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T0, T1, T2 Mold Trial Guide: Request Form, Trial Plan, Checklist & Templates

A successful mold trial is more than just collecting samples; it is a critical engineering validation process. Understanding the distinct objectives of T0, T1, and T2 stages is essential for tool qualification. While a Mold Trial Request defines the required inputs and constraints, a Mold Trial Plan governs the execution logic and sequence. This guide provides a comprehensive framework for injection molding validation, including downloadable engineering templates to ensure data-driven decision-making during every sampling stage.

T0/T1/T2 Logic Request Protocols XLS Templates

Precision injection mold trial T0 T1 T2 sampling and engineering documentation setup

What Is a Mold Trial and Why Does It Need a Defined Request?

In professional plastic engineering, a mold trial is not a "test run" to see if a part pops out—it is a scientific validation of tool geometry, thermal dynamics, and process stability.

What a mold trial actually validates

Beyond visual confirmation, a trial validates the process window. It assesses the tool's ability to produce consistent parts under specified pressures and temperatures, ensuring that the steel-safe dimensions and cooling circuit efficiency meet the target Cpk (Process Capability Index) requirements before mass production.

Why samples become unusable without defined inputs

Without a defined request, samples are "isolated data." If the resin lot, drying parameters, or machine tonnage are not recorded and controlled, any successful part is a fluke that cannot be replicated. Engineering decisions made on undocumented trials lead to catastrophic failures during final assembly or site validation.

The Mold Trial Control Chain: Request vs. Execution vs. Output

Phase 01: The Request

Trial Request

Input Control

Freezing resins, targets, and constraints before the machine starts.

Phase 02: The Plan

Trial Execution

Process Control

The logical sequence from short-shots to scientific molding stability.

Phase 03: The Report

Trial Output

Data Control

Dimensional reports, defect summaries, and tool-tuning directions.

What Is the Difference Between T0, T1, and T2 Mold Trials?

Trial Stage	Primary Objective	Typical Checks	Typical Output	Avoid These Conclusions
T0 (Internal)	Tool Function & Fill Feasibility	Gate/Vent status, cooling leaks, basic ejection, short shots.	Raw samples, Initial Condition Sheet.	Dimensional accuracy or surface finish validation.
T1 (First Article)	First Part Evaluation	Full dimensional report (CTQ), visual defects, cycle time baseline.	FAI Report, Defect Summary, Tool Tuning List.	Assuming the tool is ready for final grain/texture.
T2 (Verification)	Correction Verification	Verification of T1 fixes, repeatability check, assembly fit-up.	Updated Dim Report, Stability Record.	Finalizing packaging before CPK verification.
Pilot / T3	Process Capability (Cpk)	Continuous run stability, automated cycle check, scrap rate.	Validation Report, Final Process Window.	N/A - This is the production baseline.

T0 — Basic Tool Function and Fill Feasibility

The T0 trial is primarily for the toolmaker. It confirms that the mold opens, closes, and ejects without mechanical interference. Engineering focus is on "filling behavior"—identifying unbalanced runners or venting issues before moving to precision adjustments.

T1 — First Part Evaluation and Defect Baseline

T1 is the customer’s first look at the part geometry. Here, we establish a "Defect Baseline." Every sink mark, weld line, or dimensional deviation is mapped against the tool steel to determine the first round of corrective actions (Steel-Safe adjustments).

T2 — Correction Verification and Repeatability Review

T2 validates that all modifications requested after T1 have been successfully implemented. The focus shifts from "fixing errors" to "verifying repeatability." If assembly fits and key dimensions are within tolerance, the mold is often approved for texturing.

When a T3 or Pilot Run is Needed

A T3 or Pilot run is critical for high-volume automotive or medical projects. It involves a continuous 4-8 hour run to verify that thermal stability is maintained and that the mold can run in "full-auto" mode without operator intervention.

⚠️ Engineering Alert: What should not be concluded from T0 parts?

Never use T0 samples for assembly testing or dimensional approval. T0 parts are often molded with "guessed" parameters and non-dried resin. Using them for engineering decisions regarding fit or function will result in false positives/negatives.

What Should Be Defined Before a Mold Trial Starts?

To prevent "blind sampling," engineering inputs must be frozen before the machine is powered on. These 8 pillars ensure the data collected is actionable and scientifically valid.

01 Drawing and Part Revision

Establishing the "Single Source of Truth." We freeze the CAD version and 2D drawing revision to ensure inspection data is matched against the correct engineering ECO (Engineering Change Order) status.

