Should the rate use gross shots or good parts?

Use good parts per hour if you want the result to cover accepted output; otherwise account for rejects separately.

Can this include longer cooling time?

Yes. Include cooling-time changes in the completion rate or add expected cycle disruption in the allowance.

Does this work for multi-cavity molds?

Yes. Use a completion rate that reflects cavity count, cycle time, and expected blocked or rejected cavities.

How can I use the result?

Use it to quote machine hours, compare resin cycle impact, plan trials, and confirm whether the order fits the press schedule.

Bioplastics & Biomaterials Processing calculator

Molding Cycle Impact Calculator

Biomaterial molding cycles can change when PLA, PHA, PBS, PBAT blends, natural fibers, or starch fillers require different melt temperatures, mold temperatures, cooling times, or venting. This calculator helps processors estimate how cycle time assumptions affect available molding hours and schedule fit.

What this calculator does

Estimate injection or compression molding hours required for biomaterial parts based on part count, molding completion rate, and allowance for cooling, drying, and rework.
an injection molding or compression molding processor needs to estimate machine time for a biomaterial part order or trial
Returns estimated machine hours needed for the molded biomaterial workload.

Formula used

Base molding cycle time = biomaterial molded parts required ÷ molding completion rate
Required biomaterial molding time = base molding cycle time × molding setup and rework allowance factor

Inputs explained

Biomaterial molded parts required: Use good PLA, PHA, fiber-filled, starch blend, compostable, or bio-based molded parts required for the job.
Molding completion rate: Use the actual good-part rate based on cavities, cycle time, cooling time, shot size, and expected short-shot or warp losses.
Molding setup and rework allowance: Add time for drying checks, mold heat stabilization, purging, color change, dimensional inspection, and rework loops.

How to use the result

Use it for quote timing, press scheduling, cycle-time trials, cooling-time changes, and new bio-resin conversions.
It assumes a known good-part rate; it does not predict shrinkage, warpage, crystallinity, degradation, or dimensional capability.

Common questions

Should the rate use gross shots or good parts? Use good parts per hour if you want the result to cover accepted output; otherwise account for rejects separately.
Can this include longer cooling time? Yes. Include cooling-time changes in the completion rate or add expected cycle disruption in the allowance.
Does this work for multi-cavity molds? Yes. Use a completion rate that reflects cavity count, cycle time, and expected blocked or rejected cavities.
How can I use the result? Use it to quote machine hours, compare resin cycle impact, plan trials, and confirm whether the order fits the press schedule.

Last reviewed 2026-05-12.