In plastic injection production, mold replacement is not just removing the old mold and connecting the new one. Between the last solid part leaving the machine and the first approved part being taken from the new mold; preparation, safe stop, mold removal and handling, connections, auxiliary equipment, process parameters, test printing and quality approval. When these steps are not measured separately, long changeover time is lost in a single “machine downtime” record.
Where should you measure mold changeover time?
The most revealing measure is that of previous production. last solid piece with new production The first quality approved solid part is the time between. Physical disassembly-assembly time, time until the first test print and quality approval time should also be recorded. This way, it can be seen whether the delay is due to mechanical change, heating and adjustment, material preparation or waiting for approval.
Actual scope of mold replacement
Process that starts before the machine stops and ends with quality approval
external preparation
New mould, apparatus, hose, material, robot hand and parameters are prepared in advance.
Disassembly and installation
The old formwork is safely separated, the new formwork is transported, aligned and fixed.
Connection and setting
Water, electricity, hot runner, pusher, robot and process values are checked.
First part approval
Trial prints are made, dimensions and appearance are verified, and series production is started.
Where is the most time lost during mold change?
Looking for molds and equipment
If the location of the mold, lifting apparatus, fastening element or connection hose is searched after the machine has stopped, the preparation work is added to the downtime.
Mold Not Ready for Maintenance
If cleaning, lubrication, leakage control, hot runner or pusher problems are noticed during replacement, mechanical preparation turns into maintenance waiting.
Crane and crew not ready at the same time
If the lifting equipment is used on another machine or if the task is not distributed, operator, maintenance and quality expect each other.
Heating and material preparation starts late
When the dryer, raw material, masterbatch, mold temperature controller or hot runner are not prepared before the change, the machine remains connected.
Cannot find correct process setting
If the approved parameter bill of materials, mold-machine match or last successful production values are not recorded, the number of attempts increases.
First piece awaiting quality approval
If the control plan, sample, measuring device or quality officer is not ready, mass production cannot start even if a solid product is received.
Separate Internal and External Preparedness with the SMED Approach
SMED can be used as a rapid pattern or rapid preparation change approach in Turkish. Basic idea; which can only be done when the machine is stopped. internal preparation which can be completed while the machine is running external preparation to separate. The next step is to translate the possible internal preparations into external preparations and standardize the work remaining in the machine stop.
Tasks that can be completed while the machine is running
- Removing the new mold and bringing it to the change area
- Verification of mold maintenance status and suitability for production
- Preparation of fasteners, hoses, apparatus and hand tools
- Preparation of raw materials, dryer, masterbatch and auxiliary equipment
- Preparation of quality control plan with approved process parameters
Things to do when the machine stops
- Implementation of the safe stance and energy control procedure of the business
- Disconnecting, disassembling and removing old formwork
- Aligning, fixing and connecting the new mold
- Completion of machine, robot, thruster and auxiliary equipment checks
- Trial printing, process adjustment and first part quality confirmation
SMED's "single-digit minutes" target is not a directly achievable promise under every mold, machine and safety condition. The aim is to first see the real time, separate the work that can be taken out, and safely simplify the remaining stance steps.
Source note: SMED's internal and external preparation distinction Lean Enterprise Institute by definition; The application of the method to plastic injection mold change is 2025 LACCEI survey has been addressed by comparison with.
Things to Have Ready Before the Machine Stops
Mold suitability
Record of maintenance, cleaning, overhaul and release to production.
Transport and lifting
Suitable crane, eye bolt, sling, transport trolley and authorized personnel.
connection set
Water, electrical, hot runner, hydraulic or pneumatic connections.
Material preparation
Correct raw material, color, drying condition and clean feeding line.
Parameter bill of materials
Approved process and robot settings for mold-machine matching.
quality preparation
Responsible for control plan, sample, measuring device and approval.
Standardize Mold Change Step by Step
Plan and preparation
Change order, team, mold, materials and tools are prepared.
Safe stance
The last intact part is recorded and the operating procedure is applied.
Disassembly and installation
The old mold is separated, the new mold is placed and fixed.
Connection and setting
Lines, parameters, robot and auxiliary equipment are verified.
First part approval
The trial result is confirmed and the start of mass production is recorded.
Speed target is not a reason to remove safety steps
Mold weight, machine structure, energy sources and auxiliary equipment are different in each facility. Exchange standard; The machine and mold manufacturer's instructions should be prepared with the enterprise's risk assessment, safe stance, energy control and authorization rules. Software registration does not replace these procedures.
