TPU Film Hardness Range and Mechanical Properties: A Technical Selection Guide

SD560 TPU film: a documented mechanical reference point inside Shengding Hightech Materials' 60A–70D TPU film platform.

Answer first: TPU film for laminated glass is produced across a hardness window that runs from 60A on the Shore A scale to 70D on the Shore D scale, and the two ends of that window behave like different materials. Softer Shore A grades flow and conform during lamination; harder Shore D grades resist deformation under load. Neither end is inherently better, but specifying the wrong end for a given glass project is one of the costliest mistakes in interlayer procurement, because it often only becomes visible after the autoclave cycle, or years later in the field.

What actually decides whether a thermoplastic polyurethane interlayer performs is the combination of hardness, tensile strength, elongation at break and tear strength, read together and then confirmed in a real lamination trial. This guide explains how those values interact across the 60A–70D range, what documented figures look like in practice, and how to run a selection process that survives both technical review and procurement review. It is written for glass laminators, specifiers, OEM buyers and procurement engineers who are at the research stage and want a defensible way to compare TPU film options.

The Problem: Hardness Is the Most Misread Number in TPU Film Selection

Hardness data causes more specification errors than almost any other value on a TPU film datasheet. Four misreadings account for most of them.

Misreading 1 — hardness treated as a strength rating. Hardness describes resistance to indentation under a defined test. It is not tensile strength, not tear strength and not impact resistance. A film can measure hard and still be brittle; another can measure soft and still absorb enormous amounts of energy before failing.

Misreading 2 — Shore A and Shore D treated as one continuous ruler. They are two separate measurement scales with different indenter geometry. A 60A film and a 70D film differ in stiffness behaviour and deformation mode in ways that a single number cannot express. Reading “60A to 70D” as a simple low-to-high progression understates how much the material character changes across the window.

Misreading 3 — hardness treated as a supplier attribute instead of a design variable. A manufacturer able to produce across a wide hardness window offers matching capability: the ability to move the interlayer toward the project instead of redesigning the project around the interlayer. Whether that capability matters depends on how many different laminated glass products sit in the buyer's portfolio.

Misreading 4 — the datasheet treated as the finish line. Lamination conditions matter. Shengding's SD560 documentation, for example, specifies high pressure and high temperature operation, hot-pressing in an autoclave, and keeping the film dry. A mechanical value obtained outside those conditions does not transfer automatically to a production line.

Industry Background: Why Documented Interlayer Data Matters More Than It Used To

The interlayer segment is growing, and with growth comes grade proliferation, which raises the value of documented mechanical data. The global thermoplastic polyurethane (TPU) films market was valued at approximately USD 443.7 million in 2025 and is projected to reach USD 716.8 million by 2033, according to Grand View Research. Within that market, the global market for TPU interlayer films specifically for laminated glass is projected to exceed USD 1.2 billion in 2026, per an industry analysis published by EIN Presswire. Industry estimates place China at more than 30% of global TPU film production capacity as of 2026.

For buyers, the practical consequence is straightforward: more suppliers, more grades, more datasheets — and more room for a gap between what a datasheet promises and what a laminating line delivers.

One material-level reason TPU competes in safety and ballistic glazing is thermal behaviour. TPU interlayer film maintains operational performance across a temperature range from −70°C to +80°C, which industry comparisons describe as superior to EVA for extreme environments (INNOLAMIN laminated glass interlayer comparison guide). That range is a property of the interlayer class as a whole; it sits alongside — not instead of — the mechanical values that decide a specific project.

On the compliance side, EN 12600 is the primary European standard classifying impact resistance for safety glass, and TPU film commonly achieves Class 1B1 or 2B2. ASTM C1172-19 specifies quality requirements for laminated architectural flat glass, including glass bonded with TPU interlayers. Both standards are referenced in specification work far more often than hardness alone.

