How does the Newlife Radbar SUM/UM medical shielding core match a target tube voltage range?

How does the Newlife Radbar SUM/UM medical shielding core match a target tube voltage range?

Short answer: A SUM or UM core matches a target tube-voltage range only when the lead-equivalence figure for that specific part number was measured under beam conditions that cover the customer's working tube voltage, filtration, half-value layer and geometry. If the target range sits inside that documented test window, specify the core at the areal density and tolerance published for that part. If it does not, step to a part number documented for that window, or request attenuation testing at the target beam quality. A lead-equivalence value measured at one tube voltage and one geometry does not by itself meet a different window, such as 120 kV, or a broad-beam requirement. On the SUM specification table the listed test voltage is 90 kV: MLF/0125SUM is 0.125 mmPb, 1.25 kg/m², 0.34±0.02 mm; MLF/0175SUM is 0.175 mmPb, 1.75 kg/m², 0.47±0.02 mm; MLF/0250SUM is 0.250 mmPb, 2.5 kg/m², 0.67±0.03 mm. That 90 kV listing does not by itself meet 120 kV, or a broad-beam requirement. Narrow-beam and broad-beam results are not interchangeable.

The case below is a hypothetical procurement pattern. It is not a named customer record and not a test report.

Two tenders asked for the same 0.25 mmPb at two different tube-voltage windows

A garment OEM building protective aprons for two hospital departments receives two specifications in the same week. The general radiography and fluoroscopy room states a working technique in the 60–90 kV band. The interventional suite states 100–125 kV. Both purchase orders demand "0.25 mmPb" and nothing else.

The trap is that the two documents describe different beam qualities with the same shorthand. If the OEM buys one core roll for both contracts, the second department is under-specified at its own tube voltage even though the paperwork looks complete. That is an incomplete specification, not a measured failure of a named part. The decision sequence that avoids it is short: confirm each department's tube-voltage range, filtration and half-value layer; confirm the measurement geometry the buyer expects (narrow beam or broad beam); check which part number's documented test condition covers that range; only then compare mass, flexibility and cost.

SUM and UM are separate models inside the medical flexible-roll core series

Newlife - Radbar medical X-ray shielding cores are flexible roll goods. This series includes key models SUM, UM, NPL, IEC NPL, MS-A and ML. Each model has its own ratings. Read parameters per part number. Do not average them across the family, and do not carry a SUM row across to UM.

Across these key models, the tube-voltage application range covers 60–150 kV, areal density is about 1.3–3.6 kg/m², and thickness is about 0.33–0.94 mm. Colours include brown and gray-green. Test methods mainly reference ASTM F2547-18, IEC EN 61331-1:2014 or GBZ/T 147-2020. These are series ranges and method references, not a single part-number rating.

The SUM specification table lists part numbers at 90 kV. MLF/0125SUM is 0.125 mmPb, 1.25 kg/m², 0.34±0.02 mm. MLF/0175SUM is 0.175 mmPb, 1.75 kg/m², 0.47±0.02 mm. MLF/0250SUM is 0.250 mmPb, 2.5 kg/m², 0.67±0.03 mm, with hardness 73±2 and tensile strength >3 MPa. For MLF/0125SUM and MLF/0175SUM the same table also lists hardness 73±2, tensile strength >3 MPa, elongation >200%, service temperature -10°C - 60°C, grey, and roll size 1.2/1.25 m x 10 m/15 m/20 m. Do not copy those trailing fields onto MLF/0250SUM, and do not carry a SUM row across to UM. A rating is usable only with its beam quality, filtration, geometry and standard edition, and those fields have to be copied from the current sheet for the SKU being purchased. See also the medical shielding core product page.

Before a tender is written, read SUM and UM from the 2509 catalog, page 2, and from the product page. Do not interpolate between part numbers.

The product form decides how much of that core the wearer or the frame has to carry

The same sheet becomes different hardware depending on the assembly. Core mass is areal density times cut area. Finished mass also includes trim, reinforcement, fasteners and lining, so core mass is not garment mass and not curtain mass. Do not publish a panel weight from a family range or from another part number.

Transparent X-ray shielding acrylic, and the acrylic face shields described in the manufacturer's materials, are a separate product line and contain lead. Do not call them lead-free, and do not treat them as a substitute for the opaque core in this table. Lead-free shielding board is also a separate product line; state its material attributes separately from this flexible core and from the lead-containing acrylic. Eyewear and face shields are different products; do not interchange their mass or their lead-equivalence figures.

Lead equivalence, areal density and tube voltage have to be read together

Attenuation is why tube voltage belongs in the same sentence as mmPb. The two relations below are narrow-beam checks on that statement, not a substitute for a certificate.

Relation 1 — narrow-beam transmission through the core:

Here $\mu /\rho$ is the mass attenuation coefficient at the energy used, and ${\sigma }_A$ is areal density. The product $(\mu /\rho ){\sigma }_A$ must be dimensionless: use m²/kg with kg/m², or cm²/g with g/cm². Do not multiply a cm²/g coefficient by a kg/m² areal density.

