Witness still exists
A tip mark is not invisible. Hide it or accept it on CAD.
Hot tip gates
Hot Tip Gates: Heated Drops, Witness, and Heat History
Mark faces that cannot take a tip mark. Name the resin. DFM review comments on CAD before a hot drop is locked.
Design guideline
A heated drop, not a cold tree
A hot tip injects through a heated drop. It is part of a hot runner, not a separate machine. The tip still leaves a witness. Sensitive resins can degrade if residence time is long.
Hot systems keep plastic molten in the drop, so there is no cold runner tree. Tip location on a cosmetic face still leaves a mark. Hot runner glossary defines the system. Gate types compare this drop to cold gates. DFM review needs vestige limits.
This page covers the heated tip. Runner design owns layout. Sub gates are a cold-runner hide. The design guide lists every topic.
Roles
Which page answers which hot-tip question
Stay here for the heated drop. Open a related guide for the system, types, or location.
| Page | Use it for |
|---|---|
| Hot tip gates (this page) | Heated drop, witness, heat history |
| Hot runner glossary | The manifold system |
| Gate types | Compare drop versus cold gates |
| Gate location | Where the mark lands |
| Runner design | Cold versus hot layout |
| Cold slug wells | A cold-runner pocket, not used here |
| Wall thickness | A drop still has to fill the wall |
| DFM review | CAD check before steel |
Checks
What DFM review looks for on hot tips
Qualitative checks. No figure on this page is a NetProto specification.
Heat history
Sensitive resins can degrade in a hot drop. Name the grade.
Not the same as the system
Hot runner is the manifold. This page covers the tip into the part.
Color changes
A hot system can hold the last color. Call out color-change needs.
Decision
A hot tip on a class-A face versus a hidden cold gate
Wrong: assume a hot tip leaves no mark. Right: place the drop, then compare a cold hide if cosmetics lose.
What goes wrong
- A tip on a class-A face with no vestige note
- Treat hot tip and hot runner as the same question
- A heat-sensitive resin with no residence note
What to try first
- Mark keep-off faces
- Open gate types if a cold edge or sub gate hides better
- Name the resin and color-change needs
RFQ
Send these notes with CAD for a hot-tip review
The quote can start from CAD alone. These notes make the DFM pass specific.
Faces that cannot take a tip mark
Resin family and heat sensitivity
Color-change or many-color intent
Preferred drop location if you have one
Whether a cold gate is an acceptable alternative
Cavity count
Related
Related design guidelines
Related guides for the next question, plus a CAD check when you are ready.
Hot runner glossary
The manifold behind the tip.
Hot runner glossaryDFM review
How NetProto checks tip marks before steel.
DFM reviewFAQ
Hot tip gates FAQ
What is a hot tip gate?
A heated nozzle that drops melt into the cavity. It is the last opening of a hot runner, not a separate process.
Are hot tips the same as hot runners?
No. A hot runner is the manifold. A hot tip is how that system enters the part. Open the glossary for the system.
Can hot tips change color quickly?
Color changes can be slower than a cold tree because melt stays in the drop. Call out color-change needs on the RFQ.
Who selects hot tip diameter?
The tooling team. This page does not publish a tip size. Mark vestige and resin. DFM review comments on CAD.
Does a hot tip leave a mark?
Yes. Hide it or accept it. Gate location owns the face. Gate types compare other hides.
How is this page different from runner design or sub gates?
This page covers the heated drop. Runner design owns layout. Sub gates are a cold hide. DFM review checks CAD.
Next step
Upload CAD for DFM review of hot-tip witness
Share keep-off faces, resin, and color-change intent so review can place the drop before quoting.