捻比对横机织物线圈歪斜的影响

以毛、腈(30/70)Z捻单纱双合股反向加捻成股线为原料,在横杌上编织纬平针织物,分析捻比对织物线圈纵向歪斜角度的影响,结果表明,织物纵行线圈歪斜角度与股线捻度之间呈线性关系,当线圈歪斜方向向右时,线圈歪斜的角度随捻度增大而减小,当线圈歪斜逐渐减小到0°之后,线圈歪斜的方向开始变为向左,此时线圈歪斜的角度随捻度增大而增大,此外,水洗能加剧织物纵行线圈歪斜的趋势.     

平行纺真丝包麻横机产品的线圈歪斜性研讨

本文探讨了平行纺真丝包麻横机产品的线圈歪斜形成原因,通过对各种试样线圈歪斜性的测量分析,得出了改变织物密度及使用不同捻向的纱线合织可以大大改善线圈歪斜的结论.     

纺织后整理加工中使用的传感器(下)

二、纱线和针织物线圈歪斜的检测校直纱线和针织物线圈横格的重要性无需说明。纱线的歪斜(当然是纬斜)将以歪斜百分比或织物幅宽上的歪斜宽度加以计测。检测织     

横机芳纶针织物线圈歪斜原因分析

综合分析了引起芳纶横机针织物线圈歪斜的原因。实验及理论分析表明,芳纶的高摩擦因数和脱圈时纱线转移阻力是导致横机针织物线圈歪斜的主要原因,横机芳纶针织物的线圈歪斜度与线圈长度成反比的关系。     

用多股棉纱编织的平针织物的线圈歪斜度

线圈的扭曲变形,象线圈横列的弓形变形和线圈纵行的歪斜,对纬编针织物的质量有很大的影响。线圈横列的弓形变形是在多三角机编织时,由于不均匀牵拉引起的。而线圈的歪斜则是纱线退捻力组成的扭转力距     

改善单面纬平针织物直向扭歪的方法

分析了纬平针单面针织物直向扭歪的原因;指出纱支捻度是造成线圈纵行歪斜的根本原因;并提出了改善直向扭歪的几种方法:采取Z捻、S捻纱编织,是克服线圈纵行歪斜的最有效途径;通过降低纱支捻度活性,可以改善线圈纵行的歪斜;后整理前,对织物充分退扭;剖幅时进行斜剖;改进裁缝方法。     

用气流纺棉纱编织的平针线圈的几何结构和尺寸性能 第三部份 纵行的转曲度

平针织物纵行的转曲度或歪斜引起织物变形,它由不对称线圈造成。一些学者已经发现用捻度不稳定的短纤纱会引起不对称的线圈,甚至用单丝编织同样会产生线圈不对称,针筒或三角座回转的方向也影响线圈歪斜程度,由棉纱编织成的织物纵行转曲度取决于     

纱线残余扭矩对纬平针织物线圈歪斜的影响

分析纱线残余扭矩的产生原因和影响因素,即纤维性能、纤维种类和纱线结构等,指出纬平针织物线圈歪斜的最主要原因是所使用纱线的残余扭矩现象。简要阐述目前常用的减少纱线残余扭矩的方法,即定形处理法和物理平衡法,但是这两种方法都存在一定的缺陷,如污染环境、生产成本高等问题。针对这种不足,重点给出两种用于改善织物线圈歪斜现象的新型纱线,即扭妥纱和少毛羽低扭矩纱,这两种纱线能够减少污染,提高产量,并且达到产品指标要求。     

纬平针中的线圈歪斜现象及解决方法

纬平针中的线圈歪斜现象及解决方法一、前言：造成纬乎针线圈歪斜的原因有两个：一是因机械原因造成的，这种现象只能从个别机台上织出的衣片上发现，可能是因牵拉不均匀；针床口不平直；左右两侧的压针毛刷不一致等原因而产生的，二就是因纱线的品质而造成的。就专业生产...     

针织圆机扩布装置的形状设计

针织圆机的牵拉辊机构会引起针筒圆周上的织物张力不匀,导致线圈长度和织物的横向密度发生变化。由于纵行线圈的伸长不一,织物进入卷布辊时的线圈横列是歪斜的,卷入卷布辊后,     

水平偏转线圈热成型系统通电参数的闭环控制

在对当前水平偏转线圈通电热成型工艺分析的基础上，设计了一种通电参数的闭环控制系统，介绍了其控制原理和通电参数的软件控制算法。     

基于环锭细纱机改造的竹节纱竹节长度的确定

在EJM128K型环锭细纱机上加装PLC控制的伺服电动机进行机械改造,生产高精度竹节纱.通过分析竹节纱生产控制系统的传递函数,确定该闭环控制系统在控制竹节长度参数上具有稳定性、精确性和快速性的特征.用USTER(R) TESTER5测量该系统纺制的竹节纱,获得竹节长度和竹节间距分布图.分析了竹节长度设定值、竹节纱捻系数...     

