformation of nylon‐12 crystals during ferroelectric switching. Namely, at a zero electric field, crystalline nylon‐12 chains adopt a more or less antiparallel arrangement of amide groups. Upon high‐field poling, ferroelectric domains are enforced with more twisted chains adopting a parallel arrangement of amide groups. Meanwhile, extensional S₁ is observed for P6333 at electric fields above 150 MV m^?1. This is attributed to the elongation of the amorphous phases (i.e., amorphous nylon‐12 and PTMO). Therefore, competition between shrinking S₁ from mesomorphic nylon‐12 crystals (i.e., nanoactuation) and elongational S₁ from amorphous phases determines the ultimate electrostriction behavior in stretched PEBAX films.     

Biodegradation of nylon4 and its blend with nylon6

The nylon4 portion in the blend films composed of nylon4 and nylon6 was degraded and completely disappeared within 4 months in two kinds of composted soils gathered from different university farms as well as pure nylon4 film reported previously, while the nylon6 portion remained even after the burial test for 15 months. Nylon4 powder was also degraded to carbon dioxide in the degradation test in an activated sludge obtained from a sewage disposal institution in Kogakuin University. Three species of microoganisms (i.e., ascomytous fungi) were isolated through the inoculation from the nylon4 film partially degraded in the soil on a medium containing nylon4 powder as a carbon source. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2307–2311, 2002     

Preparation of conductive nylon 6 film

Electrically conducting nylon 6 films was prepared by introducing amide group or cyan group into the nylon 6 film and then introducing Cu_xS, which is known as the p-type semiconductor, into the grafted nylon films. The graft copolymerization of acrylamide (AM) and acrylonitrile (AN) onto nylon 6 film was investigated using ceric salt as the initiator. The graft yield was influenced by the concentration of ceric salt, sulfuric acid and monomer, and the reaction time. The optimum conditions for the introducing of Cu_xS were studied. Electrical conductivity of Cu_xS-treated nylon film was found to be higher by order of 10⁹ than that of the original nylon 6 film, and then properties of the resulting modified films were investigated.     

新型聚酰胺热熔胶的研制与开发

采用尼龙1010代替尼龙66,从配方上改进了聚酰胺热熔胶的耐水洗性能,同时,采用环氧改性技术,提高了热熔胶的粘接强度和耐水洗性能。     

Surface passivation of nylon‐6,6 films by graft copolymerization for reduction of moisture sorption

To improve the moisture sorption property of nylon‐6,6 film, ally pentafluorobenzene (APFB) was incorporated on the argon plasma‐pretreated nylon film by UV or thermally induced surface graft copolymerzation. The plasma pretreatment introduced peroxides that were degraded into radicals to initiate the graft copolymerization of APFB on the nylon surface. The modified surfaces were characterized by X‐ray photoelectron spectroscopy (XPS) and contact angle measurement. The moisture sorption was assessed by the coulometric test method. The efficiency of surface graft copolymerization was affected by plasma pretreatment time of the nylon substrate, as well as by the UV or thermal graft copolymerization time. The UV graft‐copolymerized nylon film exhibited a significantly lower extent of moisture sorption when compared to that of the pristine films, even at low graft concentration. However, the moisture sorption behavior for the thermally graft copolymerized films was similar to that of the pristine films. Contact angle and XPS measurements suggested that the reduction in moisture sorption for the UV graft‐copolymerized nylon‐6,6 film was attributable to the fact that the hydrophobic polymer layer was formed on the nylon surface, and the hydrophobic layer of an appropriate thickness could serve as an effective barrier to moisture. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1366–1373, 2000     

Constrained-Film Sintering of a Borosilicate Glass: In Situ Measurement of Film Stresses

We have measured in-plane stresses developed in a borosilicate glass (BSG) film during its constrained sintering on a rigid substrate. Samples were prepared by casting BSG slurries on a silicon substrate and sintered inside a hot stage at 715°C just above the glass-softening temperature. Inplane stresses from the constrained-film sintering were determined by wafer-curvature measurements using an optical system. The measured stresses were tensile and rose rapidly from zero to a maximum level of 20 kPa during the initial stage of sintering and gradually decreased to zero at the final stage; these stresses were considerably smaller than those calculated from available microstructural models. We also measured the densification profiles of the free and constrained films. The stresses had no apparent effect on the densification profile of the constrained film up to 90% relative density; but beyond that, the densification kinetics were reduced in the constrained film. We believe that the stresses could have prevented a few large pores from shrinking during the initial stage of sintering, which then leads to an overall lower density and larger pores in the constrained film.     

Hot compaction of woven nylon 6,6 multifilaments

We describe a study of the hot compaction of woven nylon 6,6 multifilaments produced by a patented procedure, developed at the University of Leeds, for creating novel single‐polymer composites. In this process, an assembly of oriented elements, often in the form of a woven cloth, is held under pressure and taken to a critical temperature so that a small fraction of the surface of each oriented element is melted, which on cooling recrystallizes to form the matrix of the single‐polymer composite. This process is therefore a way of producing novel high‐volume‐fraction polymer/polymer composites in which the two phases are chemically the same material. Nylon is an obvious candidate material for this process because oriented nylon multifilaments are available on a commercial scale. The aim of this study was first to establish the conditions of temperature and pressure for the successful hot compaction of oriented nylon 6,6 fibers and second to assess the mechanical properties of the manufactured hot‐compacted nylon sheets. A crucial aspect of this work, not previously examined in hot‐compaction studies of other oriented polymers, was the sensitivity of the properties to absorbed water, with a significant change in the properties measured immediately after hot‐compaction processing and 2 weeks later when 2% water had been absorbed by the compacted nylon sheets. As expected, the water uptake had a greater effect on those properties that depended on local chain interactions (e.g., the modulus and yield strength) and less effect on those properties that depended on the large‐scale properties of the molecular network (e.g., strength). The only negative aspect of the properties of the hot‐compacted nylon sheets was the elevated‐temperature performance of the wet sample, with the modulus falling to a very low value at a temperature of 80°C. However, apart from the elevated‐temperature performance, the majority of the measured properties of the hot‐compacted nylon sheets were comparable to those of hot‐compacted polypropylene and poly(ethylene terephthalate). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 991–997, 2006     

油基钻井液井筒清洗液的研制及现场应用

研制了油基钻井液井筒清洗液,并将其应用于现场。结果表明,该清洗液对井筒上的油膜有较好的清洗效果,清洗率达90%以上,具有较好的储层保护性能。     

Transport of acid dye in nylon and concentration dependence of the diffusion coefficient

The dyeing kinetics of an acid dye (C. I. Acid Blue 40) in a nylon 6 film were investigated using partition-cell and film-roll methods at 80°C and pHs 2.3 and 3.05. The concentration dependence of diffusion coefficient of the dye in the nylon substrate measured by both methods was interpreted in terms of parallel diffusion with biomodel sorption of the Nernst and Langmuir modes. As the concentration of dye increases, the transport of dye inside the nylon film becomes dominated by pore diffusion and surface diffusion of sorbed Nernst populations.