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。     

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。     

三层共挤聚烯烃热收缩膜(POF)的加工及应用

采用PP作为内外层材料,LLDPE作为中层材料,经三层共挤吹塑形成第一膜管,第一膜管经过加热后进行吹胀拉伸形成第二膜泡,制得三层共挤聚烯烃热收缩膜(POF)。研究了POF的加工工艺,并进行产品性能测试,结果均符合包装要求。具有极高的收缩率和其它类型的热收缩不能比拟的性能,应用范围特别广泛。     

市场动态

五层共挤热收缩膜机组在哈问世 哈尔滨市罡昊塑料研究所与哈尔滨工业大学联合开发出五层共挤热收缩膜机组(即SBJZ-35/5A-Ⅲ),并获得了国家发明专利,该机组已落户哈尔滨糖果饮料总厂。经过几个月的运行,机组性能可靠,产品经权威部门检测其质量可与国外同类产品相媲美。     

一种热收缩共聚酯薄膜及其制备方法

本发明公开了一种热收缩共聚酯薄膜,其特征在于：包括主要由PETG 共聚酯组成的表面层、PET/PBT 共聚酯组成的夹芯层、PCTG 共聚酯组成的底层。将膜用PETG 共聚酯切片、膜用PCTG 共聚酯切片和膜用PET/PBT 共聚酯切片通过螺杆挤出机制备得到。与常规热收缩聚酯薄膜相比,本发明制备的三层共挤横向拉伸共聚酯热收缩薄膜透光率和单向热收缩率高,光泽度好,稳定性强,收缩均匀,且具有优良的透明性、延展性和韧性,可在现有的BOPET 薄膜生产线上生产,产品适用于各种容器的标签、食品饮料、电子电器、机械或五金制品的直接包装。     

天津石化小乙烯装置POF专用树脂工业化

<正>日前,天津石化小乙烯装置成功完成POF专用树脂的工业化生产,打破了进口产品在国内市场的垄断地位。POF膜为环保型多层共挤聚烯烃热收缩膜,是将线型低密度聚乙烯作为中间层,共聚丙烯作为内外层,经特殊工艺将内、中、外三层共同挤压而制成的热收缩薄膜。该产品因其较好的透明度,被广泛应用于饮料、方     

天津石化小乙烯装置POF专用树脂工业化

日前,天津石化小乙烯装置成功完成POF专用树脂的工业化生产,打破了进口产品在国内市场的垄断地位。POF膜为环保型多层共挤聚烯烃热收缩膜,是将线型低密度聚乙烯作为中间层,共聚丙烯作为内外层,经特殊工艺将内、中、外三层共同挤压而制成的热收缩薄膜。该产品因其较好的透明度,被广泛应用于饮料、方便食品、日化用品、音像制品、书刊、医药、电子元器件等异型产品的包装领域,是目前国际上广泛推广使用、并经欧洲和美国市场认可的环保型热收缩包装材料。     

天津石化POF专用树脂工业化

日前,天津石化小乙烯装置成功完成POF专用树脂的工业化生产,打破了进口产品在国内市场的垄断地位。POF膜为环保型多层共挤聚烯烃热收缩膜,是将线型低密度聚乙烯作为中间层,共聚丙烯作为内外层,经特殊工艺将内、中、外三层共同挤压而制成的热收缩薄膜。该产品因其较好的透明度,被广泛应用于饮料、方便食品、日化用品、音像制品、书刊、医药、电子元器件等异型产品的包装领域,     

天津石化POF专用树脂生产打破国外垄断

<正>日前,天津石化小乙烯装置成功完成POF专用树脂的工业化生产,打破了进口产品在国内市场的垄断地位。POF膜为环保型多层共挤聚烯烃热收缩膜,是将线型低密度聚乙烯作为中间层,共聚丙烯作为内外层,经特殊工艺将内、中、外三层共同挤出而制成的热收缩薄膜。该产品因其较好的透明度,被广泛应用于饮料、方便食品、日化用品、音像制品、书刊、医药、电子元器件     

