SU1631363A1 - Device for determining gas permeability of polymer materials - Google Patents

Description

The invention relates to measuring technique and can be used to determine the gas permeability coefficient of polymeric materials. The aim of the invention is to improve the accuracy of determination. For this, a receiver consisting of two cavities separated by a diaphragm is inserted into the device between the diffusion cell — a gas cylinder. One of the cavities of the receiver is connected to a gas cylinder, and the other is connected to a compressor connected to an electrical contact pressure gauge, which is located on the gas pipeline between the receiver and the diffusion cell. 1 il.

The invention relates to a measuring technique, namely, means of testing polymeric materials, and can be used in various industries to determine the transfer coefficients of non-aggressive gases through polymeric materials.

The purpose of the invention is to improve the accuracy of determining the coefficient of permeability.

The drawing shows a diagram of the proposed device.

The device consists of a chromatograph 1 connected through a metering valve 2 to the lower chamber 3 of the diffusion cell 4. The cylinder 5 is intended for the test gas supplied through the gas line 6 through the receiver 7 to the upper chamber 8 of the diffusion cell 4. The receiver 7 consists of two cavities 9 and 10, separated by a diaphragm 11. The cavity 9 of the receiver 7 is equipped with a safety valve 12 and is connected to the compressor 13. An electric contact pressure gauge 14 is installed on the gas pipeline 6 between the receiver 7 and the diffusion cell 4 and is electrically connected to the compressor 13. Reci 10 Faith 7, located ι between the gas cylinder 5 and the diffusion cell 4, is connected through a gas pipeline through a gas pipeline ^; gas 5 and the upper chamber 8 of the diffusion cell 4. A polymeric material 15 is located between the lower 3rd upper 8 chambers of the diffusion cell 4. Carrier gas from ί gas cylinder 16 is supplied to chromatograph 1.

The device works as follows. ,

A sample of polymeric material 1

placed between the bottom 3 and top 8

chambers of the diffusion cell 4. Seal the diffusion cell 4 using screw clamps (not shown).

1631363 A1

3

1631363

four

The lower chamber 3 through the dosing valve 2 is washed with a carrier gas from cylinder 16 to the absence of chromatographic peaks recorded by chromatograph 1. From a cylinder

5 test gas is supplied through the pipeline

6 into the cavity 10 of the receiver 7 and into the upper chamber 8 of the diffusion cell 4. Pre-set the working pressure on the electrical contact pressure gauge 15 and replenish the cavity 9 of the receiver 7 with air from the compressor 13, and also calibrate the safety valve 12. The working pressure of the test gas in the upper chamber 8 is the pressure of the carrier gas in the lower chamber 3 of the diffusion cell 4.

When the working pressure in the cavity 10 of the receiver 7 increases, the gas acts on the diaphragm 11 — the pressure in the cavity 9 rises and the safety valve 12 opens (opens), releasing part of the air from the cavity 9. The pressure in the cavities 9 and 10 and in the system decreases to working.

When the working pressure is lowered, the electric contact pressure gauge 15 is activated, giving a signal to the compressor 13, including it. The air from the compressor 13 enters the cavity 9 and acts on the diaphragm 11 - the pressure in the cavity 10 rises to work, the Electrocontact pressure gauge 15 sends a signal to turn off the compressor 13.

The sampling of the test gas passed through the sample of the polymer material 15 is carried out using

metering valve 2 of the chromatograph 1 after the accumulation of gas in the lower chamber 3 of the diffusion cell. Gas accumulation time is determined experimentally.

After establishing a steady state of transfer of the test gas through the sample of polymer material 15 (the height of the chromatographic peak reaches a constant value), the permeability coefficient is calculated over the area of the chromatographic peak, taking into account the geometric dimensions of the sample and the gas pressure,

.

Claims (1)

Claim A device for determining the gas permeability of polymeric materials, containing a diffusion cell made of two chambers arranged one above the other, the upper of which is connected by a gas line to a gas cylinder, and the lower one is connected through a metering tap to the chromatograph gas system, characterized in that improve the accuracy of determining the permeability coefficient, a receiver is included in the gas pipeline, consisting of two cavities separated by a diaphragm, one of the cavities of the receiver being connected to a gas cylinder and an upper gas cylinder measure the diffusion cell, and the other cavity of the receiver is equipped with a safety valve and is connected to a compressor connected to an electrical contact pressure gauge, which is located on the gas pipeline between the receiver and the diffusion cell. >