PTFE Film Gas Pressure Reduction Testing Service

PTFE Film Gas Pressure Reduction Testing Service – Accredited ISO/IEC 17025 Permeability and Mechanical Performance Assessment for the Colombian Market

PTFE (polytetrafluoroethylene) films are widely used in chemical processing, pharmaceutical manufacturing, semiconductor fabrication, food processing, oil and gas, and aerospace applications as liners, seals, gaskets, diaphragms, and barrier layers due to their exceptional chemical resistance, thermal stability, low friction, and non-stick properties. However, the ability of PTFE films to maintain their barrier function and mechanical integrity under gas pressure differentials is critical to ensure safety, process efficiency, and environmental protection. In the Colombian market, the Superintendencia de Industria y Comercio (SIC), the Ministerio de Minas y Energía (MinMinas), the Agencia Nacional de Hidrocarburos (ANH), and the Dirección de Impuestos y Aduanas Nacionales (DIAN) enforce rigorous quality and safety standards for materials used in the chemical and oil and gas industries. Our laboratory offers a comprehensive PTFE film gas pressure reduction testing service, applying standardized methods that evaluate gas permeability, pressure resistance, deformation behavior, and fatigue performance under controlled pressure differentials and temperatures. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Colombian authorities, making them essential for product certification, supplier qualification, quality control in manufacturing, and import-export processes.

PTFE Film Samples We Regularly Test

Our laboratory receives a wide variety of PTFE films and related components for gas pressure reduction testing. Typical samples include:

• Unfilled PTFE films – of various thicknesses (from 0.05 mm to 5 mm), for general-purpose sealing and lining applications.
• Glass-filled PTFE films – with enhanced dimensional stability and wear resistance, for high-pressure and high-temperature applications.
• Graphite-filled PTFE films – with improved creep resistance and thermal conductivity, for sealing in aggressive environments.
• Bronze-filled PTFE films – for high-load and high-pressure bearing and sealing applications.
• Expanded PTFE (ePTFE) films – microporous films used in breathable membranes and venting applications.
• Skived and extruded PTFE films – produced by different manufacturing methods, which can affect the permeability and mechanical properties.
• PTFE films with surface treatments (sodium etching, plasma treatment) – for bonding or coating applications, where surface modification may affect gas permeation.
• Prototype and new PTFE formulations – submitted by manufacturers for validation of gas pressure reduction performance before series production.
• Films retrieved from field service – for assessment of degradation and remaining barrier life.

Gas Permeability Testing – Steady-State and Transient Measurement

Gas permeability is the primary parameter for evaluating the barrier performance of PTFE films under pressure differentials. Our tests measure the rate at which gas penetrates the film, determining the pressure reduction over time. We use both steady-state and transient methods to provide a comprehensive characterization of the film's barrier properties.

