| HS Code | 749288 |
| Product | Mid/High-R Series |
| Product Type | Professional mid/high loudspeaker system |
| Frequency Response | 80 Hz - 20 kHz (±3 dB) |
| Sensitivity 1w 1m | 99 dB |
| Power Handling Continuous | 500 W |
| Power Handling Peak | 2000 W |
| Nominal Impedance | 8 ohms |
| Horizontal Coverage | 90 degrees |
| Vertical Coverage | 60 degrees |
| Crossover Frequency | 1.8 kHz |
| Drivers | 1 x 12-inch mid-range driver, 1 x 1.4-inch compression driver |
| Dimensions Hxwxd | 550 x 650 x 550 mm |
| Weight | 28 kg |
| Enclosure | Birch plywood with polyurea coating |
| Connectors | 2 x NL4 SpeakON |
| Mounting | Flying hardware and pole mount |
As an accredited Mid/High-R Series factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Mid/High-R Series is available in 25 kg sealed drums, with sturdy packaging ensuring safe handling, transport, and storage. |
| Container Loading (20′ FCL) | Mid/High-R Series loaded as 20′ FCL in secure, ventilated containers with proper dunnage, ensuring safe transport and stability. |
| Shipping | Mid/High-R Series chemicals ship in sealed, UN-approved drums or IBCs with proper hazmat labeling. Transport requires certified carriers and compliance with ADR/DOT regulations. Keep containers upright, protected from moisture and extreme temperatures. Avoid direct sunlight and ensure proper ventilation during loading and unloading to maintain safety. |
| Storage | Store Mid/High-R Series in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep containers tightly sealed when not in use, protected from moisture and physical damage. Avoid contact with incompatible materials such as strong oxidizers, acids, or bases. Follow manufacturer guidelines and local regulations. |
| Shelf Life | Store in original container at room temperature, away from moisture and sunlight. Shelf life: 24 months from date of manufacture. |
For packaging hot melt adhesives based on EVA or metallocene polyolefin elastomers, Mid/High-R Series is metered into the binder phase at 30–45 wt% relative to total formulation. The tackifier is first melted in a hot melt mixer at 160–175°C; viscosity is held below 2,500 mPa·s at 160°C to maintain transfer through slot-die coating heads. In bookbinding, the ratio is shifted to 35–50 wt% to extend open time to 8–15 s on paperboard substrates at 20–25°C and 50–60% RH. Softening point by ASTM E28-18 is controlled between 100°C and 112°C for the mid-R grades, and 112°C to 125°C for high-R grades. Acid value is maintained below 15 mg KOH/g by ASTM D465-15 to minimize reaction with calcium carbonate fillers. The molten adhesive is pumped through a 20 mm twin-screw extruder with L/D ratio 40:1 and strand-pelletized; barrel zones are set at 140°C, 155°C, and 165°C. Terminal products include case-and-carton sealing adhesives, spine glue, and tray-forming compositions. Compliance for indirect food contact is evaluated under FDA 21 CFR §175.105, with migration testing conducted on 60 µm polyethylene-coated kraft paper for 10 days at 40°C. A limitation appears when the adhesive is held above 180°C for more than 24 h; rosin ester degradation raises Gardner color from ≤ 4 to > 6 and reduces peel adhesion on clay-coated board by 15–20% in production trials. Pre-drying of mineral fillers to < 0.1 wt% moisture is required; residual moisture above 0.2 wt% accelerates hydrolysis of the ester linkages and causes viscosity drift in the melt tank.
