Last updated: 2026-09-02 · 5 min read

What Should a Mold Trial Video Actually Show You?

A credible mold trial video shows the mold running in a named machine, producing consecutive unedited shots, with the mold number and a timestamp visible in the footage. It is the difference between evidence and assertion: photos of beautiful parts prove nothing about whether they came out of your tool, on the stated machine, in a continuous run. A structured video proves all three at once — and it costs the shop fifteen minutes at the press.

Shrinkage — The dimensional reduction from mold cavity to cooled part. Amorphous resins: 0.4–0.7% (uniform). Semi-crystalline: 1.0–2.5% (directional). Mold makers apply shrinkage factor when machining cavity. Actual shrinkage varies with wall thickness, gate location and packing pressure. See also related guide.

Key Facts

  • The video’s job is continuity of evidence. One continuous take shows the machine, the mold, the cycle, and the parts leaving the tool without a cut — which means nothing could be substituted between shots. An edited reel of individual moments is marketing; a continuous take is a record.
  • Audio matters more than buyers expect. The sound of a press cycling — screw recovery, injection, mold open, ejection, part drop — has a natural rhythm that is difficult to fake with cuts. If the audio is missing or replaced with music, ask why.
  • A trial video complements the T1 dimensional report; it never replaces it. The video shows the process is real and repeatable; the report shows the parts are dimensionally correct. Accept a tool only when both arrive together, referencing the same mold number and date.

    • Shrinkage — The dimensional reduction from mold cavity to cooled part. Amorphous resins: 0.4–0.7% (uniform). Semi-crystalline: 1.0–2.5% (directional). Mold makers apply shrinkage factor when machining cavity. Actual shrinkage varies with wall thickness, gate location and packing pressure. The related guide covers adjacent topics.

    What the Footage Must Cover, Shot by Shot

  • Machine identification — a clear shot of the machine nameplate and the clamp tonnage display, so you can verify the machine matches the one quoted for your production tool.
  • Mold identification — the engraved or stamped mold number on the tool, visible while the mold is in the press. This single frame ties the footage to your build record.
  • Date and time — an on-screen timestamp from the camera or a phone lock screen in frame. Footage without a date proves nothing about when the trial happened.
  • A full uncut cycle — mold close, injection, hold, screw recovery, cooling, mold open, ejection, part removal or drop. At least five consecutive cycles in one take, no cuts.
  • Part close-ups — the surface finish, gate area, and any cosmetic zone under steady lighting, filmed right after ejection while the parts are still in order.
  • Shot weight or parts on a scale — a brief clip of five consecutive parts weighed one after another shows shot-to-shot consistency in the most direct way possible.

    • How to Spot a Staged or Recycled Video

    1

    Check the take structure

    A real trial runs continuously; a staged video is stitched from highlights. Ask for the raw file straight from the camera or phone — not a re-export. Raw files carry metadata (device, creation time) and single-take durations that match the cycle math: if your cooling time is 30 seconds and the video claims ten shots, the raw file must run several minutes.

    2

    Listen to the audio

    Continuous machine sound across the whole take is strong evidence of an unbroken run. Music, silence, or audio that jumps at every cut means the footage was assembled — ask for the original.

    3

    Match the details to your project

    The mold number must match your build; the part must match your CAD; the machine tonnage must match the quoted press. A generic “our molding shop” video tells you the shop has a shop — not that your mold passed a trial.

    4

    Cross-check against the report

    The video date, mold number, and material should appear identically on the T1 dimensional report. If the report says T1 ran on March 4 and the video shows a different season of daylight, reconcile before payment.

    What to Ask For in the RFQ, Before Steel Is Cut

    Put the video requirement in the quotation stage, not after T1.
    The clause is one sentence: a continuous, unedited trial video of at least five consecutive cycles, showing the mold number and a timestamp, delivered together with the T1 dimensional report and raw CMM data. Shops that run honest trials agree without hesitation — the footage already exists on their phones. The request only costs a dishonest shop something, which is exactly why it belongs in the scope sheet you compare quotes against.

    Frequently Asked Questions

    How long should the video be?

    Long enough that the cycle math works: five consecutive cycles at a realistic cycle time. A 20-second reel cannot contain five full cycles of a part with 25 seconds of cooling. If the file duration does not support the claimed shot count, the footage was cut.

    Can a live video call replace the recording?

    A live call at T1 is excellent for interaction — you can request a specific close-up on the spot. But keep the recording as well: a call cannot be re-examined, and a file can. Ask for both when the time zones allow, or just the file when they do not.

    Does the video replace the dimensional report?

    No. The video proves the run happened and the process is stable; only the dimensional report proves the parts are to drawing. A tool with a beautiful video and no report is unverified; a tool with both is ready to accept.

    Key Takeaways

    1. Demand a continuous, unedited take of at least five cycles with the mold number and timestamp in frame — continuity is what makes the footage evidence.
    2. Read the video like an engineer: check take structure, audio continuity, machine and mold identification, and cross-check the date against the T1 report.
    3. Write the video requirement into the RFQ scope sheet so every shop includes it in the quoted price instead of treating it as a favor.

    A trial video costs fifteen minutes at the press and prevents the most expensive misunderstanding in offshore tooling — paying for a finished mold you have never seen run. aCatMould sends the footage with every T1 because the report tells you the parts are right, and the video tells you the record is real; together they are the basis for a clean acceptance decision.

    Sources
    MoldMaking Technology — mold trial documentation
    Plastics Technology — process verification
    Plastics News — supplier qualification practice

    Sources: Plastics Technology · Plastics Technology Online · Society of Plastics Engineers (SPE) · ThomasNet