Need some help pulling a screw...

[moldingppm]

What's going on guys?
I'm running some white electrical wall plate covers, and I'm getting a lot of parts with a bluish streaking throughout the part (which is funny because I don't run blue). I also get a lot of dirt in the parts which I'm not surprised about.

I'm thinking best bet is to pull the screw, clean it, and clean down the barrel 100% to be able to relieve this issue. Problem is, I've never removed a screw before. Can someone please walk me through it? I've done mostly all maintenance on my machines except pulling the screw.

The machine is a Shinwa Seiki S-160

Thanks in advance.

[brentb]

The press manual should show procedure, but in general:

Have barrel up to heat (purge with something like DynaPurge followed crystal styrene if heat settings permit.
Take cover off where screw quill attaches to screw drive ( could have splines and collar, key-way, or other method of attachment, detach screw from coupling device.
move screw motor back to release screw completely
Swivel injection unit
Remove end cap of unit (along with nozzle/nozzle body)
Nudge screw forward by prying gently or using screw motor and wood or brass.
Remove screw with sling and hoist if heavy or by (heat resistant) gloved hands.
Clean components with copper gauze and brass brushes.
Reverse to assemble, don't assemble cold!

Keep on Molding.

brent

www.matrixtooling.com

[brentb]

In a hurry, Rick see if you want to add anything!, you to Suhas, pls.
KOM
brent

[rickbatey]

First thing to make it easier. Run crystal styrene through press if you have it. It helps make the screw pull easier and can be peeled off when cooled. Run the unit empty with the CPS inside.
Get a brass brush for the screw, I like to mount it on a side grinder for cleaning parts.. A screw brush from one of the IMM suppliers (PPE or so). Some anti-seize for the end cap bolts. I use brake fluid for cleaning the barrel. A drill big enough to run the barrel brush. Some hot gloves and straps/slings for screw. Allen/socket head sockets for removing parts. A torque wrench.Print of unit in case you don't know the press but they appear to be similar, and the torque specs for endcap bolts.
The next ones are options I recommend:spare end cap bolts and a new screw assembly (tip.
, ring and seat).
Remove nozzle bands and T/C and turn off zone. Break end cap bolts loose then run out with small air impact, remove. Remove yoke coupling (this ties screw to rotation drive and makes decompression possible). Set injection speed to 1 and bump screw forward.Using slings and cotton rags (other rags melt), pull screw out and place on bench as flat as possible. Inspect and clean all parts,replacing bad parts as needed. Recommended: Coat screw drive splines and inside of end cap with anti-seize. Reverse procedure and Only torque down the end cap when back to running temp, using a star pattern. I torque the bolts down in 3-4 rounds to keep endcap aligned. First time will take you about a day depending on press size.
Hope this helps, Rick.

[brentb]

Lunch Time, so I can thank Rick for the detail.
As he says, it takes a fairly long time the 1st go-around, but then it drips. I think Engel presses are some of the easiest of modern presses to do, and am providing an opening for Engel Rick to comment

KOM
brent

[moldingppm]

Hmm, seems easy enough. Looks like I need to get my hands on some CPS...

Thanks guys.

Here's another question. I've tried removing the nozzle on this machine. I've used MAPP torches, MAPP/OXY, and coated with liquid wrench. It still will not break free. Does someone have any tricks other than using Acetylene? If not, would acetylene be guaranteed to work?


Mitchell

[rickbatey]

Often times the reason you can't get the nozzle off is due to over tightening and no anti-seize the last time. I find the machine heats to be the best source, just don't heat the bands with a torch. You may need a rosebud on the big torch but I hope not.
The blue you see is more than likely in your resin to offset the yellowing that can happen.
I do think an Engel is one of the easiest to pull as well. On the early EC88's I would take one bolt out of the screw motor and let it hang on the other. Then pull the screw out the back of the press.
Rick

[pjhall]

A few things to add...