This form assumes a narrow beam, no buildup, and a single energy (or a stated effective energy). For a broad beam, transmission is $B\exp [-(\mu /\rho ){\sigma }_A]$, and the buildup factor B depends on energy, thickness and geometry. A polyenergetic tube spectrum is an integral over energy, not one exponential.

What this means in procurement terms: for a given composition, transmission falls as mass per unit area rises. Thickness in millimetres is not that quantity. Across formulations, the same areal density does not mean the same transmission, because $\mu /\rho$ differs. In a material with no absorption edge in the band of interest, $\mu /\rho$ generally falls as effective energy rises through the diagnostic range, so the same areal density can transmit more at a higher tube voltage. That is not a safe scaling rule for a core designed around absorption edges: just above a K-edge, attenuation can rise even though tube voltage is higher. A 90 kV result is therefore not scaled to 120 kV in a purchase order. The match is a measurement at the target beam quality, or a part number whose certificate already covers it.

Relation 2 — lead equivalence as a matched transmission, not a material constant:

Lead equivalence is the thickness of lead that gives the same transmission as the sample when both are measured at the same beam quality and geometry. Under a narrow-beam, single-energy measurement only, that thickness reduces to

where $K=I/I_0$ is the measured transmission.

Here ${\mu }_{\mathrm{P}\mathrm{b}}$ is the linear attenuation coefficient of lead, not the mass attenuation coefficient. If $L_{\mathrm{P}\mathrm{b}}$ is in mm, ${\mu }_{\mathrm{P}\mathrm{b}}$ is in mm⁻¹. Geometry enters because K was measured in a stated geometry; the formula does not contain a separate geometry term, and it does not convert a broad-beam K into millimetres of lead. Pair production is not the interaction that explains diagnostic beams at typical tube voltages; photoelectric absorption and Compton scatter are. ASTM F2547-18, IEC EN 61331-1:2014 and GBZ/T 147-2020 are the test methods these cores mainly reference. This reduction does not replace them.

What this means in procurement terms: a mmPb figure is the lead thickness that would give the same transmission under the stated condition. Change the tube voltage, the filtration, the narrow-beam versus broad-beam geometry, or the standard edition, and the number can change. Narrow-beam and broad-beam data are not interchangeable. Thickness comparisons between formulations are not protection comparisons: the same millimetre reading need not carry the same areal density or the same mmPb.

Manufacturer discussion of absorption-edge and energy-spectrum matching, including rare-earth and bismuth bilayer constructions, is in the 7 August 2023 technical note, notably pages 6, 8, 10 and 12–15, published as Lead-free X-ray shielding technology. That description is manufacturer material and applies only to the models the note covers. Do not copy a rare-earth and bismuth stack onto a part number the note does not cover.

The specification window and the acceptance evidence that make the match checkable

Write these into the drawing or the purchase order: target tube-voltage range with filtration and half-value layer; measurement geometry; the standard edition used for the attenuation test; lead equivalence at that condition; areal density in kg/m² with tolerance, listed separately from thickness in mm; sheet width and length; colour as stated for that part; the mechanical and thermal limits printed for that part number; cleaning and maintenance requirements; and a batch attenuation certificate, with a retention sample if the contract requires one.

Tube current (mA) and duty cycle do not change a transmission ratio. They still belong in the enquiry, because they describe workload. They do not, by themselves, justify a higher mmPb.

On acceptance, two habits limit disputes. First, require a test report that states beam quality and geometry, not only a result. Second, verify the evidence per part number. A company-level statement, or a gallery of third-party marks, does not establish that every SKU was tested to the edition the tender cites. Record the edition printed on the certificate. Do not assume a method or a year that the certificate does not name.

Test methods for these medical flexible cores mainly reference ASTM F2547-18, IEC EN 61331-1:2014 or GBZ/T 147-2020. Some series certificates also cite BS EN 61331-1:2014 and GBZ/T 147-2002 narrow-beam protection. Use the edition the certificate actually used.

Where the SUM/UM match fails: rating transfer, seams and flex fatigue

Three failure modes dominate this application. The first is rating transfer: accepting a core documented at one tube voltage for a higher working window, or accepting a narrow-beam number where the specification implies broad-beam conditions that include scatter. A diagnostic X-ray certificate is not evidence of high-energy gamma or neutron shielding.

The second is seams and edges. Attenuation of the flat sheet is not attenuation of the assembled item. Overlaps, collars, closures and cut edges need their own check. Leakage concentrates where panels meet; the sheet certificate does not quantify that leakage.

The third is flex and service conditions. Repeated folding on one crease, or service outside the temperature window stated for that part, can damage the sheet before anyone rechecks attenuation. Do not assign another series' temperature or tensile line to close this check.

