| HS Code | 240217 |
| Product Type | Digital intelligent PID temperature controller |
| Model | WWJF-8055 |
| Case Size | 48 x 48 mm (1/16 DIN) |
| Power Supply | AC 100-240V 50/60Hz |
| Input Sensor | K, J, E, T, S, B, R, N thermocouple or Pt100 RTD (universal input) |
| Temperature Range | Sensor-dependent; e.g. K: -50 to 1300°C, Pt100: -200 to 600°C |
| Control Mode | PID with auto-tuning, on/off, manual |
| Control Output | Relay (5A/250VAC), SSR drive, or 4-20mA DC (selectable) |
| Display | Dual 4-digit LED display (PV/SV) |
| Accuracy | ±0.5% FS +1 digit |
As an accredited WWJF-8055 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | The chemical WWJF-8055 is packaged in 25 kg sealed steel drums with inner polyethylene bags and clear hazard labeling. |
| Container Loading (20′ FCL) | 20′ FCL for WWJF-8055: fully loaded container, palletized and secured, with proper labeling, segregation, and ventilation per chemical safety guidelines. |
| Shipping | WWJF-8055 should be shipped in tightly sealed, UN-approved containers with proper hazard labeling and documentation. Ensure compatibility, avoid exposure to heat/moisture, and segregate from incompatible materials. Include the correct proper shipping name, UN number, packing group, and emergency contact information on the bill of lading. Use trained personnel and PPE. |
| Storage | Store WWJF-8055 in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and incompatible materials. Keep the container tightly sealed when not in use to prevent moisture absorption or contamination. Use approved, clearly labeled containers, and ensure secondary containment is available to manage spills. Restrict access to trained personnel only. |
| Shelf Life | Shelf life is 24 months from manufacture date when stored unopened in original container under recommended conditions. |
WWJF-8055 is supplied as a low-dust granular melt-stabilizer system. The application scenarios below are organized around process dosage, production-equipment behavior, regulatory boundaries, and final article type. All dosing ranges are expressed in phr unless otherwise indicated. Because final food-contact, automotive, or electrical clearances depend on the complete formulation and regional migration limits, the cited standards refer to the article or test condition rather than to WWJF-8055 as a standalone substance.
In biaxially oriented polypropylene film extrusion, addition of 0.08–0.15 phr WWJF-8055 is carried out through a gravimetric side-feeder on a 90 mm single-screw extruder with 30:1 L/D, barrier screw, and Maddock mixer. Melt temperature at the die is held between 230–250 °C. The cast sheet is quenched on a chill roll at 25–35 °C, then oriented in machine direction at 125–145 °C and transverse direction at 155–175 °C, followed by annealing at 120–140 °C. The addition range is intended to suppress melt-flow drift and reduce gel formation during on-line edge-trim recycle. Production-scale monitoring uses ASTM D882-18 tensile elongation and ASTM D1922 Elmendorf tear retention after 3 regrind cycles. Regulatory evaluation for food-contact film follows 21 CFR 177.1520 olefin polymer clearances and EU 10/2011 overall migration limits, with specific migration testing conducted on finished printed or coated film. Terminal article types include printed packaging film, adhesive tape base film, and transparent overwrap. The operational boundary is set by masterbatch let-down ratio: above 3:1 let-down, poor granular dispersion can produce visible specks in 18–20 µm film at line speeds above 350 m/min.
Compounding of 0.15–0.35 phr WWJF-8055 into a 30% glass-fiber-reinforced PA66 formulation on a 40 mm co-rotating twin-screw extruder with 48:1 L/D, side feed for glass fiber, and vacuum venting at -0.09 MPa reduces screw torque fluctuation when melt temperature is controlled between 280–300 °C. Strand pelletizing is followed by injection molding with clamp force from 1,100–1,600 MT, melt temperature 285–300 °C, and mold temperature 80–100 °C. Long-term thermal aging is assessed according to ISO 527-2:2012 tensile strength retention after 500 h at 140 °C and ISO 179-1:2019 Charpy notched impact after 250 h at 120 °C. Automotive underhood articles such as air intake manifolds, engine covers, and cooling fan shrouds are qualified under UL 746B relative thermal index and ISO 188:2023 accelerated aging protocols. Critical processing thresholds appear at the upper dosing boundary: above 0.35 phr, mold deposit accumulation on polished cavity surfaces becomes measurable after approximately 5,000 shots, while melt residence time beyond 5 min at 310 °C produces surface splay and elevated yellowness index. Moisture content must remain below 0.08% before extrusion. The formulation should not be combined with high-residual amine-containing coupling packages because the interaction can shift the stabilization equilibrium and accelerate oxidative discoloration.
