SU958967A1 - Device for checking sheet material mechanical properties - Google Patents

Description

(54) DEVICE FOR CONTROL OF MECHANICAL PROPERTIES OF SHEET MATERIAL

one

The invention relates to the control of the mechanical properties of sheet materials, preferably rigidity, and can be used in the pulp and paper and other industries.

Closest to the invention is a device for controlling the mechanical properties of the sheet material, comprising a pneumatic generator, an air flow former, support rollers and a measurement circuit 1.

The disadvantage of this device is that the jet of compressed gas is directed at a right angle to the surface of the sheet material and, striking it, generates waves in the material.

The use of this mechanism of action on sheet material is ineffective for detecting such a property as rigidity, since the amplitude of oscillations is small, its registration and evaluation are relatively complex.

The aim of the invention is to simplify the control and improve the accuracy of its results.

This goal is achieved by the fact that the device for controlling mechanical properties

sheet material, predominantly stiffness of the paper, containing a pneumatic generator, an air flow former, support rollers and a measurement scheme, contains pressure rollers. mounted above the support rollers, and the air flow former is made in the form of a rectangular cross-section chamber with a removable top wall, the support rollers located on both sides of the chamber, and the horizon, 0 tal plane drawn through the contact lines of the pressure and support rollers, is located inside cameras.

The drawing shows a device for controlling the mechanical properties of a sheet material.

Claims (2)

15 It has a pneumatic generator 1, an air flow former, which is made in the form of a rectangular casing with a removable upper wall. 2. The device has pressure rollers 3 and support rollers 4, which are mounted on the side walls 5 of the housing, while the plane drawn through the contact lines of each pair of rollers 3 and 4 is located between the top wall 2 and the bottom wall 6. This installation of the rollers is determined The position of the test specimen 7 of sheet material, for example paper, in the flow path of the flow path. Weights are used to tension the material. The device has a measurement circuit. The scheme can be made in various ways. The drawing shows one of them. The measurement circuit has a receiver-converter 9 mounted on the upper wall 2 of the housing, and a device 10 for recording pressure readings of acoustic waves and / or oscillation frequencies of the sheet material of sample 7. The circuit can be equipped with an optical or other indicator of the amplitude of oscillations of the middle part of the sample located in shaper enclosure flow. The device works as follows. When removing the top wall 2 with the pinch rollers 3, on the support rollers 4 lay a sample 7 of sheet material in the form of a tape with weights 8 at its ends. Install on the case of the upper wall 2 with pressure rollers 3 and clamp the tape between the support rollers 4 and pressure. Include pneumogenerator 1, which supplies air with installed pressure and flow into the body of the flow former. Under the influence of the flow, the sample 7 of sheet material begins to oscillate between the upper and lower walls of the housing, without touching them. The pressure of the acoustic waves and / or the oscillation frequency of the sample 7 are perceived by the receiver-converter 9 and, as informative parameters, are produced by the device 10. If there is an optical or other known indicator of the amplitude of oscillations, the rigidity of the material is estimated. The informative parameters obtained, the acoustic wave pressure and / or the frequency and amplitude of the sample oscillations serve to determine, estimate and control the stiffness of the sheet material. The device can also be used to determine the mechanical strength of sheet materials, for example, the strength of some types of paper — thinner, copiers, etc. The design of the proposed device ensures that the sample is located in a rectangular section channel between the upper and lower walls of the housing, the effect of flow on the sample from both sides and the ability to generate maximum amplitude oscillations. At the moment of resonance, the amplitude of the standing wave in the middle part of the sample can be determined without resorting to the use of complex techniques. The measured value of the resonant amplitude, taking into account the linear dimensions of the sample is much simpler than in the prototype, it is possible to determine the stiffness of the sheet material. The nature of the effect of flow on the sample most fully meets the solution of the problem and improves the accuracy and consistency of controlling the rigidity of the material, while the device provides control of paper, films, fiber-reinforced, synthetic and other sheet materials. Apparatus of the Invention A device for controlling the mechanical properties of a sheet material, preferably paper stiffness, comprising a pneumatic generator, an air flow former, support rollers and a measurement circuit, characterized in that, in order to simplify control and improve the accuracy of its results, it contains pressure rollers mounted above the support rollers. rollers, and the air flow former is made in the form of a rectangular chamber with a removable upper wall, while the supporting rollers are located on both sides of the chambers ry and the horizontal plane drawn through the nip line of contact and support rollers, arranged inside kaIstochniki information received note in the examination 1. Copyright certificate USSR № 717653, cl. G 01 N 33/34, 1978.