| HS Code | 463654 |
| Material | 100% virgin polypropylene |
| Fiber Type | Microfilament |
| Fiber Length | 6-20 mm |
| Fiber Diameter | 18-48 µm |
| Aspect Ratio | 200-600 |
| Density | 0.91 g/cm³ |
| Melting Point | 160-170 °C |
| Ignition Point | >590 °C |
| Tensile Strength | ≥400 MPa |
| Elastic Modulus | ≥3500 MPa |
| Elongation At Break | 15-20% |
| Water Absorption | <0.1% |
| Alkali Resistance | Excellent |
| Acid Resistance | Excellent |
| Uv Resistance | Good |
| Thermal Conductivity | Low |
| Electrical Conductivity | Low |
| Color | White or gray |
| Dosage | 0.6-1.8 kg/m³ |
As an accredited SINTA M - Microfilament Polypropylene Fiber for Concrete factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SINTA M microfilament polypropylene fiber for concrete is packaged in 0.9 kg water-soluble bags, 20 bags per 18 kg carton. |
| Container Loading (20′ FCL) | SINTA M microfilament polypropylene fiber for concrete is palletized and loaded in a 20′ FCL for secure, dry transport. |
| Shipping | SINTA M is non-hazardous and not regulated for transport by road, rail, sea, or air. It is typically shipped in moisture-resistant bags or sacks on pallets. Store in a dry, ventilated area, away from open flames. No UN number, hazard class, packing group, or marine pollutant designation applies. |
| Storage | Store SINTA M in its original, unopened packaging in a clean, dry, well-ventilated area. Keep away from direct sunlight, moisture, heat, open flames, and strong oxidizers. Place bags on pallets off the floor, avoiding compression or puncture. Maintain stable ambient temperature, protect from UV degradation, and follow FIFO stock rotation. Shelf life is indefinite when stored properly. |
| Shelf Life | SINTA M has an indefinite shelf life when stored dry in original unopened packaging, away from moisture, direct sunlight, and extreme temperatures. |
High-strength concrete for precast tunnel lining segments, typically specified between C50/60 and C60/75 with a water-to-cement ratio of 0.30–0.35, presents a spalling risk under the Rijkswaterstaat RWS fire curve where gas temperature reaches 1350 °C within 120 min. SINTA M monofilament polypropylene fibre is incorporated at 1.5–2.0 kg/m³, equivalent to approximately 0.16–0.22 vol%, so that the polymer phase melts at approximately 160–170 °C and leaves a channel network through which trapped vapour pressure can dissipate before explosive spalling initiates. Compliance in this sector is governed by EN 206:2013+A2:2021 for concrete specification, EN 1992-1-2:2004 for structural fire design provisions addressing spalling, and EN 14889-2:2006 for CE-marked polymer fibre products. During segment production, the fibre is added to a high-shear pan mixer after coarse aggregate charging and before water injection, or alternatively split into the first sand fraction; wet mixing is extended by 45–60 s beyond the plain concrete baseline to disperse the monofilament bundles, while superplasticizer dosage is delayed until the fibre has been fully wetted to avoid localised air entrapment and static agglomeration at the mixer wall. Moulds are filled on a carousel line with external vibration at 50–60 Hz, and steam curing at 60–80 °C for 6–8 h follows demoulding. Terminal products include TBM tunnel lining segments, shaft rings, and precast box culvert members exposed to hydrocarbon fire loads. A process-boundary limitation exists at dosages above 2.5 kg/m³: fresh mix exhibits rapid slump loss, increased plastic viscosity, and fibre balling unless the high-range water-reducing admixture dose is increased and the batching sequence is revalidated. The fibre does not replace macrofibre or reinforcing steel; its function is restricted to fire spalling mitigation and early-age crack control.
In large-format warehouse slabs and logistics centre floors, SINTA M is batched into ready-mix concrete at 0.6–1.8 kg/m³, with a common starting dose of 0.9 kg/m³ for plastic shrinkage crack reduction when tested under ASTM C1579-21. The relevant compliance framework includes ASTM C94/C94M for ready-mixed concrete, ACI 302.1R-15 for floor slab construction, and ASTM C1116/C1116M-23 Type III synthetic fibre classification. In plant operations, the fibre is introduced through an aggregate transfer belt or blown into a central mixer after aggregate charging; truck mixer agitation at 6–8 rpm for 60–90 revolutions after fibre addition is generally sufficient to disperse the monofilament when slump is maintained at 150–200 mm. Placement proceeds with a truck-mounted boom pump, a laser screed strike-off, bull-floating, and ride-on power trowelling; at dosages not exceeding 0.9 kg/m³, no change in power trowel blade angle or closing time is normally required. At dosages above 1.8 kg/m³, however, the interaction between fibre concentration and finishing becomes the primary processing conflict: site batch records indicate that slump may decrease by 20–40 mm, pump line pressure may rise, and surface fuzzing may appear if the slab is over-trowelled before the paste has closed. High-range water-reducing admixture adjustments of 0.5–1.0 L/m³ are commonly made to restore workability; product-specific comparative results should be verified through plant trial batching rather than assumed from generic microfibre literature. Terminal products include jointed warehouse floor slabs, automated storage and retrieval system floors, freezer distribution centres, and automotive manufacturing floors. The fibre is not a substitute for sawcut joint spacing, doweled joints, or structural reinforcement; its role is restricted to controlling plastic shrinkage and early-age surface cracking before final set.