BOPET差异化和功能化的应用及发展

介绍了BOPET的性能及改性方法,包括共聚改性、共混改性、表面涂布、多层共挤/多层复合,采用功能性母料,用纳米材料改性等。论述了BOPET差异化、功能化产品及其应用如热封膜、热收缩膜、抗静电膜、高阻隔膜、环保型硬糖扭结膜、抗菌膜、玻璃贴膜、PET阻燃膜、低温辐射电热膜,PET农用大棚膜。指出了未来BOPET的发展方向。     

Study of the interfacial adhesive strength of a heat-shrinkable multilayer film

A heat-shrinkable multilayer film is widely employed as labels of plastic bottles. A new heat-shrinkable multilayer film without an adhesive layer was designed in this study. The interfacial adhesive strength between the layers was controlled to avoid layer separation. We assumed a polyethylene terephthalate glycol-modified (PETG)/styrene-co-butadiene block copolymer/PETG shrinkable film substitute as the general poly(ethylene terephthalate) (PET)/polystyrene/PET shrinkable film. The interlayer adhesive strength between the layers was retained for industrial utilization even after drawing. Additional polybutadiene (PB) infiltrated the butadiene layer in the microphase-separated structure. Further addition of PB could not infiltrate the butadiene layer. The excessive PB contents coexisted with the interface between the layers, as observed by transmission electron microscopy (TEM). The segregated PB enhanced the interfacial adhesive strength. We concluded that the selective distribution of adhesive functional materials along the interface could appropriately retain its adhesive strength.     

提高BOPP香烟包装膜品质的探讨

对共挤双向拉伸聚丙烯(BOPP)香烟膜和涂覆BOPP香烟膜的生产方法、物理性能及使用效果进行了分析比较,指出共挤BOPP香烟膜的发展前景,并提出了改进品质的一些途径和方法。     

LDPE热收缩集装薄膜的工艺研究

研究了LDPE热收缩集装薄膜的性能,讨论了原料和挤出、拉伸、冷却、卷取等工艺控制要点对该膜的收缩性能和物理性能的影响,并提出了工艺参数。实验结果表明,采用国产原料和设备,在合适的工艺条件下,可制得具有良好的物理性能和理想的收缩性集装材料。     

Mechanical and transport properties of coextruded films

Two-layer films were produced by using the blown-film coextrusion apparatus constructed in our laboratory. For this study, we have produced films of the following combinations: (1) LDPE/CXA 3095; (2) LDPE/Plexar 3; (3) LDPE/EMA; (4) nylon 6/LDPE; (5) nylon 6/CXA 3095; (6) nylon 6/Plexar 3; (7) nylon 6/EMA. Tensile properties of the coextruded films were measured with an Instron testing machine, and correlated to processing variables, namely, takeup ratio and blowup ratio. From tensile property measurements, we have found that both the ultimate tensile strength and the tensile modulus of coextruded films follow the additivity rule with respect to the volume fraction of the individual components. With the films produced, we also conducted dynamic mechanical measurements with the aid of a Rheovibron Dynamic Viscoelastometer DDV-II, and attempted to test the Zorowski–Murayama theory to determine the adhesion characteristics of the coextruded films. Furthermore, permeability of the coextruded films to gases (namely, N₂, O₂, and CO₂) was measured by using a pressure differential apparatus constructed in our laboratory. We have found that the permeability of composite films follows the inverse additivity rule, i.e., the reciprocal of the permeability of composite film is given by the sum of the reciprocals of the permeabilities of the individual layers.     

共挤保护膜研究概况

介绍了共挤保护膜的特点及国外发展现状以及共挤保护膜所用基材种类及特点，压敏胶主要成分及作用。     

Studies on multilayer film coextrusion I. The rheology of flat film coextrusion

Multilayer flat film coextrusion was studied, both experimentally and theoretically. For the experimental study, a sheet-forming die with a feedblock was designed, and plastic films of three and five layers were coextruded. The die was provided with three pressure transducers in the axial direction in order to determine the pressure gradient in the die, allowing the determination of the reduction in pressure drop when different combinations of two polymer melts were coextruded. Polymers used for coextrusion were: (1) low density polyethylene and ethylene-vinyl acetate; (2) low density-polyethylene and high density polyethylene; (3) low density polyethylene and polystyrene. For the theoretical study, the z-component of the equations of motion for steady fully-developed flow were solved using a power law non-Newtonian model, Comparisons were made between the experimental and the theoretically predicted volumetric flow rates. Predictions of the velocity distributions, shear rate profiles, and shear stress distributions were made as functions of the processing conditions and the rheological properties of the individual polymers concerned.     