02 Trial Objective & Approval Criteria

Is this for "Fill and Pack" (T0) or "Dimensional Approval" (T1)? Clearly defined success metrics prevent wasted machine time and ambiguous sample reviews.

03 Mold Status Before the Trial

A pre-trial bench check of the cooling circuit (flow rate/pressure), ejection stroke, and limit switch functionality to avoid preventable downtime on the press.

04 Machine Tonnage and Constraints

Selecting the press based on projected clamping force and shot capacity. We document machine-specific constraints (tie-bar spacing, nozzle radius) to ensure process portability.

05 Resin Grade, Drying, and Lot Control

Complete traceability of the raw material. This includes the exact manufacturer grade, colorant ratio, drying time/temp, and lot numbers to isolate material variables from process variables.

06 Inspection Scope and CTQ Dimensions

Defining Critical-to-Quality (CTQ) features before sampling. This dictates which dimensions must be measured immediately at the press versus those requiring a CMM lab.

07 Sample Quantity and Cavity ID Logic

Pre-defining the number of "stable shots" to collect and the method for cavity identification (e.g., cavity tagging) to enable accurate cavity-to-cavity variation analysis.

08 Customer Participation and Review

Scheduling real-time review windows (physical or virtual). Clear alignment on who signs off on the "first shots" ensures the trial moves toward the next stage without delay.

What Should Be Included in a Mold Trial Request Form?

Project and mold identification fields

Standardizing baseline tracking: Project ID, Part Name, Mold Number, and current Tool Revision status to ensure all data points are mapped correctly in the ERP/PLM system.

Trial stage and engineering objective

Defining the "Why": Is this a T0 (Function), T1 (Geometry), or T2 (Validation)? Explicitly stating the objective prevents misaligned expectations between the toolroom and the customer.

Machine and resin requirements

Critical process constraints: Required press tonnage, nozzle radius, resin grade/color, and mandatory drying parameters (Time/Temperature) before the first shot.

Inspection and validation request

Establishing the "Must-Check" list: Defining CTQ (Critical to Quality) dimensions that require immediate measurement and visual inspection standards (e.g., Gate Vestige, Flash).

Deliverables required after sampling

Data output expectations: Scientific molding sheets, cavity-specific sample sets, dimensional reports, and defect photo documentation for remote review.

Internal approval routing

Ensuring accountability: Workflow sign-offs from Project Engineering, Quality Assurance, and the Toolroom Manager before samples are dispatched.

What Should Be Included in a Mold Trial Plan?

Step 01

Trial Schedule and Team Ownership

Establishing clear accountability: Who is the Lead Process Engineer? Who from Quality is signing off? Defining ownership ensures that decisions made at the press are final and documented.

Step 02

Machine Setup and Window Targets

Pre-defining the "Scientific Molding" baseline. We establish target melt temps, injection velocities, and hold pressures before the first shot to ensure the process starts within a calculated window.

Step 03

The Sequence: Short Shot to Stable Shot

The core execution logic. We document the progression from filling balance analysis (short shots) to viscosity curve establishment, ensuring the mold reaches thermal equilibrium before sampling.

Step 04

Sampling Plan by Cavity and Condition

Defining the "Capture Logic." We specify exactly which shots to keep (e.g., 5 consecutive stable shots) and ensure cavity identification is preserved for downstream variation analysis.

Step 05

In-Process Inspection Checkpoints

Establishing "Gatekeeper" checks. Defining which dimensions or visual defects must be validated at the press before allowing the trial to proceed to the next DOE (Design of Experiments) stage.

Step 06

Post-Trial Review and Reporting

The closing loop. A structured plan for consolidating machine logs, defect photos, and measurement data into a Tool Tuning Recommendation for the mold shop.

Mold Trial Execution Control

Move beyond simple scheduling. Download our professional Trial Plan Template to manage the scientific sequence and engineering ownership of your next sampling run.

Download Mold Trial Plan Template

What Should Be Checked During the Mold Trial?

Verification during the sampling stage is the last line of defense before tool modification. We utilize a four-tier inspection matrix to ensure every critical engineering attribute is quantified.

