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1.
粉状落叶松单宁酚醛树脂胶生产胶合板的研究 总被引：3，自引：0，他引：3
试验研究了粉状落叶松单宁酚醛树脂胶（ＴＰＦ）的调胶工艺和胶合板胶合工艺，结果表明：粉状ＴＰＦ树脂胶与水按１０：９的重要比混合均匀并陈效２４ｈ后再使用，胶合板的胶合强度比较理想；在胶液中添加５％的面粉或５％面粉及５％木粉，可以改善胶粘剂的性能，最后，确定粉状ＴＰＦ树脂胶生产马尾松胶合板的最佳工艺条件。 相似文献
2.
木材工业用胶粘剂的现状及发展趋势(续) 总被引：1，自引：0，他引：1
３．３苯酚－甲醛（ＰＦ）树脂 ＰＦ树脂有着良好的耐候性，但存在着成本较高、热压温度高、时间长和对单板含水率要求高等缺点［１２］。在ＰＦ树脂中引入价廉的尿素是降低ＰＦ树脂价格的主要途径。一般来讲，向ＰＦ树脂中引入１０％左右的尿素不会影响树脂的胶合性能和耐老化性，相反可以降低树脂的游离酚和游离甲醛。另外将ＰＦ树脂与ＵＦ树脂共混可以克服ＰＦ的树脂易透胶的缺点。苯酚－尿素－甲醛（ＰＵＦ）树脂的反应机理和结构的研究近年取得了一些进展，在弱碱性条件下，（ｐＨ９．０）反应所得ＰＵＦ树脂中不存在苯酚－亚甲基．尿… 相似文献
3.
胶合板用新型、高效、低毒PF-95型酚醛树脂研究 总被引：3，自引：0，他引：3
高效、低毒ＰＦ－９５型酚醛树脂由苯酚与甲醛、烧碱和添加剂在一定条件下，采用特定的生产工艺合成，系生产Ⅰ类防水胶合板专用树脂。该树脂毒性低、污染小，其游离酚、游离醛含量均在０．１５％以下，碱度为３．５％，且生产成本低，比现有普通型号的木工用酚醛树脂降低３０％左右。用它生产胶合板，热压温度为１２５℃，热压时间比普通ＰＦ树脂缩短１５％左右，且无需分段卸压。用该树脂生产Ⅰ类防水胶合板符合ＧＢ９８４６．１～９８４６．１２－８标准要求。 相似文献
4.
按不同的（甲配合）Ｆ／／Ｐ（苯酚）摩尔比（１．７０，２．００和２．３０）及ＮａＯＨ／Ｐ的摩尔比（０．４和０．６０）合成了一系列甲阶酚醛树脂。用粘度、密度、分子量、表面张力和接触角表征，采用第配方合成的宽分子量分布的酚醛树脂（ＰＦ）的特性。关于合成配方及树脂特性的变化，通过测定树脂的表面特性、湿润性及木材的表面特性的改变来表示。研究结果认为，甲阶ＰＦ胶的表面张力随ＮａＯＨ、甲醛数量及分子量而变化，毛 相似文献
5.
6.
单宁胶用PUF树脂的制备工艺与结构和交联性能关系的研究 总被引：3，自引：0，他引：3
提出了一种单宁胶用ＰＵＦ树脂的制备方法。用＾１３ＣＮＭＲ研究了制备条件对ＰＵＦ树脂组分、结构和交联性能的影响。压板试验表明ＰＵＦ树脂配制单宁胶时，只有折合甲醛值大于１０％，压制的胶合板才能符合室外级板的强度要求。用ＤＳＣ研究了固化温度对该单宁胶固化程度的影响。 相似文献
7.
改性脲醛树脂的合成及其对木材改性效果试验 总被引：2，自引：0，他引：2
以聚顺丁烯二酸二乙醇酯（ＰＭ）和三聚氰胺（Ｔ）分别改性脲醛树脂（Ｕ－Ｆ），合成了两种稳定改性脲醛树脂－ＰＭ－Ｕ－Ｆ和Ｔ－Ｕ－Ｆ，考察了改性树脂中ＰＭ的含量和Ｔ／Ｕ摩尔比对木材改性效果的影响，试验结果表明，这两种改性脲醛树脂对板栗木、青岗木均有良好的改性效果。 相似文献
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9.