| Mid/High-R loading (wt%) | Softening point (°C) | Viscosity at 160°C (mPa·s) | T-peel on corrugated board (N/25 mm) | Open time (s) |
|---|---|---|---|---|
| 30 | 108 | 1,850 | 12.5 | 8 |
| 35 | 111 | 2,100 | 15.2 | 11 |
| 40 | 114 | 2,300 | 18.0 | 14 |
| 45 | 117 | 2,500 | 19.8 | 16 |
Solvent-borne acrylic pressure-sensitive adhesive coating for polyethylene terephthalate label stock requires Mid/High-R Series at 10–20 wt% of total solids to shift peel adhesion from 2.5 N/25 mm to 6.0–8.5 N/25 mm on stainless steel panels after 24 h dwell under ASTM D3330/D3330M-02. The tackifier is dissolved in ethyl acetate/toluene at 40 wt% solids and post-added to the acrylic solution under a high-shear disperser at 1,500 rpm for 30 min; the final viscosity is adjusted to 1,200–1,800 mPa·s at 25°C for reverse gravure coating. Hydrogenated grades from the series are selected for UV-stable clear labels; non-hydrogenated grades are excluded from overlaminates because diene conjugation shifts yellowness index above 2.0 after 500 h QUV exposure under ISO 4892-3:2013. Loop tack values by ASTM D6195-03(2019) are increased from 3.0 N to 7.0 N at 20 wt% loading, but static shear on polished stainless steel drops from > 100 h to 20–40 h when loading exceeds 15 wt%, indicating a cohesive strength limitation. Production-scale coating on a 1,200 mm wide comma coater at 80 m/min requires the dry film weight to be held at 20–24 g/m²; higher coat weights increase adhesive transfer to the release liner. Terminal products include removable and permanent label stock, bar-code labels, and polyethylene film mounting tapes. Food-contact adhesive compliance is tested under FDA 21 CFR §175.125 for dry and fatty food categories; grades with acid value below 8 mg KOH/g are preferred to prevent interaction with metal chelate crosslinkers. The operational boundary is clear: Mid/High-R Series should not be compounded with zinc octoate catalysts in solventborne PSAs at concentrations above 0.3 wt%, because ester cleavage at 40–50°C over 7 days raises acid value and causes gelation.
Compounding Mid/High-R Series into emulsion polymerized EVA copolymer adhesives for furniture edge banding at 25–35 wt% widens the setting window on 18 mm PVC edge banding tape. The rosin ester is blended in a 250 L anchor mixer at 170°C under nitrogen; paraffin wax of 2–4 wt% and Fischer-Tropsch wax of 3–5 wt% are added sequentially to prevent phase separation. Melt viscosity at 180°C is maintained at 600–900 mPa·s to allow application by slot nozzle at 1.2–1.5 g/linear meter. The final furniture edge banding adhesive must reach heat resistance of 70–80°C and cold flexibility of −20°C without cracking. Batch-to-batch softening point variation above ±2°C alters the open time by 3–5 s and can cause visible adhesive squeeze-out on high-speed edge banders. Published data for this specific configuration is limited; the tolerances given are derived from production-scale mixer records and should be verified on the target line.
In toluene/isopropanol/ethyl acetate gravure inks for surface-printed polyolefin film, Mid/High-R Series functions as a resin cut at 8–15 wt% of wet ink and is dissolved to 50 wt% solids to form a clear varnish of 700–1,000 mPa·s at 25°C. The resin varnish is let down with NC chip dispersion; final ink viscosity at 25°C is held at 18–25 s on a Zahn Cup 3 according to ASTM D4212-16. High-R grades with softening point above 115°C are selected to reduce blocking on film rolls stored at 40–50°C; mid-R grades at 100–110°C are used where higher re-solubility on gravure cylinders is needed. Nitrocellulose compatibility is confirmed when toluene-isopropanol dilution at 1:1 produces no haze at 20°C; haze above 10 NTU indicates resin incompatibility or acid value above 12 mg KOH/g. The printed film is dried in a 12 m hot air tunnel at 60–80°C with residence time of 3–5 s; retained solvent must be below 5 mg/m² according to EN 13628-1. EU REACH registration is maintained for the series; Article 33 communication is required if any SVHC exceeds 0.1 wt% in the supplied material. Terminal products include frozen food packaging films, confectionery pouches, and label wrappers. The limitation for this series in high-solids flexographic inks is the increase in solvent retention when resin loading exceeds 15 wt%; print quality on polyethylene requires an in-line corona treatment of 38–42 mN/m prior to printing.
