How to Read a Plastic Technical Data Sheet (TDS)

Two datasheets for “PA66 GF30” can look identical and describe materials that behave quite differently in your part. Two sheets with very different numbers can describe almost the same material tested two ways. Reading a TDS well means knowing what each line was measured on, and what it leaves out.

What a TDS is, and is not

The values on a TDS are typical results for the uncoloured material, moulded into standard specimens and tested at 23 °C unless stated. Well-built sheets follow ISO 10350-1, the standard set of single-point data that the CAMPUS database uses so that grades from different producers can be compared. They are not minimums, they are not measured on your part, and they do not reflect your colour, wall thickness, gate position or weld lines.

Start with the header. A designation such as PA66-GF30 follows ISO 1043 and tells you the polymer and the filler: here, polyamide 66 with 30% glass fibre by mass. Then check whether the mechanical values are given dry, conditioned or both.

The lines at a glance

Melt flow: MFI, MFR and MVR

MFI, the melt flow index, is the trade name for what ISO 1133-1 calls melt mass-flow rate (MFR, grams per 10 minutes) and melt volume-flow rate (MVR, cubic centimetres per 10 minutes). Molten material is pushed through a standard die under a set weight at a set temperature. Those conditions differ by polymer, commonly 230 °C and 2.16 kg for PP and higher temperatures for nylons and polyesters, so only compare values measured under the same conditions. ISO notes that MVR is the better basis for comparing filled and unfilled grades.

Melt flow is a quality-control number: good for spotting lot-to-lot drift, poor at predicting flow length in a thin-walled tool. For flow length, ask for spiral-flow or viscosity data.

Density

Density (ISO 1183) confirms the filler level and turns price per kilogram into price per part. A 30% glass PP sits around 1.13 g/cm³ and a 30% glass PA66 around 1.36 g/cm³, so the nylon part weighs about 20% more for the same volume. For filled grades, density and ash content together are the quickest check that a lot carries the filler it should.

Tensile and flexural properties

ISO 527 gives tensile modulus (stiffness at very low strain), stress at yield or break, and strain at break. ISO 178 gives the same in three-point bending. The two moduli are often close but not equal: one PA66 GF30 datasheet lists 10,000 MPa tensile against 8,600 MPa flexural, dry. Use the one that matches how your part is loaded, and compare like with like.

For polyamides, the condition column matters more than the polymer. The same PA66 GF30 drops from 10,000 to 7,200 MPa tensile modulus once conditioned at 23 °C and 50% RH. Temperature matters too: a PA6 GF30 sheet shows 9,600 MPa at 23 °C and 4,500 MPa at 80 °C, dry. If your part runs warm, ask for modulus at your temperature.

Impact: Charpy and Izod

Both tests break a bar with a pendulum. Charpy (ISO 179) supports the bar at both ends; Izod clamps one end. Each can be run notched or unnotched, and the notched value tells you how sensitive the material is to sharp corners. A low-temperature value, often at -30 °C, matters for exterior and cold-climate parts.

The trap is units. ISO 180 Izod divides the energy by the area under the notch and reports kJ/m², on an 80 x 10 x 4 mm bar. ASTM D256 divides by specimen thickness and reports J/m, on a 64 x 12.7 x 3.2 mm bar. There is no reliable conversion between them. Compare Izod values only within one standard.

HDT and Vicat

Heat deflection temperature (ISO 75) is the temperature at which a loaded bar, heated at 120 K per hour, bends by a set amount. Method A uses 1.80 MPa, method B 0.45 MPa and method C 8.00 MPa. ASTM D648 uses 1.82 or 0.455 MPa with the bar on edge. The load changes the answer dramatically: in one published example, a polypropylene measured 57 °C at 1.8 MPa and 99 °C at 0.45 MPa. Check the method before comparing.

HDT is not a maximum service temperature. For glass-filled semi-crystalline polymers it sits close to the melting point: 250 °C HDT against a 260 °C melt for PA66 GF30. Long-term capability is better read from a temperature index. The same PA66 sheet gives 165 °C for 5,000 hours and 135 °C for 20,000 hours: the temperatures at which tensile strength falls by half over those times.

Flammability

A UL 94 rating applies at a stated thickness, and sometimes a colour. The same PA66 GF30 sheet lists HB at 0.75 mm and at 1.5 mm. A V-0 at 3 mm does not cover a 0.8 mm rib, so ask for the rating at your thinnest wall and check the UL file if your customer requires a listing. Glow-wire and tracking values are separate lines; our flame-retardant compounds page sets out how to specify all three.

What a one-page TDS leaves out

• Creep and fatigue: how the material behaves under constant or cyclic load over time (ISO 899-1 for tensile creep).
• Heat ageing: retained strength and impact after hours at temperature.
• Chemical and UV resistance: fuels, coolants, cleaning agents, sunlight.
• Weld-line strength: often well below the bar value in glass-filled grades.
• Multi-point data: stress-strain curves and modulus against temperature for simulation (ISO 11403).

TDS, CoA and material specification

The TDS describes the grade. The certificate of analysis (CoA) reports measured values for one lot against agreed limits. The material specification, usually the customer’s, sets what is acceptable. Every AAP batch is tested before dispatch and every lot ships with a CoA, with ERP batch genealogy back to raw materials; see our quality page. Grade pages such as OSAMIDE AISG 6 (PA66, 30% glass), OSABATE 506 GF (PBT, 30% glass) and OSALENE PPTF 20 (PP, 20% talc) show each grade’s property profile, and the full TDS is available on request.

What to ask your supplier

1. The test standard and condition behind every value, ISO or ASTM.
2. Dry and conditioned values for polyamides.
3. Modulus and strength at your service temperature.
4. Creep, heat-ageing and chemical data for your environment.
5. UL 94 rating with thickness and colour, plus glow-wire and CTI where relevant.
6. Which properties appear on the CoA, with their limits.
7. The processing sheet: drying, melt and mould temperatures.
8. RoHS and REACH declarations and the SDS.

If you are matching an existing grade from another producer, our equivalent-grade tool and the material finder are a quick first filter.

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