合成了造纸填料用分散剂，讨论了马来酸酐与丙烯酸比例，引发剂体系种类对树脂粘度及分散性的影响，结果表明：丙烯酸与马来酸酐的摩尔比为1．5时分散碳酸钙浆效果较好，而纯丙烯酸的分散性最佳，引发体系以过硫酸铵－亚硫酸氢钠－硫酸亚铁为优，亚硫酸氢钠占单体质量的13．5％，硫酸亚铁占单体质量的0．0067％，通过优化确定了合成的最优条件。 相似文献
10.
水溶性丙烯酸改性松香酯的研制 总被引：3，自引：0，他引：3
研究了水溶性丙烯酸改性松香酯的合成，确定了最佳工艺条件，丙烯酸改性松香与多元醇的重量比为１：０．０４，催化剂用量为丙烯酸改性松香重量的０．７％，反应温度２５０℃，反应时间２ｈ，将该树脂用于水溶性油墨的连结料及丙烯酸系乳液的增稠剂，性能良好。 相似文献
11.
The distribution of shear strain across a 3–ply wood sheet bonded with PRF and PUR, respectively, was measured by means of electronic laser speckle interferometry. Owing to the higher shear modulus of PRF compared to PUR, shear strains were more evenly distributed in PRF bonded specimens than in PUR bonded specimens. However, considering the different shear moduli of earlywood and latewood bands in the core layer of the 3–ply sheet, it is concluded that shear stress is distributed more evenly along PUR bond lines compared to PRF bond lines. Since it is less prone to stress concentrations, PUR should provide more durable adhesive connections than stiff adhesives such as PRF. 相似文献
12.
A method based on high-performance liquid chromatography (HPLC) and proton magnetic resonance (PMR) spectroscopy for analyzing phenol-resorcinolformaldehyde (PRF) resins is reported. The equations that describe the number-averaged structures of PRF resins in terms of the PMR absorption intensities of acetylated resins have been derived on the basis of the work of Woodbrey et al. and Anderson et al. The P/R molar ratio of the resin calculated from the PMR intensities was in good agreement with the synthetic P/R molar ratio when correction was made for the loss of phenol evaporated during the drying process that preceded the acetylation. The number-averaged molecular weight (Mn) of the acetylated resin calculated from the PMR intensities agreed with the Mn determined by cryoscopy. Unreacted phenol and resorcinol could be determined by analyzing the water-soluble fraction of the resin by use of high-performance liquid chromatography.Part of this paper was presented at the 4th annual meeting of the Kyushu branch of the Japan Wood Research Society, Miyazaki, November 1997, and at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 相似文献
13.
PENG Limin FU Feng LU Keyang Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2007,6(2):20-24
In the article, with the instruments of the Research Institute of Wood Industry, Chinese Academy of Forestry, the experiment method of Forintek Canada Corp. was used to test the laminating of lodgepole pine containing beetle-transmitted bluestain; finally the result was compared with Canada report. The results show that the presence of glue joints of bluestained wood made with either PVA or PRF adhesive makes no difference to the shear strength of the joints, and no difference to durability of the joints using PRF. Also the presence of beetle-transmitted bluestain in wood does not affect the adherence of the interior finishes tested. 相似文献
14.
Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was employed to examine the chemical emissions from the glued wood
samples at elevated temperatures (150, 200, 250, 300, 350, 400, 450, and 500°C). Two wood species, Douglas-fir (Pseudotsuga menziesii) and southern pine (Pinus palustris), one structural adhesive, phenol–resorcinol–formaldehyde (PRF), PRF-bonded Douglas-fir, and PRF-bonded southern pine were
evaluated. The volatile compounds with a mass range of 35–300 m/z emitted from the pyrolysis samples were separated by gas
chromatography (GC) and identified by mass spectrometry (MS). The results indicated that compared to neat wood and resin film
samples, several additional pyrolysis products were observed for the PRF-bonded wood samples including (1) acetaldehyde and
butanedial for PRF-bonded Douglas-fir and (2) acetaldehyde, furfural, 2-furanmethanol, butanedial, 2,3-butanedione, cyclopropyl
carbinol, 1,2-benzenediol, and 1-(acetyloxy)-2-propanone for PRF-bonded southern pine. These additional compounds were possibly
associated with the interaction between wood and PRF resin. The results also indicated that bonded wood products would be
less thermally stable than those of neat wood and PRF resin samples. 相似文献
15.
