Why Kamath Plastics Has 0% Rejection Rate and How We Do It Every Time

Tool Validation Process Explained - Graphic - Kamath Plastics

Last month, one of our customers contacted us. He had a problem and asked us to fix it. He was bombarded with failed parts from their previous supplier. To be precise, 80% were rejected on arrival. The problem? Not Design. 

The mould seemed perfect, until it produced a faulty batch, and then another. 

At first, his teams blamed “QC slippages as the source. And no matter what they did, the problem persisted. Their former supplier reworked the line, and they changed the inspection protocol. Nothing worked.

So when this client came to us, he asked what the issue could be, and if we can guarantee that it wouldn’t happen from our side. Our answer, based on what we were told: “It’s the tool”.

How Kamath Plastics prevents defects in the long run

At Kamath Plastics, we control each batch to ensure that your injection mold is not worn, your ejector pins are not sticking, and your cooling is uniform through regular checks and direct tool maintenance. 

We continuously check for tool wear, misalignment, and thermal imbalances to ensure that every part we deliver matches. With these processes in place, the quality is maintained, and your plastic parts are always up to the mark. The result? 0% rejection rates

Detecting tool problems early: Start treating “bad batches” as signals: 

How do you detect tooling failure in injection molding?

• Sink marks (small surface dents): Often caused by inconsistent cooling or thick wall sections. Eliminating them improves product aesthetics and dimensional accuracy, key in consumer-facing or precision-fit parts.

• Flashes (excess plastic overflow): Usually due to worn parting lines or low clamp force. Addressing this reduces post-processing and ensures better sealing and part integrity.

• Short shots (incomplete mold fills): A sign of poor venting or flow issues. Solving it means fewer rejects, stronger parts, and consistent weight.

• Degraded surface finish: Often due to tooling wear or temperature imbalance. Fixing this protects brand perception and avoids costly cosmetic rejections.

• Inconsistent output across repeat orders: Indicates tool fatigue or poor mold maintenance. Resolving it improves batch consistency, forecast accuracy, and trust with your buyers.

Top-performing procurement teams don’t budge on tool validation 

At Kamath Plastics, we work with product teams before a single cavity is cut.

Here’s our injection mold validation process:

• Tool design simulation to detect filling, cooling, and warpage risks early. 

• T0–T3 validation with part comparison, dimensional analysis, and material stress testing

• Cycle life prediction based on material + geometry + part complexity

Information that ends up on paper, on your quotation. 

And we keep monitoring post-launch. For example, if surface defects cross thresholds, we know before the customer does.