木塑复合材料力学性能影响因素研究

采用木材刨花与LDPE、HDPE.和PP等热塑性高分子聚合物,经热压复合工艺制成木塑复合板材,研究了塑料基质种类、刨花用量与偶联剂种类对木塑复合材料力学性能的影响。结果表明:相较于LDPE和PP,由HDPE制成的木塑复合材料力学性能更佳;所使用的三种偶联剂,以硅烷偶联剂的效果最好;随着刨花用量的增加,木塑复合材料的抗弯曲性能逐步提高,但内结合强度逐渐下降。     

挤出温度和螺杆转速对木塑制品外观性能的影响

介绍了木塑复合材料的主要生产工艺.实验采用两步法挤出成型工艺制作HDPE基木塑复合材料,研究挤出温度和螺杆转速对木塑复合材料外观性能的影响.结果表明:当木塑复合材料使用HDPE和杨木粉作为主要原料,木塑比为6∶4时,与之相适应的工艺条件为:挤出成型温度为130℃,150℃,155℃,155℃,135℃;螺杆转速为7.5r/min.     

填料和润滑剂对木塑复合材料力学性能的影响

研究填料和润滑剂对挤出成型工艺制作木粉/高密度聚乙烯(HDPE)木塑复合材料力学性能的影响。研究结果表明,当木塑质量比为6:4,选择碳酸钙为填料,硬脂酸为内润滑剂,PE蜡为外润滑剂时,木塑复合材料可以获得较好的力学性能。     

HDPE基木塑复合材料力学性能的研究

为研究如何改善HDPE基木塑复合材料的力学性能,分别考察了不同木粉含量、不同偶联剂及增容剂对复合材料力学性能的影响,通过测试和观察复合材料的力学性能和微观形貌,得出以下结论:木粉的加入增加了复合材料的刚性,但降低了材料的韧性;添加了硅烷偶联剂制备的复合材料力学性能较好;MA-PP使材料综合性能最好.     

光和水热对HDPE/稻壳复合材料颜色的影响

通过定量测量HDPE/稻壳粉木塑复合材料的颜色物理量参数,研究分析其在光和水热条件下颜色的变化规律。结果表明:自然光和紫外光照射过程中,木塑复合材料表面颜色的各个参数随时间的推移虽有波动但总体呈上升趋势,自然光照射8星期后木塑复合材料表面颜色变化可察觉,紫外光照射192h后木塑复合材料表面颜色有轻微变化;单纯热干燥和冷水对木塑复合材料表面颜色影响不大,人眼不易察觉;但热水对木塑复合材料表面颜色有显著影响,人的视觉达到可察觉和可区别程度,同时随着温度的上升,色差变化也逐渐增大。     

机械参数对木塑复合材性能的影响

以桦木粉和HDPE为原料,采用双螺杆挤出机造粒,单螺杆挤出机成型的方法加工木塑复合材.在加工过程中,改变双螺杆挤出机三、四、五区的温度和螺杆转速,并加入一定比例的MAPE做为偶联剂.结果表明,转速在40RPM时,温度是130℃、135℃、145℃、152℃、157℃、170℃时的复合材料的综合性能较好.     

制浆过程有机固体废弃物压制木塑复合板初探

研究了以造纸工业有机固体废弃物压制木塑复合板的可行性,对成品板的厚度、密度、静曲强度、弹性模量、内结合强度、吸水厚度膨胀率等指标进行了测定,发现含纤维固废和含塑料固废经粉碎后,按一定比例混合热压后,可以压制成各项指标均合格的木塑复合板材。实现有机固体废弃物的高值化利用。     

木塑复合纤维板生产工艺研究

介绍了以低密度聚乙烯和木纤维为主要原料制造木塑复合纤维板的生产工艺,研究了木塑比例、偶联剂加入量、热压温度及热压时间对木塑复合纤维板力学及防水性能的影响。     

聚乙烯基共挤木塑复合材料研究进展

多层共挤是提高木塑复合材料性能的新型挤出技术.相比传统单一结构的木塑复合材料,具有芯表多层结构的共挤木塑复合材料可以赋予材料更优异的性能.本文主要介绍了我国聚乙烯基共挤木塑复合材料的发展历程,概述了聚乙烯基共挤木塑复合材料在抗吸水性、理化性能、抗老化和阻燃方面的优越性,并总结了在表层仿木纹理和芯表层界面相容性等方面研究...     