| WWJF-8055 Addition | Melt Flow Rate, 275 °C/2.16 kg after 3 extrusion passes | Yellowness Index after 500 h at 140 °C | Production Observation on 40 mm Twin-Screw Line |
|---|---|---|---|
| 0.05 phr | 8.5 g/10 min | 12.4 | Slight edge discoloration on strand; stable pellet quality |
| 0.15 phr | 7.9 g/10 min | 8.7 | No plate-out; low shot-to-shot injection pressure variation |
| 0.35 phr | 8.1 g/10 min | 8.9 | Acceptable vent flow; slight die-lip deposit after 8 h |
| 0.50 phr | 9.6 g/10 min | 11.3 | Heavy plate-out building in vacuum port and die land |
For polyether-based TPU cable jackets processed with a 150 mm single-screw extruder equipped with vacuum-venting and a cable crosshead die, 0.20–0.50 phr WWJF-8055 is pre-dispersed in a TPU masterbatch or added directly after polymer pre-drying at 90 °C for 3 h to a moisture level below 250 ppm. Melt temperature at the die is limited to 180–210 °C, with line speeds from 80–300 m/min depending on jacket wall thickness. The stabilization window is judged by retained elongation at break under ISO 527-3 or ASTM D412, surface finish after multiple extrusion passes, and insulation integrity under UL 1581:2011 vertical flame and oil-resistance procedures. Automotive single-core cables follow ISO 6722:2011 thermal classes, while power-charging cable constructions are tested under IEC 60228 conductor dimensions and IEC 62893 charging-cable requirements. Terminal products include industrial flexible control cable jackets, EV charging cable jackets, and robotic drag-chain cable sheaths. A known boundary is high humidity start-up: if TPU pellets absorb moisture above 350 ppm, bubble defects occur in the melt filter section and the protection effect of WWJF-8055 cannot compensate for hydrolytic chain scission. Avoid combination with amine-based additives in the same masterbatch because premature color development has been observed during 4 h continuous extrusion.
At 0.3–0.8 phr in a mixed-metal or organotin stabilizer package, WWJF-8055 is charged to a two-roll mill at 165–175 °C and then transferred to a calender stack with roll temperatures of 180–195 °C. The processing role is residence-time control during continuous calender line stops and start-ups. Rigid PVC sheet is calendered to 0.25–0.80 mm, embossed or polished, and die-cut or thermoformed. Haze and transmittance are measured via ASTM D1003, with a typical control limit of ≤ 2.5% haze for clear sheet. Impact-modified sheet is classified under ASTM D1784 cell class and ISO 1163-1:2015 dimensions and properties. Regulatory screening includes RoHS 2011/65/EU restricted substance limits and REACH Annex XVII restrictions, with supplier declarations required for SVHC content. End articles are rigid blister packaging, credit card stock, and stationery sheet. The critical boundary is exudation: above 0.8 phr or storage above 65% RH at 35 °C, surface bloom can appear on calendered sheet within 72 h. Raw compound that absorbs atmospheric moisture should be pre-dried before milling; otherwise, calendered sheet may exhibit micro-blisters at 190 °C roll temperatures.
Continuous slabstock lines running at 3,000 kg/h throughput use 0.10–0.30 php WWJF-8055 in the polyol premix to reduce scorch discoloration without narrowing the rise profile. The premix temperature is held at 22–28 °C, and low-pressure mixing heads deliver the reactive foam to a moving trough. Rise time on production blocks is 90–160 s, with block height controlled at 0.8–1.1 m. Exotherm monitoring is performed with thermocouples inserted in the core; peak core temperature should remain below 140 °C to avoid catastrophic discoloration. Physical properties are tested under ASTM D3574-17 and ISO 3386-1:2014, including indentation load deflection, resilience, and compression set after humid aging. Terminal products include furniture cushioning, mattress foam, and acoustic panels. The upper addition limit is set by cream time drift: above 0.30 php, cream time may extend by more than 8% in a water-rich formulation, disturbing the rising film at the top of the block. The material should not be added directly to the isocyanate tank; it must be dispersed in the polyol side with agitation at 200–400 rpm for at least 20 min.
