Melt flow indexers (extrusion plastometers) · Test method and procedures A–D, MFR and MVR, load application by weights or load cell, displacement measurement, flow rate ratio
A melt flow index tester (extrusion plastometer) heats a thermoplastic in a barrel, pushes it through a standard die under a set load, and reports the extrusion rate as a mass flow rate (MFR) or a volume flow rate (MVR). Settle three things before ordering: the standards and procedures your customers specify, how the load is applied and changed, and how piston travel is timed and measured for volume-rate procedures.
Melt flow indexers and extrusion plastometers for thermoplastic MFR and MVR testing to ASTM D1238 and ISO 1133. Capillary rheometers, rotational rheometers, Mooney viscometers and moisture analysers are outside this page.
01
ASTM D1238 covers determination of the rate of extrusion of molten thermoplastic resins using an extrusion plastometer. It states that the flow rate is not a fundamental polymer property but an empirically defined parameter influenced by the polymer's physical properties and molecular structure and by the measurement conditions, and that values may not correlate directly with large-scale processing. [1]
Where two or more conditions are used, D1238 obtains a flow rate ratio (FRR) by dividing the flow rate at one condition by that at another, and its Procedure D provides a way to measure more than one condition on a single charge. [1]
Editorial note: list the procedures and conditions your material specifications call for before choosing a tester, because a manual instrument that runs only one procedure may not run the volume-rate or multi-condition procedures without upgrades. [1] [2]
Give the supplier the standards and editions (ASTM D1238, ISO 1133), procedures (A, B, C, D), MFR and/or MVR, test loads and temperatures, materials tested, sample throughput, cutting method (manual or automatic), cleaning and purge needs, software and data export, power supply, calibration certificate, and quantity.
02
Tinius Olsen describes its manual MP1200 as supplied with everything needed for ASTM D1238 Procedure A except weights and a laboratory balance, with a motorised MP1200M version. It can be upgraded with ISO 1133 tooling and an encoder-based programmable piston displacement transducer for Procedures B and C or volume measurement, and offers manual or automatic specimen cutting, pneumatic purge and cleaning, a motorised weight-lowering platform and quick die release. [2]
Its MP1500 applies load through a load cell and a PID-controlled drive with no dead weights, over 0.325 to 45 kg, and is stated to conform to ISO 1133 and ASTM D1238 and to perform MFR and MVR under Procedures A, B, C and D, with a 7.1-inch touchscreen. [3]
Editorial note: a dead-weight tester changes load by swapping weights; a load-cell tester sets load in software, which matters if you run Procedure D or more than one condition per day. [3] [2] [1]
03
GÖTTFERT publishes a side-by-side table for its mi-series melt flow indexers, which shows the automation steps a buyer can choose between. All four models listed (mi1, mi2, mi3 and mi40) are given for ISO 1133 and ASTM D1238 Procedures A, B and C. The mi1 and mi2 use a single test weight with manual selection and a 0.003 mm per impulse displacement sensor; the mi2 adds an automatic weight-lifting device that starts the measurement after the melting time and returns the weights to the start position. The mi3 carries a magazine of up to 8 test weights with manual selection, the mi40 selects from that magazine automatically and runs single or multi-weight tests, and both use a 0.006 mm per impulse sensor with force-controlled compaction up to 80 kg (optional on the mi3). [4]
GÖTTFERT lists options for the mi2 including a heated die plug and melt cutting unit for Procedure A, customised capillaries for ASTM D1238 Procedure C ("half die") or ASTM D3364, nitrogen purge for hygroscopic materials, die swell measurement, alternative barrel and piston steels for corrosion or abrasion resistance, and final acceptance to ISO 17025. [4]
Editorial note: a multi-weight model such as the mi40, or a load-cell instrument such as Tinius Olsen's MP1500, is the route to running D1238 Procedure D or a flow rate ratio on one charge without manual weight changes; confirm which procedures the quoted configuration runs as delivered. [4] [3] [1]
| GÖTTFERT model | Test weights | Displacement sensor | Compacting |
|---|---|---|---|
| mi1 | Single weight, manual selection. [4] | 0.003 mm / impulse. [4] | By test weights. [4] |
| mi2 | Single weight, manual; automatic weight lifting. [4] | 0.003 mm / impulse. [4] | By test weights. [4] |
| mi3 | Magazine, up to 8 weights, manual selection. [4] | 0.006 mm / impulse. [4] | By weights; force-controlled to 80 kg optional. [4] |
| mi40 | Magazine, up to 8 weights, automated selection. [4] | 0.006 mm / impulse. [4] | By weights and force-controlled to 80 kg. [4] |
04
The manufacturer cards below state what each reviewed source shows.