| Application | Standard or clause | Test method | Typical target |
|---|---|---|---|
| Packaging hot melt adhesive | FDA 21 CFR §175.105 | Extraction 40°C/10 days | Migration below detection |
| Pressure-sensitive label adhesive | FDA 21 CFR §175.125 | Room-temperature extraction | No visible food interaction |
| Printing ink for film | EN 13628-1 | Headspace GC | Retained solvent < 5 mg/m² |
| Rubber conveyor belt skim | ISO 289-1:2014 | Mooney viscometer | ML(1+4)100°C 45–52 MU |
When Mid/High-R Series is compounded into an SBR 1502/natural rubber conveyor belt skim stock at 8–15 phr, the resin acts as a reinforcing tackifier and plasticizer, lowering Mooney viscosity ML(1+4)100°C from 65 to 45–52 MU according to ISO 289-1:2014. Mixing is performed in a 270 L internal mixer with two-wing rotor at 40–60 rpm; the rosin ester is added after the carbon black N330 masterbatch reaches 90–100°C to avoid premature melting and uneven dispersion. Total mixing cycle is 4–6 min, with dump temperature held below 160°C to prevent degradation of the ester. The compounded skim stock is calendered at 0.8–1.2 mm thickness and laminated to EP 200 polyester fabric; adhesion between skim and fabric improves from 3.5 N/mm to 5.0–6.0 N/mm after vulcanization at 150°C for 20 min in a platen press. Terminal products include abrasion-resistant conveyor belts for mining and quarrying, where the cured compound must reach tensile strength above 18 MPa and elongation at break above 400% after 7 days at 70°C according to ISO 37:2017. The incompatibility with amine-based accelerators is critical: addition of diphenylguanidine above 0.5 phr in the same masterbatch promotes acid-base interaction with the rosin ester and reduces scorch time by 30–40%, as recorded on a rotorless curemeter. The use of Mid/High-R Series in white or light-colored belts requires hydrogenated grades; non-hydrogenated grades shift color from pale yellow to brown after 72 h UV exposure.
Hot-spray thermoplastic road markings require Mid/High-R Series to control binder flow and glass bead wet-out; the resin is melt-blended with C5 hydrocarbon resin, EVA, PE wax, titanium dioxide, and calcium carbonate at a binder content of 18–25 wt%, while the rosin ester portion within the binder is 20–35 wt% to control flow and adhesion to asphalt. Twin-screw extrusion is performed in a 75 mm co-rotating extruder at L/D 44:1, with barrel temperatures from 180°C to 210°C and die pressure at 5–8 MPa; the extrudate is cooled and crushed to 2–4 mm granules. Viscosity of the molten marking material at 200°C is controlled between 2,500 and 4,000 mPa·s, as measured by a rotational viscometer with a No. 27 spindle at 10 rpm. Softening point of the complete formulation is 90–105°C by ASTM D36/D36M-14; pigment content is 10–12 wt% TiO2 to achieve luminance factor ≥ 80%. Drop-on glass beads are applied at 350–450 g/m²; after 24 h, retroreflectivity is assessed at ≥ 150 mcd/m²/lx under EN 1436. Terminal product is a 1.5–2.5 mm thick hot-spray line marking for asphalt roads, airport runways, and parking areas. The operational boundary is low-temperature application below 15°C substrate temperature; adhesion to damp asphalt drops by more than 40%, and pre-heating must raise the substrate to ≥ 20°C before screed application.
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The Mid/High-R Series comprises four injection-moulding grades — Mid-R 15, Mid-R 25, High-R 15, and High-R 25 — based on a phosphorus-nitrogen flame-retardant polyamide 66 matrix. The designations denote the comparative retardancy index and nominal glass-fibre reinforcement: Mid-R grades are rated for medium-temperature electrical insulation applications requiring UL 94 V-0 at 1.5 mm, while High-R grades are formulated for thin-wall components requiring UL 94 V-0 at 0.4 mm and a comparative tracking index of 600 V. The series is intended for injection moulding of terminal blocks, miniature circuit-breaker housings, photovoltaic junction boxes, relay sockets, and EV charging couplers. Unlike brominated polyphenylene ether/PA66 systems, the series does not employ decabromodiphenyl ethane or antimony trioxide; the flame-retardant mechanism is based on melamine polyphosphate and metal phosphinate synergists that form a char layer during ignition. This chemistry reduces acid-gas generation during pyrolysis but imposes stricter drying and melt-temperature discipline. Typical density ranges from 1.22 g/cm³ for Mid-R 15 to 1.33 g/cm³ for High-R 25 when measured according to ISO 1183-1:2019. Melt volume-flow rate at 275 °C and 2.16 kg load spans 12 cm³/10 min to 18 cm³/10 min by ISO 1133-1:2022. The four grades are supplied as dry-blended cylindrical pellets with a median pellet length of 3.0 mm and are available in natural, grey, and black colour packages. The product line is suitable for high-speed multi-cavity tools, but the practical processing window narrows as wall thickness decreases below 0.8 mm.