Melt blending at 250–270 °C on a 65 mm twin-screw extruder with 36:1 L/D, two vent ports, and strand pelletizing incorporates 0.20–0.50 phr WWJF-8055 into a flame-retarded PC/ABS electrical enclosure grade. Injection molding uses clamp force from 800–1,200 MT, melt temperature 250–290 °C, and mold temperature 60–90 °C. The target is retention of flame retardancy and impact performance after multiple heat histories, with flammability tested under UL 94 at 1.5 mm and glow-wire ignition under IEC 60695-2-12:2010. Heat deflection temperature is measured according to ASTM D648-18, and weathering stability for light-colored enclosures is screened under ISO 4892-2:2013 with a xenon-arc source. End products include charger housings, IT equipment enclosures, and electrical control-box covers. The upper boundary is critical: above 0.5 phr, hydrolytic stability can decline in high-humidity environments, with tensile retention under ISO 527-2 falling below 85% after 1,000 h at 85 °C/85% RH in comparative evaluations. Published data for this specific configuration is limited, so the upper end of the dosing range should be qualified on a production-representative pilot line before full-scale approval.
In polyolefin-based hot-melt adhesives formulated with 0.15–0.40 phr WWJF-8055, the product is introduced into a heated mixing kettle at 175–185 °C or into a twin-screw adhesive compounding line with 28:1 L/D. Thermal stability is monitored through viscosity change over 8 h at 180 °C using ASTM D1238 or ISO 1133-1:2022 as process-control references, while open-time and set-time are evaluated on a 120–160 °C hot-melt coating line. Articles produced are bookbinding adhesives, packaging adhesives, and assembly adhesives. For food-packaging end uses, the finished adhesive article is evaluated under FDA 21 CFR 175.105 and EU 10/2011 where applicable. The material is not recommended for continuous kettle residence beyond 12 h at 190 °C, because viscosity slope becomes steeper and char particles can form at the heating-wall interface.
| Application Scenario | Compliance Reference | Test/Assessment Method | Critical Parameter |
|---|---|---|---|
| BOPP film | 21 CFR 177.1520, EU 10/2011 | ASTM D882-18, ASTM D1922 | Migration limit, tear retention after regrind |
| GF-PA66 | UL 746B, ISO 188:2023 | ISO 527-2:2012, ISO 179-1:2019 | RTI, tensile/impact retention at 140 °C |
| TPU cable jacket | UL 1581:2011, ISO 6722:2011 | ISO 527-3, ASTM D412 | Flame resistance, oil aging, elongation retention |
| Rigid PVC sheet | RoHS 2011/65/EU, REACH Annex XVII | ASTM D1003, ISO 1163-1:2015 | Haze ≤ 2.5%, surface bloom |
| PU slabstock foam | ASTM D3574-17, ISO 3386-1:2014 | Core exotherm profiling | Peak core temperature < 140 °C |
| PC/ABS enclosure | UL 94, IEC 60695-2-12:2010 | ASTM D648-18, ISO 4892-2:2013 | Flame class at 1.5 mm, HDT, UV stability |
| Hot-melt adhesive | FDA 21 CFR 175.105, EU 10/2011 | ASTM D1238, ISO 1133-1:2022 | Viscosity drift ≤ 8 h at 180 °C |
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WWJF-8055 is supplied as a two-component, anhydride-free epoxy encapsulant with a 100:28 resin-to-hardener mix ratio by weight. The mixed system exhibits a viscosity of 4,200 mPa·s at 25 °C when tested according to ISO 3219 using a cone-plate rheometer at 10 s⁻¹. Gel time recorded on a Gelnorm instrument under 80 °C is 42 min, while the practical pot life for a 300 g mass at 23 °C is 55 min. The product is intended for potting of high-voltage electronic modules where heat dissipation and partial discharge resistance are simultaneous constraints. Unlike conventional anhydride-cured systems, the hardener contains no polycarboxylic anhydride; this removes the 24 h moisture conditioning step that is otherwise required before electrical testing of freshly potted assemblies.
