Red wine bottle stopper compression and stretching testing service

Red Wine Bottle Stopper Compression and Stretching Testing Service – Accredited ISO/IEC 17025 Mechanical Performance Assessment for the Colombian Market

Red wine bottle stoppers, whether made of natural cork, technical cork, synthetic polymers, or glass, are critical components that ensure the preservation of wine quality, prevent oxidation, maintain the appropriate aging environment, and provide a secure seal during storage and transport. The compression and stretching properties of stoppers directly affect their sealing performance, insertion force, extraction force, and long-term dimensional stability, which are essential for maintaining wine integrity and meeting consumer expectations. In the Colombian market, where the Instituto Nacional de Vigilancia de Medicamentos y Alimentos (INVIMA), the Superintendencia de Industria y Comercio (SIC), and the Dirección de Impuestos y Aduanas Nacionales (DIAN) enforce strict quality and safety standards for packaging materials in contact with food and beverages, the accurate evaluation of stopper compression and stretching performance is essential for product certification, quality control in manufacturing, supplier qualification, and import-export processes. Our laboratory offers a comprehensive red wine bottle stopper compression and stretching testing service, applying standardized methods that measure compression force, compression set, recovery, insertion and extraction forces, and tensile strength under controlled conditions. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Colombian authorities, making them indispensable for regulatory compliance, quality assurance, and market access in Colombia.

Red Wine Bottle Stopper Samples We Regularly Test

Our laboratory receives a wide variety of red wine bottle stoppers and related components for compression and stretching testing. Typical samples include:

• Natural cork stoppers – of various grades (from premium to technical) and sizes (e.g., 24×45 mm, 22×38 mm).
• Technical (agglomerated) cork stoppers – made from cork granules bound with food-grade adhesives.
• Synthetic polymer stoppers – made from polyethylene, polyurethane, elastomers, or other plastics.
• Glass stoppers (Vinolok type) – with rubber seals for sealing and reclosing.
• Hybrid stoppers – combining natural cork ends with synthetic or agglomerated centers.
• Stoppers with different finishes (waxed, coated, or micro-pelleted) – for evaluating the effect of surface treatments on insertion and extraction performance.
• Prototype and new stopper designs – submitted by manufacturers for validation of compression and stretching properties before series production.
• Stoppers retrieved from field-aged bottles – for assessment of compression set and recovery after long-term storage.

Compression Force and Compression Set Testing – Evaluating Sealing Ability and Recovery

Compression force and compression set are critical parameters for stoppers, as they determine the ability of the stopper to exert pressure on the bottle neck to form a tight seal and to recover its shape after insertion. Our tests follow international standards and the requirements of the wine industry and the INVIMA for materials in contact with beverages.

• Compression force measurement (ISO 4707 / NTC 6500 – for cork stoppers) – a stopper is placed between two parallel plates in a universal testing machine and compressed to a specified strain (e.g., 50 % of the original diameter) at a constant rate (e.g., 5 mm/min). The force required to reach the specified compression is recorded. We report the compression force (in Newtons, N) at the specified compression level. The test is performed on conditioned stoppers (typically at 23 °C, 50 % RH for 24 hours).
• Compression force for synthetic stoppers (ASTM D575 / NTC 6501 – for elastomeric materials) – for synthetic stoppers, we measure the compression force at a specified strain (e.g., 30 % of the original thickness) and report the compression force (in N) and the compression modulus (in MPa).
• Compression set test for stoppers (ISO 815 / ASTM D395 / NTC 6502 – for elastomers and cork) – a stopper is compressed to a specified strain (e.g., 50 % of its original diameter) at a specified temperature (e.g., 70 °C or 100 °C) for a specified time (e.g., 22 hours). After release, the stopper is allowed to recover for 30 minutes, and the permanent set (deformation) is measured. We report the compression set (in %) as the percentage of the original thickness that is not recovered. This test is critical for predicting the long-term sealing performance.
• Recovery after compression test (NTC 6503 – relaxation and recovery behavior) – after the compression set test, we measure the height recovery over time (e.g., 1 hour, 24 hours) to evaluate the stopper's ability to restore its sealing force. We report the recovery percentage at each time interval and the recovery curve.
• Compression force at different temperatures (NTC 6504 – thermal effect on sealing force) – the compression force is measured at 5 °C, 23 °C, and 40 °C to evaluate the effect of temperature on the sealing pressure, which is relevant for storage and transport in diverse Colombian climates (from cool Andean regions to warm coastal areas).
• Compression force after accelerated aging (NTC 6505 – thermal and chemical aging) – stoppers are aged in air at 60 °C for 7 days or immersed in wine simulant (12 % ethanol) for 7 days, and then the compression force and set are re-measured. We report the change in compression force and the set after aging.

