Injection Shot Volume
Compute the shot volume of a plastic part by dividing the injected mass by the molten material density. The shot is the total volume of plastic injected per cycle (parts + runners), a parameter that must fit the injection barrel capacity. Together with the machine capacity, it defines how many cavities can be filled per cycle. Enter the injected mass (g) and the material density (g/cm³).
Result
—
Volume de injeção (shot)
O shot é a 'porção' de plástico que a injetora dispara a cada ciclo — o volume total que enche as peças e os canais de alimentação de uma vez. Calcula-se dividindo a massa injetada pela densidade do material fundido: vol = massa/densidade. Esse volume precisa caber na capacidade do canhão (a câmara à frente da rosca) — e, por boa prática, deve usar entre 25% e 80% dessa capacidade: menos que isso deixa o plástico tempo demais aquecendo (degrada); mais que isso não sobra colchão de material. O shot, junto com a capacidade da máquina, determina quantas cavidades dá para encher por ciclo. Por isso é um dos primeiros números calculados ao escolher a injetora para um molde. Informe a massa injetada e a densidade do material.
Related Tools
Injection Capacity (PS Equivalent)
Convert a machine's nominal injection capacity (always specified in polystyrene, PS, density ~1.05) to the equivalent capacity in another material by multiplying by the density ratio. Since the barrel has a fixed volume, the mass it injects changes with the plastic's density — denser materials yield more grams per shot. Essential to size the machine for the real material. Enter the nominal PS capacity and the material density.
Injection Cycle Time
Compute the total cycle time of a plastic injection by adding the injection time (fill + pack), the cooling time and the mold open/eject time. Cooling is usually the largest share (50–80% of the cycle). The cycle time directly determines productivity: parts/hour = 3600/cycle × cavities. Reducing it is the constant focus of optimization. Enter the injection, cooling and opening times.
Volume/Capacity Ratio (V/C)
Calculate the volume/capacity ratio (degree of saturation), X = V ÷ C, dividing the traffic volume V by the capacity C of the road or intersection. The dimensionless result measures the road's utilization: X near 0 indicates a free road; X = 1 means the road operating exactly at capacity; X > 1 indicates demand above capacity, with growing queues and congestion. The V/C ratio is the main indicator to classify the level of service (LOS A to F) and identify bottlenecks. Values above 0.85–0.90 already indicate near-saturation operation. Enter the volume and the capacity.
Mold Cavity Pressure
Estimate the pressure that actually reaches the mold cavity by multiplying the injection pressure (at the screw tip) by the pressure transmission factor, which accounts for pressure losses along the runners, nozzle and gates to the cavity. Typically only 40–60% of the machine pressure reaches the part. It is the cavity pressure that defines the clamping force and fill quality. Enter the injection pressure and the transmission factor.
Annular Grout Volume (Backfill)
Calculate the theoretical annular backfill grout volume per lining ring of a mechanized tunnel, V = (π/4)·(De² − Di²)·L, from the excavation diameter De (the TBM cutterhead cutting diameter), the segment ring outer diameter Di and the ring length L. Behind the TBM shield an annular gap forms (between excavated ground and lining, from overcut and shield taper) that must be filled immediately with grout injected through the tail. This filling is essential: it prevents ground relaxation (reducing volume loss and surface settlement), locks the ring in place and ensures uniform ground-lining contact. Actual injected volume exceeds theoretical (factor 1.1-1.5). Enter the excavation and ring diameters and the ring length.
Pump Work (Rankine)
Calculate the specific work consumed by the pump of a Rankine cycle, w_pump = v × (P₂ − P₁), multiplying the liquid specific volume (m³/kg, ~0.001 for water) by the pump pressure rise (kPa). The result, in kJ/kg, is the energy spent pressurizing the condensate before the boiler. Because the liquid is nearly incompressible, this work is tiny compared with the turbine's — which is why the Rankine cycle pumps a liquid (not a gas, as a gas Carnot cycle would), sharply reducing the back work. Enter the specific volume and the pump outlet and inlet pressures.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.