Mold Clamping Force
Compute the clamping force needed on a plastic injection machine, F = projected area · cavity pressure, to keep the mold closed against the molten plastic pressure. If the force is insufficient, the mold opens during injection and plastic leaks out at the parting lines (flash). It is the parameter that defines the machine tonnage required for a part. Enter the part's projected area (mm²) and the cavity pressure (MPa).
Result
—
Força de fechamento do molde
Durante a injeção, o plástico fundido entra na cavidade do molde a altíssima pressão e empurra as duas metades do molde para abrir. A injetora precisa segurá-las fechadas com uma força de fechamento maior que essa pressão vezes a área: F = área projetada · pressão na cavidade. A 'área projetada' é a sombra da peça vista na direção de abertura do molde — a área sobre a qual a pressão age. Se a força for insuficiente, o molde abre uma fresta e o plástico vaza pela linha de partição, formando rebarbas (flash). É justamente essa força que dá nome ao porte da máquina: uma injetora de '150 toneladas' aplica até 150 tf de fechamento. Superdimensionar gasta energia e dinheiro; subdimensionar arruína as peças. Informe a área projetada e a pressão na cavidade.
Related Tools
Mold Cavity Count
Compute the maximum number of mold cavities the machine can fill per cycle by dividing the machine's injection capacity by each part's mass (rounding down). More cavities increase productivity but require a larger machine and a more expensive, complex mold. It is a key calculation in production planning and mold selection. Enter the machine injection capacity and each part's mass.
Plastic Mold Shrinkage
Compute the final dimension of a plastic part after molding shrinkage, part_dim = mold_dim · (1 − shrinkage%/100). Every thermoplastic shrinks as it cools and solidifies in the mold — from ~0.5% (amorphous like ABS) to 2–3% (semicrystalline like PP and PA). That is why the mold cavity is machined larger than the final part, compensating exactly for this shrinkage. Getting it wrong ruins an expensive mold. Enter the mold dimension and the material's shrinkage rate.
Screw L/D Ratio (Injection)
Compute the L/D (length/diameter) ratio of an injection or extrusion screw by dividing the effective length by the diameter. It is a central parameter of the plasticizing design: long screws (L/D 20–24) give better melt mixing and homogenization; short ones (L/D < 18) plasticize less but are more robust. It defines melt quality and the ability to process different materials. Enter the screw length and diameter.
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.