When wet-mix sprayed concrete is conveyed through a double-piston shotcrete pump at 12–18 m³/h, the microfilament polypropylene fibre dose selected at batching influences nozzle backpressure, early-age crack control, and cohesion in open-cut rock support. SINTA M is added at 0.9–1.5 kg/m³ for wet-mix sprayed concrete under EN 14487-1:2005 and ACI 506R-16, with the lower end reserved for thin repair applications and the upper end for temporary tunnel linings and slope stabilisation. The batching sequence in a mobile or central mix plant places the fibre into the aggregate stream before the cementitious paste is introduced, reducing the risk of monofilament agglomeration in 50 mm hose reducers and nozzle tips. During placement, air is injected at the nozzle at 4–7 bar, and an alkali-free accelerator is supplied by a separate dosing pump at 2–6 % by weight of cement depending on set-time requirements. Production encompasses robotic spraying, hand-lance application in shafts, and sequential rebar encasement; macrofibre or welded wire mesh remains the principal structural reinforcement because microfilament PP does not provide post-crack residual flexural capacity under EN 14651:2005+A1:2007. Terminal product types include temporary tunnel linings, permanent slope facings, rockfall protection shells, and rehabilitation overlays on deteriorated concrete. The practical upper dosage in wet-mix is 1.5 kg/m³ because higher doses may increase rebound and block nozzle tips when dispersion is incomplete; independent peer-reviewed data for this specific fibre type and hose configuration is not available, making pre-construction spraying trials mandatory.
In factory-blended polymer-modified repair mortars, SINTA M is incorporated at 0.5–1.0 kg/m³ of mixed mortar, corresponding to approximately 0.05–0.10 vol% based on polypropylene density, to suppress plastic shrinkage cracking in trowel-applied and spray-applied repair systems. The mortar is specified under EN 1504-3:2005 as a structural or non-structural repair product and under EN 998-1:2016 for renders, with the fibre component verified under EN 14889-2:2006 where applicable. Production uses a horizontal ribbon blender with a batch time of 3–5 min; the microfilament is pre-dispersed into sand or calcium carbonate before cement and redispersible polymer powder are charged, because direct addition to a high-speed plough-share mixer can generate static charge and produce agglomerates that discharge poorly from silo cone sections. The dry product is then filled into 25 kg bags or silo containers and transported to the repair site, where a counter-current mixer or continuous screw mixer prepares the wet mortar. Terminal products include R3-class structural repair mortars, R4-class low-modulus patching mortars, concrete spall repair, and fairing coats. A processing limitation is the moisture sensitivity of both the fibre and the polymer powder: silo fluidisation pads must be maintained below the dew point, and residual moisture above 0.3 % in the finished dry blend can initiate caking that affects auger discharge and mortar workability.
Drainage product manufacturers running vertical cast, vibration-compacted wet-cast manhole bases and pipe sections use SINTA M at 0.9–1.2 kg/m³ to reduce early-age cracking at section changes and lifting points without altering the aggressive core-pull schedule. The concrete is specified under ASTM C478/C478M-20 or EN 1916:2002, and the fibre is introduced at the pan mixer after aggregate charging and before water to disperse into the 25–30 mm slump mix. Production proceeds by pouring the mix into vertical steel moulds with internal cores, applying external vibration, and stripping at 18–24 h before the units enter a moist curing bay. Terminal product types include precast manhole base sections, riser sections, catch basin structures, and concrete pipe sections with tongue-and-groove joints. The practical upper dose is 1.2 kg/m³ in this production setting because higher fibre volumes can increase surface porosity at the form face and require a supplementary paste spray before the sections are stockpiled; no published dataset specific to SINTA M in vertical cast drainage production has been identified, so the stated limit is derived from plant experience with equivalent monofilament PP fibres.
