Відео

they're great!

😊

interesting! what's the difference between specific and back pressure?

Video is very helpful, thanks. I have a question though, Duponts nylon guide says to use the maximum pressure for the holding stage. This bottoms out the screw though. Or if I increase the shot size too far I get flash. Should I not use such a high pressure?

Another thing i have seen is guys increase the shot size when the shit goes short and i have to fix the fucking nozzle leak plastic everywhere!

Flash could be caused by a lot. Over venting the mold, big shot size, barrel heates too high, or mold damage/tool damage. Shorts are usually just not a big enough shot but usually if you are short on one side and flasing on the other there is a problem with the mold or how the press is leveled.

You forgot the real reason for Back Pressure - air will travel to the area of least resistance - no bp - air goes to the front of the screw

Clamp tonnage not set right and mold cooling working correctly will cause flash....now is the die-height set correctly is your lockup position correct. Do you have a broken tie-bar and is the mold there damage causing the flash?

Please make a detailed video that how a molding machine works …like each step …injection pressure ,injection speed ,injection position in barrel ,screw recovery back pressure suck back

Sir u mean we should fill the part by using two profiles?

Poly is easy to mold. Try 14 inch cpvc sch 80 tees 😅.

Sad times, I will miss the edart

excellent explanation, thank you

thank you for your presentation. I would like to ask you, what do you recommend to use instead of safety couplings?

why dont you do one course in algeria ? alot of people here are interessted in the injection machines

I never was a big fan of flash… kind of a wimp, only power he had was speed, but Superman was just as fast if not even faster

Great video. Just wondering why there is 2ejection cycles instead of one?.... lol

We call them cams. Never heard of a slide.

Ahh perfect. Building a machine myself and this was a question ive had that hasnt been well answered or addressed. Thanks

Too much hold pressure or hold time will cause flash also incorrect shot size and not enough tonnage

So after that semi confusing information you advise to not adjust backpressure? All that nonsense about 'drying the material' via the back pressure setting was just added confusing drivel too. Hygroscopic material needs to bd suitably prepared and conditioned pre moulding, end of. Backpressure is purely an adjustable parameter to ensure consistency in melt preparation. Multiple factors can add inconsistency, wear, polymer, additives and environmental changes. You should use scientific optimisation to determine the ideal backpressure for each and every product you trial/run. Once the process is optimised and passed IQ there is no reason to adjust backpressure (or anything else for that matter) as any defects witnessed at this stage during normal production will stem from an underlying issure that needs revolving NOT by adjusting machine settings. Setters/techs - Dont piss about with machine settings if production was running fine beforehand, examine route cause first. Only once everything has been tripple checked should you consider batch to batch material variation and make minute changes to settings while informing your process engineer.

this video was very informative , didnt know that you had to grease the leader pins . Could you use alchol for an alternative cleaning solution for the mold .

How long does resin needs to dry before going into production.

Excellent lecture.

Hi sir, background noise disturb a lot.

Hi there, we are mold maker in Shenzhen China, please contact us if need make injection molds.

Machinery manufacturers like to boost the recovery rates of their machines in terms of oz/second. Therefore they design their screws for maximum recovery. This can lead to unmelted resin, poor mixing with colorants….. Back pressure will certainly help this situation.

I recognise the 1ltr PET bottle 👌👌🤣 hope you're well

Also mold temperature can cause flashing. If the temperature is too high, plastic don't freeze in time.

I just had an issue with HIPS, where I kept getting trapped gas in the barrel, leading to bubbled parts. I increased the back pressure, in an attempt to exhaust the gas through the hopper. I don't have any formal training, so you'll have to excuse me if anything I say is wrong. But, it seems to have worked. I have a ring of splay I'm trying to work out, next. Great video!

I can understand about the explaination on this video. This is simple but a lot of information. Thank you

mould temperature and turbulent water flow is vital, in all injection molding process not just medical, bit surprised RJG say especially medical? learned how important water temperature can be 15 years ago, when trialing a a closure mold on an electric machine, and they had over speced the chiller and temperature of the chiller was varying by 7 degrees ,the melt cushion was trending with it,we ended up removing the chiller and replacing it with water heaters, this reduced the melt cushion variation by 0.6 mm,

If youre shot size is too big

Dry your material!

What kind of clamps are on this mold?

been in processing about 14 years there are so many things and variations that can cause flash.i work with machines from 120 tons to 1100 tons.if youre process is where it is supposed to be to the original than obviously something changed.

I have been working in plastic for over 10 years and started from zero knowledge to working up to supervisor and now learning process more and more each day. I can say everything in this video is well explained and true in every way. These are the exact steps I take to prevent flash in almost every case when you can tell you are overpacking pressure and blowing the tool open. Obviously sometimes it can be from clogged venting and in "some" cases even injection speed can play a huge factor. But at the root of it all, you have to see how much material you are truly trying to push into a tool and where your cut off point needs to be. Your machines are a lot different than mine but also a great point to make is your shot cushion should not be your exact transfer point. There should always be a little "room for pressure" between the sprue break and the injection nozzle as to not cause a bonnet

Other cause too much back pressure?

These webinars are really educational and very informative .. Thanks for sharing

What about flashing the gate? Everything you said makes sense for flash on the part.

Holding not working how to check

that was extremely helpful, Thank you for sharing

hope you release more videos about nissei machine.

Hi, thank you for video. I have a question. If during the injection we do more cooling, semi-crystalline are could increase o no? Cooling can effect more creating semi-crystalline area?

Hi and thanks so much for the great topic, I watched your webinar on this topic and it is excellent. I know my question is not that related to this video but I found no better place to ask from you, I'm trying to make a true picture of what the injection machine does and a ask you to clarify this for me if possible, "We know that the driving force in the injection machine is hydralic or electric motor, so when we enter a value for injecion rate or injection velocity in first stage or filling stage what the machine does to maintain the value we set for velocity is it exerts a pressure to see what the resulting velocity is and in a closed loop it sets different pressures to keep the velocity on the value we have entered". What I'm pointing is actually the velocity is a result of a profile of different pressures adjusted by machine to maintain our prefered velocity. Am I correct about this? Thank you.

Hi and thanks so much for the great topic, I watched your webinar on this topic and it is excellent. I know my question is not that related to this video but I found no better place to ask from you, I'm trying to make a true picture of what the injection machine does and a ask you to clarify this for me if possible, "We know that the driving force in the injection machine is hydralic or electric motor, so when we enter a value for injecion rate or injection velocity in first stage or filling stage what the machine does to maintain the value we set for velocity is it exerts a pressure to see what the resulting velocity is and in a closed loop it sets different pressures to keep the velocity on the value we have entered". What I'm pointing is actually the velocity is a result of a profile of different pressures adjusted by machine to maintain our prefered velocity. Am I correct about this? Thank you.

I have to ask because I have been looking to purchase a few platen stones for the plant I work in but I am having a difficult time finding where to purchase them. Any suggestions?

Example LSR injection , the solidify temperature is around 140 degree Celsius. Should use pressurised water for better uniform surface temperature?

Thank you sir!

That last tip on the bolt is something I stress so much to mold setters.