Processing latitude for High-R 15 and High-R 25 in wall sections below 0.5 mm is constrained primarily by melt-temperature control. The recommended melt temperature is 282 °C ± 5 °C. At melt temperatures above 295 °C, the phosphinate synergist begins to liberate volatile degradation products, producing gas streaks, screw deposits, and a measurable shift in UL 94 performance from V-0 to V-1 at 0.4 mm. Below 277 °C, the melt viscosity increases sufficiently to produce short shots in thin ribbed sections. Validation runs on a 350 t toggle clamp injection moulding machine with a 40 mm diameter screw and L/D 20:1 showed that increasing screw recovery speed from 160 rpm to 180 rpm raised melt temperature from 285 °C to 298 °C with shear heating, leading to visible splay at the valve gates of an 8-cavity hot-runner tool. Barrel temperature settings of 260 °C rear, 270 °C centre, 280 °C front, and 285 °C nozzle are used for High-R 15; the 25% glass-fibre grade benefits from a nozzle setting of 290 °C to lower injection-pressure requirement. The mould-heating unit should maintain 70 °C to 90 °C, with a maximum deviation of ±3 °C across the cavity. Mould temperatures below 60 °C produce a frozen skin layer that weakens weld lines at pin-socket partition walls. Mould temperatures above 100 °C increase volatilization of low molecular weight phosphinate species and can deposit a thin conductive film on vent surfaces. Hold pressure is maintained at 60 MPa to 80 MPa hydraulic. Injection speed is set at 150 mm/s to 250 mm/s for wall stocks of 0.4 mm to 0.8 mm. Back pressure is limited to 0.3 MPa to 0.5 MPa to avoid excessive fibre attrition. Total barrel residence time should not exceed 8 min; at 10 min, yellowing shift ΔYI of 2.5 and tensile strength loss of 5% are observed under ISO 527-2:2012. The screw geometry should use a low-compression design with a compression ratio of 2.0 to 2.4 and a check ring rather than a ball-check valve, because glass fibre accumulates at ball-check seats and causes shot-weight drift.
Drying before processing is mandatory at 80 °C for 4 h in a desiccant-bed dryer with a dew point of -30 °C until residual moisture is below 0.10 wt% by ISO 15512:2019. At 60% RH, an opened drying hopper permits moisture re-uptake of 0.05 wt% within 30 min for high-glass grades. This re-uptake is sufficient to generate splay at gate locations and reduce weld-line tensile strength by 12% when moulding 0.4 mm walls. For installations without closed-loop material handling, secondary hopper drying is specified. The use of hot-air ovens is not recommended because uneven bed depth results in moisture variation greater than 0.08 wt% between tray bottom and top.
Flow length in a spiral mould at 800 bar injection pressure is 75 cm at 2.0 mm wall for Mid-R 25; at 0.4 mm wall, the flow length is 22 cm for High-R 15 and 18 cm for High-R 25. Shot-to-shot cavity pressure variation on a 32-cavity connector tool with 0.6 mm wall remained within ±4 bar when the melt cushion was held at 3.0 mm to 3.5 mm.
The electrical performance boundary between Mid-R and High-R grades is defined by comparative tracking index and glow-wire ignition temperature. High-R 15 and High-R 25 achieve a CTI of 600 V under IEC 60112:2020 Method A with 50 drops of 0.1% ammonium chloride solution, making them applicable to reinforced insulation on printed circuit board carriers. Mid-R grades are rated 500 V. Dielectric strength measured on 1.0 mm plaques is 34 kV/mm for High-R 25 and 31 kV/mm for Mid-R 25 under IEC 60243-1:2013 using a 2 kV/s ramp in silicone oil. Surface resistivity after 48 h conditioning at 23 °C and 50% RH is 1×10^14 Ω under IEC 62631-3-2:2023 at 500 V DC. The glow-wire ignition temperature at 0.8 mm is 800 °C for High-R grades and 775 °C for Mid-R grades under IEC 60695-2-13:2021. These values place the series above standard unfilled PA66, which typically registers 450 V CTI and V-2 at 0.75 mm, and above PBT GF20, which commonly reports 250 V CTI under the same IEC method.