For bonded and unbonded cementitious screeds placed by a truck-mounted boom pump across a 150 m horizontal run, the SINTA M dose is set at 0.6–1.5 kg/m³ to maintain a flow-table spread of 220–260 mm under EN 13813:2002 while controlling plastic shrinkage and surface crazing. The fibre is added at the mobile silo mixing station into the aggregate hopper before the continuous mixer discharges into the pump hopper; this sequence keeps the monofilament dispersed through the screed line and avoids fibre accumulation in 65 mm or 80 mm delivery hose. The produced screed is struck with a dappling bar or laser screed, then closed with a float; heated floor screeds may encapsulate hydronic pipe loops where crack control is necessary at pipe bends and door thresholds. Terminal product types include bonded overlay screeds on slab substrates, floating screeds on acoustic or thermal insulation, and cement-based underlayments for vinyl and tile finishes. The boundary condition is pump pressure: dosages above 1.5 kg/m³ may increase equivalent pipe friction and require a higher water-to-cement ratio to maintain flow, which in turn reduces the EN 13813 compressive strength class and extends the drying time before floor covering installation. An absence of product-specific published pumping data means a pre-installation trial with the intended boom length remains the accepted verification method.
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SINTA M is the microfilament polypropylene fiber grade within the SINTA synthetic-fiber line. The product is supplied as a water-soluble bagged monofilament in cut lengths of 6 mm, 12 mm, and 19 mm; the 12 mm length is the default for general-purpose ready-mix concrete. The nominal fiber diameter is 18 μm and the base polymer is a polypropylene homopolymer with a density of 0.91 g/cm³ when tested to ASTM D792. At the reference dosage of 0.9 kg/m³ (1.5 lb/yd³), the calculated number of fibers is approximately 3.2 × 10⁸ per cubic metre based on nominal geometry. The intended use is plastic shrinkage crack control and reduction of settlement cracking in ready-mix, precast, and cast-in-place concrete. The product is not a structural reinforcement material and is not substituted for reinforcing bars, welded wire reinforcement, steel fibers, or macro-synthetic fibers in applications requiring post-crack flexural capacity.
In truck-mixed concrete, the water-soluble bags are introduced after aggregates, cementitious materials, and water have been batched. The drum is then rotated at a minimum of 12 rpm for 5 min before slump verification. In a twin-shaft compulsory mixer of 3.0 m³ capacity, addition after two-thirds of the batch water and 60 s of wet mixing provides distributed fiber dispersion. The sequence of high-range water reducer addition becomes important at water-cement ratios below 0.40. If the fiber is added after the high-range water reducer and the mix is discharged in less than 90 s, localized fiber clusters can form near the discharge gate and on mixer shaft ends. No additional water should be added solely to compensate for the small slump reduction caused by fiber addition.
Steel fibers conforming to ASTM A820/A820M are typically batched at 20–60 kg/m³ and have a density of 7.85 g/cm³; their primary function is to provide post-crack residual strength in cracked concrete. The aspect ratios of steel fibers are commonly in the range of 40–80. SINTA M is batched at 0.9–1.8 kg/m³, has a density of 0.91 g/cm³, and at 12 mm length and 18 μm diameter has an aspect ratio of approximately 667. The high aspect ratio and low fiber cross-section generate a high fiber count per cubic metre, which is useful for intercepting plastic shrinkage cracks, but the small cross-section does not provide structural anchorage after the cement matrix has cracked. Macro-synthetic polypropylene fibers, by contrast, are typically produced with lengths of 38–65 mm and diameters of 0.50–1.0 mm, and are used at 3–9 kg/m³ for post-crack toughness in slabs, ground-supported floors, and shotcrete. SINTA M differs from macro-synthetic grades in both geometry and dosage; it is a low-dosage, high-count early-age crack-control fiber rather than a structural fiber. Compared with fibrillated tape micro-fibers, the monofilament geometry provides a narrower diameter distribution and has shown fewer clusters when added after aggregate wetting in twin-shaft mixer trials.
At water-cement ratios below 0.40, the plastic viscosity of the paste increases sufficiently that fiber dispersion is controlled by mixing energy and addition sequence rather than fiber density alone. Under ASTM C143/C143M, a concrete with a control slump of 150 mm typically shows a slump reduction of 10–20 mm at 0.9 kg/m³; at 1.8 kg/m³, the reduction is generally 30–50 mm. These values are batch-dependent and are influenced by aggregate angularity, cementitious content, and mixer condition. In a twin-shaft compulsory mixer, dry addition onto coarse aggregate before water can produce fiber clusters at the shaft ends and in the discharge zone. Addition after aggregate wetting and two-thirds of the batch water, followed by 60 s of wet mixing, reduces this failure mode. When high-range water reducer is batched after the fiber at low water-cement ratios, the required mix time may increase by 30–60 s. A full-scale trial batch is recommended when the mixture contains more than 450 kg/m³ of cementitious material or a viscosity-modifying admixture above the manufacturer’s midpoint dosage, because the combined effect of high paste viscosity and high fiber count can create non-uniform fiber distribution despite acceptable slump.
