Spontaneous ignition of corrugated cardboard under dynamic high radiant flux

Understanding the response of solid combustibles under high radiant fluxes is critical in predicting the thermal damage from extreme scenarios.Unlike the more moderate radiant fluxes in conventional hydrocarbon fires,extreme events such as strong explosion,concentrated sunlight and directed energy can generate dynamic radiant fluxes at the MW/m^(2) level,creating a unique threat to materials.This study investigates the pyrolysis and spontaneous ignition behaviors of corrugated cardboard by using both experimental and numerical methods,under 10-cm dynamic high radiant fluxes ranging from 0.2 to 1.25 MW/m^(2) for 10 s.The spontaneous ignition process at dynamic high radiant fluxes was recorded and quantified.Two ignition modes were found at the critical radiant flux of 0.4 MW/m^(2),namely hot-gas spontaneous ignition and hot-residue piloted ignition.The latter is not the focus of this paper due to its extremely small probability of occurrence.The research reveals that the increase in flux intensity induces shorter delay times for both pyrolysis and ignition,lower ignition energy density,along with a corresponding rise in the critical mass flux and surface temperature at ignition moment.The simulation results are generally aligned with the experimental findings,despite some divergences may be attributed to model simplifications and parameter assumptions.The work contributes to a deeper insight into material behavior under extreme radiation,with valuable implications for fire safety and hazard assessment.

Determination of Five (5) Possible Contaminants in Recycled Cardboard Packages and Food Simulants Using Ultrasound Assisted Extraction Coupled to GC-MS

A modified analytical procedure has been developed to test for 5 organic pollutants [benzophenone, 2 diisopropylnaphthalenes (DIPNs) {2,6- and 2,7-diisopropylnapthalene} and 2 hydrogenated terphenyls (HTPs) {m-terphenyl and o-terphenyl}] that can be found as residues in recycled cardboards intended for use as food packaging materials and to test for migration levels of these compounds in a food simulant (Tenax). A main objective was to develop a modified rapid and reliable method for the identification and quantification of these compounds at low concentrations. The method was based on ultrasound-assisted solvent extraction (UAE) followed by gas chromatography-mass spectrometry (GC-MS) analysis. The developed method was applied to analyze 3 commercially available recycled carton board food-packaging materials and also to study the potential migration of the 5 organic pollutants from these materials into Tenax to check if these recycled cardboards can be considered as suitable for use in direct contact with foodstuffs. The limits of detection (LODs) of standard solutions of the 5 compounds were determined at a signal-to-noise ratio of 3. The LODs and the limits of quantification (LOQs) of examined pollutants ranged between 0.005 to 0.5 mg/kg, and 0.1 to 1 mg/kg, respectively. The extremely low amounts of most contaminants that migrate from packaging materials to Tenax indicate that the recycled cardboards tested can be safely used for direct food contact applications.

Evaluation of Aqueous Product from Hydrothermal Liquefaction of Cardboard as Bacterial Growth Medium: Co-Liquefaction of Cardboard and Bacteria for Higher Bio-Oil Production

Hydrothermal liquefaction (HTL) processing of lignocellulosic biomass to bio-oil produces aqueous co-product (AP) which contains significant (~40 wt%) carbon from the original feedstock. This study evaluates macro and micronutrient composition of AP from Ca(NO3)2 catalyzed HTL of cardboard (CbAP) to cultivate bacteria. HPLC, GC-MS and ICP-MS analysis of CbAP revealed presence of C1-C3 carboxylic acids, aldehydes, ketones, phenolics, sub-optimal phosphorous and bio-incompatible levels of calcium. Dilutions (5 - 80 vol%) of detoxified CbAP (DTP-CbAP) in potassium phosphate buffer (pH 7.2) were supplemented with 50 mg·mL-1 of yeast extract and inoculated with metabolically versatile Enterobacter species. The cultures were incubated at 25°C under aerobic conditions. A maximum 9.4 fold increase in the dry cell weight was observed in DTP-CbAP-15 vol%. Co-liquefaction of the bacteria with cardboard in 1:1 and 1:3 weight ratios each produced ~33% more total bio-oil. These had higher HHVs of 34.11 and 31.05 MJ·kg-1, respectively compared with bio-oil from cardboard feedstock alone which had HHV of 30.61 MJ·kg-1. The study highlights the challenges in cultivating microbes in AP from HTL of lignocellulosic biomass (LCB) and the possibility to integrate microbial capture and recycle of the AP carbon for enhanced bio-oil production and quality.

