Injection Molding Machine Clamping Position Varies

CR4 is the wrong location to search for <...the possible reasons...>. The correct source of this information is the Service Technician, "Anonymous Poster #2", who is investigating and clearing the fault. After all, the equipment cannot be seen from here.

On a properly set and maintained Injection moulding machine, the injection unit will not move forward and engage with the fixed mould side and start injection if the mould is not closed and the correct clamping pressure is not reached. What make and year model machine is this? The fact that injection takes place tells me that some safety systems are not working. Get the manufacturer to repair this first.

Several possibilities come to mind in no particular order:Hysteresis in the mechanical portion of the clamp,noise in signal from position transducer,electrical noise from recently installed new equipment,such as variable frequency drives,dirty electrical connections in signal wiring,loose connections.Intermittent problems are the worst kind to troubleshoot.As previously stated ,refer to your technician for possibilities he knows more about the machine than anyone on this forum,who have never seen your particular machine.

new scale is fine. also clamping open is working as per set parameter. clamp stop position read by system and physical is same. only problem is when closing.

now come to clamp setting parameter, is seems good as at same parameter we did well before(also check with changing in its low pressure and high pressure position to its minimum as 25 and 2 resp , which is not suitable generally but this will extend the time of error i.e clamp stop occurance . however its not full solution. our technician is looking at but we will now go further if problem will not resolve.

thanks for each comment.

What type actuator?Hydraulic,pneumatic,electric,servo?Full information will give better answers.Pictures,schematics,etc?

Here is a link that may help you.It covers similar problems:

https://www.sensorprod.com/news/articles/2009-04_pt/pr_pt-2009-04.pdf

Do you have the manuals?

Have you read the manuals, specifically the troubleshooting section?

Have you called customer service of the company that built the machine for assistance?

Have you gone on-line to search for similar machine problems?

Why do you withhold the make and model of the machine from the forum?

As HTRN said, have you asked the operator if they have any ideas?

In my experience, if it can't be rectified in less than a day, call a service tech. It will save you money in the long run, because if the machine is down you're losing money.

Sounds like poor setting of clamping system on machine.

Toggles not fully cycled and locked. (If it's a toggle clamp machine)

You might have a broken or loose machine tie bar, meaning that the machine is actually bending open during cycle.

You might simply have air in the hydraulic system (for both hydraulic or toggle clamp)

You might have a bent tie bar (or two) so that friction stops the machine reaching clamp setting before actual distance. Cuts out on pressure rather than stroke.

You might have pressure threshold set too low for "close" sequence and that trips before the "clamp" settings come into play.

You could have flash/material caught inside tool from previous short cycle that is holding tool open.

You might be exceeding your hydraulic pump capacity by the "requested" speed and stopping on "time" rather than pressure.

Your machine might be injecting "Hunt closed" before the tool is closed.

Your tool might be loose in the clamps and then material between fixed platen and fixed half of tool.

Etc. Your technician should be able to work though these.

Add a few seconds to the closing time and see what happens.

As this error is random we are running the machine and observe the situation.

Planning to fill hydraulic oil to main tank (observe it's level is middle of gauge).

Suggest how to remove air from hydraulic system (clamp valve assembly manifold)

Ranjan, you seem to miss important advice given on this forum. There is nothing wrong with the oil. Stop Micky mouse around. That machine should not move the barrel forward and apply pressure to the fixed mould if the clamping force was not reached. It will shear the fix mould retaining bolds right off. That machine should not inject material into a mould that is not closed except if the setting is so random that the program are totally confused. There are safety interlocks that are inoperative or tampered with. Get professional help and get production going. You are wasting your company resources.

Since many people have now attempted to solve this issue, it's good to hear that you are getting a professional to come and assist you to resolve the issue.

One "way out these" problem that I saw once was when a technician changed a machine from metric to imperial. The machine was doing multiple "strange" things within the cycle.

Fortunately we had back-up files for the running settings for each tool. Once the machine was reset and re-calibrated all was good again.

Do you have software back-up of the necessary programs and files? Your visiting technician will probably want something like that to be able to confirm his work.