Adhesive properties of heat-sealed EVAc/PE films in dependence on recipe,processing, and sealing parameters

The investigated peel system in this study consists of a polyolefine-based, coextruded, three-layer film having ethylene-vinyl acetate (EVAc) copolymer at the interface, heat sealed against a biaxial-oriented polyethylene terephthalate film. This system can primarily be found in the packaging industry offering a residue-free and non-destructive peel behavior. The peel force required to separate the joint depends on the mass fraction of vinyl acetate (VAc) in the EVAc copolymer, the processing conditions in the blowing process of the PE/PEVAc film, and on the sealing parameters. In dependence on the processing conditions and sealing parameters, the standard peel system with EVAc copolymer containing 18 wt.% VAc was investigated. The processing parameters were varied among the processing line of the blown film and their influence on the peel properties were studied. As processing parameters the screw speed within the extruder and the resulting layer thickness, the cooling behavior of the film bubble and the blow-up ratio (BUR) of the film bubble were investigated. The effect of pretreatment conditions was also investigated. The investigations revealed a significant dependence of the peel force on the pretreatment conditions. Processing conditions and the VAc content have a minor impact on the peel properties.     

基于PLC的盒式气调包装机设计

设计一种盒式气调包装机,整机采用西门子S7-200PLC进行控制。该气调包装机能够自动完成包装盒的输送与热封,包装膜的输送与切裁,包装盒内气体置换和成品输出等功能,可以根据实际生产需要调节包装速度,以及根据不同的包装材料调节热封温度。     

塑料薄膜超声波热封工艺实验研究

通过对包装中常用的PE,PVC,PP 3种热塑性塑料薄膜超声波热封工艺实验的研究,得到了影响封合质量因素的规律,初步确定了以上3种热塑性塑料薄膜超声波热封工艺参数,为超声波热封技术的推广提供了一定的理论基础.     

PCL / 纸板复合膜的包装特性及回收工艺研究

为了提高纸板的力学性能和水蒸气阻隔性,采用热压法制备了聚己内酯(PCL)/纸板双层复合膜。分别使用质构仪、动态力学分析仪、透湿仪对材料的力学性能、动态热力学性能以及阻隔性能进行了评价,并对PCL的热封性能和纸板的回收工艺进行了评估。研究表明,与PCL复合后,纸板的拉伸强度提高了约3倍,弹性模量提高了约5倍,阻湿性也显著提高;PCL的复合量和热封温度对材料的热封强度影响较大;纸板回收速度快,平均回收率可达到99%。     

Effects of corona treatment on surface properties of co-extruded transparent polyethylene film

Current study encompasses that the effect of corona treatment on the outer surface of transparent co-extruded polyethylene films was at various levels by applying different wattages, in tandem with the blown film extrusion process. A maximum treatment of 42 dynes/cm was achieved at 4.5 KW of applied wattage. The heat seal joint strength of the films sealed at different combinations of treated/untreated surfaces was evaluated and an untreated/untreated surface combination was found to exhibit maximum strength (2.8 kgf/25 mm), while a treated/treated surface combination showed the minimum (1.41 kgf/25 mm) under identical conditions of sealing and testing. The peel adhesion to ascertain the treatment level on the treated surfaces was inspected by a standard Scotch tape method, and the results exhibited a linear relationship between the applied wattage and the pulling force of adhesion. The Fourier transform infrared spectroscopy (FTIR) spectra of the treated and untreated film samples in an attenuated total reflection (ATR) mode showed the peaks' characteristics mostly of polyolefin films. The morphologies of the treated surfaces displayed relatively rough surface compared to the untreated one. The barrier properties of the treated films in respect of water vapor and oxygen transmission rate do not undergo any appreciable change.     

锂离子电池软包装用CPP薄膜热封特性的研究

通过DSC测试锂离子电池软包装用聚丙烯流延膜熔限,研究温度、压力及材料厚度与热封时间的关系。实验结果表明:热封温度和材料厚度都对热封范围有较大影响,随着温度的升高,热封范围变小;CPP厚度由25μm增大到50μm,热封范围扩大50%,强度增大66.7%;热封压力对热封范围影响不大;热封温度对热封强度有明显影响,热封强度随热封温度的增加而增大至平衡。     

PET/PE复合材料最佳热封工艺参数研究

PET/PE复合薄膜广泛应用于食品和药品包装,但在生产过程中存在热封质量不稳定的问题,为了探索PET/PE复合薄膜热封质量的影响因素,采用热封机对复合材料进行热封,并用拉伸实验对热封强度进行测试,比较分析了热封方向、热封温度、热封速度对热封质量的影响作用,总结得出了PET/PE复合薄膜的最佳热封工艺参数。     

双铝箔自动填充热封包装机控制系统设计

本文对双铝箔自动填充热封包装机工艺过程进行了分析,对控制系统进行了设计。给出了电气控制原理图,PLC控制硬件接线图,并对控制软件设计进行分析。