PETG热收缩标签褶皱问题分析

本文探究了油墨中溶剂残留、收缩速率、摩擦系数、厚度偏差和瓶型等指标对热收缩效果的影响.研究表明:降低油墨中溶剂残留、增加热收缩时间、降低摩擦系数、提高厚度的均匀性和改用规整瓶型能显著改善热收缩标签在瓶身的收缩效果,减少收缩褶皱问题发生的概率.     

热收缩包装薄膜的最新发展

热收缩包装是一种新颖和有效的包装方法,发展时间较短但发展前景很好,最早应用于食品包装方面,近来在其他包装方面亦取得了长足的发展。近来有热收缩包装来代替纸箱包装的动向。 热收缩薄膜的种类较多,有聚乙烯、聚丙烯、聚氯乙烯、聚偏二氯乙烯、聚酯、尼龙等热收缩薄膜。 这些热收缩薄膜一般为单组分结构,收缩包装后能紧紧贴合在被包装物表面,没有绉纹,具有光泽。而随着社会经济和生活水平的提高,以及生产技术的发展,对热收缩包装提出了更高更新的要求,人们也能研究和生产出各种具有特殊功能的热收缩薄膜。下面介绍几种最新研究开发的热收缩特种薄膜。 1.具有凹凸绉纹的热收缩薄膜     

具有窄热触发域的HDPE单丝热收缩行为

通过口模拉伸的工艺制备获得了具有高强度的模力学性能的ＨＤＰＥ纤维，通过测试纤维的热收缩行为，发现该纤维的热收缩触发域很窄，即在临界温度１３２℃以下时，其热收缩率很低（小于１０％），而高于此温时，收缩率可高达９４％以上，同时又具有较高的收缩力，有望作为一种热收缩元件的理想材料。     

POF热收缩薄膜的包装应用性能研究

以线性低密度聚乙烯(LLDPE)作为中间层,共聚丙烯(PP)作为内、外层,采用3层共挤的方法制成的POF复合热收缩薄膜,可弥补单一材料制成的热收缩薄膜所不能满足的收缩包装需要.研究了POF热收缩薄膜的包装应用性能,包括在不同温度下的热收缩率、薄膜的厚度随收缩温度的变化、不同热收缩温度处理后的拉伸性能和透湿性能.这些性能的研究为POF的热收缩包装应用,提供了有价值的参考依据.     

Al含量对Mg-Al亚共晶合金热收缩行为的影响

利用一种可使合金在凝固冷却过程中实现近似一维收缩的实验装置,以纯镁及含Al量分别为1.1%、3%和5%(质量分数)的二元亚共晶镁合金为研究对象,检测其在凝固冷却过程中自由收缩时的冷却曲线及一维收缩量的变化,旨在获得纯镁及这三种Mg-Al二元亚共晶合金的热收缩规律,估算合金在低温区间的平均线膨胀系数,最终实现对这几种合金热收缩行为的系统表征。结果表明,Mg-Al合金铸件凝固过程中收缩速率随温度降低先增大后减小,其最大收缩速率vl,max随含Al量的增加(0%~5%)而降低,但降低幅度逐渐减小。当铸件完全凝固后,每一种合金在其对应的某一高温区间内(高温固态收缩阶段)均存在固态收缩速率随冷却温度降低先增大后减小的现象,而所有铸件在低温固态收缩阶段均表现为线性匀速收缩(固态收缩速率趋于一恒定值)。Mg-Al合金铸件在低温收缩阶段(400℃)的固态平均线膨胀系数随含Al量的增加(0%~5%)而增加。     

2006年我国热收缩膜市场规模2亿元

随着PET瓶装饮料市场趋向繁荣，热收缩薄膜市场也正在快速打开局面。据预测，今年中国热缩膜将有2亿元市场规模，增长率约20％。热收缩膜包装用途广泛，多用于一次性包装，作为饮料收缩标签的用途是其各种用途中增长前景最好的。     

