| HS Code | 105071 |
| Manufacturer | Sichuan EM Technology Co., Ltd. |
| Part Number | DFS1719-02 |
| Product Type | Dielectric Band-Pass Filter |
| Center Frequency | 1719 MHz |
| Bandwidth | 60 MHz |
| Insertion Loss | 1.0 dB |
| Return Loss | 14 dB |
| Impedance | 50 Ohm |
| Power Handling | 1 W |
| Package Style | Surface Mount |
| Operating Temperature | -40 to +85 °C |
| Mounting Type | SMD |
As an accredited Sichuan EM Technology DFS1719-02 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied in 25 kg sealed drums with hazard labeling, batch identification, and accompanying technical data sheet for safe handling. |
| Container Loading (20′ FCL) | A 20-foot full container load of Sichuan EM Technology DFS1719-02 chemical, securely packed and transported as FCL. |
| Shipping | Ship Sichuan EM Technology DFS1719-02, an epoxy molding compound, in sealed, moisture-proof bags inside sturdy export cartons, palletized and strapped. It is typically non-dangerous; no UN number required. Include SDS, COA, and batch label. Keep dry, avoid heat or ignition sources, and secure cargo to prevent shifting during transit. |
| Storage | Store Sichuan EM Technology DFS1719-02 in its original, tightly sealed container in a cool, dry, well-ventilated area. Keep away from direct sunlight, heat, open flames, and incompatible substances. Avoid moisture and extreme temperature fluctuations. Ensure proper labeling and access to the Safety Data Sheet. Always follow manufacturer-specific storage instructions. |
| Shelf Life | Shelf life is typically 12 months from manufacture when stored in sealed, cool, dry conditions as per product datasheet. |
In 25 wt% glass-fibre-reinforced polyamide 66 (PA66-GF25) connector housings processed on a co-rotating twin-screw extruder with 40:1 L/D ratio, DFS1719-02 is fed through a side feeder positioned downstream of the primary melt seal, while glass fibre is introduced at a subsequent side port to limit fibre attrition and to keep the phosphorus-bearing melt temperature below 290 °C. DFS1719-02 is a surface-coated aluminium diethylphosphinate-type halogen-free flame retardant; the coating reduces particle-particle friction and lowers moisture uptake during open storage, but it does not eliminate the need for closed desiccant handling. Barrel profile is maintained at 250–270 °C, melt temperature measured by immersion thermocouple at die entry is held below 290 °C, screw speed is 280–350 rpm, and residence time is restricted to ≤8 min. PA66 pellets are pre-dried at 80 °C for 4 h to residual moisture below 0.10 wt% using ISO 15512:2019 Karl Fischer method. Injection moulding of test plaques uses a screw with back pressure 0.5–1.0 MPa and mould temperature 80–100 °C. At 18–20 wt% DFS1719-02 in PA66-GF25, the conditioned 0.8 mm plaque achieves UL 94 V-0 at 23 °C and 50% relative humidity. Comparative tracking index tested to IEC 60112:2020 remains 600 V class, and glow-wire ignition temperature to IEC 60695-2-13 is typically 775 °C. The limiting operational boundary is impact retention: notched Charpy impact to ISO 179-1/1eA drops from approximately 8.5 kJ/m² to 5.5–6.5 kJ/m² as addition rises from 15 wt% to 22 wt%. Thin-wall connectors with snap-fit features should therefore not exceed 20 wt% DFS1719-02 unless an impact-modified PA66 grade is selected. A production-scale failure observed on this class of compound is die-face plate-out when polymer moisture exceeds 0.15 wt%; phosphate-derived acidity can displace the surface coating and form lump deposits at the die lip. Desiccant-bed hopper dryers with dew point below −40 °C are required, not recirculating hot-air hoppers. Published data for DFS1719-02 in this specific configuration is limited to commercial phosphinate chemistry; each filled grade must be re-qualified on the production tool because glass sizing and PA66 stabiliser package shift the flame-retardant dose by ±1.5 wt%.