LLDPE‐based mono‐ and multilayer blown films: Property enhancement through coextrusion

In this study we investigated the performance of multilayer coextruded linear low‐density polyethylene (LLDPE) blown films. Five‐layer films were compared with monolayer dry‐blended films, and the effects of layer composition and layout on the end‐use properties of the coextruded films were highlighted. Three different LLDPEs were used: a conventional Ziegler‐Natta LLDPE gas phase butene copolymer, an advanced Ziegler‐Natta LLDPE solution octene copolymer, and a single‐site LLDPE solution octene copolymer. Numerous five‐layer coextruded structures comprising the single‐site resin and the other two Ziegler‐Natta resins were produced. The coextruded structures composed of the LLDPE butene and the single‐site resin yielded improved end‐use properties relative to the monolayer‐blended films. This result was ascribed to the presence of interfacial transcrystalline layers. Also, blends of the single‐site LLDPE and the advanced Ziegler‐Natta LLDPE octene resins within selected layers of coextruded films showed slightly enhanced tear resistance. Finally, it was found that haze was significantly reduced when the outside layers were composed of the single‐site resin. POLYM. ENG. SCI., 45:1222–1230, 2005. © 2005 Society of Plastics Engineers     

Stress relaxation in low‐shrink‐force polyolefin films

The morphology and stress relaxation of coextruded five‐layer LLDPE (linear low‐density polyethylene)/EVA (ethylene‐vinyl‐acetate) copolymer films were studied. Increasing VA (vinyl acetate) content in EVA causes a decrease of shrink tension in the films, which can be explained by a decrease in amount of crystallinity. The relaxation time spectrum of the coextruded crosslinked LLDPE/EVA films is similar to the relaxation time spectrum of crosslinked LLDPE film at room temperature. However, at elevated temperatures, an additional peak appears on the spectrum of coextruded film. The cause of this peak is temperature‐ and stress‐induced recrystallization of EVA during the relaxation test. This recrystallization was confirmed with DSC and wide angle X‐ray analysis. Polym. Eng. Sci. 44:1716–1720, 2004. © 2004 Society of Plastics Engineers.     

Comprehensive experimental study of a starch/polyesteramide coextrusion

A comprehensive study of the three‐layer film coextrusion was performed. Plasticized wheat starch (PWS) was chosen as the film central layer, and poly(ester amide) (PEA) was used as the surface outer layers. Single‐screw extruders and a standard feedblock attached to a flat coat‐hanger die were used to prepare the three‐layer films. The layer deformation and interfacial instability phenomena, inherent to multilayer flows, were thoroughly investigated. The effect of process variables, such as viscosity ratio, extrusion rate, layer thickness, and die geometry, were studied. Encapsulation of the central layer by the skin layers readily occurred at the edges of coextruded films. The stability of PEA/PWS/PEA coextrusion flows was closely related to the shear stress at the interface. Increasing global volumetric flow rates and the die gap geometry seemed to promote instabilities. Finally, the existence of instabilities at the interface increased the adhesion strength of multilayered products, due to mechanical interlocking between adjacent layers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2586–2600, 2002     

Interlayer delamination and adhesion of coextruded films

Efforts to evaluate interlayer adhesion of coextruded films are often hampered by the inability to initiate delamination. On the other hand, interlayer delamination was often noticed at cut or trimmed edges of coextruded films. In this study, a test method was developed by first initiating delamination by uniaxial stretching and then measuring interlayer adhesion by peel test. Delamination was initiated by uniaxial stretching under controlled conditions for samples with double‐neck geometry. The double‐neck geometry was designed to create a specimen for the subsequent 180° peel test. Peel force was used to quantify interlayer adhesion of coextruded films based on polycarbonate and its copolymers. With this two‐step technique, coextruded films with peel force as high as 5300 N/m or 30 lb./in. were quantified. In addition, effects of copolymer composition and coextrusion processing condition on interlayer adhesion of these coextruded films were clearly demonstrated. A great deal of variation of interlayer adhesion across film surface was also revealed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3901–3909, 2004