Defect Map & Limit SamplesFAI / CPK ReportWeight Deviation ChartFlatness Deviation MapCavity Balance AnalysisGo/No-Go VerificationTrial Condition Sheet

Inspection Item	Why It Matters	Method
Visual Defects (Flash, Sink, Burn, Weld Lines)	Establishes the cosmetic baseline and identifies venting or cooling inefficiencies.	100% Visual Inspection under standard lighting (D65).
CTQ Dimensions & Steel-Safe Features	Ensures critical tolerances are met before finalizing "metal-off" tool tuning.	CMM, OMM, or Calibrated Hand Tools vs. 2D Drawing.
Weight Consistency & Fill Stability	Indicates process repeatability and potential cavity-to-cavity imbalance.	Precision scale measurement (5-10 consecutive shots).
Warpage, Flatness & Sealing Surfaces	Crucial for assembly fit-up and leak-proof performance in functional parts.	Surface plate check, Feelers, or 3D Laser Scanning.
Cavity-to-Cavity Variation	Validates that multi-cavity tools produce identical parts within the target window.	Comparative measurement across all tool cavities.
Assembly Fit & Function Check	Confirms real-world performance (e.g., Snap-fits, Leak tests, Thread engagement).	Mating part fit-up or dedicated functional test fixtures.
Process Observations & Recordables	Captures "unseen" data: abnormal noises, ejection sticking, or erratic cycle times.	Real-time machine monitoring and operator log review.

What Should Be Recorded During the Trial?

Beyond checking parts, the core mission of a trial is to establish a repeatable data baseline. Without recording these parameters, you are merely guessing the cause of future defects.

Thermal Management

Machine & Barrel Temp Settings

Record every zone from hopper to nozzle. This ensures that the material's residence time and melt temperature are consistent for subsequent tool tuning or mass production transfer.

Cooling Logic

Mold Temp & Cooling Conditions

Document flow rates, inlet/outlet temperatures, and cooling circuit sequence. Thermal equilibrium is the primary factor in warpage control and cycle time optimization.

Process Window

Speed, Pressure & Cooling Time

Establishing the Scientific Molding baseline: Injection speed profile, hold pressure/time, and transfer position (V/P switchover). This defines the "safe" process window.

Stability Data

Sample Weight & Shot Sequence

Capturing the gram-weight of parts by cavity across 10-20 consecutive shots. Weight stability is the most accurate real-time indicator of process drift or cavity imbalance.

Event Black-Box

Abnormal Events & Adjustments

Recording every manual intervention: "Why did the operator change the holding pressure?" "What happened during the 5-minute stop?" This context is vital for root cause analysis.

Quality Baseline

Stable-Shot ID & Retention Rules

Clearly defining which samples are "Golden Parts." We record the retention logic (e.g., shots 51-60) to ensure inspection data represents the mold's true stable performance.

What Documents Should Be Delivered After a Mold Trial?

Trial Condition Sheet

The "DNA" of the sampling run. Includes barrel temps, injection pressure profiles, and cycle times to enable precise process replication in production.

Sample Photos & Cavity ID

High-resolution visual documentation of stable shots, including detailed mapping of cavity identification for multi-cavity tool balance review.

Defect Summary & Probable Causes

A transparent engineering review of visual anomalies (weld lines, sink, flash) paired with root cause analysis and immediate mitigation steps.

Dimension Report for CTQ Features

Quantitative validation of Critical-to-Quality features. Essential for determining if the tool steel needs "metal-off" adjustments or if it's within tolerance.

Mold Issue List & Steel-Safe Recs

A technical roadmap for tool tuning. We emphasize steel-safe recommendations to minimize tool risk while achieving target geometry.

Next-Trial Objective & Action Plan

Clear transition logic. Defines the engineering success criteria for the subsequent T1/T2 run, ensuring project momentum and accountability.

Validation Level

When FAI, Capability Review, or Validation Records are needed?

For high-precision automotive, medical, or aerospace components, we provide full First Article Inspection (FAI), Cpk/Ppk capability studies, and OQ/PQ validation records to support your final PPAP or device master record requirements.

Download Mold Trial Engineering Templates

Standardize your injection molding validation process with our professional-grade templates, designed for precision T0, T1, and T2 sampling runs.

Excel / PDF Format

Mold Trial Request Form

Establish a single source of truth before the machine starts. Use this form to define resin parameters, tool revisions, and CTQ inspection requirements.

Download Request Form

Excel Format

Mold Trial Plan Sheet

Drive the execution logic. Manage your trial sequence from scientific filling balance to stable-shot collection and team ownership assignments.

Download Trial Plan

PDF Checklist

Mold Trial Review Checklist

A supplemental guide for on-site reviews. Ensure no visual defect or mechanical observation is missed during the sampling window.