热收缩包装的优势及生产应用情况

热收缩薄膜是一种在生产过程中被定向拉伸,而在使用过程中受热收缩的热塑性塑料薄膜。热收缩薄膜是利用薄膜在高弹态下纵向或横向拉伸了的能量储存在薄膜中,利用热塑性塑料具有的对双向或单向拉伸前的形态具有的记忆效应．     

燃气管道防腐补口失效分析及对策建议

良好的补口是燃气管道防腐层质量的重要保障，目前城镇燃气管道3PE防腐层补口广泛应用热收缩带，根据施工现场工作经验，本文提出了热收缩带补口常见的三种失效方式，并通过故障树分析，对热收缩带补口失效原因进行有效分析研究，最后针对城镇燃气管道补口的现状，从三个方面提出预防和控制热收缩带补口失效的建议和对策。     

PVA热收缩包装薄膜的研究与应用

PVA热收缩薄膜具有优异的水溶性和生物降解性能,目前其生产方法主要有流涎法(湿法)和挤出吹塑法(干法),其热收缩工艺可分为一步法和两步法。PVA薄膜通过增塑改性可以降低结晶度,从而增加热收缩性能。其中,增塑改性工艺中的主要影响因素为增塑剂,拉伸工艺中的主要影响因素是拉伸温度和拉伸倍数,骤冷工艺中的主要影响因素是冷却温度及受冷均匀,收缩工艺中的主要影响因素是热收缩温度。PVA热收缩薄膜的市场应用空间较大,其研究方向主要为新型绿色可降解热收缩包装薄膜。     

低能电子束辐射交联改性PP/LLDPE五层共挤POF热收缩膜的性能EI北大核心CSCD

通过低能电子束辐射改性聚丙烯(PP)/线型低密度聚乙烯(LLDPE)五层共挤聚烯烃(POF)热收缩膜,制备耐温性强、收缩温度窗口宽的POF交联热收缩膜。文中研究了辐照气氛和吸收剂量对POF热收缩膜结构、力学性能和热收缩性能的影响。结果表明,在氮气和空气气氛辐照后,POF热收缩膜的结构、力学性能和热收缩性能未有明显差别。POF热收缩膜交联度和耐温性均随着吸收剂量增加而增加。POF热收缩膜的断裂伸长率随吸收剂量增加无明显变化;拉伸强度随吸收剂量增加先增加再降低。低能电子束辐照交联改善了POF热收缩膜低温收缩性能,增宽了热收缩温度窗口。     

植物油类调味品防漏油包装材料及措施探索

目的 寻找合适的植物油调味品包装材料、试验配件,以获取热封压力范围,解决植物油调味品行业实际生产中产品包装漏油问题。方法 采用PA15/PE62,PA15/PE65,PA15/PE55,PET/PET镀铝/PE,PET/Al/PE,PET12/PE38等7种包装材料,在使用自动制袋式填充包装机实际生产环境下进行50,150,300 g等3种规格的清油类底料灌装,并施加30 kg重物进行90 d储存试验,每隔15 d观察包装的封口质量;添加热封压力调节配件,在实际生产中可间接指示热封压力范围,进而探索不同材质的热封压力调节范围。结果 在进行了90 d压力储存后,发现3种规格的样品包装材料漏油率在0~17.95%之间,其中PA15/PE62在50,150,300 g等3种规格下的漏油率均为0,可见该材质在现有生产条件下能够有效缓解漏油现象;该压力配件效果较好,得出2种卷料的热封调节配件调节圈数集中在7.4~6.25圈,7.4~5.75圈。结论 PA15/PE65能有效缓解实际生产中的热封部位断根现象、漏油现象;该压力配件的使用便于生产企业找寻热封压力与热封温度的平衡点,进而缓解漏油现象。     