• Steady-state gas permeability test (ASTM D1434 / ISO 15105-1 / NTC 6400) – a PTFE film sample is mounted in a diffusion cell, with a high-pressure gas (typically nitrogen, helium, or methane) applied to one side and a vacuum or low-pressure atmosphere on the other side. The pressure increase on the low-pressure side is measured over time using a pressure transducer or a manometer. The gas permeability coefficient (P) is calculated from the steady-state pressure rise rate. We report the permeability coefficient (in cm³·mm/(m²·day·atm)), the gas transmission rate (GTR, in cm³/(m²·day)), and the permeability at the test temperature (typically 23 °C, 40 °C, or 60 °C).
• Transient gas permeability test (ASTM D1434 – variant, NTC 6401 – time-lag method) – the pressure rise on the low-pressure side is monitored continuously from the start of the test. The time lag (the time before steady-state permeation is reached) is determined, and the diffusion coefficient (D) is calculated from the time lag using the equation D = L² / (6 · τ), where L is the film thickness and τ is the time lag. We report the diffusion coefficient (in cm²/s), the solubility coefficient (S), and the permeability coefficient (P = D · S).
• Gas permeability test at different temperatures (NTC 6402 – thermal effect on permeability) – the test is performed at 23 °C, 40 °C, 60 °C, and 80 °C to evaluate the temperature dependence of the permeability. The activation energy for permeation is calculated from the Arrhenius plot. We report the temperature-dependent permeability coefficients and the activation energy (in kJ/mol).
• Gas permeability test with different gases (NTC 6403 – selectivity measurement) – for PTFE films used in gas separation or selective barrier applications, we measure the permeability of nitrogen, oxygen, carbon dioxide, methane, and other gases. We report the gas selectivity (ratio of permeabilities) for the relevant gas pairs.
• Gas permeability test under high pressure (NTC 6404 – high-pressure differential) – for films used in high-pressure gas systems, we measure the permeability at pressure differentials of up to 10 MPa, using a high-pressure permeability cell. We report the permeability as a function of the pressure differential and the pressure dependence of the permeability.
• Leak testing by helium detection (NTC 6405 – for integrity assessment of film seals) – in addition to bulk permeability, we perform helium leak testing (using a mass spectrometer) to detect localized pinholes, defects, or defects in the film that could cause direct gas leakage. We report the helium leak rate (in mbar·L/s) and the integrity of the film.

Pressure Resistance and Burst Strength – Mechanical Integrity under Differential Pressure

PTFE films used in sealing and barrier applications must withstand the mechanical stress imposed by pressure differentials without bursting, tearing, or excessive deformation. Our pressure resistance and burst tests evaluate the film's mechanical integrity under increasing pressure, providing data for design safety factors.

• Burst pressure test (ASTM D1599 / ISO 1402 / NTC 6410 – for films and diaphragms) – a circular PTFE film sample (typically 50 mm to 100 mm in diameter) is clamped in a pressure cell. A gas (or liquid) is applied to one side of the film at a controlled rate (typically 0.1 to 0.5 MPa/s) until the film bursts. The burst pressure (in MPa) is recorded. We report the burst pressure and the mode of failure (e.g., tearing at the clamp, central rupture, or delamination).
• Pressure cycling test (NTC 6411 – resistance to repeated pressure pulses) – the film is subjected to cyclic pressure pulses (from 0 to 80 % of the burst pressure) at a frequency of 0.5 to 2 Hz, for a specified number of cycles (typically 10,000 to 100,000 cycles). The film is inspected for cracks, permanent deformation, or leakage after the cycling. We report the number of cycles completed, the deformation, and the leakage status.
• Pressure holding test (NTC 6412 – pressure decay and seal integrity) – the film is pressurized to a specified level (e.g., 50 % of the burst pressure) and the pressure is held for 24 hours. The pressure drop over time is measured. A low pressure drop indicates good sealing integrity. We report the pressure decay rate (in Pa/min or kPa/hour) and the sealing efficiency.
• Creep and deformation under constant pressure (NTC 6413 – long-term deformation) – the film is subjected to a constant pressure (e.g., 30 % of the burst pressure) for 100 hours, and the deformation (bulging, sagging) is measured over time. We report the deflection (in mm) and the creep strain (%).
• Combined pressure and temperature test (NTC 6414 – thermal pressure resistance) – the burst pressure or pressure holding test is performed at elevated temperatures (e.g., 60 °C, 100 °C) to evaluate the reduction in pressure resistance due to thermal softening. We report the burst pressure at elevated temperatures and the temperature derating factor.

Deformation and Deflection Analysis – Dimensional Stability under Pressure

Under gas pressure, PTFE films may deform or deflect, which can affect their sealing performance and mechanical integrity. Our tests quantify the deformation and deflection behavior of the film under pressure, providing critical data for the design of diaphragms and sealing elements.

