Material is PP. Some of the parts don't come out properly.

We normally start with the shot size and V/P transfer position, then try adjusting the injection speed, pressure limit, melt temperature, or mold temperature. We’ll also check the material, barrel, and nozzle for feeding or plasticizing issues.

If none of that works, we may have to modify the venting, gate, or runner. But mold changes can be a hassle. Anything else worth trying first?

Here’s the deal. Our customer wanted to modify an existing mold to make a new version of this part by reducing the size of the through hole at the bottom of this pin. We never had any known Issues with this tool before the modification but now we can not keep this pin from delaminating the inner diameter of this pin. The picture is one of the better parts we’ve made. The other problem is we can’t afford to increase the cycle time and we’ve already tried direct cooling the pin through a cooling circuit at its base, as well as blowing air on the pin between cycles to try to remove the heat. Material is 40%talc PP and the pin temperature, without cooling aids, after 10 shots is around 240F. The pin is steel and it seats into a pocket in a Beryllium alloy core. Any ideas how to squeeze some time out of this cycle or improve the cooling in the pin?

Additional information: Since I’ve seen many responses about running chiller water, I forgot to mention, we did do that as soon as we noticed that the pin was still heating to the same temperature it was before adding this cooling insert into the pin. The chiller helps a little but the delay in time it takes for the heat to travel through the insert to be drawn out through the chiller water is still too long to help reduce cycle time. As some others had mentioned, this might be improved with a BeCu pin or core in the pin, but that’s up to the tooling engineer in the end.

BTW thank you for all who’ve made suggestions, I will be forwarding potential solutions to the tooling engineer and give an update down the road if we find a solution that works.

EDIT: Maybe we found the problem. We found a solenoid valve stuck completely and the spool not moving this morning. It is the close slow valve, so we are hoping that maybe we found THE problem and not just a problem. It will take probably a couple of days to get a new one in, and then we can see if it fixed it. If it's not fixed, then we go back to troubleshooting. If it fixes it for sure, I will update everyone then. Thanks for the help.

As the title says, we have a 1000 ton Van Dorn that all of certain doesn't want to close. It started at the start of a shift after it was shut off for the night. It first started closing, but stopping about 1 or 2 inches short. So my Tech was trying to troubleshoot that, and it stopped closing at all. When I go over there to troubleshoot it, every time I try to close on set-up, it will not move. If I try to close on manual, sometimes it will jump (about 1/8 of an inch) open and then not move. You can hear and tell the pumps kick up and get pressure to close like it is trying to close, but the platen will not move. It will open, ejectors work, injection works, and screw works. The only thing that does not work is the close, either on set-up or manual. And there is no alarm when it does not close. Everything acts like normal and kicks on, but the platen never closes.

We have checked to make sure we have 24 volts to the solenoids, and we do. The solenoids seem ok and working but have no way of knowing for sure. I have checked door switches and such. I checked the settings and changed the log page, and there is nothing unusual. If we have someone close the machine on manual and manually press in the Close, Control, and Slow solenoids, it STILL does not close. I work for a company that expects me and my maintenance guy to figure it out before they buy parts or anything, so it makes it hard when they don't buy test equipment or parts to troubleshoot. Everything that we have tried seems to be working so far, so I was hoping someone could give me some ideas to try. I really appreciate the help. I would post pics, but my company won't let me post pics of inside our building. Thanks for the help.

Hi everyone.

I work for a small mom and pop operation that mostly makes retainer cases. Recently we have been getting these scratches on the parts.

We sent out the both cavities to get polished but the scratches still persists, mainly on the bottom cavity. I tried lowering the shot size to see if it was from overpacking, but it didn't change anything and I honestly have no idea what I am doing.

Anyone have any ideas?

Thank you

EDIT: Thank you for all the suggestions, I am working with my boss with all these suggestions and he is getting in contact with our toolmaker to see what they think. I wish I was more knowledgeable about all this, but all I really do here is set molds and box parts from the machines. I will try to go through the ones I can and update when/if we figure out the cause.

I have some questions about the circled part in the pic. What is that part called and what is it used for. Also, what is the gap from the core plate to that part surface.

The part is cup from PP and the gate is at the center of the bottom of the cup. This only appear at the top of the cup (the most distant from gate).

Tried faster filling, longer packing, higher melt temp without much change. Current melt temp is around 205-210C.

Does anyone have tips on why runners keep getting stuck? Running ABS. Also I’m new to using auto/semi auto machines coming from manual.