两探头电涡流法食品罐头真空度无损检测

利用电涡流法原理 ,开发出一种测量密封罐头内部压力或真空度装置。用第 1个传感器测量罐头柔性盖与该传感器之间的平均距离 ,第 2个传感器测量盖中心位置与该传感器之间的距离。 2个传感器输出电信号之差与内部压力或真空度成比例关系 ,进而得出罐头内部的压力或真空度。     

Zeitstandversuche mit Spanplatten

Tests regarding fatigue behavior of particle boards bonded with different glue types, the characteristics of which are given, have been carried out with a loading period of 588 days. The periodically measured deflections were compared with the initial deflection and the deflection ratiof _t/f₀ was determined. After a loading period of one year the best of the tested boards had doubled their initial deflection showing no essential increase of deflection until determination of tests. The worst boards reached, already after 150 days, a deflection 5 times higher than the initial one and increased it up to more than 7 times until determination of tests. The course of the deflection ratio and the respective moisture content of the boards in dependence on the surrounding climate is demonstrated.     

丝线在两支点间的挠度分析

分析了两种情况下的丝线的挠度．一种是两个支点同丝线的直径是均匀的；另一种是丝线的直径是均匀变化的．根据力学求解最大挠度的表达式，并讨论影响最大挠度的因素以及在实际(特别是纤维的烧结和拉伸环节)中的应用．分析结果表明：由于丝线长径比很大，丝线的最大挠度跟密度以及跨度的平方成正比，与所受的应力成反比，而同丝线的直径的具体数值和材料的刚度无关。     

Zeitstandversuche mit Spanplatten

Tests regarding fatigue behavior of particle boards bonded with different glue types, the characteristics of which are given, have been carried out with a loading period of 588 days. The periodically measured deflections were compared with the initial deflection and the deflection ratiof _t/f₀ was determined. After a loading period of one year the best of the tested boards had doubled their initial deflection showing no essential increase of deflection until determination of tests. The worst boards reached, already after 150 days, a deflection 5 times higher than the initial one and increased it up to more than 7 times until determination of tests. The course of the deflection ratio and the respective moisture content of the boards in dependence on the surrounding climate is demonstrated.     

Bending creep performance of modified timber

The present study is a supplement to Epmeier and Kliger (2005), which investigated the effect of three different modification methods (acetylation, modification with methylated melamine resin and heat treatment in vegetable oil) on four material properties (density, modulus of elasticity (MOE), creep deflection and relative creep) and their inter-relations. In this study, another modification method (furfurylation) and four additional material parameters (“relative stiffness”, i.e. MOE/density, moisture content, change in moisture content and anti-creep efficiency) and their correlations are included. In addition, the creep curves were analysed to assess the development of bending creep performance. The properties were assessed by experimental work on 132 specimens of Scots pine sapwood with dimensions of 45×70×1100 mm³. It was found that modification leads to significant changes in material properties. Furfurylation increases density and reduces creep deflection, relative creep and moisture content. Modified timber tends to deflect and creep significantly less than untreated timber. However, the extent of reduction in relative creep appears not to be related to the extent of reduction in creep deflection. Initial deflection and/or modulus of elasticity are suitable for predicting the creep deflection of untreated and modified timber.     

Creep of wood in bending and non-symmetrical moistening

The effect of one sided moistening zones under both tension and compression, as well as the effect of simultaneous moistening both of these zones of bent wood on the course of creep was investigated. The increase in deflection of the bent samples was registered and the changes in moisture content distribution were observed in control samples. Moistening of the compressed zone has the maximum effect on creep in the bent wood samples. It was found that a bending stress of not more than 17% of the ultimate strength when moistening the compressed zone, decreases the deflection and even a reversion in its direction can be expected. The warping forces are probably responsible for this behaviour. The increase in deflection in the bent and moistened wood may sufficiently be described by a parabolic function of creep compliance.     

Experimental cutting on the table band-sawing mashine

This article presents the results of experiments, aimed at studying the influence of chosen technical and technological factors (cutting speed, width of saw band, cutting height, radius of sawing) on the side deflection of the saw band of a table bandsawing machine in curvilinear sawing. The contactless opto-elektronical method was used for observation. The light deflection of the reflected infrared ray from the tool was measured by means of a planar diode.     

基于宏指令编程的小刚度轴的加工误差控制

为了高效率解决小刚度轴的弯曲变形引起的加工误差问题,在合理选择工艺参数的基础上,通过弯曲变形量计算来分析工件的加工误差,并给出了具体的误差控制措施应用宏指令编程进行误差补偿。这种方法可以最大限度地减少加工误差,获得理想的效果。