可连续生产的生物质包装材料配方与工艺研究

目前国内外对于生物质包装材料的研究多采用热压成型工艺,以淀粉、纤维及增塑剂等为基材进行制备,其生产效率较低,且原料中一般都含有对环境有害的成分。因此,以绿色环保的废纸纤维、淀粉生物质材料、丙三醇等为原料,采用正交试验法,研究了一种可连续生产的环保型生物质包装材料挤出式加工最佳工艺及其配方。结果表明:生产环保型生物质包装材料的最佳配方为质量分数为11%的淀粉、11%的丙三醇、78%的废纸纤维,且原材料的含水率为80%;最佳工艺为螺杆挤出机的3段温度分别设定为65,65,80℃,螺杆转速为45 r/min。在选定的最佳配方与工艺条件下,所制备的生物质包装材料试样的性能最优,并可实现连续生产。     

利用凤眼莲制作生物质复合包装材料的研究

通过对凤眼莲破碎、热压成型和干燥加工,制备了生物质复合包装材料。 通过分析凤眼莲的纤维特性,并添加胶黏剂等助剂,成功制备了生物质复合包装材料。 研究结果表明,添加胶黏剂等助剂制备的生物质复合包装材料,强度要高于未添加助剂的材料,其助剂适合于生物质复合包装材料的制作。 利用生物质材料的特性,运用精密模压技术加工的生物质复合包装材料,在食品包装、农林牧副产品的包装及运输材料等方面,具有广泛的应用前景,符合绿色化学及可持续发展的战略方针。     

一种模压代木包装材料的制备工艺及性能研究

利用速生杨树木材加工剩余物,制备了一种用于运输包装的代木材料,并研究其物理、机械性能。采用正交试验设计方法制备了不同代木包装材料试样,并利用极差分析方法分析了不同工艺参数对代木包装材料物理、机械性能的影响。试验结果表明,制备代木包装材料的较佳模压工艺参数如下:热压温度为120~125℃、热压时间为10 min、热压压力为10 MPa、胶黏剂的添加质量分数为10%,在此工艺条件下制备的代木包装材料,其静曲强度、内结合强度、吸水厚度膨胀率、密度分别为17.7 MPa,1.61 MPa,6.1%,0.73 g/cm3。所制备的代木包装材料满足国家标准(GB/T4897—1992)的A类刨花板一等品物理力学性能要求,是一种绿色环保的包装材料。     

药用植物剩余物发泡缓冲包装材料的制备及性能研究

以药用植物剩余物纤维为主要原料,淀粉 / PVA 胶黏剂为基体,添加一定量发泡剂及相关助剂,在密闭模具内热压成形了发泡缓冲包装材料。 通过实验与分析,确定了制备材料的工艺与实验条件,研究了药用植物纤维粒度、发泡剂用量、发泡温度及淀粉 / PVA 配比对材料性能的影响。     

改性大豆蛋白用于轻质代木包装材料的制备

目的以大豆蛋白为胶粘剂,制备轻质代木包装材料并研究其性能。方法以不同形态和配比的废旧瓦楞纸板、小麦秸秆为基材,以大豆分离蛋白(SPI)为胶粘剂,通过热压工艺制备轻质代木包装材料并对材料性能进行测试,从而确定最佳配方及工艺参数。结果改性剂、复配剂、基材、工艺参数的选择与材料性能密切相关,当Na OH,Ca(OH)2,CMCNa,Na2B4O7·10H2O,SPI,水,纸纤维和秸秆质量比为0.01︰0.01︰0.2︰0.06︰1︰10︰7︰3,热压参数为热压温度140℃,热压时间为30 min时,方案最优,微波预热能使热压时间减至11 min,最终制得的轻质代木包装材料密度为550 kg/m3,静曲强度为18.38 MPa,弹性模量为1926.73 MPa,符合相关标准。结论 SPI改性及复配能改善其胶粘性和防水性,微波预热能提高热压效率与试样性能,以制备满足一定性能要求的零甲醛释放轻质代木包装材料。     

