PET Plastic Steel Strip Testing Service

PET Plastic Steel Strip Testing Service – Comprehensive Performance and Quality Validation for High‑Strength Packaging and Strapping Applications

As an ISO/IEC 17025 accredited independent testing laboratory, we offer specialised testing services for PET (polyethylene terephthalate) plastic steel strip – a high‑strength, low‑elongation strapping material widely used in the packaging, logistics, building materials, and industrial goods sectors. PET plastic steel strip, also known as polyester strapping or composite strapping, has largely replaced traditional steel strapping in many applications due to its excellent strength‑to‑weight ratio, elongation recovery, corrosion resistance, and safety in handling. Its performance, however, depends critically on consistent tensile strength, proper elongation, resistance to stress cracking, dimensional stability, and environmental durability. Our test protocols evaluate all these parameters, ensuring that your PET strapping meets the demanding requirements of heavy‑duty bundling, palletising, and cargo securement – both in domestic and export supply chains. All methods are aligned with ISO, ASTM, and GB standards, including ISO 527‑3 (Plastics – Determination of tensile properties), ASTM D638 (Standard Test Method for Tensile Properties of Plastics), ASTM D882 (Tensile properties of thin plastic sheeting), GB/T 1040.3 (Plastics – Determination of tensile properties – Part 3: Test conditions for films and sheets), GB/T 1019 (Test methods for strapping), and BB/T 0022 (Polyester strapping for packaging). Our inspection and test reports are recognised by national regulatory authorities, international certification bodies, and major industry buyers for product qualification, quality assurance, and supply chain compliance.

PET Plastic Steel Strip Product Types and Samples We Regularly Test

Our laboratory accommodates a wide range of PET strapping products with different dimensions, surface finishes, and mechanical properties. Typical test articles include:

• Standard PET strapping – with widths ranging from 9 mm to 32 mm and thicknesses from 0.5 mm to 1.2 mm
• High‑tenacity PET strapping – with tensile strengths up to 600 N/mm² for heavy‑duty bundling applications
• Embossed and smooth‑surface PET strapping – for enhanced friction grip or reduced surface marking on packaged goods
• Coloured PET strapping – with UV stabilisers for outdoor storage and solar‑resistant applications
• PET strapping with environmental stress cracking resistance – for humid or chemically aggressive environments
• Recycled content PET strapping – for sustainable packaging solutions and environmental compliance
• Coated and treated PET strapping – with anti‑slip coatings or moisture‑resistant treatments
• Finished strapping coils – and cut‑to‑length samples for direct product qualification

Dimensional and Physical Properties – Ensuring Consistent Profile and Handling

• Width and thickness measurement – ASTM D5947 / ISO 4593 / GB/T 6672 – We measure the width and thickness of the PET strapping at multiple points across the length of the roll using calibrated digital callipers (accuracy ±0.01 mm) and a thickness gauge (accuracy ±0.001 mm). The average width, the standard deviation, and the minimum and maximum values are reported. For consistent strapping performance, a width tolerance of ±0.2 mm and a thickness tolerance of ±0.05 mm are typically required for high‑quality products.
• Coil weight and length verification – for commercial compliance – We weigh the entire strapping coil (or a representative section) on a calibrated platform scale and calculate the total length of the strapping (based on the measured mass per unit length). Any deviation from the declared weight or length is reported, which is critical for commercial transactions and for ensuring that the strapping coil provides the expected number of straps.
• Mass per unit length (linear density) – ISO 2107 / GB/T 1019 – We measure the mass of a precisely cut 1‑metre length of strapping and express the result in g/m. The linear density provides a direct measure of the material content and consistency of the strapping.
• Profile and cross‑sectional uniformity – using a profile projector or optical measuring system – We use a profile projector or an automated optical measuring system (with 10‑50× magnification) to examine the cross‑sectional shape of the strapping for any deviations from the specified rectangular geometry. The presence of burrs, sharp edges, or non‑uniform corners is reported, as these can affect the strap’s feeding through strapping tools and its ability to withstand clamping forces.