Cardboard虚拟现实软件教育应用探析

Cardboard是虚拟现实的一款应用软件,帮助虚拟现实技术进入课堂,形成新型教育模式。从自主学习与协作学习两个方向探讨促进学生沉浸式学习的教学设计,论证虚拟现实技术在单个与多个学习者学习的功用。从学生与教师两方面说明,学生完成任务的方式以及教师教学设计的改变。

Evaluation of the Survivability of SARS-CoV-2 on Cardboard and Plastic Surfaces and the Transferability of Virus from Surface to Skin

Objective: To 1) characterize the decay curve of infective SARS-CoV-2 over time on the surface of cardboard packaging and plastic mailer packaging;2) characterize the transferability over time of virus-inoculated cardboard packaging and plastic mailer packaging to skin. Methods: We inoculated samples of plastic and cardboard packaging with a titer of SARS-CoV-2 > 106 TCID50/ mL to evaluate the survivability and transferability to the skin (pig skin) over time. A cell culture-based infectivity assay (TCID50) was used to determine viral titers. Regression analysis was used to characterize decay curves. Results: The time that SARS-CoV-2 remained transferable to skin was reduced on both packaging substrates compared to the total time of survivability, though cardboard demonstrated a substantially larger reduction. Virus inoculated plastic substrates continued to transfer the virus to the skin after 7 hours of holding time and regression analysis predicts this transferability would remain detectable up to 9.5 hours of holding time. Inoculated cardboard substrates demonstrated detectable transfer at 15 minutes of holding time, but no viable virus could be detected on the skin after 30 minutes of holding time. Conclusions: The type of material used as a packaging substrate substantially modifies the potential for SARS-CoV-2 fomite transmission. The use of materials that limit fomite transmission from packaging should be considered among strategies to reduce the transmission of SARS-CoV-2. Future research should investigate the generalizability of these findings for other viral pathogens that potentially transmit via fomite.

Wastewater Treatment of a Cardboard Manufacturing Plant by Infiltration Percolation

Different coastal sands of the city of El Jadida are used to filter wastewater from a cardboard manufacturing plant combined with fly ash and bottom ash （by-products of a local power plant）. The performances of five matrices of these elements are compared in infiltration-percolation in vertical columns. The study of particle size sand is performed beforehand. The chemical and mineralogical composition of fly ash and bottom ash are produced by X-ray fluorescence and X-ray diffraction respectively. The wastewater samples were collected during a complete cycle of production of the cardboard. The heavy metals content before and after filtration was obtained by atomic emission spectrometry with inductively coupled plasma （ICP-AES）. The parameters analyzed were： total suspended solids （TSS）, organic matter COD, BODs, the potential hydrogen pH and heavy metals （iron, zinc and arsenic）. The results are very conclusive and respect the essence of control required by Moroccan regulations （law 1606-06） related to discharges from the papermaking and cardboard industry.

The cardboard furniture design under low carbon economy

This paper presents the furniture design in the face of resource, energy consumption and environment accelerate the lasting damage to low carbon economy circumstances, human face the challenges of survival, should consider how to meet the low carbon era of mankind to the demand for the use of green furniture. Through the low carbon economy society demand, I think the current board furniture is under low carbon economy best green furniture, in the current, the cardboard furniture design of the low carbon times in addition to meet the use function, we should pay more attention to environmental protection and resource utilization, reduce the damage to the environment, with cardboard furniture design scientifically, reduce waste.

