热封材料的分析

随着高速自动包装的发展,具有低温热封性,热粘性能优良,气密性好的热封材料发展迅速。为了更好替代塑料吹塑瓶,玻璃瓶,有效提高产品的保质期,降低产品包装成本,热封形状从三边封袋,中封袋发展到目前的自立袋,异型袋还有使用方便,可重复利用的拉链袋也在服装业、食品业流行起来。     

包装机中常热式薄膜热封过程的仿真研究

通过对包装机常热式封头结构和封合参数的分析，建立薄膜热封过程的数学模型，并在Matlab/simulink下建立可实时运行的仿真模型。根据仿真结果得出了一些有价值的结论和改进包装机中热封装置设计的措施。     

浅谈包装材料热封性能的影响因素

本文概述了常用的热封包装材料和热封理论,详细论述了材料热封性能的影响因素,并对实际生产中热封部位的开裂模式进行了归纳。     

略论复合袋热封强度的影响因素

本文根据生产实践，总结和分析了影响复合袋热封强度的各项因素。     

软包锂离子电池铝塑膜的热封性能研究

选取40μm流延聚丙烯热封层铝塑膜(1~#样品)、80μm流延聚丙烯热封层铝塑膜(2~#样品)和80μm接枝改性PP热封层铝塑膜(3~#样品)作为研究对象,在不同热封温度、热封时间、热封压力、热封层厚度和热封层种类的条件下,对3种不同软包锂离子电池铝塑膜进行热封研究。利用万能试验机和扫描电镜等,对3种不同铝塑膜的热封强度和热封结合界面进行分析。结果表明,3种不同铝塑膜的最佳热封工艺均为热封温度为230℃,热封时间为12 s,热封压力为1.0 MPa。1~#样品的热封强度最高仅为98.9 N/15 mm;3~#样品的热封强度最高为114.3 N/15 mm;2~#样品的热封强度最高可达144.4 N/15 mm。在0.5～1.0 MPa的范围内,热封压力对铝塑膜热封强度的影响不显著,热封温度和热封时间成为影响样品热封强度的主要因素。在相同的热封条件下,CPP热封层的热封效果要明显好于PP-g-PGMA热封层。热封剥离失效界面的研究表明,剥离实验失效模式为界面破坏和剥离破坏两种破坏模式并存,CPP与铝箔间的界面没有紧密机械啮合,如果对铝箔进行表面处理,增加铝箔与CPP间的机械结合力,可能会成为提高铝塑膜热封强度的有效手段之一。     

如何获得软塑包装材料最准确的热封性能

封口强度对包装材料来讲是一个重要性能指标，对任何一种软包装材料都要做成包装袋来包装各种商品，包装商品都要热封或粘接来封口，达到包装目的。封口要有一定的强度才能够承受一定重量的内装物的压力，保证商品在流通过程中不开裂。     

基于插值与神经网络的包装薄膜热封参数分析

目的研究塑料薄膜热封工艺中热封参数之间的非线性关系,建立一种可用于自动包装机热封过程的数学模型。方法通过实验采集样本数据,并用附加动量法训练BP神经网络,建立热封参数之间的非线性数学模型,最后通过神经网络预测热封时间,并采用插值算法建立目标热封强度下热封温度和热封时间之间的多项式数学模型。结果通过插值算法与神经网络的结合运用,较为精确地描述了热封温度和热封时间之间的数学关系,插值函数实现了神经网络模型的简化,两者误差较小。结论通过文中方法确定了包装材料热封参数之间的非线性关系,将其用于热封包装设备,可提高设备的智能化程度。     

一种热封剪切装置的设计与仿真

目的为了实现大型或多件物品热收缩包装过程中薄膜高效精准的热封、剪切,设计、分析并优化一种热封剪切装置。方法基于双膜裹包和热封、剪切工艺要求,从机械设计角度出发,结合生产实际,对机械结构进行设计,并进行运动仿真和结构优化。结果通过仿真分析,证实切刀和热封板之间实现了"先封后切"工序,一次热封剪切过程持续时间约为1 s,热封板间工作压力约为250 N,装置的整体工作性能良好。结论该装置设计合理、工作稳定、动作精准,能够实现热收缩包装中的热封剪切功能。     

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。     

包装用塑料薄膜热密封技术

对包装用塑料薄膜制品封合工艺中,常用的各种热密封技术和工艺方法予以较全面和详细的评述。     

制袋机热封装置温度场模拟与优化设计

目的解决制袋机热封装置中烫刀热封表面温度差偏大的问题。方法用Solid Works软件对制袋机热封装置进行参数化建模,再调用Ansys Workbench插件进行稳态温度模拟仿真,分析其温度场的分布情况。然后通过增加电热管的数量来设计电热板的内部结构,对改进的模型进行有限元分析,并对电热板内电热管安装孔的长度进行优化设计。最后进行试验验证。结果将软件模拟结果与实测数据进行比较分析,两者基本吻合。基于有限元分析模拟的温度场的优化改进设计,可使热封装置的热封面温度差由原来的4.4℃降低至2.9℃。结论基于温度场模拟的电热板内部结构的改进设计可取得令人满意的热封面温差效果。     

Evaluation of Jaw Profile on Heat Sealing Performance of Metallised Flexible Packages

