双向拉伸塑料薄膜的发展趋向

近年来为了适应高质量双向拉伸塑料薄膜的生产和节省劳动力 ,双向拉伸机械装备的硬件和软件两个方面均有改进。双向拉伸加工可使塑料薄膜增加新的物理性能 ,包含提高机械强度、弹性模量 ,耐冲击和耐折叠性 ,尺寸稳定性 ,透明度和光泽 ,保湿 (或抗潮 )性、气体阻隔性 ,耐寒性以及耐油性等。如果在加工过程中作一定的热处理 ,双向拉伸薄膜能出现热收缩性 ,可用作收缩包装材料。几种主要的双向拉伸薄膜有双向拉伸聚乙烯薄膜、双向拉伸聚丙烯薄膜、双向拉伸聚苯乙烯薄膜、双向拉伸聚偏二氯乙烯薄膜、双向拉伸聚酯薄膜、双向拉伸尼龙薄膜、双向拉…     

聚乙烯薄膜加工方法及BOPE新产品

比较了聚乙烯薄膜的三种加工方法:吹塑法、传统的流延法和新兴的双向拉伸平膜法,其中着重介绍了新兴的双拉法及其产品——双向拉伸聚乙烯薄膜。     

广东华业绿色软包装材料问世

由广东华业包装材料有限公司研制的双向拉伸聚苯乙烯窗口膜和双向拉伸聚苯乙烯扭结膜顺利通过省科技成果鉴定。省专家组认为，两者均是新兴的绿色软包装材料，双向拉伸聚苯乙烯窗口膜创新性地解决了窗口膜厚度均匀性、薄膜表面电阻低等关键技术问题，而双向拉伸聚苯乙烯扭结膜具有强度高、刚度大、无毒性、易降解、扭结性强、加工方便等优点，     

国内塑料包材成长势头良好

塑料包装以其质轻、耐水的特点,在传统的纸、木、铁、玻璃等包装材料中脱颖而出,成为包装材料中增长最快的材料。而其制品因设计灵活、使用方便、保鲜性好、成本低等优点也日益被人们认可和接受。我国的塑料包装材料发展很快,很多材料的产能,尤其是性能相对较好的产品产能增长较快,其中包括双向拉伸聚丙烯薄膜、双向拉伸聚苯乙烯片材、高阻隔性肠衣膜和涂覆膜,三层以上共挤薄膜及其他各种复合薄膜等。其中,以能够热灌装的聚对苯二甲酸乙二醇酯(PET)应用前景看好。在已经开发的新品中,以生物降解塑料实用化进程为最快,一些国家已将淀粉降解…     

同步拉伸速率对双向拉伸聚乙烯薄膜结晶结构及性能的影响

实验采用双向拉伸聚乙烯(BOPE)原料线型低密度聚乙烯(LLDPE),用同步双向拉伸的方法制备BOPE薄膜,研究了双向拉伸过程中拉伸速率对薄膜结构和性能的影响。使用偏光显微镜(PLM)和差示扫描量热法(DSC)对未拉伸聚乙烯流延片的结晶形貌和热性能进行了研究。研究了不同拉伸速率下机器方向(MD)拉伸力的实时变化趋势,用DSC表征了不同BOPE薄膜样品的热性能。发现拉伸速率影响拉伸过程中聚乙烯晶体和分子结构及最终样品的结晶度和晶片厚度分布。实验研究了BOPE薄膜的力学和光学性能,分析了薄膜的宏观性能和分子结构之间的关系。实验结果表明,较高的拉伸速率有利于薄膜性能的提高。     

陶氏推出创新型双向拉伸聚乙烯材料(TF-BOPE)满足商业化大规模生产需求

正陶氏化学公司(纽约证交所代码:DOW)旗下包装与特种塑料业务部(PSP)在ProPak China2017推出一款创新型材料——双向拉伸聚乙烯(TF-BOPE),为陶氏INNATETM精密包装树脂家族又增添一款革命性产品。与传统聚乙烯薄膜相比较,双向拉伸聚乙烯(TF-BOPE)薄膜具有更高的力学性能和材料刚性、更佳的光学和印刷性能,是陶氏包装与特种塑料亚太区研发团队与北美材     

交叉定向复合重包装薄膜技术小结

<正> 交叉定向复合薄膜,是由二层单向拉伸的高密度聚乙烯薄膜交叉复合而成,各个方向都有优异的机械性能,实际使用中表现了突出的高强度和抗穿刺、耐撕裂等特点,因此可以用作颗粒状,粉状等轻化工原料,水泥,矿砂以及人造纤维的包装材料,同时还可以作为重要的建筑结构薄膜。     