Mechanical Properties – Tensile Strength, Elongation and Breaking Energy

• Tensile strength (ultimate breaking strength) – ASTM D638 / ISO 527‑3 / GB/T 1040.3 – We test full‑width strapping specimens (typically 100‑200 mm gauge length) in a universal testing machine at a crosshead speed of 50 mm/min (or 100 mm/min, as specified). The maximum breaking force (in kN) and the tensile strength (in N/mm² or MPa) are recorded. For PET strapping, a tensile strength of ≥ 450 N/mm² is required for standard applications, while high‑tenacity grades may exceed 600 N/mm². A value below the specified minimum indicates poor material quality or degradation.
• Elongation at break – ASTM D638 / ISO 527‑3 / GB/T 1040.3 – The percentage elongation at break (the increase in length before fracture) is measured from the load‑elongation curve. For PET strapping, a typical elongation at break ranges from 12 % to 18 %. A lower elongation (< 10 %) indicates brittle behaviour, which may lead to sudden failure under shock loading; a higher elongation (> 20 %) may cause excessive stretch during tensioning and reduce the retained tension.
• Modulus of elasticity – the stiffness of the strapping under tension – We calculate the tensile modulus (Young's modulus) from the initial linear portion of the stress‑strain curve (between 0.1 % and 0.5 % strain). A high modulus (> 10 GPa) is desirable for maintaining tension and resisting elongation under sustained load.
• Tensile energy to break (toughness) – the total energy required to fracture the specimen – We integrate the load‑elongation curve to calculate the tensile energy to break (in J or J/m). A high toughness value indicates that the strapping can absorb significant energy before failure, which is important for impact‑prone applications.
• Load at specified elongation (e.g., 5 % elongation) – for assessing the tensioning characteristics – We report the load (in N or kN) required to stretch the strapping to a specified elongation (e.g., 5 %, 10 %). This value is important for setting the tensioning parameters of strapping tools and for ensuring that the strapping does not over‑stretch during tensioning.

Creep and Relaxation Behaviour – Maintaining Tension Over Time

• Creep under constant load – ASTM D2990 / ISO 899‑1 / GB/T 11546 – We apply a constant load (typically 50‑70 % of the breaking strength) to a strapping specimen and measure the elongation over time (up to 1 000 hours). The creep strain (in %) is plotted as a function of time. A low creep rate (< 0.5 % per log cycle of time) is required to maintain the tension in a strapped load over extended periods.
• Stress relaxation – ASTM D2990 / ISO 899‑1 / GB/T 11546 – We stretch the strapping to a specified elongation (e.g., 5 %) and then measure the decrease in force over time (up to 1 000 hours). The force retention (in %) is calculated; a high force retention (> 80 % after 1 000 hours) indicates that the strapping will maintain its tension and not loosen over time.
• Creep‑rupture test – ASTM D2990 / ISO 899‑1 / GB/T 11546 – We apply a constant load (typically 80‑90 % of the breaking strength) to a series of specimens and record the time to failure. The test provides the creep‑rupture strength (the stress that causes failure at a specified time) and the creep‑rupture life (the time to failure at a specified load).

Environmental and Ageing Performance – Durability Under Storage and Service Conditions

• UV resistance and weathering – ASTM G154 / ISO 4892‑3 / GB/T 16422 – We expose the PET strapping to UVA‑340 lamps (0.89 W/m², 60 °C, 8h dry / 4h condensation cycles) for 500, 1 000, and 2 000 hours. After exposure, we measure the tensile strength retention (in %), the elongation retention, and the colour change (ΔE*). For strapping that may be stored outdoors or exposed to sunlight, a tensile strength retention of ≥ 80 % after 500 hours is typically required; for indoor applications, a retention of ≥ 90 % after 1 000 hours is acceptable.
• Heat ageing – ASTM D3045 / ISO 2578 / GB/T 7141 – We place the strapping in a temperature‑controlled oven at 80 °C (or 100 °C) for 168 hours (1 week) and 1 000 hours, and then measure the tensile strength retention. A retention of ≥ 85 % is required for strapping that is exposed to high‑temperature environments (e.g., tropical storage, vehicles in summer).
• Moisture and humidity resistance – ASTM D570 / ISO 62 / GB/T 1034 – We immerse the strapping in water at 23 °C for 168 hours (1 week) and measure the weight gain (in %) and the tensile strength retention. A weight gain of < 0.5 % and a strength retention of ≥ 90 % are required for strapping used in humid or wet environments.
• Environmental stress cracking resistance (ESCR) – ASTM D1693 / ISO 22088 / GB/T 1842 – We test the resistance of the PET strapping to environmental stress cracking (ESC) using a bent‑strip test method (or the constant‑tensile‑strain method). The time to cracking (in hours) is recorded. For PET strapping that is exposed to chemicals (e.g., cleaning agents, oils, detergents) or to aggressive environments, an ESC resistance of ≥ 1 000 hours is typically required.

