连续平压法刨花板生产常见的质量问题分析

介绍连续平压法生产的刨花板常见的表面大刨花、板面花斑、板面裂纹、凹坑、变形、分层鼓泡等质量缺陷,分析其产生的原因,并提出了相应的解决办法。     

桉木“三剩物”生产优质刨花板刍议

桉木"三剩物"在刨花板生产过程中存在一些技术问题,主要是其树皮对板面质量的影响,以及树皮和碎单板对削片和刨片加工的影响。通过调整生产工艺和设备配置、去除树皮、改变碎单板刨花制备方法,可解决这些问题,顺利生产出高质量的刨花板。     

从设备上确保定向刨花板对刨花质量的要求

从设备上确保定向刨花板对刨花质量的要求镇江林机厂王新男定向刨花板是采用窄长型刨花，经施胶后，通过铺装机，刨花以同一方向排列，相邻层刨花方向垂直相交，逐层交叉叠合，铺装成型，经热压成板材。其特点是耗胶量少，结构均匀、重量轻、强度大，可达到或接近同等厚度...     

刨花形态对高密度刨花板性能影响的研究

研究了在相同工艺条件下刨花形态对微米级薄刨花高密度刨花板性能的影响。试验得出,刨花越长越薄其刨花板的静曲强度、弹性模量越大,但是内结合强度越低;刨花形态较为均匀的混合型微米级薄刨花制成的刨花板具有较好的力学性能;利用微米级薄刨花制成的刨花板比利用普通针状刨花制成的刨花板在力学性能上更有优势。     

刨花板发明专利

申请号:CN201911362482.4发明名称:一种定向刨花板的制备方法公开号:CN111113586A申请人:广西大学摘要:本发明公开了一种定向刨花板的制备方法。包含以下操作步骤:1)刨花筛选;2)施胶,依次进行顺、逆时针旋转搅拌,对刨花进行施胶;3)干燥;4)铺装,刨花按照一定的方向定向均匀排列,一份刨花作为下层,再将另一份刨花铺在下层之上作为中层,中层刨花与下层刨花呈30~90°方向定向均匀排列,最后再将一份刨花铺在中层之上作为上层,上层刨花与中层刨花呈30~90°方向定向均匀排列,得到板坯;5)热压;6)陈放,即得。本发明方法将层与层之间按照不同的角度铺装热压在一起,纵横垂直的定向排列过程使得刨花间接触紧密,无空隙,充分利用了刨花的超长结构单元,在节约生产成本的同时,大大提高材料的力学性能。     

刨花板生产的刨花制备

从理论和生产实际两方面阐述刨花制备的重要性.论述刨花的种类及刨花形态对刨花板物理力学性能的影响.介绍工业生产中如何控制刨花粒度、刨花含水率、表层和芯层刨花的比例.     

刨花板生产的刨花制备

从理论和生产实际两方面阐述刨花制备的重要性。论述刨花的种类及刨花形态对刨花板物理力学性能的影响。介绍工业生产中如何控制刨花粒度、刨花含水率、表层和芯层刨花的比例。     

知识窗

定向刨花板的刨花制备要求 1 刨花的制备 刨花的质量在很大程度上取决于刨花的尺寸和形状。定向刨花板生产所用的刨花形状、尺寸与普通刨花板所用的刨花有所不同。定向刨花板要求长度50～100mm、宽度5～20mm、厚度0.4～0.7mm的宽长薄平刨花,为此只有采     

转子式刨花干燥机结构简介

为了提高刨花干燥的热效率,北京林机所消化,吸收我国从西德引进设备,设计了年产一万五千立方米和年产五千立方米转子式刨花干燥机。其由壳体、转子、蒸汽接头传动装置、预热器、灭火装置等主要部分组成,其结构见图1。 转子式刨花干燥机也称为转束式刨花干燥机。其中心为管束,由一定数量的热管组成,刨花从进料口进入后,主要靠刨花和管束接触,和有效的热传导,辐射和对流进行热交换加热刨花,使之干燥。     

刨花施胶效果的定量表征与分析

在回顾国内外刨花施胶效果检测技术研究状况的基础上,建立了全新的量化刨花施胶效果表征参数体系,并采用胶黏剂扫描(GlueScan)系统对刨花施胶效果进行量化分析.结果表明,该法可高效、准确地测定刨花表面的胶黏剂分布状况,通过对各参数的分析,为刨花施胶工艺改进的效果提供依据.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the