Wound Roll Research Articles

Elastohydrodynamic Lubrication of Air-Lubricated Rollers

Abstract The lubricating air film between two rotating rollers in close contact was studied numerically. The numerical model used in this study accounts for the effects of air compressibility, material deformation, and the slip flow which occurs when the air film thickness is not much larger than the mean-free-path of the air molecules. The air film profiles and the pressure profiles for the nip region between the rollers were calculated. It was found that the calculated air film thicknesses are lower than predicted by the liquid elastohydrodynamic calculation. From this study, equations for the minimum air film thickness, the air film thickness at the center of contact, and the amount of air that passes through the nip were obtained. This study has application to the prediction of the amount of air entrained in a winding roll.

A Nonlinear Wound Roll Model Allowing for Large Deformation

A new model is developed for predicting the internal loads in a wound roll. The principal contribution is the ability to account for large deformation. This is important for applications that require tightly packed rolls with large interlayer pressure and web compression. A nonlinear, orthotropic, plane-strain, pseudoelastic constitutive law is used. Arguments are made as to why the “material symmetry condition” does not apply to the wound roll. An efficient numerical solution scheme is developed, and a good correlation is achieved with interlayer pressure measurements available in the literature.

A Hypoelastic Model for Computing the Stresses in Center-Wound Rolls of Magnetic Tape

A hypoelastic finite element model for the calculation of continuous internal stress and deformation distributions in wound rolls used in center winding is presented. The stress problem is formulated as an initial boundary value problem and its solution satisfies continuity of deformation as one rewinds more layers on the growing roll. Hypoelasticity is shown to be a natural way to account for the growing body nature of a magnetic tape during winding. Several cases are examined with constant and radial stress dependent radial elastic modulus. The agreement with Hakiel’s model and experimental data obtained through the sandwiched pull strip method is very good. The results for the static linear and nonlinear cases examined found to be weakly dependent on the winding speed. The present analysis is more versatile than previous models in simulating the growing nature of the tape pack and it can naturally be extended to include nonlinear time and history-dependent phenomena.

The Internal Stresses in Wound Rolls With the Presence of a Nip Roller

Models which can be used to calculate the internal stresses within wound rolls of web material have all been confined to the center winding technique to date. In this publication, a new boundary condition is presented which will allow existing models to calculate the internal stresses within a wound roll which has been center wound with an undriven nip roller impinged upon the outside of the roll. Experimental verification of the new boundary condition is presented.

The Mechanism of Nip-Induced Tension in Wound Rolls

Models which can be used to calculate the internal stresses within wound rolls of web material have all been confirmed to the center winding technique to date. The mechanism by which a nip roller can increase the wound in tension in the outer layer of the wound roll is presented. Results of this work have been used to establish new winding models which can accurately predict the internal stresses within a center wound roll with an impinged nip.

フィルム巻取りロールでの静電気帯電と放電現象

フィルム巻取りロールでの静電気帯電と放電現象

Resolution of a Core Problem in Wound Rolls

Previous misunderstandings about the behavior of stresses in the vicinity of the core of wound rolls are resolved through the development of an explicit closed-form analytical solution for the radial and circumferential stresses which are generated during winding; the solution holds in the general case of variable winding tension. Asymptotic series are derived and then employed to compute profiles of stresses within the wound material for several cases of practical interest. A parametric analysis of the influence of core elasticity on structural integrity of the roll underscores the indispensable support provided by the core at the inner boundary of the roll. Results show that the circumferential stress in the vicinity of the core strongly depends on core stiffness. A relation that is derived between interlayer pressure and circumferential stress at the core boundary may be useful as a guide in core design and in preventing roll collapse.

Filament winding machine

The utility model relates to the technical field of copying machine lamp tube machining equipment. The utility model relates to a filament winding machine. Including a base, first supporting columns are welded to the left side and the right side of the upper end of the base. Bearing pedestals are fixedly installed at the upper ends of the first supporting columns through bolts, a threaded rod is rotatably connected between the two bearing pedestals, a movable block is in threaded connection with the threaded rod, a boss is welded to the left end of the outer side face of the movable block, anda protruding column used for being connected with a limiting ring in a sleeving mode is integrally formed and connected to the right side of the movable block. The wire feeding roller is convenient to assemble and disassemble; a filament winding roller of a corresponding specification can be selected according to the specification of a filament needing to be wound, and the rotating shaft is sleeved with the filament winding roller. The rotating shaft and the filament winding roller are driven by the second motor to rotate to wind the filament, and the threaded rod is synchronously driven by the first motor to rotate, so that the moving block and the filament feeding roller move towards the filament winding direction under the limitation of the guide rod, the operation is convenient, and the working efficiency is improved.

A position regulator for paper slitters

PAPER slitters are used to trim the edges of paper webs so that a paper roll with even sides can be wound from an unevenly wound roll. When the paper has printed designs on it, the slitting must be done at a definite distance from the printed design. The slitter knives are stationary as shown in figure 1. In order to slit the paper at the same position relative to the design when the position of the paper relative to the shaft of the unwinding roll is varying, it becomes necessary to adjust the position of the unwinding roll transversely.

A position regulator for paper slitters

PAPER slitters are used to trim the edges of paper webs so that a paper roll with even sides can be wound from an unevenly wound roll. When the paper has printed designs on it, the slitting must be done at a definite distance from the printed design. The slitter knives are stationary as shown in figure 1. In order to slit the paper at the same position relative to the design when the position of the paper relative to the shaft of the unwinding roll is varying, it becomes necessary to adjust the position of the unwinding roll transversely.

Improvements in motion picture laboratory apparatus

A number of miscellaneous improvements in laboratory apparatus are described, which have for their object the elimination of spots, scratches, and unevenness of density in processed motion picture film. Modifications in developing room equipment include a vacuum cleaner for removing sludge from developers, a cooling coil for adjusting developer temperature, a new type of rack guide for a developer tank, a compact rack light lock, a waterproof and corrosion-resisting portable darkroom lamp, and some auxiliaries for the prevention of spots and contamination on film. — Improvements in printing room equipment include the addition of a flywheel to a continuous printer to eliminate unevenness in density due to variation in the motion of the film during exposure. Also, a light change has been equipped to control either of two lamps of different wattage giving in each case exposure values which have precisely equal relationships. — Some changes have been made in rewinding equipment which include the addition of a weighted roller to make more firmly wound rolls and a large portable winding core. The design of a standard disk rewind has been changed to facilitate removal of the wound roll. — A film storage cabinet has been designed for laboratory use which gives an increased degree of protection from fire and water, at the same time assisting in the convenient and orderly arrangement of the film.