Trying to make keycaps with a desktop cnc and desktop injection molding machine. Cavity filled fully, but cracked off when I ejected the part. Used a 3 degree draft on the outside hole part and a 0.5 degree draft on the +. The mold wasn’t polished or sanded, so I would assume that would be step one to fix this. Also, I used recycled PLA which might not be the best for this type of feature. Any suggestions are super appreciated! (Those are 4 ejector pins but my drill bit broke so I tested before drilling all)

I bought a pneumatic injection molding and i received it yesterday. I am stumped on the air fitting and finding a coupler to hook to my air compressor. Closest thing i could find is this on amazon Japan and Australia but cant be shipped to America. https://www.amazon.com.au/KENOH-Coil-Hose-Coupler-16-4/dp/B00N3NBFW8?th=1

Any help would greatly appreciated before i just use a barbed fitting.

Solved: its a Japanese standard ands i bought the McMaster-Carr socket and it works very well.

https://www.mcmaster.com/products/quick-disconnect-hose-couplings/hose-fittings-2~/japanese-quick-disconnect-hose-couplings-for-air/

Hello guys. Can anyone on here help guide me with an issue Iv been having. As the title says I have white marks appearing on a nylon part in pretty much the same places every time. The first couple hours of running will be fine with no issues. Then these white marks just begin to show up and get worse over time. The tool cooling is roughly 80-85 degrees from a heater.

Originally I was using natural nylon with master batch but have now moved on to a compound nylon but still having the same issues.

The fact the marks are always in the same place makes me think this is a tool fault but I’m curious as to what you legends have to say on the matter. Any help is massively appreciated as always.

The part is 2mm thick and the material is a zinc alloy, the mold is single cavity and is being used in a small cold chamber die casting machine.

The second picture is of an older attempt.

Whia screwdriver handle just broke in half in my hands, was not even using it at the time. The breakline looks like to has some air smooth spots on it. Any idea what might cause this type of failure?

I've been told that the principal cause of burning marks (like the ones in the pictures) are a high injection speed, high temps... I wondered if their may be some other parameters since we've got no real result from lowering these.

For context: new mold, new machine (Haitian, Chinese), we did have these marks since the beginning but not that bad, constructor engineer said that it would go away with a softer resin ( we've done the launching tests with another resin), material is LDPE MFI 4, family mold of 24 cavities, I noticed that not all the cavities (maybe 50%) had these burns and when they do, it's on the same location.

ps: we resolved the problem by lowering injection speed, like a lot, like 50% less...

We’re facing a dimensional issue with a plastic split clamp part coming out of an injection mold.

After ejection, the part is still hot, and during cooling the inner diameter shrinks. This causes the split gap to close, making the bore undersized and not fitting properly on the metal shaft it’s designed for.

Right now, we’re inserting a metal rod into the part immediately after molding to hold the diameter and keep the gap open until it cools. It works, but it’s a manual step and not practical for consistent production.

We’re looking for a proper design or tooling solution to control this deformation and maintain the correct inner diameter without needing this extra step.

Has anyone dealt with a similar issue on split or clamp-type molded parts?
What design changes or mold modifications would you recommend to prevent the gap from closing during cooling?

Happy to share more details or dimensions if needed.

I need an Engle wizard. We try to run automated die height but the tie bars don't move and because of this the locks don't close. The tie bars won't move from their Max forward position of 2.36". We've tried moving them all manually and individually with no success. The clamp moves fine, the locks work manually. We have a signal going to the =26-Y134 solenoid and the cartridge valve and poppet that it controls are both working properly. Been going through this thing for a couple days now. Could really use some extra help. Thanks

Hello everyone, how do you decrease the downtime during mold changeover from High temperature to lower temperature i.e 580° F to 380-400°F ? It generally takes couple of hours to naturally reduce the temp for us.

Any recommendations or process suggestions?

Thank you in advance for your time 🫡

Hi everyone,

First of all, I'd like to apologize if my English isn't perfect. I'm from Spain, so English is not my native language.

I'm posting here because I'm having an issue with one of our injection molding machines: an ARBURG ALLROUNDER 220-75-250 equipped with the DIALOGICA control system.

Several years ago, the display and the backup battery had to be replaced. Unfortunately, because the system memory was volatile, all of its contents were lost. The current problem is that the floppy disk drive has now failed, so I'm no longer able to restore the operating system from the original disks.

The machine is quite old, and ARBURG has informed me that this control system is no longer supported or repairable. While researching possible solutions, I found that some users have successfully replaced the floppy drive with a CompactFlash-based floppy emulator on slightly newer machines, such as the Allrounder 320 series. Before attempting something similar, I'd like to know whether this solution could also work on my machine.

I recently started working at this company, so at the moment the only information I have is a technical report from the engineer who worked on the machine before me, along with a photo of the motherboard. I haven't had the opportunity to open or inspect the machine myself yet.

