Analysis of yarn tension based on yarn demand variation on a tricot knitting machine

2016 ◽  
Vol 87 (4) ◽  
pp. 487-497 ◽  
Author(s):  
Xing Liu ◽  
Xuhong Miao
Keyword(s):  
Tension Control ◽  
Active Tension ◽  
Dynamic Tension ◽  
Yarn Tension ◽  
Warp Tension ◽  
Change Trend ◽  
Tension Curve ◽  
Demand Variation

To date, the trend in the development of knitting promotes higher requirements for warp tension control, and the fluctuation of knitting warp finally comes down to the imbalance between yarn demand and feed while forming every loop. According to warp knitting machine characteristics, four typical points are chosen to calculate the value of yarn demand, and in this way a model is built to obtain and plot the overall change trend in yarn demand in one knitting cycle. Combined with the theoretical tension curve calculated based on the yarn demand and the measured one, it is verified as coincident. The model is useful for analyzing the factors causing warp dynamic tension variation, and lays the groundwork for accurate active tension compensation.

Research and Application of a New Constant Tension Control Device of the Carbon Fiber Warping Machine

2013 ◽  
Vol 846-847 ◽  
pp. 40-43
Author(s):  
Jian Feng Qin ◽  
Xiu Ming Jiang ◽  
Jian Cheng Yang ◽  
Hua Qing Wang ◽  
Kai Yang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Carbon Fiber ◽  
Control Device ◽  
Tension Control ◽  
High Tensile Strength ◽  
Yarn Tension ◽  
Warp Tension ◽  
Constant Tension ◽  
Low Shear

This paper presents a new constant tension control device which is suitable for warping of the carbon fiber or the flake yarns which are zero twist, high tensile strength, low shear strength, high specific modulus and self-lubrication and can meet the requirements of the warp tension of the carbon fiber multi-layer weaving equipment which is in the process of development. The device can make yarn tension consistent in warping process. Especially with the decrease of the diameter of yarn tube, the tension of yarn sheet is consistent in warping process. In the process of warping the warp doesnt twist and wear is small. The experimental results show that the mechanism can realize accurate control on the tension of the single yarn and the yarn sheet, and is able to meet the requirements of the warp tension of the carbon fiber multi-layer weaving equipment which is in the process of development.

Tension Control Strategy in Plastic Film Printing Process

2013 ◽  
Vol 655-657 ◽  
pp. 1321-1325
Author(s):  
Peng Sun ◽  
Peng Cao
Keyword(s):  
Control Method ◽  
Friction Torque ◽  
Tension Control ◽  
Rotational Inertia ◽  
Plastic Film ◽  
Diameter Measurement ◽  
Dynamic Tension ◽  
Drive Control ◽  
Coil Diameter ◽  
Constant Tension

The character of the tension control in the plastic-film printing was introduced, and the coiler drive control method was given. The indirect constant tension control method was analyzed, and the key parameters were given, also the method of coil diameter measurement with distance meter, the friction torque in different rotate speed was given by the friction torque test; the method of rotational inertia measurement which influence the dynamic tension was put forward.

Mechanical properties of porcine intralobar pulmonary arteries

1988 ◽  
Vol 64 (4) ◽  
pp. 1537-1545 ◽  
Author(s):  
H. Ohtaka ◽  
J. C. Hogg ◽  
R. H. Moreno ◽  
P. D. Pare ◽  
R. R. Schellenberg
Keyword(s):  
Pulmonary Arteries ◽  
Pressure Change ◽  
Passive Tension ◽  
Active Tension ◽  
Balloon Inflation ◽  
Optimal Length ◽  
Active Volume ◽  
Calculated Length ◽  
Passive Pressure ◽  
Tension Curve

The isobaric and isovolumetric properties of intrapulmonary arteries were evaluated by placing a highly compliant balloon inside arterial segments. The passive pressure-volume (P-V) curve was obtained by changing volume (0.004 ml/s) and measuring pressure. The isobaric active volume change (delta V) or isovolumetric active pressure change (delta P) generated by submaximal histamine was measured at four different transmural pressures (Ptm's) reached by balloon inflation. The maximal delta P = 11.2 +/- 0.6 cmH2O (mean +/- SE) was achieved at 30.8 +/- 1.2 cmH2O Ptm and maximal delta V = 0.20 +/- 0.02 ml at 16.7 +/- 1.7 cmH2O Ptm. The P-V relationships were similar when volume was increased after either isobaric or isovolumetric contraction. The calculated length-tension (L-T) relationship showed that the active tension curve was relatively flat and that the passive tension at the optimal length was 149 +/- 11% of maximal active tension. These data show that 1) a large elastic component operates in parallel with the smooth muscle in intralobar pulmonary arteries, and 2) the change in resistance associated with vascular expansion of the proximal arteries is independent of the type of contraction that occurs in the more distal arterial segments.