Different profiles of jaws are used in the Brazilian market for heat sealing flexible materials used in food packaging by heated bar. The objective of this study was to evaluate the influence of the jaw profile on the quality of the top and bottom heat seals of pouches made of biaxially metallized polypropylene/biaxially co-extruded polypropylene (BOPPmet/BOPPcoex) amd biaxially metallized polypropylene/low density polyethylene (BOPPmet/LDPE). These materials are traditionally used for snacks and ground coffee packages. Five jaw profiles were evaluated: one flat and four grooved, using lengthwise, crosswise at profiles 120 and 90° and inclined. The heat sealing temperature and time were optimized for the two packaging materials for all profiles. The sealing pressure was fixed at 40 lbf/in². Heat sealing quality was evaluated through visual examination, integrity, tensile strength and drop testing. All the tests were done before and after transport simulation on the packages. BOPPmet/BOPPcoex 100 g snack packages and BOPPmet/LDPE 250 g ground coffee packages were prepared under laboratory conditions. The transport simulation was done on these packages by placing them into paperboard boxes (for snacks) or kraft paper sacks (for ground coffee). The BOPPmet/BOPPcoex packages presented integrity problems for all the profiles tested. The best heat sealing, tensile strength, drop impact resistance and appearance were obtained with the crosswise 90 and 120° and inclined grooved profiles, therefore these profiles are the recommended ones for top and bottom heat sealing of snacks MOPP/met/BOPPcoex packages. The flat profile had the worst performance among the ones that were studied. Heat sealing quality was not affected by the transport simulation, for all profiles. The BOPPmet/LDPE packages did not show integrity problems. However, the transport simulation reduced the heat sealing quality for all profiles. The crosswise 120 and 90° grooved profiles showed similar performance and they are the recommended ones for BOPPmet/LDPE packaging of ground coffee or any product of similar appearance and density. The inclined, lengthwise and flat profiles are not recommended for these applications.     

放射性物品C型货包密封结构设计及性能研究

目的确定一种可抵御放射性物品C型货包撞击试验环境的内容器密封结构,为类似放射性物品运输容器的密封结构设计提供参考和依据。方法开展C型货包内容器密封结构设计,利用数值分析方法确定一种可行的密封结构,通过撞击试验校验此密封结构的有效性。结果货包在经历速度不小于90m/s的箱顶角碰、箱顶正碰及箱体侧碰至刚性靶试验后,内容器的整体标准漏率均小于0.01 mPa·m~3/s。结论设计的密封结构可抵御冲击刚性靶速度不小于90 m/s的撞击试验环境,可对放射性物品进行有效防护。     

包装材料EPE热封工艺的实验研究与分析

目的研究EPE包装袋的热封质量与热封参数(电热丝直径、热封时间、热封压力)的关系,分析弹性包装材料热封过程的特性。方法通过观察显微封口形貌,比较不同参数下的热封强度,研究热封参数对珍珠棉热封强度的影响,并分析其原因。结果在热封1.0 mm珍珠棉过程中使用直径为0.8 mm电热丝,热封压力为0.2 MPa,热封时间为2 s时,热封质量最好、效率较高。结论弹性材料的可压缩性导致封切压力对热封强度的影响随电热丝直径的增加而明显增加,弹性材料的回弹特性使电热丝直径以及热封时间对其热封缺陷产生更加显著的直接影响。     

全自动封口旋盖机控制系统的设计

针对软管封口旋盖机的工作流程及响应快、精度高的控制要求,设计了以PLC为核心的控制系统,结合交流伺服及其他硬件,对软管封口旋盖的生产流程进行了较好的控制。详细介绍了封口旋盖机的工作流程和控制时序方案,给出了程序流程图、工作时序图。最后提出了旋盖转矩的控制方法以及控制系统的设计方案。该控制系统性能稳定,控制精度高,生产速度快。     

Ultrasonic Sealing of Flexible Packaging Films – Principle and Characteristics of an Alternative Sealing Method

The closure process for packaging is a key process. It ensures the protective function of packaging and assures the packaged goods a long life. In this context, efficient and reliable sealing processes are essential for the production of sustainable packages. In this paper, several characteristics of the ultrasonic sealing process will be discussed and accompanied by experimental results. The introduction provides an insight into the ultrasonic sealing process, its heating mechanisms and the process steps. A comparison is made with conduction sealing. Furthermore, basic principles of heating and energy dissipation are related to the influences of the sealing parameters on the seam strength. The experimental studies were carried out on typical packaging films, such as polyamide‐polyethylene laminates. The seam strength in ultrasonic sealing is compared with that in conductive sealing. A lower seam strength was found for ultrasonic sealing in all the tested films. Furthermore, the sealing behaviour of the packaging films contaminated with different kinds of foods was analysed for both sealing methods. Although the ultrasonic sealing method has marginal advantages for bulk materials such as wheat flour, conduction sealing was shown to be better for other products. A comparison of the energy consumption during the ultrasonic and conduction sealing verified the advantages of ultrasonic sealing. In particular for thick packaging films, the amount of energy required for bonding is significantly lower than for conduction sealing. In summary, this paper provides a survey of the characteristics of the ultrasonic sealing method in packaging applications – its advantages and limitations. Copyright © 2011 John Wiley & Sons, Ltd.     

热封切制袋机中多通道温控系统的设计

阐述了一种高精度多通道温度控制器的设计方案。通过高速转换输出的16 位AD 芯片AD7705 以及ARM 处理器,可以实现快速轮番采集多路温度信号。采用积分分离的PID 算法,计算并输出PWM 控制信号,通过固态继电器控制加热器件通断时间,使得各通道温度达到预设温度并在控制精度允许范围内小幅度波动。通过Modbus 通信协议与上位机进行通信,可以实现单台上位机同时监控多个温度控制器。