Comparison of the Bacterial Microbiota in a Bale of Collected Cardboard Determined by 454 Pyrosequencing and Clone Library

Biofouling, the accumulation of microorganisms, is a major problem in paper mills processing paper and cardboard. This leads to the production of lower quality recycled products. Several studies have focused on the microbial content in the paper mill and the final products. Our aim was to determine the microbial biota in a bale of collected cardboard prior to entering the paper mill. Total genomic DNA was isolated and analyzed using two different methods for comparison purposes: 454 pyrosequencing and clone library. A total of 3268 V6-V8 454 pyrosequencing reads and 322 cloned V6-V8 16S rRNA nucleotide sequences were obtained. Both methods showed the presence of three major bacterial genera: Bacillus, Solibacillus and Paenibacillus, all members of the spore-forming phylum Firmicutes. Pyrosequencing, however, revealed a richer and more diverse bacterial community than clone library. It showed the presence of additional minor Firmicute genera and of a small number of Proteobacteria. The sorting at the recycling plant, the storing, and the processing at the paper mill, the end uses, will all contribute to the bacterial microbiota present in a bale of collected cardboard as revealed here.

基于Cardboard平台虚拟博物馆的开发

介绍了Cardboard平台的虚拟博物馆"模型动态加载"模块的开发过程,其中包括了Cardboard与Unity、模型数据文件的设计、模型动态加载几个步骤,可将组织好的模型资源文件动态地添加到虚拟博物馆程序中,实现动态的布展。

开孔缺陷对蜂窝与瓦楞纸板侧向临界屈曲载荷弱化效应的研究

目的以蜂窝纸板和瓦楞纸板为对象,研究2种纸板圆孔缺陷对侧向承载能力的弱化效应。方法利用ANSYS Workbench软件的数值模拟功能,对2种纸板的开孔模型进行特征值屈曲分析,研究了2种纸板临界屈曲载荷随孔径大小的变化趋势,分析了2种纸板侧向承载能力对孔洞缺陷的敏感性。结果随着孔径的增大,蜂窝纸板与瓦楞纸板的屈曲临界载荷均呈逐渐下降趋势;开孔大于临界值后,瓦楞纸板的屈曲载荷下降率明显高于蜂窝纸板。结论随着孔径的增大,蜂窝纸板侧向承载能力的下降速度小于瓦楞纸板,蜂窝纸板表现出比瓦楞纸板更优的开孔缺陷弱化效应。

瓦楞纸板方管柱力学性能与压溃模式研究

目的研究不同构造瓦楞纸板方管柱在准静态轴向荷载作用下的力学性能和破坏模式,获得综合性能最优构造方案。方法通过改变瓦楞纸板方管柱构造方向和层数,设计制作4种构造形式的瓦楞纸板方管柱,通过开展轴向荷载作用下的静载荷试验,系统研究典型构造瓦楞纸板方管柱的力学性能和破坏模式。结果获得了4种构造形式瓦楞纸板方管柱载荷-位移曲线、分阶段变形破坏形态和试验关键参数。竖向瓦楞纸板方管柱呈现2种变形模式,平台阶段为体现瓦楞板叠层压缩小变形特征的塑性坍塌渐进屈曲模式,压溃阶段为体现薄壁管凹凸大变形特征的塑性坍塌渐进屈曲模式,破坏阶段呈现明显的脆性特征。横向瓦楞管柱呈现稳定的锯齿形塑性坍塌渐进屈曲模式。双层瓦楞管柱在压缩过程中会发生相互作用,脆性破坏特征减弱。外横内竖瓦楞管柱构件整体压溃模式稳定,呈现塑性破坏特征。结论瓦楞纸板方管柱的力学性能和破坏模式与构造形式有关,外横内竖瓦楞纸板方管柱融入了约束设计和导向设计理念,其力学性能优越。

新型纸板卸垛机的设计及其创新

目前全自动纸箱包装机被广泛地应用于包装行业中,尤其是啤酒饮料制造领域更是加大了对其应用。针对传统包装机纸板卸垛作业仍以人工操作为主,耗时、耗力且技术含量较低的问题,本文设计了一种新型的纸板卸垛机,介绍了纸板卸垛机的整体结构和工作流程,设计了纸板卸垛机的主要机构,采用电缸和气缸组合驱动,实现对纸板的准确提取,采用智能相机视觉检测方式判定纸板是否卸垛完成;对纸板卸垛机控制系统的软硬件进行了设计;智能化的纸板包装箱生产线需求量越来越高,对此进一步对纸板包装箱的生产线工艺进行了分析,以期为纸板卸垛和后续生产线的创新设计提供参考。