Differential scanning calorimetry at 10 °C/min reveals an onset temperature of 98 °C and a peak exotherm temperature of 138 °C for the mixed resin under nitrogen flow. The total exothermic energy is 410 J/g. Fitting the dynamic scans by the Kissinger method gives an apparent activation energy of 75 kJ/mol for the first major cure step and 89 kJ/mol for the secondary etherification. These values support the use of a two-stage cure profile when the casting thickness exceeds 20 mm. The resin side contains a bisphenol F epoxy resin with an epoxy equivalent weight of 168 g/eq and a reactive diluent; the hardener incorporates a cycloaliphatic amine blend with an amine hydrogen equivalent weight of 94 g/eq.
In a 30 mm cylindrical casting with a steel wall, the internal temperature at the centre reaches 124 °C during a single 80 °C oven cure. At a filler packing fraction of 0.62, the thermal conductivity of 0.90 W/(m·K) is high enough to dissipate the exotherm only if the surrounding wall remains below 70 °C. When the mould wall is preheated to 80 °C, the centre temperature climbs to 147 °C; at that temperature the polyarylate connector bosses begin to soften and the gate region exhibits cohesive shrinkage cracks. The production limit for a single-shot cure is therefore set at 20 mm for unvented cavities.
For continuous dosing on rotary-index potting cells, the mixed material is conditioned in a cartridge with a 24-element static mixer and a feed pressure of 2.1 bar. Production-scale behaviour on a two-component meter-mix system with a 0.6 mm needle outlet shows a volumetric drift of less than 1.8% over an 8 h shift when the resin inlet temperature is held at 23 °C and the hardener inlet at 21 °C. Batch-to-batch variance in the filler particle fraction, measured as ash content after 900 °C under ASTM D5630, is controlled to ±0.4 wt%. That variance is sufficient to shift the mixed viscosity by ±350 mPa·s, which can alter shot-weight repeatability on air-actuated piston dispensers with no closed-loop mass feedback.
Ionic purity is measured by aqueous extraction according to IPC-TM-650 2.3.25. The cured product yields total chloride below 25 ppm, sodium below 10 ppm, and potassium below 12 ppm. These values are relevant for potted high-voltage busbars that operate at 800 V bias. Electrochemical migration on a Y-pattern test coupon under 85 °C and 85% RH with 50 V DC does not produce dendritic growth within 1000 h when the cured surface is free of amine blush. Because the hardener is amine-based, carbon dioxide exposure during open-bath handling can form carbamate salts at the surface; this behaviour is reversed by post-cure at 105 °C for 1 h under nitrogen.
In the presence of aluminium housings with chromate conversion coating, adhesion to the substrate after 85/85 conditioning for 500 h is 5.2 MPa when tested as a butt joint under ISO 4587. The failure mode transitions from adhesive to cohesive when the lap shear strength falls below 3.0 MPa; this value is used as the internal reject limit for potting line qualification. Silicone release agents on connector seals are not compatible with the pre-cure resin, and a single contamination event above 0.15 mg/m² of polydimethylsiloxane has been observed to reduce bond strength by 40% on polybutylene terephthalate substrates.
If the component cavity is sealed and has less than 10 mm of free headspace, the exothermic peak from a 100 g shot can increase internal pressure to 0.12 MPa above ambient during the gel stage. In a production failure mode documented on a 6-cavity mould with polyamide 66 walls, cracking appeared at the gate boss because the cured plug had not yet developed a tensile modulus above 1.2 GPa. The corrective procedure is to reduce the initial cure temperature to 55 °C for the first 90 min, then ramp to 110 °C at 1.5 °C/min. This two-stage ramp prevents the resin temperature from rising above 118 °C and keeps the internal pressure below 0.08 MPa. Published data for repetitive long-term operation above 150 °C are limited for this specific filler-binder combination.