Reduce the Number of Mold Changes in the Production Plan
The fastest mold change is the one that is not made unnecessarily. While preparing the production plan, not only the order date; Machine tonnage, mold compatibility, raw material, color, temperature requirement, hot runner, robot apparatus and mold preparation status should be evaluated together. Scheduling similar products in the appropriate order can reduce the burden of cleaning, material handling and setup. However, it is not right to break customer deadlines or overstock costs just to produce long series.
mold family
View molds that use the same machine, clamping structure, robot attachment or auxiliary equipment.
Material and color order
Include in the plan the material, color and drying conditions that affect cleaning and raw material transfer.
deadline balance
Evaluate replacement savings with order deadlines, stock target and capacity.
Why machine occupancy, preparation times, and order deadlines should appear on the same schedule manual production planning and inefficiency In his article; The general structure of the work order, capacity and material plan in the production management guide and review it.
What Pattern Change Data Should Be Kept in ERP?
Plan information: Machine, old product, new product, old mold, new mold and planned replacement time.
Timestamps: Time for the last solid part, downtime, disassembly, assembly, first try and first approved part.
Responsible parties: Mold change team, operator, maintenance and quality approval people.
Reasons for waiting: Crane, mould, apparatus, material, heating, malfunction, adjustment or quality waiting.
Initial loss: Number of trials printed until first approval, amount of scrap and reason for nonconformity.
Mold status: Last maintenance, obvious fault, number of uses and next maintenance required.
sample measurement
See substeps instead of single total time
The values below are examples prepared to demonstrate the method; It is not a facility performance target.
Mold Change Indicators to Follow
Total replacement time
First certified piece - last solid piece
plan deviation
Actual duration - planned duration
First part approval time
Between the first trial and quality approval
Starting loss
Inappropriate amount before approval
completion of preparation
Rate of tasks finished before the machine stops
Recurring delay
Loss based on mould, machine and cause
It is necessary to monitor mold change stoppage separately from machine malfunction, micro stoppage and speed loss. For the general framework of machine operation and downtime records machine efficiency and downtime tracking his writing; for automatic data collection options from the field barcode and machine data collection guide and review it.
7 Steps to Improve Mold Changeover Time
- 1
Observe the real change with video and time recording. See steps, walks, calls and waits instead of estimated time.
- 2
Separate internal and external preparation. Move the tasks that can be done while the machine is running to the pre-replacement checklist.
- 3
Standardize mold and equipment layout. Reduce searching, carrying and unnecessary walking time.
- 4
Examine connection and binding methods. Select appropriate quick coupling and standard element options through technical and safety assessment.
- 5
Keep the approved process bill of materials. Keep the last successful parameters of the mold-machine-product matching version controlled.
- 6
Include quality in the change plan. Reduce the initial part check from being a separate job called after the changeover is finished.
- 7
Turn off the cause after each change. Record the plan deviation with the reason code and open a recovery task for the most frequently recurring losses.
Frequently Asked Questions
How is the mold changeover time calculated in plastic injection?
The difference between the last good part time of the previous product and the first quality approved good part time of the new product is taken. Disassembly-assembly, connection, adjustment, trial and quality approval sub-times are also recorded.
Is SMED just quick demolding?
No. SMED first separates internal and external preparation; It aims to complete the work that can be done while the machine is running, standardize the remaining steps and reduce waiting times.
Should quality time be included in the measurement during mold changeover?
Yes. If mass production does not begin until the first approved part is received, quality waits and test prints are part of the total changeover time; It should also be monitored as a sub-period.
How does ERP track mold changeover time?
Combines work order, machine, mold, product, team and time records; It reports planned-actual time, waiting reasons, first part approval and initial waste.
Do not manage mold changeover separately from the production plan
KG Palaimon production ERP solution; It helps to track work order, machine, operation, production realization, downtime, waste and cost data in a common production record. Process scope of plastic and similar manufacturing businesses sectoral ERP solutions on the page.
To evaluate mold, bill of materials and wastage needs together plastic and packaging production program Check out the page; Test mold change records with your own production sample.
Plastic injection production tracking
See the reasons behind lost time in mold change
Measure the difference between the planned time and the actual time by monitoring the mold, machine, work order, change steps, first part approval and initial waste together.