• Deflection measurement under uniform pressure (NTC 6420 – bulge test) – the film is clamped in a circular aperture and subjected to a gas pressure. The deflection at the center is measured using a dial gauge or a laser displacement sensor. We report the deflection (in mm) and the deflection-pressure curve.
• Deflection measurement under differential pressure (NTC 6421 – pressure difference versus deflection) – the test is performed with a pressure differential across the film, and the deflection is measured as a function of the differential pressure. We report the pressure-deflection characteristic curve.
• Viscoelastic deformation under pressure (NTC 6422 – creep and recovery) – the film is loaded to a specified pressure, and the deflection is monitored over time (e.g., 1 hour). The pressure is then released, and the recovery of the deflection is measured. We report the creep deflection, the permanent set, and the recovery percentage.
• Deformation under cyclic pressure (NTC 6423 – fatigue deflection) – during the pressure cycling test, the deflection is measured at intervals to track the accumulation of permanent deformation. We report the deflection as a function of the number of cycles.
• Finite element analysis (FEA) validation – NTC 6424 – correlation with simulation – using the measured mechanical properties (elastic modulus, Poisson's ratio, creep behavior), we compare the experimental deflection data with finite element simulations to validate the material model and to predict the behavior under more complex loading conditions. We report the FEA validation results and the comparison with the test data.

Fatigue and Long-Term Durability under Gas Pressure Fluctuations

PTFE films in industrial applications are often subjected to fluctuating pressures, which can cause fatigue failure and premature cracking. Our fatigue tests evaluate the durability of the film under simulated pressure fluctuations, which is essential for safety-critical applications in the Colombian oil and gas and pharmaceutical industries.

• Pressure fatigue test (NTC 6430 – cyclic pressure endurance) – the film is subjected to a cyclic pressure load (from 10 % to 80 % of the burst pressure) at a frequency of 0.5 to 5 Hz, for a specified number of cycles (e.g., 10⁶ cycles). The test is continued until the film fails (leakage, cracking, or bursting) or until a specified number of cycles is reached. We report the number of cycles to failure and the fatigue life (cycles) at the given pressure amplitude.
• Step-stress pressure fatigue test (NTC 6431 – accelerated life testing) – the pressure amplitude is increased stepwise (e.g., every 10,000 cycles) until the film fails. This provides a rapid estimate of the fatigue life and the pressure tolerance. We report the pressure amplitude at failure and the cumulative fatigue damage.
• Pressure fatigue under environmental stress (NTC 6432 – combined pressure, temperature, and humidity) – the pressure fatigue test is performed at an elevated temperature (e.g., 60 °C) and high humidity (90 % RH) to simulate the conditions in tropical environments (such as coastal areas of Colombia). We report the fatigue life under combined environmental stress.
• Fatigue crack propagation test (NTC 6433 – determination of fracture toughness under cyclic pressure) – for films with a pre-existing notch or defect, we measure the crack propagation rate under cyclic pressure loading. We report the crack propagation rate (da/dN) and the critical pressure intensity factor (ΔK_IC).
• Life prediction using cumulative damage models (NTC 6434 – Palmgren-Miner rule) – using the fatigue data from the constant amplitude tests, we apply the Palmgren-Miner rule to predict the life under variable pressure spectra (e.g., measured from field data). We report the predicted service life and the damage accumulation.

Complementary Tests – Material Characterization, Thermal Stability, and Aging

To fully understand the gas pressure reduction performance and to identify any material degradation mechanisms, we complement the functional tests with material characterization and aging analyses. These tests are essential for product certification, failure analysis, and quality improvement.