热解油脲醛树脂有机覆盖垫制备工艺研究

以园林废弃物为原料,热解油脲醛树脂作为胶粘剂,制备了一种新型的裸土覆盖用有机覆盖垫产品。以热压温度、热压压力、热压时间及施胶量为考察因素,以抗压强度、保水性和甲醛释放量为评价指标,优选出有机覆盖垫的最佳制备工艺。结果表明,有机覆盖垫的最佳制备工艺为热压温度140℃,热压压力0.7MPa,热压时间7min和施胶量10%(相对于有机覆盖垫原料质量百分数)。在此工艺条件下制备的有机覆盖垫强度大于体重100kg实验者行走时对地面的最大压强(约0.52MPa),甲醛释放量达到国标E1级标准(≤1.5mg/L),保水性良好(≥40%)。     

轻质环保生物质材料挤出加工生产线的研究

近年来,环保、无污染、可再生利用的生物质包装材料研究已成为国内外学者研究的热点之一。传统的以绿色环保的废纸纤维等原料制备环保生物质包装材料的方法,多是间歇式热压成型工艺,其效率较低、不适于机械化大规模生产。本文在作者单位已有研究基础上,提出了以废纸、淀粉生物质材料、丙三醇等为原料,基于连续挤出式加工工艺的环保生物质包装材料加工生产线配置方案,并设定生产线生产效率为20m3/h,针对其中物料搅拌、供送、挤出加工三个关键部件进行了结构分析与参数设计。本文的研究对进一步开发新型生物质包装材料、提高生产效率及降低生产成本具有一定理论和应用价值。     

响应面法优化稻草模塑材料热压工艺参数

目的 探讨热压过程中压力、温度和湿纸胚含水率等因素对稻草秸秆纤维模塑包装材料主要力学性能的影响,确定各因素的权重及最佳工艺参数。方法 采用单因素试验法和响应曲面法,以裂断长和弯曲强度为评价指标,确定最佳工艺条件。结果 最佳热压工艺条件,热压温度为175 ℃,热压压力为6.9 MPa,湿纸胚含水率为70%,此时得到的平均裂断长为7697.93 m,弯曲强度为72.36 MPa,与理论裂断长7712.62 m、弯曲强度71.44 MPa接近,优化结果可信。热压过程中各因素对模塑包装材料裂断长和弯曲强度影响的大小为湿纸胚含水率＞热压压力＞热压温度。结论 过高的温度会造成半纤维素的热解,过高的压力会导致纤维的压溃,过高的含水率产生的能耗过高。适当的热压工艺参数能够降低能耗,保证模塑包装材料的品质及性能。     

面向缓冲包装材料的麻杆刨花板制备及应用性能研究

利用提取麻纤维后的加工剩余物——麻杆作为原材料,制备了缓冲刨花板。以不同的密度、施胶量以及厚度进行正交试验,测定了刨花板的性能,分析了麻杆刨花板作为缓冲包装材料的应用性能特点。实验结果表明:以麻杆为原料,在热压温度175℃下,用分段式热压工艺制备的刨花板,具有色浅、质轻的特性;在施胶量为10%时,刨花板的静曲强度和弹性模量均为最佳值;当σ190N/cm2时,所制备的麻杆刨花板具有较低的缓冲系数,可替代EPE作为缓冲包装材料。     

含微胶囊的抗菌淀粉膜制备工艺及性能研究

目的研究一种含微胶囊的抗菌淀粉膜制备工艺,并对其性能进行评价。方法以淀粉作为成膜基材,加入具有抗菌性的微胶囊,以及明胶、甘油、CaCl_2等助剂,采用流延法制备出含微胶囊的抗菌淀粉膜。将淀粉/甘油/明胶的质量比、微胶囊含量、CaCl_2含量、干燥温度作为影响因素,进行正交试验,选取膜的水溶性、力学性能、抗菌性能作为指标,对其性能进行检测和综合评价。结果当淀粉/甘油/明胶质量比为6∶3∶1,微胶囊质量分数为20%,CaCl_2质量分数为2%,干燥温度为50℃时,薄膜具有较好的综合性能。结论通过加入丁香精油微胶囊,制得的淀粉基薄膜具有抗菌性。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to