How to Quote Injection Molding Jobs Faster

Where Molding Quote Time Actually Goes

An RFQ for a molded part usually arrives as a 3D model, a 2D drawing with tolerances, an annual volume, a resin callout and sometimes a mold quote request. The estimator then has to decide cavitation for the volume, pick a press, estimate cycle time, check for secondary operations such as ultrasonic welding, pad printing or assembly, and price resin with current supplier numbers. Each of those steps is quick in isolation.

The delay comes from hunting for a similar part, chasing the purchasing person for a resin price, and waiting on the toolroom for a mold estimate. When a shop sees 30 to 60 RFQs a month, those waits are the whole problem.

• Searching old quotes and jobs for a comparable part by memory or file name
• Waiting on resin pricing from the distributor or compounder
• Re-deriving clamp tonnage and shot size from the model every time
• Rebuilding the same Excel quote sheet with slightly different assumptions per estimator

Build a Standard Quote Model Once

The core formula is stable: piece price equals resin cost per part (part weight plus runner share, divided by cavity count effects, times resin price, adjusted for scrap and regrind), plus machine cost (cycle time divided by cavities, divided by 3600, times the press hourly rate), plus direct labor, plus secondary operations, plus packaging and freight, plus margin. Put the press hourly rate by tonnage band in one table, owned by finance. Put scrap allowances by part class in another.

Then the estimator only enters weight, cavities, cycle and secondaries. Shops that skip this step end up with quotes that differ by 15 to 25 percent for similar parts depending on who built them.

• Press rate table by tonnage band, updated at least annually
• Standard scrap and startup allowances by resin family and part complexity
• Fixed packaging and freight rules per customer
• Required margin floors by program type so exceptions are visible

Three Estimating Decisions That Need a Human

Cavitation, cycle time and press selection drive most of the price and cannot be fully automated. Cavitation depends on annual volume, tool budget and lead time, and a 4-cavity versus 8-cavity decision changes both tooling and piece price. Cycle time is dominated by cooling, which scales roughly with the square of the wall thickness, so thick sections or heavy ribs on glass-filled nylon need real judgment.

Press selection depends on projected area times cavity pressure for tonnage, plus shot size staying roughly 20 to 80 percent of barrel capacity. A calculator helps, but a senior estimator should confirm these three numbers before the quote leaves.

Use Actual Cycle Times and Scrap From Past Jobs

The most valuable data for quoting is already in your system: actual cycle times, actual scrap rates, actual changeover time and actual material usage from comparable jobs. In DELMIAworks, Plex, Epicor Kinetic or SyteLine, those live in production reporting and job cost history, but they are rarely pulled into the quote because the query takes too long. Pull actuals for the same resin family, similar part weight and similar cavitation, and compare them to your standard.

If your quotes assume 3 percent scrap and the last ten similar jobs ran 6 percent, you have found margin leak before the quote goes out.

• Compare quoted versus actual cycle for the last 10 comparable jobs
• Flag resin families where actual scrap exceeds the quote allowance
• Reuse the tool's real cycle when quoting a transfer mold

Where AI Fits Without Replacing the Estimator

AI is useful at the front and back of the process. At the front, it reads the RFQ email, drawing and spec, pulls out resin, tolerances, volumes and secondary operations, and searches the ERP for similar parts with actual cycle and scrap. At the back, it drafts the quote in your template with every number cited to a source for the estimator to approve.

Netray builds this as a private agent over your ERP and documents, running on your own hardware if you need it, with approval before anything is written back. It does not choose cavitation or press for you.

When This Is Not Worth Doing

If you mold mostly repeat work for three or four customers, quote under 10 RFQs a month, or already run a quoting tool that holds your press rates and history, the gain will be small. A well-built spreadsheet with locked rate tables and a disciplined similar-part lookup may be all you need. Start by timing three recent quotes end to end.

If most of the elapsed time is waiting rather than estimating, fix the waiting first, with resin price agreements and a standing tooling quote process, before adding any software.