木塑型材

木塑型材是木塑复合材料。它是以性能优良的木粉和高分子材料加工制作的复合材料。木塑产品在欧美已有几十年的历史．并形成研究、原材料收集、设备制造、模具制造的完整产业。日本、韩国、新加坡等国木塑技术发展也很快．其产品已进入国际市场。     

Effects of Wood Particle Size and Mixing Ratios of HDPE on the Properties of the Composites

The main goal of this research is to innovate wood-plastic composites by using various wood particle sizes and different mixture ratios (weight ratio) of HDPE (High Density Polyethylene). After mixing the wood particles (recycled wood waste) and the plastic powder, we use a molding and pressing process to make composites with a thickness of 12 mm. By doing so, the wood particle content can be increased to 75%. This kind of composite provides excellent dimensional stability, its moisture content is under 2.5%, and the thickness swelling rate after 24 hr water absorption is under 7.5%. The maximum static bending strength of this composite reaches 20.7 N/mm², and is better than that of general commercial particleboards. The composite made of larger sized wood particles has better strength properties. In addition, when the plastic content ratio increases, the dimensional stability of the composite will increase as well. After the soaking process in boiling water, the static bending strength of wet composite remained at 50%; this shows the good weather resistance of the composite. The surface veneer overlaid peeling strength of the composite showed 1.02–1.63 N/mm. After the evaluation of processing, cost of material and strength properties of the composite, we would suggest that the use of 70% of wood particles and 30% of plastic powder is practical to produce proper sized composites.     

冷冻食品的复合式泡沫包装箱设计研究

目的 设计一种能提高结构强度的复合式泡沫包装箱。 方法 将由护边套和护板构成的护架套装在泡沫包装箱的外部,组合成复合式泡沫包装箱,通过静态压缩实验和跌落实验,对比测试普通泡沫包装箱和复合式泡沫包装箱的抗压强度、抗破损性能。结果 复合式泡沫包装箱单体抗压强度1959.29N,普通泡沫包装箱单体抗压强度1557.22N;对于交错堆码条件下的抗压强度,由普通泡沫包装箱的1039.18N提升到复合式泡沫包装箱的1978.56N。采用护架后,箱体载物面跌落破损高度由800mm提高到1400mm,棱跌落破损高度由600mm提高到1200mm,角跌落破损高度由400mm提高到1000mm。结论 采用护架的复合式泡沫包装箱,箱体结构强度、耐破损性能都得到提升,解决多层堆码箱体压损问题,降低箱体的破损率,提高包装箱重复使用率。     

马来酸酐偶联剂对麦秸／废旧聚丙烯复合材料性能的影响

以麦秸和废旧聚丙烯为原料,以马来酸酐作为偶联剂,异氰酸酯(MDI)作为胶黏剂,采用热压工艺压制麦秸/废旧聚丙烯复合材料,通过正交实验研究了偶联剂对该复合材料力学性能的影响。结果表明:单独施用马来酸酐偶联剂,内结合强度极低,静曲强度较低,吸水厚度膨胀率较高,板材性能差;与施用马来酸酐偶联剂相比较,单独施用MDI胶黏剂,内结合强度提高,吸水厚度膨胀率值降低,材料的综合性能好于施用马来酸酐偶联剂的情况,但还不能完全达到刨花板国家标准(GB/T4897.1-4897.7-2003)要求;同时施用马来酸酐偶联剂和MDI胶黏剂时,除密度对内结合强度影响较大外,聚丙烯含量对内结合强度、马来酸酐用量对内结合强度、施胶量对静曲强度和吸水厚度膨胀率均有显著影响,其中马来酸酐用量对内结合强度的影响最为显著。但过多的马来酸酐不但起不到促进作用,反而影响了胶黏剂的胶结性能。     

喷水工艺对木质素胶黏剂刨花板性能影响的研究

就板坯制备工艺对采用木质素胶黏剂制备刨花板进行试验研究,通过设计正交试验,获取和分析所制备刨花板的物理力学性能,探讨制板工艺过程对木质素胶黏剂刨花板性能的影响.试验结果表明,制板过程中,采用喷水工艺对木质素胶黏剂刨花板的静曲强度和弹性模量影响最大,对24 h吸水厚度膨胀率影响次之,对内结合强度影响较小;随着喷水量的增大...     