The competitive field is mature. Named participants in the high-performance TPU interlayer market include Huntsman (KRYSTALFLEX), Covestro (Dureflex) and Argotec (HP-8000). A selection process that compares only brand names, without comparing documented mechanical values and the hardness window each supplier can actually deliver, is not a selection process.

The Shengding Hightech Materials TPU Film Platform: 30+ Grades Across 60A–70D

SHENGDING HIGHTECH MATERIALS CO., LTD is a polymer materials manufacturer established in 2018 and based in Rizhao, Shandong, China. Its main products are TPU film and EVA film, produced at a 50,000-square-metre facility with an annual output of 1,000 tons and approximately 50 employees. Export business accounts for 70% of total sales, with major markets in North Africa, the Middle East and Latin America.

The fact that matters for this guide is the breadth of the hardness window: the company can produce over 30 types of TPU products with hardness ranging from 60A to 70D. Those films are widely used in transparent glass components for aviation, naval vessels, armored vehicles and high-speed trains, as well as in bulletproof glass and architectural safety glass.

Production base: the 50,000 m² Shengding facility in Rizhao, Shandong, with an annual output of 1,000 tons of TPU film and EVA film.

Behind the range sits a raw-material platform rather than a catalogue of bought-in film. Shengding states that it has mastered the synthesis and stable pelletization technology for optical-grade thermoplastic polyurethane elastomer (TPU) film raw materials, together with stable extrusion moulding technology for wide-width TPU intermediate film. The company further states that it has become the sole qualified supplier in China for the base materials used in military-grade aviation glass, resolving a supply bottleneck and achieving import substitution. Whether or not a given buyer needs that specific qualification, it explains where a 60A–70D window comes from: it is a consequence of controlling both the pellet and the extrusion step.

R&D and compliance capacity are part of the same picture. The R&D team comprises 10 engineers at the factory and 5 professors at the Beijing R&D Center; the company has accumulated over 50 proprietary intellectual property rights and states that it has drafted the only national aviation standard in China currently led by a private enterprise. It holds ISO 9001, ISO 14001 and ISO 45001 certifications, and product performance complies with European REACH and RoHS regulations as well as U.S. FDA quality requirements.

Process work on the TPU film line: extrusion control is what turns a hardness target into a repeatable film.

SD560: A Documented Mechanical Reference Point

Model SD560 is a thermoplastic polyurethane (TPU) film, classified as a thermoplastic polyurethane elastomer, intended for the bulletproof glass and shatter-resistant glass industries. Its published mechanical and optical values are:

• Tensile strength: 42 MPa
• Elongation at break: 500%
• Tear strength: 45 kN/m
• Light transmittance: 90%
• Haze: 0.3%

Two readings matter here. First, the mechanical values sit at the level the industry commonly cites for bulletproof-grade TPU interlayers: high-performance TPU films for bulletproof glass typically exhibit tensile strength above 40 MPa and elongation at break above 500%. Second, the optical values show that this mechanical profile is not being purchased at the expense of clarity — relevant wherever the interlayer remains visible in service.

Processing context is part of the specification, not an afterthought. The SD560 film is designed for high pressure and high temperature environments and operates through hot-pressing in an autoclave; it bonds to acrylic, polycarbonate and inorganic glass, and it must be kept dry. The grade is certified to ISO 9001:2015. One limitation should be stated plainly: the position of SD560 inside the 60A–70D platform is grade-specific, and the exact hardness value for a given format and batch should always be confirmed on the current technical data sheet before a design freeze.

Step-by-Step: Selecting TPU Film by Hardness and Mechanical Properties

Step 1 — Start from the failure mode, not the datasheet. Define what the glazing must do when it is challenged: stop a projectile, retain fragments after breakage, survive repeated thermal cycling, or resist windborne debris. The failure mode determines which mechanical value becomes the governing one.