Download PDF Checklist

Word / PDF Format

Post-Trial Summary Template

Consolidate your findings. A professional structure for documenting defect root causes and tool tuning recommendations for the mold shop.

Download Summary Doc

Example of a Standard Mold Trial Workflow

Preparation Phase

Before the machine starts

Standardizing the Input Control: Engineering verification of resin drying logs (Time/Temp), mold cooling circuit pressure tests, and finalizing the Trial Objective. We ensure the Tool Revision matches the latest CAD before any resin is loaded.

Precision injection mold pre-trial inspection and resin preparation

Execution Phase

During the trial run

Implementing Scientific Molding protocols: Establishing viscosity curves, determining V/P switchover points, and conducting a filling balance study. The focus is on reaching thermal equilibrium to ensure samples represent a stable process window.

Injection molding machine control panel during scientific trial

Data Capture Phase

After sample collection

Executing Traceability Protocols: Immediate cavity identification, shot sequence tagging, and on-site visual defect mapping. We record actual cycle times and cooling water flow rates into the Trial Condition Sheet for future replication.

Quality inspection of molded samples with cavity identification tags

Closure Phase

Before scheduling the next trial

Conducting Root Cause Analysis: Reviewing dimensional reports against the process window. Action items for "Steel-Safe" tool tuning are frozen, and the engineering success criteria for the subsequent T1 or T2 run are established.

Engineering team reviewing mold trial results and planning tool tuning

Common Mistakes in Mold Trial Planning

Rejected injection molded parts due to poor trial planning

Why Trial Planning Fails

Inconsistent data and unusable samples are rarely caused by the machine or mold alone—they are the result of poor planning. Avoiding these five critical errors can reduce tool development time by up to 30%.

Using an unapproved resin grade

Testing with "similar" materials leads to false data. Resin shrinkage, viscosity, and thermal behavior vary by manufacturer; using the wrong grade renders dimensional reports invalid.

Running T1 without CTQ definition

Without pre-defined Critical-to-Quality (CTQ) dimensions, the inspection team wastes time measuring irrelevant features while missing the ones that drive assembly fit.

Mixing cavities during sample collection

For multi-cavity tools, mixing samples makes it impossible to isolate cavity-specific issues. Proper cavity identification is the only way to perform root-cause analysis on tool steel.

Reviewing dimensions before stabilization

Measuring parts before the mold has reached thermal equilibrium or before parts have properly cooled leads to "ghost" dimensions that won't hold up in production.

Sending samples without a condition sheet

Samples without process logs are "black box" parts. If the customer doesn't know the pressures and temperatures used, they cannot approve the process window for mass production.

Engineering FAQ: Mold Trial Management

What is the main purpose of a mold trial request?

The primary purpose is Input Control. It freezes the engineering variables—such as resin grade, tool revision, and validation targets—before the machine starts, ensuring that the trial results are scientifically valid and repeatable.

What is the difference between a trial request and a trial plan?

A Trial Request defines what is needed (targets, constraints, and materials), while a Trial Plan defines how to execute it (the sequence of steps, machine settings, and team responsibilities at the press).

Can T0 samples be used for dimensional approval?

No. T0 is strictly for functional verification of the tool (e.g., ejection, cooling leaks, and fill balance). Since the process is not yet stabilized or optimized, T0 dimensions do not represent the final part geometry.

What resin information should be fixed before T1?

You must freeze the specific manufacturer grade, colorant ratio, and lot-controlled drying parameters (time and temperature). Using a surrogate resin at T1 will invalidate your shrinkage and warpage data.

What inspection items should be included in a mold trial checklist?

Essential items include visual defects (flash, sink, burn), Critical-to-Quality (CTQ) dimensions, part weight consistency, cavity-to-cavity balance, and functional assembly fit-up.

What documents should be delivered after sampling?

Standard deliverables include the Scientific Molding Condition Sheet, high-res photos with cavity identification, a dimensional FAI report, and a prioritized list of tool tuning recommendations.

Should the customer join the mold trial?

For T1 or T2 trials, customer presence (physical or virtual) is highly recommended. It allows for immediate decision-making on cosmetic trade-offs and accelerates the approval of corrective actions.

When is a T3 or pilot run needed?

A T3 run is required for process capability validation (Cpk). It is common in automotive and medical sectors to ensure the mold maintains stability over a multi-hour continuous production run.

Need a Trial Plan Reviewed Before Sampling?

Avoid costly tooling delays by validating your trial parameters early. Our engineering team provides professional audits for sampling logic, resin conditions, and CTQ inspection scope.

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