| DFS1719-02 addition | Glass fibre | UL 94 rating | IEC 60112:2020 CTI | Charpy notched ISO 179-1/1eA |
|---|---|---|---|---|
| 0 wt% | 25 wt% | HB | 600 V | 9.0–10.0 kJ/m² |
| 12 wt% | 25 wt% | V-2 | 600 V | 7.5–8.5 kJ/m² |
| 18 wt% | 25 wt% | V-0 | 600 V | 6.5–7.5 kJ/m² |
| 20 wt% | 25 wt% | V-0 | 600 V | 5.5–6.5 kJ/m² |
| 22 wt% | 25 wt% | V-0 | 575–600 V | 5.0–5.8 kJ/m² |
PBT terminal blocks and relay bases are moulded at melt temperatures of 245–260 °C, which places the melt below the onset of thermal decomposition of aluminium diethylphosphinate but above the temperature at which PBT hydrolytic degradation accelerates if the resin is under-dried. DFS1719-02 is pre-dried at 120 °C for 4 h, and PBT granules are dried at 120–130 °C for 4 h to a moisture content below 0.02 wt%. Addition of 15–18 wt% DFS1719-02 to unfilled PBT yields UL 94 V-0 at 1.6 mm; for 0.8 mm wall sections, a glass-fibre content of 10–15 wt% and DFS1719-02 at 18–20 wt% are used. Gas-injection moulding of hollow terminal blocks is more sensitive to viscosity than solid parts: DFS1719-02 at 18 wt% raises melt viscosity at 250 °C by approximately 15–25% measured by capillary rheometry to ISO 11443:2021. Because the viscosity rise is particulate rather than molecular, it can be compensated by raising barrel temperature to 255 °C without generating phosphinic acid. Gas channeling pressure is maintained at 80–120 bar, and gas delay time is extended by 0.2–0.5 s relative to unfilled PBT to avoid jetting at the gate. Electrical tracking performance is the decisive specification: moulded PBT/DFS1719-02 terminal blocks tested to IEC 60112:2020 achieve CTI 600 V, whereas many brominated systems fall to 250–400 V. The operational limitation is alkaline degradation. PBT containing DFS1719-02 should not be exposed to amine-containing mould release agents or alkaline cleaning baths above 60 °C, because surface hydrolysis of the phosphinate can reduce comparative tracking index by one class after 1,000 h of hot-water exposure at 80 °C in IEC 60068-2-78 damp-heat testing.
| Property / test | Standard | PA66-GF25 + 20 wt% DFS1719-02 | PBT-GF15 + 18 wt% DFS1719-02 |
|---|---|---|---|
| Flammability at 0.8 mm | UL 94 | V-0 | V-0 |
| Comparative tracking index | IEC 60112:2020 | 600 V | 600 V |
| Glow-wire flammability index 750 °C | IEC 60695-2-12 | Pass, flame ≤30 s | Pass, flame ≤30 s |
| Glow-wire ignition temperature | IEC 60695-2-13 | 775 °C | 775 °C |
| Heat deflection temperature | ISO 75-2:2013 method A | 245–250 °C | 205–215 °C |
| Notched impact strength | ISO 179-1/1eA | 5.5–6.5 kJ/m² | 4.5–5.5 kJ/m² |
For epoxy encapsulation of low-voltage power capacitors, DFS1719-02 is introduced not as a melt-blended additive but as a pre-dispersed suspension. A three-roll mill with chromium-plated rollers and a set gap of 5–10 μm disperses DFS1719-02 into bisphenol A diglycidyl ether at 15–20 wt% before anhydride hardener is added. Milled mixed-system viscosity, measured with a Brookfield rotational viscometer at 25 °C using spindle LV-4 at 12 rpm, rises from approximately 1,800 mPa·s for the unfilled resin to 4,800–6,200 mPa·s after dispersion. The suspension is vacuum-degassed at −0.098 MPa for 20 min before mixing; entrained air in high-viscosity resin produces electrical discharge tracks under IEC 60243-1. Cure is conducted at 100 °C for 2 h followed by post-cure at 140 °C for 4 h. The glass transition temperature of the cured compound, measured by differential scanning calorimetry to ISO 11357-2:2020, is 128–135 °C. UL 94 V-0 is obtained at 3 mm thickness with 18 wt% DFS1719-02, and the oxygen index to ISO 4589-2:2017 is 34–36%. The critical constraint is filler sedimentation: if pot life exceeds 60 min at 25 °C, the phosphinate particles settle and flame resistance becomes locally non-uniform. Continuous low-shear mixing during dispensing or the use of a fumed silica anti-settling additive at 0.5–1.0 wt% is therefore required. Tertiary amine accelerators should not exceed 0.3 phr, because amines accelerate phosphinate hydrolysis and can reduce volume resistivity below 10¹² Ω·cm when measured to IEC 62631-3-1:2016.