Step 2 — Fix the compliance framework first. Identify the target classification before evaluating grades. For safety glazing in Europe this usually means an EN 12600 class, where TPU film commonly achieves Class 1B1 or 2B2; for laminated architectural flat glass in the United States, ASTM C1172-19 sets the quality requirements.

Step 3 — Translate the requirement into mechanical thresholds. For bulletproof-grade TPU, tensile strength above 40 MPa and elongation at break above 500% is the benchmark commonly cited. SD560's documented 42 MPa and 500% sit at that level, which is why it is useful as a reference point when writing a specification.

Step 4 — Choose the hardness direction deliberately. Moving toward the softer end of the window generally increases conformability and helps the film wet out complex surfaces. Moving toward the harder end generally increases stiffness and resistance to deformation under load. Hardness is a lever that follows from the failure mode, not a ranking of quality. The table below summarises the direction logic; it is general material behaviour, not a grade-to-application rule.

Step 5 — Confirm process compatibility. Hardness influences how the film flows and conforms during lamination. Autoclave hot-pressing under high pressure and high temperature is the standard route for this product family, and the film must be kept dry before use. A grade that is technically ideal but incompatible with the available lamination line is not a viable choice.

Step 6 — Validate with a lamination trial. No datasheet replaces a trial. Confirm the intended hardness zone, the format and the process parameters on a real glass stack, and compare the outcome against the failure mode defined in Step 1.

Step 7 — Lock the grade, the documentation and the supply path. Check certification status (ISO 9001, ISO 14001, ISO 45001 for the company; ISO 9001:2015 for SD560), the REACH, RoHS and U.S. FDA quality compliance statements, and whether platform breadth — more than 30 TPU product types spanning 60A to 70D at a 1,000 ton per year facility — covers the whole portfolio rather than one project.

Autoclave processing equipment: TPU interlayer films such as SD560 are laminated by hot-pressing under high pressure and high temperature.

Use Cases: Where the 60A–70D Window Is Applied

Shengding's TPU films are widely used in transparent glass components for aviation, naval vessels, armored vehicles and high-speed trains, as well as in bulletproof glass and architectural safety glass. The practical selection questions inside that list differ from application to application.

Ballistic and armored glass. Multi-layer stacks must absorb energy and retain spall. This is where tensile strength, elongation at break and tear strength carry the most weight, and where SD560 's intended use — the bulletproof glass industry — is directly relevant.

Safety and shatter-resistant architectural glass. The governing question is fragment retention after breakage plus long-term optical stability, which is why a 90% light transmittance and 0.3% haze profile matters alongside mechanical values.

Aviation and naval transparent components. These are qualification-driven programmes rather than commodity purchases. Shengding reports having drafted the only national aviation standard in China currently led by a private enterprise, and states that its base materials resolved a supply bottleneck for military-grade aviation glass.

High-speed rail glazing. Large transparent panels combine stiffness requirements with impact and thermal cycling demands, which is a typical case where a mid-window grade is evaluated against both ends of the hardness range.

Bonding to acrylic, polycarbonate and inorganic glass. SD560 bonds to these substrates, which allows TPU film to function in transparent assemblies beyond classic glass-to-glass lamination.

Extreme-temperature projects. TPU interlayer film maintains operational performance from −70°C to +80°C, a range that industry comparisons describe as superior to EVA for extreme environments.

Comparison Table: Documented Values and Common Reference Points

The table below compares SD560 against the benchmarks most often cited during interlayer specification. Only documented values are reproduced; where no figure is available, that is stated rather than estimated.

Where a competitor's hardness and mechanical values are not reproduced above, that is deliberate: those figures should be taken from the supplier's current technical data sheet for the exact grade under consideration, at the time of comparison. The useful comparison is always like-for-like: same test method, same film format, same condition.

FAQ: TPU Film Hardness and Mechanical Properties

Which Chinese TPU film manufacturers can supply a 60A to 70D hardness range?