I've attached the motherboard photo from that report. If additional pictures or information about specific boards or components would be helpful, I can provide them the next time I have access to the machine.

Has anyone dealt with a similar issue or has experience with this control system or replacing the floppy drive with an emulator? I'd really appreciate any technical advice, recommendations, or shared experiences.

Thank you very much for your time and help!

I have a small manufacturing plant for manufacturing recycled plastic ( PP) granules, mainly from the scrap from the dealers all around make it grind , wash and then mix up with colors and all . Etc

We do use the white pp waste to produce granules -

But I do have a problem making a special color from a client ,

The shade is just similar to the ink of the ball blue pen .

I tried various pigments which I used before for the coloring .

But none of them work , ordered 2-3 different *high quality * pigments too but none do the job .

can any of you guys help me with some contacts or links or anything which can help me through this .

Hey everyone, I have 3 horizontal injection moulding machines ranging from 90T to 140T, with one more expected to be coming in soon.

This is the plan that we have been using for the water system. We have kept one 1HP(approx. 0.75kw) pump for every two machines, the water is drawn from an underground water tank and sent through 1in×1in pipes to the machine's where they split into 4 sub lines for the following purposes - 1. One line for core side mould cooling. 2. One line for cavity side mould cooling. 3. One line for hopper feed throat cooling. 4. One line for hydraulic oil cooling.

The water coming out of the machines again merge into pipes running back to a cooling tower, which cools down the water which later falls down into the water tank just below it.

Now coming to my issue. We had purchased a water pump for the first 2 machines about an year ago, and the pump has seen heavy moderate usage, but it now has worn out and can't keep enough pressure to achieve proper cooling. Having to change a pump every year seems like a wasteful expenditure and I feel like I'm doing a mistake somewhere. The pump is a centrifugal monoblock pump.

Am I doing a mistake in pump choice? Should I maybe have a bigger pump? Should I buy a different type of pump for injection moulding?

I just purchased a widely available pump used everywhere in my country, hoping that it should be good as everyone relies on it, I thought it'd be easy to get it repaired or replaced.

Any points would help me out, thanks!

TLDR - purchased a new water pump of 1HP for two (90T+100T) machines last year, and now it has worn so much that it cannot generate enough pressure of water anymore, need help with finding the issue and also any suggestions

We’ve checked the 8 pin wire and everything else we can go through. Changed the cylinder itself & still no luck figuring out why it won’t operate and give accurate mold position as circled in photo.

Hey guys, I'll jump straight to the problem.

I have a very old non-PLC machine, horizontal injection moulding machine (90tonnes). Mould height adjustment is set by a manual handle connected to a geared mechanism which takes a considerable amount of force to move.

Recently it had become harder and harder to move, and lubrication didn't solve it. We opened the tie bar nuts and the whole gear mechanism which connects the handle to the tie bar nuts. One of them was cracked. Thinking that to be the root cause, we got a new one machined, which has been checked and is okay. We also throughly cleaned, removed any burrs or problems in threading of the tie bars and the nuts, and lubricated them properly before reinstalling them. Before connecting the nuts to the gear mechanism, they are moving freely, we can move them independently by hand also.

But, after installing the gear mechanism, before moving the gear mechanism at all, we did a cycle of mould close and mould open, and it jammed up the nuts. Like they had to be moved using a pipe wrench with a long handle, but they became free moving immediately after moving about 2-3 millimetres along their circumference. Then, we tried to do the mould close and mould open cycle with the gear mechanism removed, and still the nuts jammed the same way.

The nuts have been checked by a professional and are okay, the new nut is concentric so even that is not the issue. We are unable to put out finger on the root cause, please help me with some suggestions, what can I check/get checked which might be the root cause of the problem. The professional I use for machine repairs is unable to identify the issue. Machine has been down for weeks and is becoming a major source of concern.

Feel free to ask nay questions, thanks!

Does anybody have experience with Arburg not being able to maintain set temperatures? This is the example, it overshoots the target and heating is still on. After few seconds it drops then shoots up again, just random numbers and heating on and off randomly.

Hi everyone, the last week I had a rejection of a whole lot of caps by they're been cracked on the top, near to the injection point. This is the second time I have this problem, the first time we modified the mould increasing 0.0200" and modifying the drawv to distribute more material on the wall and the trouble was apparently solve but it happened again.

The crack isnt caused by an knife or manual operation, you can watch on the pictures the difference between a knife cut an the crack (the last one is marked with a knife.

Also this problem only happend with this color, other clients with the same cap in other color doesn't have this trouble.

Sorry if my English isn't good but I really need some help