利用国产SL—4000型拉伸机组生产OPP薄膜的概况

<正> 一、前言 近年来,国外透明包装材料出现了由玻璃纸急剧向双向拉伸聚丙烯(OPP)薄膜转变的趋势,这是由于OPP薄膜的成本较低,性能优异,原材料丰富,生产效率高等方面的原因引起的。 OPP薄膜除了具有未拉伸PP薄膜的用途外,还广泛用作收缩薄膜,复合膜(与PE,纸的复合),电绝缘薄膜(主要     

食品包装用的复合腊通过技术鉴定

<正> 上海人民印刷一厂经过一年试验,研制出一种无毒的食品包装用复合腊。其适用于印刷用的透明纸或单向拉伸聚乙烯薄膜、铝箔、双向拉伸聚丙烯薄膜之间的复合,是热熔型粘合剂。这种复合腊用无毒粘性树脂、无毒增粘树脂、食品包装级腊、无毒增塑剂、无毒稳定     

薄膜的双向拉伸技术

本文叙述了双向拉伸薄膜的发展情况及性能特征,讨论了成型方法的选择,论述了加工工艺要求及加工设备特点。在当今的日常生活中,从一般的包装品到工业用品,都离不开各种各样的塑料薄膜,其中以双向拉伸薄膜最为突出。这种薄膜具有优良的综合性能,加工设备的大型、节能化使得所生产的双向拉伸薄膜费用进一步降低,薄膜的使用范围进一步扩大.用于生产双向拉伸膜的原料有 PS,PVC,PVDC,PE,PP,PET,PA,PVA,PVF等。薄膜经过双向拉伸,能够提高其拉伸强度、拉伸弹性横量、冲击强度、断裂强度等机械性能,也能改善其耐热性、耐寒性、气密性、透明性、光泽性等,所以特别适应于包装行业的应用。生产双向拉伸薄膜的方法有同时双向拉伸法和逐次双向拉伸法两种,但实际生产中后者得到更广泛的应用,因而本文也主要介绍后者的有关技术问题。     

Double bubble tubular film extrusion of polybutylene terephthalate–polyethylene terephthalate blends

A technology has been developed to produce biaxially oriented films of blends of polybutylene terephthalate (PBT) and polyethylene terephthalate (PET) using double bubble tubular film extrusion. The mechanical instabilities and the mechanisms associated with their sources of occurrence are described. Bubble stability varies substantially with deformation and composition. The films have been structurally characterized with wide angle X‐ray diffraction and optical techniques. The individual phases in the blends oriented differently. We have proposed a model of crystalline morphology in biaxially oriented PBT/PET blend films. The structure of the film is related to processing conditions.     

Influence of incorporation of ZnO nanoparticles and biaxial orientation on mechanical and oxygen barrier properties of polypropylene films for food packaging applications

In this work, the effect of zinc oxide (ZnO) concentration and shape on processing and properties of new biaxially oriented polypropylene (BOPP)‐ZnO nanocomposites was studied. The use of spherical nanoparticles and nanorods was expected to differently influence the properties of the final material. Films of isotactic polypropylene prepared with different ZnO incorporation were biaxially oriented under conditions of temperature and strain rate that were similar to those encountered in a commercial film process. Scanning electron microscopy analysis was performed to visualize the dispersion degree of the ZnO nanoparticles in the polymer matrix and to observe the surface and the orientation of the elongated nanoparticles. Furthermore, the prepared ZnO‐BOPP nanocomposites were evaluated for both mechanical and oxygen barrier property enhancement. A good combination of mechanical and oxygen barrier properties was obtained for the ZnO‐BOPP films. This result makes the ZnO‐BOPP nanocomposite a proper material for applications such as food packaging. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Influence of high power ultrasound on physical–chemical properties of polypropylene films aimed for food packaging: barrier and contact angle features

Investigation was focused on the impact of high power ultrasound (HPUS), also called thermosonication, on the oxygen permeation properties (permeability, solubility and diffusion coefficients) of barrier films aimed for food packaging. For this purpose, biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) were used. The physical–chemical profile of the samples was determined using goniometry. There is a significant impact only of extreme HPUS conditions (the longest time and the highest amplitude) on the permeability, solubility and diffusion coefficients of oxygen through the BOPP films. The highest influence on the oxygen permeability in both investigated BOPP samples involved an HPUS with an amplitude of 100% during a 6 min treatment. However, BOPP samples showed different sensitivities at lower HPUS treatments. © 2017 Society of Chemical Industry     

Mass transfer study of chlorine dioxide gas through polymeric packaging materials

The mass transfer profile (permeability, diffusion, and solubility coefficients) of chlorine dioxide (ClO₂), a strong oxidizing agent that is used in food and pharmaceutical packaging, was determined through various common polymeric packaging materials. A continuous system for measuring permeation of ClO₂, using an electrochemical detector, was developed. It was observed that biaxially‐oriented poly(propylene), poly(ethylene terephthalate), poly(lactic acid), nylon, and a multilayer structure of ethylene vinyl acetate and ethylene vinyl alcohol were better barriers for gaseous ClO₂, as compared to polyethylene, poly(vinyl chloride), and polystyrene. The activation energies of permeation for ClO₂ through poly(ethylene terephthalate) and poly(lactic acid) were determined to be 51.05 ± 4.35 and 129.03 ± 2.82 kJ/mol, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, , 2009     