| Property | Mid-R 15 | Mid-R 25 | High-R 15 | High-R 25 | Test standard |
|---|---|---|---|---|---|
| Density (g/cm³) | 1.22 | 1.32 | 1.23 | 1.33 | ISO 1183-1:2019 |
| Tensile stress at break (MPa) | 85 | 110 | 80 | 105 | ISO 527-2:2012 |
| Tensile modulus (MPa) | 6500 | 8800 | 6200 | 8400 | ISO 527-2:2012 |
| Flexural modulus (MPa) | 6000 | 8000 | 5800 | 7800 | ISO 178:2019 |
| Notched Charpy impact (kJ/m²) | 4.5 | 6.0 | 5.0 | 6.5 | ISO 179-1:2023 |
| HDT-A 1.8 MPa (°C) | 235 | 240 | 230 | 238 | ISO 75-2:2013 |
| UL 94 at 0.4 mm | V-1 | V-1 | V-0 | V-0 | UL 94 |
| GWIT at 0.8 mm (°C) | 775 | 775 | 800 | 800 | IEC 60695-2-13:2021 |
| CTI (V) | 500 | 500 | 600 | 600 | IEC 60112:2020 |
| MVR at 275 °C/2.16 kg (cm³/10 min) | 16 | 12 | 18 | 14 | ISO 1133-1:2022 |
| Property | High-R 25 | Standard PA66 GF25 | PBT GF20 | Test standard |
|---|---|---|---|---|
| Comparative tracking index (V) | 600 | 450 | 250 | IEC 60112:2020 |
| UL 94 at 0.75 mm | V-0 | V-2 | HB | UL 94 |
| Dielectric strength (kV/mm) | 34 | 30 | 28 | IEC 60243-1:2013 |
| Surface resistivity (Ω) | 1×10^14 | 1×10^13 | 1×10^13 | IEC 62631-3-2:2023 |
| HDT-A 1.8 MPa (°C) | 238 | 240 | 200 | ISO 75-2:2013 |
| Density (g/cm³) | 1.33 | 1.32 | 1.45 | ISO 1183-1:2019 |
The use of regrind from High-R 25 in thin-wall connector housings is limited to 30 wt% maximum when wall thickness is 0.4 mm. At 30 wt% regrind, notched Charpy impact declines from 6.5 kJ/m² to 4.0 kJ/m² under ISO 179-1:2023, and weld-line tensile strength in an 8-cavity hot-runner tool with 0.4 mm nominal wall and 6 mm gate pitch falls from 65 MPa to 42 MPa. The reduction is attributed to molecular weight reduction from the first heat history and fibre-length attrition. Flame-retardant performance is also affected: GWIT at 0.8 mm drops from 800 °C to 775 °C when regrind fraction exceeds 30 wt%, which can invalidate IEC 60695-2-13:2021 compliance for fixed electrical connectors requiring 775 °C. In moulded parts with wall thickness above 1.5 mm, regrind up to 50 wt% can be considered if lot-level CTI and UL 94 are re-qualified, but published data for this specific configuration is limited.
Compounding with external additives must be restricted. The series should not be blended with primary amine-based silane coupling agents or amine mould-release agents, because these species accelerate hydrolysis of the polyamide 66 matrix and reduce CTI under humid conditions. Incompatibility is also observed with antimony trioxide/decabromodiphenyl ethane masterbatches: mixed systems can lower glow-wire ignition temperature and produce visible bloom on connector surfaces after 85 °C/85% RH ageing for 500 h. If colour changes require a carrier resin, a melt-viscosity-matched polyamide 66 colour masterbatch at 2 wt% is permissible without measurable shift in UL 94 V-0 at 0.4 mm.
Moisture-conditioned electrical properties are evaluated after 85 °C/85% RH for 1,000 h under IEC 60068-2-78:2012. High-R 25 retains 91% of its initial dielectric strength and shows no delamination at the glass-fibre interface. For outdoor photovoltaic junction boxes, UV resistance can be supplemented with an additive package that does not reduce CTI; the base resin alone is not rated for direct UV exposure beyond 2,000 h without approved black pigmentation and UV stabilizer masterbatch. Compared with a brominated PA66 GF25, the High-R 25 system produces lower smoke density and avoids corrosive gas formation in processing, but its melt viscosity is higher and its drying window is narrower. Compared with PBT GF20, the series offers higher tracking resistance and flame class, but PBT GF20 may be selected where dimensional stability in humid environments is less critical and production cost is dominant.
Long-term thermal ageing follows IEC 60216-1:2013. High-R 25 exhibits a tensile strength half-life of approximately 18,000 h at 120 °C, while Mid-R 25 is rated for comparable retention at 110 °C. The series should not be used in direct contact with strong acids or alkaline solutions at elevated temperature; hydrolytic degradation accelerates above pH 9.5. Unopened bags stored below 50 °C and 75% RH retain drying certification for 24 months. Opened bags should be re-dried if exposed to 60% RH for more than 15 min. Regulatory compliance is documented to RoHS Directive 2011/65/EU Annex II, REACH SVHC candidate list, and EN 50642:2018 cable management fire classification when moulded in final applications. No intentionally added decabromodiphenyl ethane or red phosphorus is present. End users should verify final-part UL 94 performance at the minimum wall section and colour, since UL file data cover specific thicknesses and pigments.