Heat Sealing measurement by an innovative technique

To obtain a proper heat seal is an important requirement in packaging, since seal failure is a more frequent cause of product deterioration than the package itself. Different kinds of seal, such as peelable or non‐peelable, can be obtained by changing the conditions under which a material is sealed. Therefore, identifying these conditions is very important. A new technique, the m ethod for m easuring t emperature of m elting s urface (MTMS), was used to predict the strongest peelable seal on various packaging commercial films. The temperature of the seal interface was measured using a thermocouple. The time–temperature profile, which was obtained by means of a thermocouple, was electronically processed so as to obtain the derivatives of the profile. The inflection point, also called the fusion point, was located on these profiles. This inflection point is associated with the physical change of the state of the material being sealed. The inflection point analysis was done using two different methods: (a) the MTMS method, based on the second derivative of temperature data with time; (b) ‘Table Curve’ software, based on non‐linear regression. This technique was successfully used to evaluate widely used packaging films such as LDPE, HDPE, LLDPE and CPP. The inflection point for these films was identified and the seal strength was verified using a universal testing machine. This method appears to be applicable to design the strongest peelable heat seals for many packaging materials. It also seems to have promise as a method of process measurement and validation for heat seal processes. Copyright © 2006 John Wiley & Sons, Ltd.     

Evaluation and optimization of seal behaviour through solid contamination of heat‐sealed films

A method is presented to apply solid powder/granulate contamination (ground coffee and blood powder) in between the heat conductive seals of flexible packaging materials. A response surface method is tested and validated to optimize seal strength of heat conductive sealing with and without solid contamination. In this study, a maximal seal strength is defined as optimal. Using these methods, three typical packaging films with varying seal layer composition (metallocene linear low‐density polyethylene (LLDPE), plastomer, and sodium ionomer) are maximized towards contaminated seal strength. Contamination caused a decrease in seal strength and narrowed down the process window (seal temperature and time combinations) in which at least 90% of the maximal strength is obtained. The influence of seal layer composition on the clean and solid (ground coffee and blood powder) contaminated seal performance (seal strength, process window, and leak tightness) was evaluated. The film with the plastomer‐based seal layer outperformed the other films with respect to the width of the process window. It also reached a higher seal strength and a higher amount of leak tight seals (evaluated with the dye penetration test) after optimization. The hot tack test was evaluated as predictive test for the contaminated seal strength. The results of this study do not support an indicative relationship.     

新型包装材料为饮料护航

在食品生产企业中，包装设备的主要任务是将食品从最初的灌装到最后销售过程中的产品质量损失降到最低。当纸质饮料包装盒被封口后，高营养饮料的口感和营养价值取决于纸质包装的隔离性能、产品与包装材料之间的相互影响以及不同的保存条件和环境。[编者按]     

卷筒包装材料的张力分析

以卷筒包装材料的收放卷过程为例，分析包装机械工作过程中柔性包装材料的张力。通过变质量构件的动力学分析，得出张力控制力矩随卷筒直径变化的计算公式。此外，由于张力还受张力还受许多不确定因素的影响，其变化是一个随机过程。当统计图上出现不正常变化时，调节控制力矩需加一个附加值。     

Effects of film tension and contamination on the seal quality of flexible food packaging films made of polypropylene and low density polyethylene blends containing talc filler

Seal integrity and seal strength are important requirements in the heat sealing of flexible packaging. In this article, the influence of talc compounds and different process parameters, such as film tension and contamination on the sealant films consisting of polypropylene and low-density polyethylene blend were investigated. According to the results, increasing the talc ratio from 0% wt to 30% wt positively influenced both hot and cold seal strength. Among different polymer blends having same talc ratio, the sample having the lowest melt flow index (2.84 dg/min at 230°C and 2.16 kg) showed the highest cold seal strength with 9.07 N/25 mm. On the other hand, in the samples with higher melt flow indexes, less seal integrity issues were observed in the presence of contaminants. Elevated film tensions from 0 to 0.4 N/mm² enhanced the seal strengths significantly at the seal initiation temperatures of each film. However, this situation changed at higher operating temperatures due to the increased orientation and brittleness. Besides, in the presence of contaminant coffee particles at the seal interphase, high film tensions adversely affected the seal integrity since the average leakage increased 2.7% for samples A and B, and 7.4% for sample C. In summary, it has been shown that talc incorporation can improve seal strength, high MFI can fill the gaps at the seal interphase and the high levels of film tension (above 0.16 N/mm²) during sealing as well as the contamination need to be avoided to ensure integrity sealing.     