基于双目视觉的纸箱尺寸测量立体匹配方法研究

针对智能仓库物资自动化出入库流程,对于储存于纸箱中物资的出入库,需进行纸箱尺寸测量、纸箱拆解、物资倾倒、物资拣选等任务,因此首先应对纸箱进行无人化尺寸测量,提出自适应GrabCut的SGBM改进算法,实现纸箱尺寸自动测量。该方法首先完成双目相机的标定,利用NLM算法对采集的图片进行去噪处理,完成纸箱图片的立体校正,采用NCC、SGBM、AD-Census三种立体匹配算法得到纸箱的视差图,在分析其效果的基础上,提出基于模板匹配自适应GrabCut的SGBM改进算法用于纸箱立体匹配并得到其尺寸信息。实验结果表明,改进算法可以实现纸箱尺寸信息的精确测量,尺寸误差小于10mm,满足实际的生产要求。

过滤方式对桑葚酒品质的影响

该研究以桑葚果酒为实验对象,以透光率、酚类物质含量、蛋白质含量、颜色及香气化合物成分为综合评价指标,采用纸板过滤、纸板粗滤-膜精滤复合过滤及纸板粗滤-离心精滤复合过滤三种不同类型的过滤方式对桑葚果酒进行处理,通过单因素试验对桑葚果酒品质进行分析。结果表明,不同过滤处理后酒样的基础理化指标间无显著性差异(P>0.05);总酚、总花色苷、单宁和蛋白质含量显著降低(P<0.05),色差差异显著(P<0.05);与原酒相比,不同过滤处理后酒样的香气物质含量显著降低(P<0.05),纸板粗滤-膜精滤复合过滤和纸板粗滤-离心精滤处理后香气成分含量分别降低27.02%和11.06%,主成分分析(PCA)结果表明,纸板粗滤-离心精滤处理得分较高,在提高酒样澄清度和胶体稳定性的同时对香气影响更小。因此,1.5~3.0μm纸板粗滤加5℃,7 000 r、40 min离心精滤为桑葚酒的最佳过滤方式。

无框瓦楞夹芯板极限抗拔力及家具角部结合性能的研究

无框瓦楞夹芯板是以立式瓦楞纸和中纤板为基材,经胶合而成的一种新型家具板材。本研究采用单因素分析法对影响该板材极限抗拔力的各项因素进行分析,同时通过拉伸和压缩试验测试角部结合性能,分析偏心件类型、偏心件位置和预埋螺母种类对角部结合强度的影响,为其在家具的生产应用中提供更加全面、系统的指导。结果表明:在极限抗拔力试验中,不同类型预埋螺母的极限抗拔力大小依次为拉铆螺母>小螺纹胶塞>大螺纹胶塞。对于小螺纹胶塞,当表板厚度为5 mm、螺纹间距为1 mm、引导孔直径为9.4 mm时,板材的极限抗拔力最大。在角部结合性能试验中,层板托作为偏心件强度大于偏心轮,拉铆螺母作为预埋螺母强度大于胶塞。在芯层板上使用偏心件可呈现出良好的力学性能。本文提出的拉铆螺母和层板托作为无框瓦楞夹芯板三合一连接件的组成部分具有较好的角部结合性能,为瓦楞夹芯板家具连接件的设计提供了新的思路。

基于ANSYS瓦楞纸板等效力学性能研究

目的为提升瓦楞纸板压缩性能仿真效率,采用有限元方法替代试验测试,以节省时间与成本,减少环境污染,促进可持续发展,为瓦楞纸箱的优化设计提供决策依据。方法从箱板纸和瓦楞原纸性能出发,对瓦楞纸板的最小单元进行1∶1建模分析,通过ANSYS对瓦楞纸板压缩性能进行仿真求解并对结果进行分析,找到一种瓦楞纸板力学性能的等效方法。利用瓦楞纸板的等效力学性能对瓦楞纸板模型进行一定程度的简化,以达到在保证一定求解精度的情况下,提高求解速度的目的。结果箱板纸和瓦楞原纸的力学性能可用双线性等向强化模型等效;瓦楞纸板压缩过程分为4个阶段:弹性、屈服、平台、密实化。通过ANSYS Workbench的Static Structure模块进行仿真,与试验结果对比,仿真能有效预测其压缩性能。简化瓦楞纸板为均质长方体后,仿真结果显示,简化模型平压有限元分析求解时间减少13%~60%,内存减少37%~62%,且模型尺寸越大,减少得越多。结论使用该方法对瓦楞纸板的压缩性能进行仿真,解决了以往通过反复试验来优化包装设计的弊端,能节约时间,降低瓦楞纸板的生产成本和减少环境污染,实现可持续发展。