《Wood material science & engineering》2007,2(2):83-89
To study the effect of grain angle on the adhesive bond strength in wood, three-part Norway spruce wood specimens were bonded and tested in tension. The two axially orientated outer parts of the specimens were joined with the middle part by means of three adhesives typically used for load-bearing constructions, i.e. one-component polyurethane (PUR), melamine-urea-formaldehyde (MUF) and phenol-resorcinol-formaldehyde (PRF). The grain angle of the middle part was varied from 0° (end grain to end grain) to 90° (flat grain to end grain) in incremental steps of 10°. In general, PRF- and MUF-bonded samples exhibited highest tensile strength at end grain to end grain orientation of the three parts, while specimens bonded with PUR showed only 25% of the strength measured for PRF and MUF, respectively. At high grain angles (90°) all specimens showed similar strength values in the range of 30% of maximum strength of MUF- and PRF-bonded specimens. To explain the changing strength levels at different grain angle a composite failure criterion was applied. 相似文献
16.
《Wood material science & engineering》2013,8(2):83-89
Abstract To study the effect of grain angle on the adhesive bond strength in wood, three-part Norway spruce wood specimens were bonded and tested in tension. The two axially orientated outer parts of the specimens were joined with the middle part by means of three adhesives typically used for load-bearing constructions, i.e. one-component polyurethane (PUR), melamine–urea–formaldehyde (MUF) and phenol–resorcinol–formaldehyde (PRF). The grain angle of the middle part was varied from 0° (end grain to end grain) to 90° (flat grain to end grain) in incremental steps of 10°. In general, PRF- and MUF-bonded samples exhibited highest tensile strength at end grain to end grain orientation of the three parts, while specimens bonded with PUR showed only 25% of the strength measured for PRF and MUF, respectively. At high grain angles (90°) all specimens showed similar strength values in the range of 30% of maximum strength of MUF- and PRF-bonded specimens. To explain the changing strength levels at different grain angle a composite failure criterion was applied. 相似文献
17.
间伐小径木指接技术研究 总被引：7，自引：0，他引：7
间伐材指接胶合加工，变短材为长材，弯材为直材，为合理，有效利用间伐材开辟了新路。对间伐材木材含水率，指接端压的大小和时间，指接后养护时间，涂胶量，指榫规格等对指接材抗弯强度的影响进行了研究，并测定了苯酚，间苯二酚，甲醛树脂胶胶合的指接材快速老化性能。 相似文献
18.
《中国林业科技(英文版)》2010,(2):68-72
Factors influencing bonding strength of laminated bamboo strips lumber (LBSL) were investigated in this paper. In order to find an optimized technology, this paper investigated how the thickness of bamboo strips, the assembly orientation of bamboo curtain, the type of adhesives, as well as coupling agent treatment of bamboo curtain affected the bonding strength. The following conclusions were drawn: 1)The thinner the thickness of the bamboo strips, the bigger the bonding strength of LBSL; 2) The assembly or... 相似文献
19.
Jürgen Follrich Alfred Teischinger Wolfgang Gindl Ulrich Müller 《Wood Science and Technology》2007,41(6):501-509
To evaluate the effect of grain orientation on the adhesive bond strength, three-layered Norway spruce wood specimens were
tested in shear. The two axial-oriented outer layers were jointed with the middle layer using three typical glues for load
bearing constructions, i.e. one-component polyurethane (PUR), melamine–urea–formaldehyde (MUF) and phenol–resorcinol–formaldehyde
(PRF). The grain orientation of the middle layers was varied from 0° (parallel to grain of the surface layer) to 90° (perpendicular
to grain of the surface layer) in incremental steps of 10°. Samples with middle layers oriented parallel to the outer layers
showed shear values in the range of solid spruce wood. Decreased shear strength values were expected for increased grain angles
of the middle layer. However, no explicit tendency was observed for the shear strength in dependence of the grain direction.
In general, MUF-bonded samples showed slightly higher shear strength values compared with PUR- and PRF-bonded specimens. 相似文献