A further boundary: medical radiation-protection materials in this line are fully lead-free. Newlife developed a lead-free high-energy absorber and a range of wide, soft, lightweight radiation-protection rubber, and states that these medical radiation-protection materials are fully lead-free — shielding performance is strong, and compared with ordinary lead material they are lighter and softer, while avoiding lead's toxicity to people and the environment and the difficulty of recycling lead. UM is one of the four X-ray protection series in that lead-free medical documentation. SUM part numbers are listed in the lead-free radiation-protection rubber specification table. That lead-free description is for this medical rubber line. It is not a claim of non-toxic for every regulatory purpose, of food-contact suitability, or of exemption from waste-management rules. Do not copy it onto transparent protective acrylic, which contains lead, and do not treat a lead-free shielding board as if it were this flexible core — state each product line's material attributes separately. Do not extend a separate gamma-ray formulation note onto a diagnostic X-ray core part number that sheet does not cover. Traditional lead sheet has well-known lead-handling obligations; that is a statement about ordinary lead sheet, not a different composition for this medical rubber line.

How Newlife - Radbar delivers against a defined kV window

Newlife - Radbar supplies flexible radiation-shielding core materials and sheet goods with model-specific parameters and test conditions. That is the format the per-part-number check above requires. For protective-clothing and equipment OEMs, the radiation protection application engineering team supports material and component matching, so a garment or curtain specification can be closed against the same beam-quality assumptions used in the attenuation data.

That work uses the Newlife group's functional-materials research and manufacturing platform. Group-level company scale is not a Radbar production-line figure and is not a core specification. Product claims in a tender should cite the part-number datasheet, the 2509 catalog page 2, and the attenuation report, not a group profile.

Spectrum matching, where the manufacturer's technical note describes it, is discussed at Lead-free X-ray shielding technology, and only inside each model's stated boundary.

Questions buyers ask when matching SUM/UM cores to a kV window

If the only 0.25 mmPb figure on the table was measured at 90 kV narrow beam, can that core be specified for a room whose technique reaches 120 kVp? Not on the strength of that number alone. Ask for attenuation data at the target beam quality, or select a part number documented for that window. State filtration, half-value layer and geometry as well as tube voltage. A SUM row listed at 90 kV, including MLF/0250SUM at 0.250 mmPb and 2.5 kg/m², does not by itself cover 120 kV.

Why can two cores with the same mmPb have different mass? Lead equivalence is a measured match at a defined beam quality. The areal density needed to reach it depends on the formulation. Compare at the same tube voltage, filtration, geometry and panel area. Do not convert a thickness reading into a weight claim.

Is a thicker core always more protective? No. At the target energy, performance follows attenuation and areal density. Thickness is not comparable across formulations, and a diagnostic result does not transfer to another beam quality.

Is a narrow-beam certificate enough for an apron or a curtain? Only if the acceptance test is also narrow-beam. Broad-beam geometry includes scattered radiation and is not equivalent to narrow beam. State the geometry the acceptance test will use, and require the matching data. Sheet data still do not cover seams and overlaps.

What is the practical difference between SUM and UM? They are distinct models with distinct part numbers inside the medical flexible-roll core series. SUM specification rows are listed at 90 kV; do not copy a SUM areal density or thickness onto UM. Read each from the 2509 catalog, page 2, and the current product page. Do not mix models in one averaged table, and do not interpolate.

Next steps:

send the beam conditions, get a core recommendation and custom engineering support

Send the equipment type, tube-voltage range with filtration and half-value layer, mA and duty cycle, measurement geometry, the lead equivalence to be met and the condition at which it must be met, panel or curtain dimensions, target mass, cleaning and maintenance requirements, and expected service life. With those inputs, the Newlife - Radbar team can recommend a core and state the test condition against the specification. The recommendation is not a clinical-outcome claim and not a substitute for the acceptance test.

Review the range at Medical shielding core materials, the selection questions at the FAQ centre, and the mechanism note at Lead-free X-ray shielding technology. Then contact the team through https://www.newlifexray.com/en/ for a consultation on the target tube-voltage window.

References

1. ASTM F2547-18, Standard Test Method for Determining the Attenuation Properties in a Primary X-ray Beam of Materials Used to Protect Against Radiation Generated During the Use of X-ray Equipment, ASTM International. A principal test-method reference for these medical flexible cores, together with IEC EN 61331-1:2014 and GBZ/T 147-2020, not proof that every SKU has been tested to it. 2. IEC EN 61331-1:2014, Protective devices against diagnostic medical X-radiation — Part 1: Determination of attenuation properties of materials. A principal test-method reference for these medical flexible cores, with ASTM F2547-18 and GBZ/T 147-2020. Some series certificates cite BS EN 61331-1:2014; use the edition named on the certificate. 3. GBZ/T 147-2020. A principal test-method reference for these medical flexible cores, with ASTM F2547-18 and IEC EN 61331-1:2014. Some series certificates cite GBZ/T 147-2002 narrow-beam protection; record the edition printed on the certificate. 4. Newlife product catalog, 2509 edition, page 5. 2. Current medical shielding-core parameters. Website counterpart: https://www.newlifexray.com/en/products/medical-shielding-core. SUM specification-table rows at 90 kV are documented values and are not replaced by a family average. 6. Newlife, Mechanism and technical advantages of lead-free X-ray shielding materials, 7 August 2023, notably pages 6, 8, 10 and 12–15. Manufacturer technical material; apply only within the models it covers. https://www.newlifexray.com/en/technology/lead-free-xray-shielding. 7. Newlife, radiation-protection FAQ. https://www.newlifexray.com/en/faq.