酒包装用纸板的霉变特性研究

目的分析酒包装用纸板上霉菌的生长过程,以及霉菌对纸板中2种主要成分(α-纤维素、淀粉)的侵蚀,并探究4种酒包装用纸板的耐霉变特性。方法将前期在霉变酒盒上识别鉴定的9种霉菌分别接种至单白工业纸板(Q)、灰纸板(D)、涂布白纸板(T)、双胶纸板(S)上,在温度为28℃、相对湿度为98%的环境下培养28 d。测定28 d内纸板上霉菌孢子数量以及28 d时纸板中α-纤维素含量、淀粉含量和聚合度变化,并用扫描电镜(SEM)观察霉菌在纸板表面附着状态。结果28 d时,4种纸板的孢子总数从大到小依次为Q(1.61×10^(8)CFU/mL)、S(1.51×10^(8)CFU/mL)、D(1.12×10^(8)CFU/mL)、T(9.34×10^(7)CFU/mL);纸板上孢子数量最多的4个菌种依次是匍枝根霉、黑曲霉、草酸青霉、扩展青霉;纸板中α-纤维素质量分数减少了3.90%~40.38%,从小到大依次为T、S、Q、D;纸板中淀粉质量分数减少了0.59%~6.87%,从小到大依次为D、T、S、Q;纸板聚合度下降了19.56%~40.22%,从小到大依次为D、T、Q、S。结论Q纸板易受霉菌污染,T纸板具有一定抗霉菌性,为酒包装用纸板材料的选择及防霉的措施提供了理论指导。

融合注意力机制的弱监督纸板表面缺陷检测

目的 针对目前表面缺陷检测方法因缺少实例级标签,使深度神经网络在工业检测上的应用受到限制的问题。本文面向实际的纸板表面缺陷检测任务,提出弱监督学习下融合卷积和注意力机制的神经网络算法。方法 该网络通过将通道注意力模块和梯度类激活映射模块相结合,进一步提高类激活图的精细度,实现纸板表面缺陷的精确定位;同时通过倒残缺结构和上采样层的组合操作,进一步细化浅层特征提升网络的特征提取能力,加快网络收敛速度。结果 通过在公开的纸板缺陷数据集上进行实验,本文提出的算法在使用图像级标签训练的情况下,分类正确率与定位正确率分别达到99.0%和92.2%,验证了该算法的有效性。结论 避免了实例级标签数量较少和过于主观的缺点,为基于机器人的缺陷纸板剔除奠定了基础。

瓦楞纸板结构特性和工艺改进与应用研究

本文阐述了瓦楞纸板的原纸类型及特点,分析了瓦楞纸板结构特性及对其使用性能的影响,探讨了瓦楞纸板的工艺改进和应用。经分析和探讨可得,瓦楞纸板的形状、楞型和层数是其结构特性的重要参数,在一定程度上决定了瓦楞纸板的性能和用途。在“双碳”和企业降本增效双重目标下,瓦楞纸板生产工艺需改进和进步的空间依然很大。得益于瓦楞纸板质量轻、强度高、绿色环保等优点和近年来学者对瓦楞纸板深入广泛的研究,其应用范围将进一步扩大,高价值产品将进一步被开发。

白面牛卡纸异味问题探究与控制

白面牛卡纸广泛应用于食品饮料行业的高档纸箱包装,其存在的异味严重影响客户使用体验。本研究通过探究发现,造纸系统的浆料温度、白水循环、造纸辅料的添加均会造成白面牛卡纸异味的产生。为解决白面牛卡纸产品存在的异味问题,一方面可以通过降低制浆造纸系统温度,提高生产流程中水系、浆料系统的循环流动性,破坏微生物滋生的环境;另一方面减少高氮辅料的添加,通过调整原料结构和优化打浆工艺实现原纸物理性指标,从而有效地控制异味的产生。