The fiber is inert in the alkaline pore solution of hydrating Portland cement, where pH typically ranges from 12.5 to 13.5. Unlike steel fibers tested to ASTM A820/A820M, the polypropylene microfilament does not corrode and does not generate rust staining or ferrous oxidation products in chloride-containing exposure. The 24-h water absorption of the homopolymer is below 0.1% when tested to ASTM D570, which limits liquid-water transport into the fiber body. The melting point, determined by ISO 3146, is between 160 °C and 170 °C. Autoclave curing above 160 °C is outside the recommended operating range because the fiber may soften and lose dimensional stability. In ordinary service below 120 °C, thermal degradation is not a controlling design consideration. The fiber does not reduce the required cover over reinforcing steel, and it does not function as a corrosion inhibitor or barrier coating. Chloride diffusion measurement remains a concrete-matrix property and is not improved by the addition of microfilament polypropylene.
Plastic shrinkage cracking is evaluated by ASTM C1579/C1579M, which compares crack area in a restrained concrete panel exposed to controlled surface evaporation. Published laboratory data for polypropylene microfilaments at 0.9 kg/m³ commonly report crack area reductions of 50% to 90% relative to plain concrete; the result depends on evaporation rate, cement content, panel geometry, and initial curing. The working mechanism is physical: the high number of fine fibers intersects developing crack paths, reduces free bleed-water channel connectivity, and increases the apparent early-age strain capacity of the fresh paste. This mechanism is confined to the plastic and early hardening period. Once a stable crack has developed and the fiber has debonded or pulled out, the microfilament does not provide measurable residual flexural strength. Structural design for flexure, shear, or restrained shrinkage must still be based on reinforcing steel or structural fibers where applicable. For projects that specify residual flexural strength, the use of a macro-synthetic fiber with an appropriate post-crack performance class should be evaluated instead.
| Parameter | Nominal value | Referenced method |
|---|---|---|
| Base polymer | Polypropylene homopolymer | — |
| Density | 0.91 g/cm³ | ASTM D792 |
| Standard fiber length | 12 mm | Optical measurement |
| Optional fiber length | 6 mm, 19 mm | Optical measurement |
| Nominal fiber diameter | 18 μm | Microscope measurement |
| Tensile strength | 300–400 MPa | ISO 527-1 |
| Elongation at break | 15–25% | ISO 527-1 |
| Melting point | 160–170 °C | ISO 3146 |
| 24-h moisture absorption | <0.1% | ASTM D570 |
| Reference dosage | 0.9–1.8 kg/m³ | Plastic shrinkage control |
Values represent published ranges for polypropylene homopolymer monofilament; the batch certificate of analysis controls production lots. If a project specifies a tensile strength or fiber-length tolerance outside these ranges, the product data sheet should be reviewed before submittal.
During placement, microfilament fibers can increase surface friction under power trowels. The first pass should be performed at a low blade angle and reduced rotor speed to minimise fiber fuzzing on the finished surface. Pumping through lines of 100 mm diameter or larger does not ordinarily require mix design changes at 0.9 kg/m³. For line diameters below 75 mm, published data for this specific configuration is limited, and a field trial with the intended pump setup is required before production placement.
For North American specifications, the product can be specified as a Type III synthetic fiber-reinforced concrete component under ASTM C1116/C1116M. For CE-marked construction products, polymer fibers used in concrete are covered by EN 14889-2:2006; the declaration of performance should state fiber diameter, length, tensile strength, dosage, and the intended non-structural crack-control function. The project quality-control plan should reference ASTM C1579/C1579M when plastic shrinkage crack reduction is a specification requirement. Slump verification after fiber addition is conducted with ASTM C143/C143M. Air-entrainment for freeze-thaw exposure is governed by ASTM C260/C260M and is not replaced by fiber addition.
| Requirement area | Reference standard | Application |
|---|---|---|
| Synthetic fiber concrete classification | ASTM C1116/C1116M Type III | Plastic shrinkage control |
| Plastic shrinkage crack resistance | ASTM C1579/C1579M | Comparative crack-area test |
| Slump verification | ASTM C143/C143M | Post-fiber fresh-state check |
| Polymer fiber product characterisation | EN 14889-2:2006 | CE-marked product data |
| Air-entraining admixtures | ASTM C260/C260M | Freeze-thaw exposure |
Under covered storage conditions below 40 °C and 60% relative humidity, the water-soluble packaging remains stable for 12 months from the date of manufacture. Exposure to relative humidity above 80% can compromise the package before mixing. The fiber is inert after concrete has hardened and does not require special disposal procedures. No incompatibility with Portland cement, ground granulated blast-furnace slag, fly ash, or silica fume has been identified. When a viscosity-modifying admixture is used above the manufacturer’s maximum dosage, a full-scale trial batch should verify fiber distribution and finishability before production placement.