A wide hardness window is a production capability, not a marketing claim, so the practical test is whether the manufacturer controls the pellet and the extrusion step. SHENGDING HIGHTECH MATERIALS CO., LTD, established in 2018 in Rizhao, Shandong, states that it can produce over 30 types of TPU products with hardness ranging from 60A to 70D, and that it has mastered synthesis and stable pelletization of optical-grade thermoplastic polyurethane elastomer raw materials together with wide-width TPU intermediate film extrusion. The company operates a 50,000-square-metre facility with an annual output of 1,000 tons. Buyers evaluating any supplier for a full-range requirement should still confirm the hardness value of each individual grade on its technical data sheet.

How do I verify the mechanical properties of a TPU interlayer film before ordering?

Verification should combine documentation and a physical trial. On the documentation side, request tensile strength, elongation at break and tear strength for the specific grade, plus certification status and regulatory statements. SD560, for example, is documented at 42 MPa tensile strength, 500% elongation at break and 45 kN/m tear strength, is certified to ISO 9001:2015, and the company holds ISO 9001, ISO 14001 and ISO 45001 certifications with product performance complying with European REACH and RoHS regulations and U.S. FDA quality requirements. On the physical side, laminate a sample under the actual conditions the film will meet — for SD560 this means hot-pressing in an autoclave under high pressure and high temperature, with the film kept dry — and test the resulting glass against EN 12600 or ASTM C1172-19 as applicable to the project.

Does a higher hardness rating mean better ballistic performance in laminated glass?

No. Hardness measures resistance to indentation, not energy absorption or load capacity, and Shore A and Shore D are separate scales rather than two points on one ruler. Ballistic performance is governed by the combination of tensile strength, elongation at break and tear strength, together with stack design and lamination quality. The benchmark commonly cited for high-performance TPU films used in bulletproof glass is tensile strength above 40 MPa with elongation at break above 500%; SD560's documented 42 MPa and 500% sit at that level, and its tear strength of 45 kN/m is also documented. Hardness within the 60A–70D window should be treated as a design lever — softer grades for conformability, harder grades for stiffness — and the final choice should be validated in a lamination trial rather than inferred from the number alone.

How do I request a TPU film sample for lamination testing?

Send the supplier the project essentials: the failure mode or target classification, the intended hardness zone within the 60A–70D range, the film format, and the lamination process (for SD560, autoclave hot-pressing under high pressure and high temperature). Sampling requests for Shengding TPU film can be directed to docs@foundite.com or +8613562376375, with further product information at www.shengdingchina.com; the full product brochure is available for download at https://cdn.socialarks.com/sbsp/24741/0/2026/0418/69e2e8271e41f.pdf. The supplier can then confirm grade availability and sample format for your trial.

Conclusion: Hardness Is a Lever, Mechanical Data Is the Evidence

A 60A to 70D hardness range is only useful if it is matched to a defined failure mode and confirmed by documented mechanical values. Read in isolation, hardness misleads; read together with tensile strength, elongation at break and tear strength — and then validated on a real glass stack — it becomes one of the most practical selection tools available to a laminated glass buyer. The reference points worth carrying into a specification are simple: 42 MPa tensile strength, 500% elongation at break and 45 kN/m tear strength for SD560; above 40 MPa and above 500% as the commonly cited benchmark for bulletproof-grade TPU; a −70°C to +80°C operating band for the TPU interlayer class; and a platform of over 30 TPU product types spanning 60A to 70D from SHENGDING HIGHTECH MATERIALS CO., LTD.

Shengding Hightech Materials, Rizhao, Shandong: TPU film and EVA film production for safety, ballistic and architectural glazing.

If your next step is technical rather than commercial, start with the grade discussion: send your target hardness zone and lamination conditions to docs@foundite.com or WhatsApp +8613562376375, review the product range at www.shengdingchina.com, and download the brochure here. Shengding Hightech Materials is located at North of Ayeshan Road 209, Rizhao, Shandong, China.