Simulation of Yarn Tension Control System Based on Simulink

2010 ◽  
Vol 426-427 ◽  
pp. 106-108 ◽  
Author(s):  
De Gong Chang ◽  
Zhi Juan Xiao ◽  
Y.H. Liu ◽  
H. Li
Keyword(s):  
Control System ◽  
Dynamic Performance ◽  
Digital Simulation ◽  
Tension Control ◽  
Structure Parameters ◽  
Yarn Tension ◽  
Magnetic Powder Brake ◽  
Tension Control System ◽  
The Mathematical Model ◽  
The Relationship

Based on the analyses of the yarn tension and the mathematical model of the magnetic powder brake, the digital simulation of the yarn tension fuzzy control system was performed by using MATLAB Simulink. The relationship between the structure parameters and the system dynamic performance was then obtained, and the system scheme was justified.

scholarly journals Optimisation of the warp yarn tension on a warp knitting machine

2012 ◽  
Vol 12 (2) ◽  
pp. 29-33 ◽  
Author(s):  
Vivienne Pohlen ◽  
Andreas Schnabel ◽  
Florian Neumann ◽  
Thomas Gries
Keyword(s):  
Tension Control ◽  
Weft Yarn ◽  
Warp Yarn ◽  
Yarn Tension ◽  
Process Reliability ◽  
Increasing Process ◽  
Tension Analysis

Abstract Investigations (calculations) based on a warp yarn tension analysis on a warp knitting machine with multiaxial weft yarn insertion allow prospective reduced yarn tension differences in technical warp knits. From this a future opportunity is provided to substitute the subjective warp let-off adjustment by a model of tension control. The outcome of this is a higher reproducibility with associated increasing process reliability and rising product quality.

The Control Algorithm Research of Yarn Tension for Winding Machine Based on Grey Prediction Model

2014 ◽  
Vol 519-520 ◽  
pp. 1305-1308
Author(s):  
Can Cai Wang ◽  
Hai Xia Zhao
Keyword(s):  
Control Algorithm ◽  
Magnetic Particle ◽  
Prediction Method ◽  
Control Model ◽  
The Self ◽  
Tension Control ◽  
Grey Prediction ◽  
Yarn Tension ◽  
Winding Machine ◽  
Prediction Control

For building high precision yarn tension control model, grey prediction method was first employed in this paper. The commonly used GM(1,1) model was modified by means of changing the coefficient a and b. Then the next tension value was forecasted from the previous test values by the modified GM(1,1) model. Then the forecasted values and the referred value were import into the self-adaption PID model. And the PID model output the control sign to magnetic particle clutch. The simulation of the control algorithm was completed in MATLAB 7.0. The simulation result showed that the proposed control algorithm had better precision than general PID and general grey prediction control algorithm.

Design of the Let-Off Mechanism of Carbon Fiber Multilayer Diagonal Loom Based on Virtual Prototype Technology

2013 ◽  
Vol 846-847 ◽  
pp. 61-64
Author(s):  
Jian Feng Qin ◽  
Xiu Ming Jiang ◽  
Jian Cheng Yang ◽  
Hua Qing Wang ◽  
Kai Yang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Virtual Prototype ◽  
Mechanical Analysis ◽  
Tension Control ◽  
Prototype Model ◽  
Fabric Structure ◽  
Warp Tension ◽  
Different Types ◽  
Design Software ◽  
Prototype Design

This paper presents a set of the let-off mechanism of carbon fiber multilayer diagonal loom, which can accomplish thirty layer fabric weaving. This mechanism can realize multi-layer positive warp let-off and negative warp tension control and can meet different fabric structure and different types of warp weaving requirements. According to the requirement of the multi-layer weaving and the characteristics of carbon fiber, 3 d virtual prototype model of carbon fiber multilayer diagonal loom is established by applying the 3 d design software Solidworks and using the mechanical analysis software ANSYS analyses the mechanical properties of the key parts in different working conditions. Virtual prototype design ensures the rationality and reliability of the design of the whole machine.

Dynamic Characteristics and Double Closed Loop Control Method of Warping Machine

2012 ◽  
Vol 627 ◽  
pp. 428-434
Author(s):  
Tao Yang ◽  
Lin Yin Liu ◽  
Wei Rong Dai
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Dynamic Models ◽  
Control Method ◽  
Stable State ◽  
The Other ◽  
Closed Loop Control ◽  
Loop Control ◽  
Yarn Tension ◽  
Warp Tension

The warp tension is caused by the speed difference between rewinding shaft and unwinding shaft. The mathematical dynamic models of the system are established based on rewinding shaft and unwinding shaft．Double closed loop are included in the control system. One is winding speed closed loop which could control warping speed according to the requirements; the other is tension closed loop which ensure the yarn tension to be kept constant. The experimental results show the curve of tension enters a stable state after two or three times’ oscillation. The accuracy of the yarn tension has reached ±3%.

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