Views: 684 Author: Site Editor Publish Time: 2020-01-21 Origin: Site
Supersonic flame is a high-temperature, high-speed combustion flame, generated by burning propane, propylene and other hydrocarbon-based gas or hydrogen and high-pressure oxygen in the combustion chamber, or in a special nozzle. And the speed of flame can reach Mach 5 (1500m/s. ) or above, commonly referred as HVOF (High-velocityoxygen-fuel). By feeding the powder axially into the flame, which could heat the sprayed particles to a molten or semi-molten state, and then accelerate up to 300-500m/s or more, the high-strength, dense and high-quality coatings could then be obtained. The supersonic flame has high speed but low temperature relatively. For WC-Co cemented carbide, it can effectively inhibit the decomposition of WC during the spraying process. So that not only the high bonding strength, the coating is also of high dense and excellent wear resistance. Its wear resistance greatly exceeds that of plasma spray coating, electroplated hard chromium layer or spray melt layer, and is equivalent to that of explosive spray coating. The flame is widely used in producing single-screw and twin-screw, and has been affirmed in actual use.
This article cautions against pursuing excessively short injection molding cycles (e.g., 2.8 seconds), outlining 20 improper high-speed practices and their consequences. It covers material degradation, gas entrapment, mold and machine component fatigue, hydraulic system damage, and mechanical failures, emphasizing that aggressive cycle reduction compromises part quality and equipment reliability rather than yielding genuine efficiency gains.
the use of three-dimensional response surface methodology (RSM) to optimize twin-screw extrusion parameters—temperature, screw speed, and throughput. By analyzing their interactions, RSM overcomes the limitations of traditional single-factor adjustments. Through a Box–Behnken design, response surfaces are generated to visualize performance sensitivity and identify a multi-objective optimum that balances mechanical properties with production efficiency.
Because every machine and material is different, you can’t blindly copy exact numbers. Here’s a rule‑of‑thumb rhyme to judge if your back pressure is right: “Smooth charging, no slipping; stable cushion, small deviation. Check the surface for smoke—smooth, bubble‑free, no drooling.” Next time you run into dimensional instability, surface gas marks, or color‑change issues, don’t rush to tweak injection speed. Calm down, look at the back pressure gauge first, adjust back pressure, and the problem that’s been haunting you for days might just solve itself.
This article presents four practical methods for accurately assessing screw wear in extrusion and injection molding machines without disassembly. The methods include melt pressure and position data testing, a pressure drop/backflow evaluation, process reverse deduction through torque and temperature anomalies, and direct borescope inspection. Diagnostic logic linking common symptoms—such as output loss, temperature overshoot, and pressure instability—to specific wear locations is also provided.
the wear-induced failure of screws and barrels, noting the limitations of chrome plating and nitriding. It investigates the feasibility of surface boriding treatment on 45 steel screws and barrels to enhance surface hardness and wear resistance, and validates the process through field testing.