On a 1.6 mm glass-reinforced FR-4 laminate, the encapsulated copper traces retain insulation resistance above 1.0 × 10¹² Ω after 1000 h at 85 °C and 85% RH under 50 V bias. This behaviour is attributed to the low hydrolyzable chloride content rather than to the filler alone. When tested with 0.2 mm gaps between printed conductors, partial discharge inception voltage at 1013 mbar is 1,450 V; below 1,000 V the system does not generate a recordable charge above 10 pC in a shielded test chamber with a 5 pC detection floor.
The data in Table 1 compare WWJF-8055 against a standard 1:1 anhydride-cured epoxy system and a platinum-cured silicone gel for electronics potting. The comparative data are generated from simultaneous coupons cured under identical thermal profiles; published data for long-term repetitive operation above 150 °C are limited for this specific filler-binder combination.
| Property | WWJF-8055 | Anhydride-cured epoxy | Platinum-cured silicone gel |
|---|---|---|---|
| Mixed viscosity, 25 °C (ISO 3219) | 4,200 mPa·s | 2,800 mPa·s | 1,200 mPa·s |
| Thermal conductivity (ASTM E1461) | 0.90 W/(m·K) | 0.70 W/(m·K) | 0.20 W/(m·K) |
| Dielectric strength (ASTM D149) | 18.5 kV/mm | 16.2 kV/mm | 14.0 kV/mm |
| Volume resistivity (ASTM D257) | 2.1 × 10¹⁵ Ω·cm | 1.4 × 10¹⁵ Ω·cm | 1.0 × 10¹⁴ Ω·cm |
| Flame rating (UL 94) | V-0 at 3.0 mm | V-0 at 3.0 mm | V-1 at 3.0 mm |
| Hardness (ISO 868) | 85 Shore D | 80 Shore D | 50 Shore A |
The filler is a bimodal blend of spheroidal alumina with D50 14 µm and sub-micron fused silica at a 7:3 weight ratio. This blend is selected to balance thermal conductivity against sedimentation. Accelerated settling tests at 60 °C for 72 h show a sedimentation index of 0.93 as measured by top-bottom viscosity ratio; a monomodal alumina filler of D50 10 µm gives a sedimentation index of 0.78 under identical conditions. The difference is significant in vacuum potting operations where reservoir dwell time exceeds 45 min.
For vacuum potting of toroidal inductors with gap clearances below 0.35 mm, the mixed system must be degassed at 28 inches Hg until bubble release ceases. At 50 °C the pot life shortens to 12–15 min, so shot volume per cycle should not exceed 80 g unless the mixing machine incorporates a chilled static mixer. In transformer bays with enamel-coated copper windings, a maximum filler content of 62 wt% avoids abrasive wear on the wiper blades of progressive cavity pumps during continuous dosing. The product is not recommended for connector assemblies where the polyamide grade contains more than 3.0% water-soluble plasticisers because these additives can migrate to the encapsulant interface and lower the shear strength below 3.0 MPa after 1000 h at 85 °C.
The product is formulated with a phosphinate-based synergist and alumina trihydrate filler, without brominated diphenyl ethers or antimony trioxide. The formulation therefore aligns with REACH Annex XVII restrictions applicable to certain brominated flame retardants and with RoHS Directive (EU) 2015/863 limits for lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers, and four phthalates. The compliance data are summarised in Table 2.
| Requirement | Method | Result |
|---|---|---|
| RoHS Directive (EU) 2015/863 restricted substances | IEC 62321-5 and IEC 62321-7-2 | Pass |
| REACH SVHC above 0.1% w/w | Gas chromatography-mass spectrometry screening | Not detected |
| Total bromine and chlorine by EN 14582 | Ion chromatography after combustion | 680 ppm |
| UL 94 vertical flame rating, 3.0 mm | UL 94 | V-0 |
Processing incompatibilities include exposure to free amines in secondary coatings that contain high-basicity imidazole accelerators, which can plasticise the cured surface and reduce breakdown strength by more than 10% after 7 d at 150 °C. Solvent wiping with acetone prior to encapsulation is permissible only if the housing is dried at 60 °C for 20 min; residual acetone above 0.1 mg/cm² causes foaming during gel. Pre-drying of filled resin containers is required when storage relative humidity exceeds 60% RH. Avoid combination with amine-based additives that are not part of the WWJF-8055 hardener system due to premature crosslinking.
