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ČeštinaHot runner or cold runner mould: when does it pay off?
A hot runner mould costs more up front, but there is no runner to cut off and regrind, and the cycle is usually shorter. It pays off with large series, many cavities, expensive materials and visible parts. With small series and frequent colour changes a cold runner usually wins. The calculator below works it out for your part.
- Mould warranty
- C-FORM
- Hot runner service (our moulds)
- 3–6 working days
- Hot runner repairs
- other makes too
- T0 and T1 trials
- 25–1000 t
Why a hot runner mould from C-FORM?
- Toolroom and moulding in one plantThe C-FORM toolroom and the C-TECH moulding shop work on one project in Kowary.
- Trials before handoverT0 and T1 on C-TECH presses from 25 to 1000 t, before the mould goes to you.
- Service in 3–6 daysHot runner service on moulds we built usually takes 3–6 working days. We also repair other makes, quoted individually.
- C-FORM warrantyC-FORM, the company that built the mould, gives the warranty on the hot runner mould.
One shot, two runner systems
In a cold runner mould the material solidifies in the runners together with the part, and every shot leaves a runner. In a hot runner mould the manifold and nozzles keep the material molten all the way to the cavity.
- Mould cost
- Cold runnerlowerHot runnerhigher: system, controller, assembly
- Material
- Cold runnera runner with every shot: cutting off, regrindingHot runnerno runner
- Cycle time
- Cold runnerlonger when the thick runner cools longer than the partHot runnerusually shorter
- Gate mark
- Cold runnermark where the runner is cut offHot runnersmall mark, cleanest with a valve gate
- Colour change
- Cold runnerquickHot runnerlonger, depends on the system design
- Heat-sensitive materials
- Cold runnersimpler to processHot runnerneed the right nozzles and temperatures
- Start-up and operation
- Cold runnersimpleHot runnerneeds a start-up and service procedure
- Best for
- Cold runnersmall series, prototypes, frequent changesHot runnerlarge series, many cavities, expensive materials, visible parts
Work out whether a hot runner pays off
Enter your part's data. The calculator runs in your browser and sends nothing. Enter the hot runner surcharge from a quote to see after how many months it pays for itself.
Result per year
- Material you do not have to buy
- 1 500 kg
- Fewer machine hours
- 83.3 h
- Saving per year
- 7 417 €
- Payback of the surcharge (months)
- enter the surcharge from a quote
How we calculate: shots per year = parts / cavities; material = shots × runner weight × (1 − regrind); hours = shots × cycle difference / 3600; saving = material × price + hours × rate. The calculator leaves out energy, cutting off runners and service costs, so it is an estimate, not a quote.
Who does what on a hot runner mould
One project, two companies of the C-FORM Group in the same plant. Each step shows who performs it.
- Part reviewWe check the part, material and series: does a hot runner pay off?Performed by: C-FORM
- System selectionSelecting the hot runner system for the part and material.Performed by: C-FORM
- Mould design and machining3D design, CNC machining, EDM and grinding in the toolroom.Performed by: C-FORM
- Hot runner assemblyWe fit the system into the mould in our own toolroom.Performed by: C-FORM
- T0 and T1 trialsOn presses from 25 to 1000 t in the same plant.Performed by: C-TECH
- Service and repairsService on moulds we built usually in 3–6 working days. Other makes are quoted individually.Performed by: C-FORM
When a hot runner does not pay off
A hot runner is not always better. A cold runner usually wins when:
- the series is small or infrequent and the mould has one or two cavities
- the colour changes often and the system is not designed for it
- the material is heat-sensitive or the part is very small
- the plant has no start-up and service procedure for hot runners
Hot runner service and repair
We repair hot runners in the C-FORM toolroom. Service on moulds we built usually takes 3–6 working days. We also repair systems of other makes, but we quote each such repair individually, because time and cost depend on what has happened. C-FORM gives the warranty on the hot runner mould.
What to prepare for an enquiry
For a quote on a hot runner mould it helps to have:
- the 3D model of the part (STEP, IGES or Parasolid)
- the material and the share of regrind allowed
- the annual quantity and the number of cavities
- appearance requirements, especially at the gate
- the target cycle time and how often the colour changes
- the press the mould is to run on
Frequently asked questions
What is the difference between a hot runner and a cold runner mould?
In a cold runner mould the material solidifies in the runners together with the part, and every shot leaves a runner to cut off. In a hot runner mould the manifold and nozzles keep the material molten all the way to the cavity, so there is no runner and the cycle is usually shorter.
From what quantity does a hot runner pay off?
There is no single threshold. It depends on the runner weight, number of cavities, material price, cycle difference and the system surcharge. Work it out with the calculator on this page or send us your data: our quote compares both options.
How much does a hot runner add to a mould?
We price the hot runner separately in every quote, because it depends on the part, the material, the number of cavities and gates.
Do you repair hot runners of other makes?
Yes. The C-FORM toolroom repairs hot runners of various makes. We quote each such repair individually, because time and cost depend on what has happened.
How quickly do you repair a hot runner?
Hot runner service on moulds we built usually takes 3–6 working days. Repairs of other makes are quoted individually, because the time depends on the fault.
Who gives the warranty on a hot runner mould?
C-FORM, as part of the warranty on the mould it built.
Do you test a hot runner mould before handover?
Yes. We run T0 and T1 trials on C-TECH presses from 25 to 1000 t in the same plant in Kowary.
A mould with or without a hot runner?
Send the 3D model, the material and the annual quantity. Our quote compares both options.