Seal bond characterization of laminated plastic food cups by scanning electron and optic microscopes

Heat seals of laminated semi‐rigid food cups were evaluated to characterize the seal bond. Laminated lidding material was sealed at temperatures of 160–180°C to thermoformed cups. Various seal regions of the cups with different ultrasonic signal strengths (%) were sectioned at the rim and examined using optical and scanning electron microscopes (SEM). Ultrasonic signals were able to pinpoint seal defects; however, the magnitude of the signals did not relate to the actual seal condition or seal quality affected by the sealing process. This was attributed to the very short seal width and non‐parallel surface of the heat seal, which possibly resulted in signal loss by reflection and scattering from the seal surface. C‐scan of ultrasound, SEM and optical microscopic images provided the information that the heat‐sealing process was unstable, due to insufficient and non‐uniform heat‐seal temperature or pressure, misalignment of the sealing jaws or non‐parallel sealing or cutting unit configuration. Copyright © 2004 John Wiley & Sons, Ltd.     

热封封口缺陷红外无损检测的有限元分析

从理论上分析了红外无损伤检测技术在热封封口质量检测时的热传导方程,并运用有限元技术对影响热封质量的因素进行了数值分析,讨论了影响最大温差的因素,该结论对红外无损伤检测法在软包装的应用具有重要指导意义.     

Heat-sealing integrity assessment through nondestructive evaluation techniques

Sealing is a critical step in different packaging industries. In heat sealing as one of the major types of sealing processes, two layers of materials (typically thermoplastics) are joined together through the application of heat and pressure load for a certain sealing time. Due to the capabilities of the heat-sealing process to seal different kinds and sizes of packages, it has a wide range of applications in many different industries such as the packaging of food and medical products. The quality and integrity of sealings produced by these techniques are crucial for the quality and safety of the contained materials. In this paper, different types and processes of sealing are discussed. Due to the variations in shape, size, and complexity of the sealing region, quality testing and inspection of these products is a challenging task. Nondestructive testing and evaluation (NDTE) techniques can be promising tools to overcome these challenges. Furthermore, a detailed study of various types of potential defects and their generation mechanism in heat sealing is presented. Then, various types of NDTE techniques that can be potentially used for the inspection of heat-sealing regions and their working principles, as well as their strength and weakness in sealing inspection, are debated. Finally, several cases of sealing inspection and relevant NDTE techniques that are developed as standard procedures are presented. The discussions in this study provide useful information for the selection and implementation of appropriate quality inspection and inline quality monitoring of sealing parts and processes.     

FST-01 薄膜热缩性能测试仪测量结果的比较研究

目前,国内包装行业多数采用恒温油浴和烘箱来进行薄膜收缩率的检测,而较少测试收缩力值。介绍了常用的收缩率测试标准,并重点介绍了ISO 14616与DIN 53369收缩力值的测试方法;采用ISO 14616的方法通过试验对低密度聚乙烯LDPE、非结晶型共聚酯PETG、单向拉伸聚苯乙烯OPS、多层共挤聚烯烃POF和双向拉伸聚丙烯BOPP等5种材料进行了测试。结果表明,该方法不仅可以检验聚乙烯、乙烯共聚物及其混合物的收缩性能,也可检验其他热收缩膜的收缩性能。