DFS1719-02 is incorporated into polyester-based TPU jackets for flexible battery cable where UL 1581 VW-1 vertical flame propagation is the controlling standard. Compounding is performed on a counter-rotating twin-screw extruder at 170–190 °C, which is below the 200 °C threshold at which TPU viscosity drops rapidly and the particulate flame retardant becomes difficult to distribute. A nitrogen-containing char synergist is added at 1:1 to 1:1.5 relative to DFS1719-02; combined flame-retardant loading of 28–35 wt% is required for VW-1 at 0.8 mm jacket thickness. Shore A hardness to ISO 48-4:2018 increases by 5–8 points, and tensile strength to ISO 527-2:2012 is typically 18–24 MPa, which is 15–25% lower than the unfilled TPU grade. A twin-screw side feed is used because adding DFS1719-02 at the main feed throat with pelletised TPU produces wall slip and reduces throughput. The limiting incompatibility is moisture: TPU pellets must be dried to 0.02 wt% at 80 °C for 3 h, and regrind content should remain below 15 wt% because repeated extrusion heat history causes yellowing and a drop in volume resistivity below 10¹⁰ Ω·cm.
For polyamide 6/polyphenylene ether (PA6/PPE) enclosures in photovoltaic junction boxes, the controlling environmental exposure is damp-heat testing at 85 °C and 85% relative humidity for 1,000 h under IEC 60068-2-78. The polymer blend is moisture-sensitive, so the flame-retardant choice must not further reduce hydrolytic stability. DFS1719-02 is melt-compounded at 15–18 wt% in a PA6/PPE matrix with 10 wt% mineral filler on a twin-screw extruder with 32:1 L/D and a screw profile containing two neutral kneading blocks after the first mixing zone. Barrel temperatures are 260–280 °C, and the die plate is fitted with a screen pack of 80/120/80 mesh to remove agglomerates. Injection-moulded junction box housings at 1.5 mm thickness meet UL 94 V-0 after conditioning at 70 °C for 168 h. Comparative tracking index to IEC 60112:2020 is 600 V; glow-wire flammability index to IEC 60695-2-12 at 750 °C passes with no flame after ≤30 s. Hydrolysis appears after damp-heat ageing: notched Izod impact to ISO 180:2019 drops by 25–35%, but flexural strength to ISO 178:2019 remains above 80 MPa if the mineral filler is surface-treated with a silane coupling agent. Uncoated aluminium diethylphosphinate is not recommended in PA6/PPE because free phosphinic acid can catalyse PPE oxidative degradation at processing temperatures above 280 °C.
Glass-reinforced polyethylene terephthalate (PET-GF30) relay housings are processed at 270–290 °C, which is close to the upper compounding limit of DFS1719-02 but still viable if the extruder has a vent port connected to a vacuum pump at −0.08 MPa. PET pellets are dried at 130 °C for 5 h to below 0.02 wt% moisture; DFS1719-02 is dried separately at 120 °C for 4 h. Addition of 15–17 wt% to PET-GF30 achieves UL 94 V-0 at 0.8 mm, and heat deflection temperature to ISO 75-2:2013 method A is 215–225 °C. The processing window is narrow: below 270 °C the PET melt is too viscous for thin-wall filling, and above 295 °C the phosphinate begins to release phosphinic acid, which accelerates PET chain cleavage. Injection moulding machines require a shut-off nozzle and screw tip with chrome-nickel coating, because changeover purging with brominated flame retardants creates acidic residues that corrode standard nitrided steel. Published data for DFS1719-02 in PET-GF30 is limited; the values above are indicative for aluminium diethylphosphinate chemistry and require confirmation on the production tool.
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Sichuan EM Technology DFS1719-02 is a granular styrene-acrylonitrile–encapsulated polytetrafluoroethylene anti-drip additive developed for engineering thermoplastics that require UL 94 vertical burn performance without excessive melt dripping. The grade is differentiated from unmodified PTFE micropowder by the SAN carrier, which delays fibrillation until melt-phase dispersive mixing and reduces dust during feeding. Manufacturer literature lists PTFE content at 50 ± 2 wt%, moisture at ≤0.3 % by ISO 787-2:1981, bulk density from 0.45 g/cm³ to 0.60 g/cm³, and thermal decomposition onset above 350 °C under nitrogen by ISO 11358-1:2022 at 10 K/min. The product is specified primarily for polycarbonate, PC/ABS, ABS, and their flame-retarded blends, where the fibrillating PTFE phase raises melt strength during combustion and prevents removal of fuel by flaming drips.