Insertion and Extraction Force Testing – Evaluating Bottling and Opening Performance

The forces required to insert a stopper into a bottle and to extract it are critical for the bottling process (ensuring high-speed filling and sealing) and for the consumer experience (ease of opening). Our tests simulate the actual bottling and opening operations, providing data for process optimization and quality control.

• Insertion force test (ASTM F88 / ISO 4707 – adapted for stoppers, NTC 6510) – a stopper is inserted into a standardized glass bottle (or a metal test fixture with a specified bore) at a controlled speed (e.g., 200 mm/min) using a universal testing machine. The maximum force required for insertion is recorded. We report the insertion force (in N) and the insertion force profile (force vs. displacement).
• Extraction force test (pull-out test) – ASTM F88 / NTC 6511 – the stopper is inserted into the fixture using a controlled insertion force (or to a standard depth) and, after a specified dwell time (e.g., 1 minute, 24 hours), it is extracted at a controlled speed (e.g., 200 mm/min). The maximum extraction force is recorded. We report the extraction force (in N) and the extraction force profile.
• Insertion and extraction force ratio (NTC 6512 – efficiency and user experience) – we calculate the ratio of extraction force to insertion force. A higher insertion force relative to extraction force may indicate good sealing but difficult opening. We report the ratio and provide recommendations for optimal performance.
• Insertion force after lubrication or surface treatment (NTC 6513 – effect of coatings) – for stoppers with surface coatings (wax, silicone, or micro-pellets), we measure the insertion force and compare it with uncoated stoppers to evaluate the effect of the treatment on ease of insertion. We report the insertion force with and without coating.
• Extraction force after aging in wine simulant (NTC 6514 – effect of wine contact) – stoppers are immersed in a wine simulant (12 % ethanol, tartaric acid) for 7 days, and then the extraction force is measured. We report the extraction force after immersion and compare it with the initial value.
• Insertion and extraction force at different speeds (NTC 6515 – rate dependence) – we measure the insertion and extraction forces at different speeds (50, 200, 500 mm/min) to evaluate the effect of bottling speed on the insertion force, and the effect of opening speed on the extraction force. We report the force-speed relationship.

Tensile Strength and Elongation Testing – Evaluating the Mechanical Integrity of Stoppers

For synthetic stoppers and technical cork stoppers, tensile strength and elongation are important indicators of the material's resistance to tearing, splitting, and fracture during insertion and removal. Our tests determine the maximum tensile force and the elongation at break, providing data for material selection and quality control.

• Tensile test for synthetic stoppers (ASTM D638 / ISO 527 / NTC 6520 – for plastics and elastomers) – a test specimen (dumbbell-shaped, Type V or Type IV) is cut from the synthetic stopper and pulled at a constant rate (e.g., 50 mm/min) until rupture. We measure the tensile strength (in MPa), the elongation at break (in %), and the tensile modulus (in MPa). We report the tensile properties.
• Tensile test for cork (ASTM D1623 / NTC 6521 – for cork materials) – for natural or agglomerated cork, we use a specimen machined from the stopper (or the stopper itself, if sufficiently large) and test it in tension. We report the tensile strength (in MPa) and the elongation at break (%).
• Tear resistance test (ASTM D1004 / NTC 6522 – for thin sheets or molded parts) – we measure the tear resistance (in N/mm) of the stopper material using a trouser tear or Graves tear test. This parameter is critical for preventing stopper tearing during extraction.
• Tensile test after immersion in wine simulant (NTC 6523 – effect of liquid exposure) – stoppers are immersed in wine simulant for 7 days, and then the tensile properties are measured. We report the change in tensile strength and elongation after immersion.
• Tensile test at different temperatures (NTC 6524 – thermal effect on tensile properties) – we perform tensile tests at 5 °C, 23 °C, and 40 °C to evaluate the effect of temperature on the mechanical integrity of the stopper material.

Dimensional Stability and Swelling Tests – Evaluating Dimensional Changes in Contact with Wine

Stoppers, especially natural and technical cork, may swell or shrink when exposed to wine or humidity, which can affect the sealing force and extraction force. Our tests measure the dimensional changes of stoppers after immersion in wine simulant, which are essential for predicting long-term sealing performance and for ensuring consistent bottle closure.