The effect of fine strands in core layer on physical and mechanical properties of oriented strand boards (OSB) made of beech (Fagus sylvatica) and poplar (Populus tremula)

This paper discusses the influence of three different content levels of fine strands in the core layers on the physical and mechanical properties of European beech and poplar oriented strand boards (OSB). The results show that increasing the fines content in the core layer from 10 to 50 %, based on total board weight has no significant effect on bending strength and modulus of elasticity (MOE). All panels exceeded the minimum requirement for bending strength and MOE set by EN standards. The highest modulus of rupture (MOR) and modulus of elasticity (MOE) was determined for panels solely made of poplar with different level of fines content. Increasing the amount of fines in the core layer raised the internal bond (IB). Panels made with 30 % fines in the core layer showed highest internal bond strength values. As the fines content increased from 10 to 50 %, thickness swelling decreased. Water absorption after 24 h showed the same declining trend as thickness swelling.     

Extrusion of pea starch containing lysozyme and determination of antimicrobial activity

ABSTRACT:  Pea starch, which has inherently good gel strength, was used as the source material for manufacturing a biodegradable and bioactive packaging material. Extrudates containing 99% pea starch and 1% lysozyme were produced under various extrusion conditions (high and low shear screw configurations, 30% to 40% moisture contents, 70 to 150 °C die temperatures). The physical and mechanical properties of the extrudates were determined through various expansion indices, piece and cell wall solid density, compression, and 3-point bending tests. The expansion of extrudates increased with an increase in die temperature, whereas increasing moisture content had the opposite effect. Extrudate densities decreased as extrusion temperature increased, whereas lower moisture content in the extrudate dough decreased extrudate densities. The elastic modulus and fracture strengths were highly correlated in a power-law fashion to relative density, showing that the mechanical properties of extrudates were dependent on solid density and foam structure. Up to 48% of the initial lysozyme activity was recovered from the extruded pea starch matrix. The lysozyme released from extrudates showed an inhibition zone against Brochotrix thermosphacta B2 . Extruded pea starch matrix containing lysozyme has potential application as an edible and biodegradable packaging material with antimicrobial activity.     

Vergleichende Untersuchungen an mittelharten Faserplatten (MDF) und Spanplatten

Mechanical and physical properties of commercial medium density fiberboard (MDF) and particleboard were determined and compared. The investigation showed that bending strength and face strength for MDF were considerably higher than corresponding particleboard properties. Concerning internal bond strength and screw holding ability no remarkable differences were found between the two board types. Medium density fiberboard showed lower hygroscopicity and thickness swelling but higher linear expansion than particleboard. Both board types were found to have higher bending strength and lower linear expansion parallel rather than perpendicular to feeding direction. Furthermore MDF showed lower surface roughness than particleboard.     

缓冲包装结构对箱装苹果振动损伤与动力学特性的影响

振动是引起果品运输损伤的主要因素之一,而对果品采用合理的缓冲包装是有效降低与控制果品运输损伤的关键。采用目前果品运输中常用的6种缓冲结构对苹果实施包装,进行箱装苹果的振动试验,分析缓冲包装结构形式对果品损伤与振动传递率的影响。结果表明,同一种缓冲包装结构中中间层苹果的损伤率最大,底层苹果的损伤率次之,顶层苹果损伤率最小;采用瓦楞纸板衬垫、发泡塑料网作缓冲包装时,均可有效地降低苹果损伤率,且发泡塑料网对苹果的整体保护特性优于瓦楞纸板衬垫,瓦楞纸板隔档对苹果的损伤率有一定影响。不同的缓冲包装能不同程度地降低包装箱内苹果振动传递率。     

基于陶瓷瓷碟包装的缓冲结构设计研究

目的 设计陶瓷餐具缓冲包装结构。方法 依据瓷碟尺寸,以纸浆模塑和A型瓦楞纸板建立组合结构, 通过包装件的静载实验和跌落实验分析结构在纸浆模厚度、波纹间距、结构高度变化时的缓冲性能。结果 纸浆模厚度为2.5 mm,波纹间距为25 mm时,内结构高为180 mm时组合缓冲结构能在一定的跌落高度内足以实现对瓷碟的保护。结论 陶瓷餐具包装中的瓷碟包装结构设计满足缓冲包装要求,可实现缓冲材料与结构的融合统一,有一定的应用与参考价值。