• • Differential scanning calorimetry (DSC) – ASTM D3418 / NTC 6440 – we measure the melting temperature (Tm) and the crystallinity (%) of the PTFE film, which can affect its mechanical properties and permeability. We report the Tm and the degree of crystallinity.
  • Thermogravimetric analysis (TGA) – ASTM E1131 / NTC 6441 – we measure the thermal stability and the decomposition temperature of the film. The onset of decomposition (Td) is reported, and the change in mass at 300 °C, 400 °C, and 500 °C is recorded.
  • FTIR spectroscopy (ASTM E168 / NTC 6442) – we analyze the chemical structure of the PTFE film to detect any contamination, degradation, or chemical modification (e.g., oxidation, chain scission) that may affect its barrier properties.
  • Density and porosity measurement (ASTM D792 / NTC 6443 – for ePTFE and porous films) – for expanded PTFE (ePTFE) films, we measure the apparent density and the porosity. We report the density (g/cm³) and the porosity (%).
  • Surface and cross-sectional SEM examination (ASTM E1508 / NTC 6444) – we examine the surface and the cross-section of the film before and after the gas pressure test to detect cracks, voids, delamination, or any microstructural changes caused by the pressure exposure. We report the SEM observations and any signs of degradation.
  • Thermal aging test (NTC 6445 – 70 °C for 7 days) – we perform accelerated thermal aging at 70 °C for 7 days, and then repeat the gas permeability and pressure resistance tests to evaluate the effect of aging on the barrier and mechanical properties. We report the change in permeability and burst pressure after aging.
  • Chemical immersion test (NTC 6446 – compatibility with process fluids) – for PTFE films used in contact with chemicals, we immerse the film in representative fluids (e.g., 10 % HCl, 10 % NaOH, toluene, or oil) for 7 days, and then conduct the gas permeability test to evaluate the effect of chemical exposure on the barrier performance. We report the change in permeability after chemical exposure.

Test Report and Recognition in the Colombian Chemical and Oil & Gas Sectors

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (pressure cells, gas permeability testers, thermogravimetric analyzers, DSC, FTIR, etc.) and traceability to international standards (NIST, PTB). Our test reports are issued in Spanish and include:

• Full identification of the PTFE film sample (material type, filler, thickness, manufacturing method, manufacturer, lot number, and surface treatment).
• Detailed description of the test methods applied (ASTM/ISO/NTC standards, test gas, pressure, temperature, and duration).
• Numerical results: gas permeability coefficient (P, cm³·mm/(m²·day·atm)), gas transmission rate (GTR, cm³/(m²·day)), burst pressure (MPa), pressure drop rate (kPa/min), deflection (mm), fatigue life (cycles), crystallinity (%), and decomposition temperature (°C).
• Graphical data: pressure vs. time curves, permeability vs. temperature plots, S‑N curves, and pressure-deflection curves.
• Comparative tables against the values specified by the client or against the limits of the NTC 6400 (Gas permeability), NTC 6410 (Burst pressure), NTC 6430 (Fatigue), and the requirements of the SIC, MinMinas, ANH, and DIAN for sealing and barrier materials.
• Photographs and micrographs (SEM) of the film before and after testing, showing the surface condition, deformation, and any damage.
• Recommendations for material selection, design optimization (e.g., thickness, filler type, edge sealing), and quality control to achieve the required gas pressure reduction performance.
• Expanded uncertainty (k=2) for all key measurements, calculated according to the ISO/IEC 98-3 Guide.

These reports are fully accepted by the Superintendencia de Industria y Comercio (SIC) for product registration and quality certification, by the Ministerio de Minas y Energía (MinMinas) and the Agencia Nacional de Hidrocarburos (ANH) for the validation of sealing and barrier materials in the oil, gas, and petrochemical sectors, and by the Dirección de Impuestos y Aduanas Nacionales (DIAN) for tariff classification and quality verification in the import of PTFE films and related components. Additionally, we offer consulting services for the selection of optimal PTFE film grades, the design of pressure-resistant seals and diaphragms, and the implementation of quality control programs for permeability and mechanical performance, contributing to the safety, reliability, and efficiency of industrial operations in the diverse and demanding Colombian market, from the Andean chemical plants to the coastal oil and gas facilities.