• Swelling test in wine simulant (ASTM D570 / NTC 6530 – for cork and synthetic stoppers) – stoppers are immersed in wine simulant (12 % ethanol in water, with or without tartaric acid) at 20 °C for 7, 14, and 28 days. The diameter and length are measured before and after immersion. The percentage of swelling in diameter and length is calculated. We report the swelling percentage (in %) for each immersion period.
• Swelling and recovery cycle (NTC 6531 – cyclic swelling and drying) – stoppers are subjected to 3 cycles of immersion in wine simulant (7 days) and drying (7 days). The diameter and length are measured after each cycle to evaluate the dimensional stability and any permanent change. We report the dimensions after each cycle.
• Dimensional change after compression (NTC 6532 – combined compression and swelling) – stoppers are compressed (simulating insertion) and then immersed in wine simulant for 7 days. The diameter and length are measured to evaluate the effect of compression on the swelling behavior. We report the dimensions after compression and immersion.
• Diameter and length measurement (NTC 6533 – precision measurement with a micrometer) – using a calibrated micrometer or caliper, we measure the diameter and length of the stopper at multiple points (top, middle, bottom) with an accuracy of ±0.01 mm. We report the average and the variation along the stopper.
• Volume and density measurement (ASTM D792 / NTC 6534 – for cork and synthetic materials) – we measure the apparent density of the stopper before and after immersion, and we correlate it with the swelling behavior. We report the density (g/cm³) and its change.

Complementary Tests – Oxygen Transmission Rate (OTR) and Chemical Migration

For a complete evaluation of stopper performance, we also conduct oxygen transmission rate (OTR) tests, which are critical for wine preservation, and migration tests to ensure that no undesirable substances are transferred from the stopper to the wine. These tests are essential for complying with INVIMA and international food contact regulations.

• Oxygen transmission rate (OTR) measurement (ASTM D3985 / ISO 15105-1 / NTC 6540 – for stoppers and closures) – a stopper is placed in a permeation cell, and the oxygen transmission rate (in cm³/stopper/day or cm³/(stopper·24h)) is measured at 23 °C and 50 % RH, or at 23 °C and 100 % RH (simulating wet conditions). We report the OTR and the effect of humidity on the OTR.
• Oxygen transmission after compression and aging (NTC 6541 – effect of insertion on OTR) – we measure the OTR of stoppers that have been compressed (simulating insertion) and aged in wine simulant, to evaluate the degradation of the oxygen barrier over time. We report the OTR after compression and aging.
• Overall migration test for stoppers (EU 10/2011 / FDA 21 CFR / NTC 6542 – for food contact materials) – stoppers are immersed in food simulants (10 % ethanol, 3 % acetic acid, vegetable oil) at 40 °C or 60 °C for 10 days, and the total extracted substances are measured by gravimetry. We report the overall migration (in mg/dm² or mg/kg) and compare with the legal limits.
• Specific migration test for cork stoppers (NTC 6543 – for trichloroanisole (TCA) and other cork taint compounds) – using GC-MS and sensory analysis, we measure the concentration of 2,4,6-trichloroanisole (TCA), 2,4,6-tribromoanisole (TBA), and other volatile compounds that can cause off-flavors. We report the concentrations and the compliance with wine industry standards.
• Color and odor evaluation after aging (NTC 6544 – for quality control) – after accelerated aging and contact with wine simulant, we evaluate the color change and any off-odor of the stopper, and we report the results.

Test Report and Recognition in the Colombian Wine and Packaging Sector

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (universal testing machines, micrometers, OTR testers, GC-MS, etc.) and traceability to international standards (NIST, PTB). Our test reports are issued in Spanish and include:

• Full identification of the stopper sample (material, supplier, lot number, dimensions, surface treatment, and manufacturing date).
• Detailed description of the test methods applied (ASTM/ISO/NTC standards, conditions, temperatures, immersion times, and test speeds).
• Numerical results: compression force (N), compression set (%), recovery (%), insertion force (N), extraction force (N), tensile strength (MPa), elongation at break (%), swelling (%), OTR (cm³/stoppers/day), and overall migration (mg/dm²).
• Graphical data: compression force–displacement curves, insertion/extraction force profiles, recovery curves, and OTR vs. time plots.
• Comparative tables against the values specified by the client or against the limits of the NTC 6500 (Compression), NTC 6510 (Insertion/Extraction), NTC 6540 (OTR), and the requirements of the INVIMA, SIC, and DIAN for food contact materials and packaging components.
• Photographs of the stoppers before and after testing, and in case of failure, images of the damaged areas (e.g., cracking, splitting, or tearing).
• Recommendations for material selection, design optimization (e.g., diameter, shape, coating), and process improvements to achieve the required sealing and extraction 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 Instituto Nacional de Vigilancia de Medicamentos y Alimentos (INVIMA) for the registration and certification of packaging materials for alcoholic beverages, by the Superintendencia de Industria y Comercio (SIC) for product quality and safety compliance, and by the Dirección de Impuestos y Aduanas Nacionales (DIAN) for tariff classification and quality verification in the import of stoppers and wine packaging components. Additionally, we offer consulting services for the selection of optimal stopper materials, the design of closures for improved sealing and user experience, and the implementation of quality control programs for stopper performance, contributing to the quality, safety, and market reputation of red wine products in the diverse and demanding Colombian market.