The barrier properties of polyethylene terephthalate to mixtures of oxygen, carbon dioxide and nitrogen

The diffusion and solubility of oxygen, nitrogen and carbon dioxide have been studied in amorphous and biaxially oriented films of polyethylene terephthalate (PET). To measure the sorption and desorption of each gas simultaneously in cases where mixtures of gases were studied, a mass spectrometer was used as a detector. It was found that the solubility and diffusion of nitrogen in PET were markedly affected by the presence of the other gases, oxygen and carbon dioxide with differences in detail between results for the amorphous and biaxially oriented films. It is of particular interest that the presence of oxygen reduces the solubility and increases the diffusivity of nitrogen.     

Surface modification of atmospheric plasma activated BOPP by immobilizing chitosan

Summary Chitosan was immobilized onto plasma activated biaxially oriented polypropylene (BOPP) films aimed at producing antimicrobially active barrier film for food packaging applications. 1% chitosan dissolved into 0.1 M acetic acid was mixed with 0.1% glutaraldehyde (cross-linking agent) and applied onto N₂-plasma + NH₃ activated BOPP film. Amount of immobilized chitosan was 1.8 g/m². Films had strong antimicrobial activity against both Bacillus subtilis and Escherichia coli and they reduced the oxygen transmission rate (OTR) measured in dry conditions from 1500 down to 27 cm³/(m²·24 h). Migration tests for determining the total amounts of substances migrating into food simulants (3% acetic acid, 95% ethanol and iso-octane) indicated, that chitosan coating was permanently immobilized onto BOPP without any leaching (total migration < 2 mg/dm²), thus it met the requirements stipulated in Directive 2002/72/EC relating to plastic materials and articles intended to come into contact with foodstuffs. The results suggest that chitosan treated BOPP films may be exploited in various food packaging applications requiring high oxygen barrier and/or antimicrobially active packaging materials.     

数码彩色相纸技术动态

随着数字冲印技术的持续发展,柯达、富士等公司申请了大量的可用于传统、数字两种冲印方式的银盐彩色相纸的专利。相纸乳剂中掺杂了新型金属络合物,层压的双轴取向聚烯烃片作为相纸的支持体。此外,柯达公司还推出了几种特殊结构的彩色相纸。     

Orientation development in retensilized,biaxially oriented polypropylene films

A basic study of orientation development in retensilized, biaxially oriented polypropylene films was performed. Wide-angle X-ray scattering (WAXS) and birefringence measurement techniques were used to examine films prepared under specific processing conditions. Biaxial orientation factors were determined for these films and were correlated with end-use properties of the materials. In particular, the dispensability of oriented polypropylene films was found to correlate with crystalline-phase and amorphous-phase orientation factors. Dispensability is a relatively important property of pressure-sensitive tapes; it is defined as the force necessary to cut a film backing over a serrated blade of the type used in commercially available adhesive-tape dispensers.     

Bioactive efficacy of low‐density polyethylene films with natural additives

Active packaging can be defined as packaging that includes additives that help to extend the shelf life of food; among the advantages of its use is the possibility to reduce the amount of additives added to the food during processing. The aim of this study was to develop, characterize, and apply active films of low‐density polyethylene, incorporating carotenoid and yerba mate extracts as active additives. Active films were obtained by extrusion and were characterized for water vapor permeability, thickness, color, and mechanical and thermal properties. The effectiveness of the films was evaluated using butter packed in the formulated films. There was a significant reduction in thickness, and mechanical, thermal, and water vapor barrier parameters of the films compared to the control. The concentration of additives directly influenced coloration and antioxidant and antimicrobial action of the films. The formulated films provided protection against oxidative action and inhibition of microbial growth. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46461.     

New production technologies and applications of poly(vinyl alcohol) film

The following aspects of the manufacture, properties and applications of biaxially oriented poly(vinyl alcohol) (PV-OH) films are discussed: selection of starting PV-OH; method of production by successive biaxial orientation: technical aspects of production; characteristics and applications of the film. Biaxially oriented PV-OH films have good antistatic properties, good thermal resistance, oil and solvent resistance, and excellent gas barrier properties, and are used in food packaging applications. The following aspects of the manufacture, properties and applications of poly(vinyl alcohol) film produced by a blown film technique are discussed: selection of starting PV-OH; process for the production of hot-water-soluble (HWS) film; technical aspects of film production; characteristics and applications of the film. Blown films, which are hot-water-soluble, are produced in tubular form, for conversion into disposable laundry bags.