Ask any supplier which D1238 and ISO 1133 procedures the quoted configuration runs as delivered, and which need options. [1] [2]
05
This is a functional reference built from the sources cited; it is not one maker's specification.
| Part | Role | Fix in the order |
|---|---|---|
| Heated barrel and die | Melt and extrude the sample. [1] | Standards; die set. |
| Load system | Dead weights or load cell. [2] [3] | Load range. |
| Piston displacement transducer | Volume-rate procedures. [2] | Encoder; resolution. |
| Cutter | Extrudate cutting. [2] | Manual or automatic. |
| Purge and cleaning | Barrel cleaning. [2] | Accessory. |
| Controller | Test programming and results. [3] | Software; export. |
06
A melt flow tester quotation needs values for your laboratory. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Temperature Control Accuracy | Barrel temperature control. | Accuracy; uniformity. |
| Maximum Test Load | 0.325–45 kg by load cell (MP1500). [3] | Load range. |
| Barrel Diameter | Per D1238 / ISO 1133. [1] | Conformity. |
| Die Length | Per D1238 / ISO 1133. [1] | Die set. |
| Heating Rate | Warm-up time. | Minutes. |
| Timer Resolution | Cut and displacement timing. | s. |
| Temperature Range | Test temperatures. | Range. |
| Power Supply | Mains. | V AC. |
| Power Consumption | Heater and drive. | W. |
| Operating Temperature | Laboratory conditions. | Range. |
| Humidity Range | Laboratory conditions. | % RH. |
| Ingress Protection | Bench instrument. | Rating. |
| Net Weight | With or without weights. [2] | kg. |
| Dimensions (W×D×H) | Bench space. | mm. |
07
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Standards: [ASTM D1238; ISO 1133] Procedures: [A; B; C; D] Results: [MFR; MVR; FRR] Loads/temps: [kg; °C] Load system: [weights; load cell] Options: [cutter; purge; PPDT] Throughput: [tests per day] Quantity: [units]
The manufacturers below list melt flow index testers on their own websites; each card links to the page reviewed. Confirm ratings, materials and approvals for your order.
Lists melt flow index testers including the ZL-3014D automatic MFR tester and ZL-3014A/B volumetric (MVR) models.
Product scope checked 2026-10-12
Lists the GBB-R1 melt flow indexer, which measures MFR and MVR through a standard die.
Product scope checked 2026-10-12
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
The rate of extrusion of molten thermoplastic through an extrusion plastometer; it notes the result is empirical, not a fundamental property. [1]
D1238 defines it as the flow rate at one condition divided by the flow rate at another. [1]
Tinius Olsen's MP1200 uses weights; its MP1500 applies 0.325–45 kg by load cell without weights. [2] [3]
Tinius Olsen says its MP1200 needs an encoder-based displacement transducer for D1238 Procedures B and C. [2]
GÖTTFERT's mi-series steps up from a single manually selected weight (mi1, mi2 with automatic weight lifting) to an 8-weight magazine with automated selection and force-controlled compaction up to 80 kg (mi40), all listed for ISO 1133 and ASTM D1238 Procedures A–C. [4]
Sources checked 2026-10-11. ASTM D1238 sets the test method; Tinius Olsen describes dead-weight and load-cell melt indexers, and GÖTTFERT publishes a comparison of its mi-series automation levels.
Ask for use case, specification boundaries, supplier type, and RFQ preparation information for this product.
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