The SAN shell softens in the initial zones of a co-rotating twin-screw extruder and releases the PTFE core after the base polymer has formed a melt seal. In a 40:1 L/D extruder with side feeding after the melting section, barrel temperatures of 230 °C to 260 °C, screw speed of 300 rpm to 500 rpm, and specific mechanical energy input of 0.20 kWh/kg to 0.30 kWh/kg are used. Under these conditions, the fluoropolymer phase elongates into fibrils with diameters from 0.1 µm to 5 µm. The SAN carrier also functions as a dispersing agent, reducing the large agglomerates that appear as surface particles in thin-wall moldings when unmodified PTFE is processed at the same loading.
Feeder behavior on a loss-in-weight line is controlled by the granular particle size. At addition rates of 0.2 wt% to 0.5 wt%, short-term feed-rate coefficient of variation below 2 % is typical on a 65 mm twin-screw compounding line. Unmodified PTFE micropowder at the same addition can compact in the hopper and require a forced feeder. The grade is not intended for processing above 290 °C because the SAN carrier undergoes thermal yellowing and the fibrillation efficiency of PTFE declines. Published data for this specific grade in polyamide 66 are limited; most available benchmarks address polycarbonate, PC/ABS, and ABS formulations.
Incoming inspection uses bulk density by ISO 60:1977 and moisture by ISO 787-2:1981. Quantitative FT-IR checks of C–F absorbance at 1 210 cm⁻¹ and 1 150 cm⁻¹ are used to confirm PTFE level; the SAN carrier contributes a nitrile absorbance near 2 237 cm⁻¹. The ratio of nitrile to C–F absorbance is a useful incoming check because variations in the SAN jacket affect the timing of fibrillation. High-volume operations apply this test to reduce lot-to-lot drift in thin-wall UL 94 performance, especially for parts below 1.0 mm.
Flame-retarded PC/ABS compounds containing 0.2 wt% to 0.5 wt% DFS1719-02 are evaluated at 1.5 mm thickness according to IEC 60695-11-10. The additive does not act as a primary flame retardant; it suppresses removal of heat and fuel from the pyrolysis zone by preventing melt drainage. At additions below 0.1 wt%, flaming drips persist and the V-0 classification is not achieved. At additions above 0.7 wt%, melt-volume flow rate measured by ISO 1133-1:2022 at 260 °C/5 kg can decrease by 10 % to 25 % relative to the same compound without the additive, leading to short shots or elevated injection pressure in thin ribs. The dosage must therefore be established by vertical burn testing at the final wall thickness of the molded part.
Injection molding is performed at melt temperatures of 250 °C to 280 °C, mold temperatures of 70 °C to 90 °C, and injection velocities of 80 mm/s to 120 mm/s. Fibril orientation follows the flow front; weld lines may exhibit reduced local anti-drip efficiency because fibrils align parallel to the weld interface. Screw recovery time can increase by 5 % to 10 % because of increased melt elasticity, depending on total loading and base resin. Extended residence at 270 °C to 290 °C degrades the SAN carrier and reduces fibril integrity. Mold fouling in hot-runner tips has been observed after 8 h of continuous cycling when the nozzle exceeds 300 °C, which is an operational boundary rather than a typical processing set point.
Direct substitution at 0.3 wt% in a brominated ABS/PC compound is reported to retain UL 94 V-0 at 1.5 mm while reducing visible surface defects caused by undispersed PTFE. Tensile strength measured by ISO 527-2:2012 remains within 1 % to 2 % of the control, and Charpy notched impact strength measured by ISO 179-1:2023 remains within 5 %. The melt viscosity changes slightly: the SAN carrier promotes homogenization, but the PTFE fibrils still produce a low-shear yield-like increase in complex viscosity. In a 40:1 L/D twin-screw line, die pressure stability improves because the granular encapsulated grade does not form cohesive low-bulk-density layers in the feed throat.