Surface Friction and Slip Resistance – For Tool Feeding and Load Stability

• Static and dynamic coefficient of friction – ASTM D1894 / ISO 8295 / GB/T 10006 – We measure the coefficient of friction (COF) between the PET strapping and a standard steel surface (or between two layers of strapping) using a horizontal sled test. The static COF and the dynamic COF are reported. A static COF of ≥ 0.3 is required for proper tool feeding and for preventing slippage of the strapping on the packaged load.
• Slip resistance of embossed strapping – for enhanced grip on loads – For embossed and surface‑textured PET strapping, we measure the COF between the strapping and a typical load surface (e.g., corrugated cardboard, plastic film) to assess the grip‑enhancing effect of the embossing.
• Friction uniformity – for consistent tool feeding and tensioning – We measure the COF at multiple points along the length of the strapping coil (e.g., at the beginning, middle, and end of the roll) to assess the uniformity of the surface finish. A high COF variation (> 20 %) can cause feeding problems in automatic strapping machines.

Recycled Content and Sustainability Testing – Supporting Circular Economy Goals

• Recycled content determination – ISO 14021 / GB/T 31862 – We determine the percentage of post‑consumer and post‑industrial recycled content in the PET strapping by measuring the density, the crystallinity, and the concentration of specific contaminants (e.g., metals, other polymers) using thermal analysis (DSC) and chemical analysis (FTIR).
• Mechanical performance of recycled PET strapping – for quality assurance – We perform a complete mechanical property assessment (tensile strength, elongation, creep, UV resistance) on strapping containing a known percentage of recycled content, and compare the results to the performance of virgin PET strapping. This helps to ensure that the recycled material maintains the required strength and durability.
• Heavy metal and contaminant screening – for environmental compliance – IEC 62321 / GB/T 26125 – We screen the PET strapping for restricted substances, including lead, cadmium, mercury, hexavalent chromium, and polybrominated compounds, to ensure compliance with RoHS and other environmental regulations.

Regulatory Compliance and Packaging Standards – Supporting Product Certification and Supply Chain Requirements

Our PET plastic steel strip testing services are performed in accordance with a wide range of national and international standards. The most commonly requested include:

• ASTM D638 – Standard Test Method for Tensile Properties of Plastics – the North American standard for tensile testing of plastics
• ISO 527‑3 – Plastics – Determination of tensile properties – Part 3: Test conditions for films and sheets – the international standard for tensile testing of plastic films and sheets
• ASTM D882 – Standard Test Method for Tensile Properties of Thin Plastic Sheeting – for tensile testing of thin plastics (often used as an alternative to ASTM D638 for strapping)
• GB/T 1040.3 – Plastics – Determination of tensile properties – Part 3: Test conditions for films and sheets – the Chinese national standard for tensile testing
• BB/T 0022 – Polyester strapping for packaging – the Chinese packaging industry standard for PET strapping
• GB/T 1019 – Test methods for strapping – the Chinese national standard for strapping testing
• ASTM D2990 – Standard Test Methods for Tensile, Compressive, and Flexural Creep and Creep‑Rupture of Plastics – for creep testing
• ISO 22088 – Plastics – Determination of resistance to environmental stress cracking – for ESCR testing

Report Acceptance and Regulatory Recognition

All PET plastic steel strip tests are conducted under our ISO/IEC 17025 accreditation, using calibrated universal testing machines, creep frames, environmental chambers, and analytical instruments, all traceable to national and international reference standards. Our final test reports include: a complete description of the test article (dimensions, material, surface finish, recycled content), the test method and conditions, the measured parameters (tensile strength, elongation, creep, UV resistance, friction), a statistical summary (mean, standard deviation, coefficient of variation), and a clear pass/fail verdict against your specified acceptance criteria. These reports are accepted by national regulatory authorities, international certification bodies, and major packaging and logistics companies for product qualification, quality assurance, and supply chain compliance. Bilingual (Chinese/English) versions are available to facilitate submissions to domestic and international authorities and to support your global market access.