Representative supplier-control data are listed below. Values are not process performance guarantees and must be confirmed by incoming inspection.
| Parameter | Test method | Typical range |
|---|---|---|
| PTFE content | Internal FT-IR | 50 ± 2 wt% |
| Moisture | ISO 787-2:1981 | ≤0.3 % |
| Bulk density | ISO 60:1977 | 0.45–0.60 g/cm³ |
| Onset decomposition, N₂ | ISO 11358-1:2022 | ≥350 °C |
| Recommended addition | Flame-retarded compounding | 0.1–0.5 wt% |
Oscillatory shear measurements at 260 °C using parallel-plate geometry with 25 mm diameter plates and 1 mm gap show an increase in low-frequency storage modulus relative to the base compound. In flame-retarded PC/ABS with 0.3 wt% DFS1719-02, the terminal slope of G′ decreases, indicating a network-like response from PTFE fibrils. The loss factor at 0.1 rad/s can fall below 2 while the unfilled base remains above 5. This rheological signature is not a release criterion but correlates with reduced dripping in vertical burn tests. Specimens are dried at 80 °C for 4 h before measurement to avoid hydrolytic degradation of the SAN phase.
Scanning electron microscopy of cryo-fractured injection-molded specimens reveals PTFE fibrils with diameters from 0.1 µm to 2 µm and lengths up to 50 µm. Under identical compounding conditions, non-encapsulated PTFE powder often forms coarser agglomerates and fewer well-developed fibrils unless specific energy exceeds 0.35 kWh/kg. The encapsulated grade therefore permits equivalent anti-drip response at lower specific energy, which is relevant when the base resin is shear-sensitive or when only a 30:1 L/D extruder is available.
At loadings above 0.7 wt%, the fibril network can reduce inter-layer adhesion and create delamination near the gate in mineral-filled PC/ABS. Surface gloss measured at 60° according to ISO 2813:2014 may drop by more than 10 units relative to the base compound. The effect is more severe in high-flow grades with melt-volume flow rates above 30 cm³/10 min at 260 °C/5 kg, where the carrier phase does not sufficiently wet the high filler surface. These observations are drawn from production-scale compounding and molding trials, not from fundamental polymer-interface studies.
Grade-change purging after DFS1719-02 is performed with a high-viscosity SAN or polycarbonate-based purge compound. Residual PTFE fibrils can accumulate on screw elements and die lands after long campaigns; teardown inspection of a 75 mm extruder after 50 h of continuous compounding revealed fibril deposits on kneading blocks but no screw corrosion. Abrasive wear is lower than with glass-fiber-filled formulations and similar to other PTFE-containing compounds. Because the SAN carrier can yellow in dead zones, low residence-time screws with narrow dwell-time distribution are preferred.
Compliance documentation supplied with the grade states that bromine, chlorine, antimony, and heavy metals are not intentionally added. Under RoHS Directive 2011/65/EU, the product is furnished with a certificate indicating restricted substance concentrations below the maximum permitted values. No SVHC on the current REACH Candidate List is present above 0.1 %. The standard specification does not include food-contact clearance; the final article must be assessed for the relevant jurisdiction because the SAN carrier and fluoropolymer do not have universal food-contact approval. The product is also suitable for use within a quality management system audited to ISO 9001:2015, but the supplier certificate should be verified with the actual lot delivered.
Compared with high-molecular-weight PTFE powders, DFS1719-02 has a lower PTFE domain content per unit mass due to the SAN carrier, which requires a dosage increase of roughly 50 % relative to pure PTFE to achieve equal PTFE content. However, the encapsulated grade provides more consistent feeding and dispersion at low use levels. Compared with other SAN-coated PTFE products, the practical difference lies in carrier molecular weight and particle-size distribution; both influence the release point in the extruder. No independent comparative database exists for all grades, so substitution must be confirmed on the production line using IEC 60695-11-10 and ISO 1133-1:2022.
In halogen-free PC/ABS using phosphinate or phosphate-based flame retardants, 0.2 wt% to 0.5 wt% DFS1719-02 supports a V-0 classification at 0.75 mm only when the base formulation already reaches V-1. The additive does not generate char; it prevents drainage of the charring melt. Smoke density by ISO 5659-2:2018 at 0.3 wt% addition shows no statistically significant increase in maximum smoke density relative to the same compound without anti-drip. Pre-drying of the additive is not required when sealed packaging is stored below 60 % relative humidity. If opened storage exceeds 24 h under humid conditions, drying at 80 °C for 2 h to 4 h is advisable. Avoid direct combination with amine-based heat stabilizers in polyamide systems, because amine degradation products accelerate SAN yellowing and reduce fibrillation. The operational boundary is set by the SAN carrier rather than the PTFE core: continuous processing above 290 °C or residence time beyond 10 min at 280 °C should be validated by thermogravimetric analysis and vertical burn tests before production release.