If you dont have any PS you can use natural Polypropylene (not PE too sticky). After decoupling the screw from the drive inject forward at a slow speed then suck back. You may need to place a piece of wood between the injection cyclinder and into the barrel to press the screw out further. Also, I like to stick rags in the the lower end cap screws so you don't fill them with material. When using PP I press the screw out then use an air gun and blow on the pp and you can usually peel it off as your pressing it out. Just remember to not dilly dally because the barrel is cooling. If you have a helper pull the screw out all the way and have your helper work the screw while you work the barrel. Copper Gause around a round brush and a drill for the barrel. Place a flashlight in the back of the barrel and look down from the front to see any spots you missed. If time permits let the barrel and screw cool over night and measure the barrel with bore gauges about every inch (or more depending on barrel length) and measure the corresponding OD of the flights of the screw to get a gap profile. Its a good thing to have so you can see how your screw/barrel is wearing over time.

REMEMBER Screw Tips are left hand thread!!!

[rickbatey]

REMEMBER Screw Tips are left hand thread....

Not true of ALL IMM'S! Engel turns their screws the opposite of all the others. So they are threaded like standard bolts. Pay close attention to the tear down and rebuild. Again you want new bolts for the end cap. Due to the heat and torque, coupled with the sealing requirements: you should replace them!

Rick.

[pjhall]

Rick,

I did not know that or Engels!!!

[rickbatey]

That may be the irrestible connection I feel for the brand?! We both tend to be somewhat out of sync with everyone and thing, else.
The funny thing is while at my last job, a long time Cinci guy told his maint guys that the tip was lh threads. I pointed out that Engelwas not and to get the new tip assembly and prove it to him!!

[ATI K ID]

Asaclean EX grade works way better that the styrene and it cuts screw cleaning time to nothing.

[kelley]

REMEMBER Screw Tips are left hand thread....

Again you want new bolts for the end cap. Due to the heat and torque, coupled with the sealing requirements: you should replace them!

Rick.

This is the first I've heard about using new bolts. I gotta admit I've always reused the same endcap bolts. The only problems I've ever ran into when installing the endcap is leakage, and this is has always been traced backed to someone in maintenance either using the incorrect tightening sequence or uneven torque.

kelley

[rickbatey]

Many machine manuals tell you that. Its just like head bolts on a car; these can be torqued to fairly high numbers. Add to that the pressure they must seal in the injection unit and multiply in the fact that they are under fairly high heat while torqued down....Cheap insurance to replace them.
Don't get me wrong; I've had to reuse them because we didn't have or could get metric bolts that long soon enough; we HAD to get the press back up and running; emergency tear down at 3 AM; and so on. But many times we had the head damaged when taking down or putting it all back together, and on too many occasions-the head twisted off! Better to replace them. Heck even if you replaced them every other time..You would be doing great for all involved.
I also put anti-seize aound the inside of the end cap where it seats around the barrel. You don't want that thing to seize or stick when drawing it up after all the time to tear down, inspect-replace, and put it back together
Rick.

[brentb]

This is the first I've heard about using new bolts. I gotta admit I've always reused the same endcap bolts. The only problems I've ever ran into when installing the endcap is leakage, and this is has always been traced backed to someone in maintenance either using the incorrect tightening sequence or uneven torque.

kelley
Bolt stretch!

KOM

brent

[moldingppm]

I went and pulled the screw on my Arburg this morning. Few questions, I ran the barrel empty, but there is still some HDPE in the barrel and on the screw, best way for removing that from the barrel? How about getting it off of the screw? Also what kind of solvents should I use with a brass power brush for the barrel cleaning?

[rickbatey]

Brass brush (mounted on side grinder or bench grinder if small enough) or copper gauze to clean the screw. A proper sized barrel brush mounted on a drill large enough to turn it. I always use clean brake fluid to brush barrel clean (with drill). DO NOT use sand paper or Scotch brite as they scratch the screw and barrel. Then carbon builds up in the low spots and you have black specks from now on.
Rick.

[ATI K ID]

Easiest screw/barrel clean was with asaclean EX grade pulled a screw out of a 500T with less than 50lbs. force and screw took less than 5 min. to clean I mean NO DEPOSITS left.

[ATI K ID]

Stuff peeled right off.

[Suhas]

Good Advice on the purging. I know Brent is a fan of ASA Clean, correct?
Suhas

[moldingppm]

Upon cleaning my screw from my Shinwa, I've noticed a gouge has been taken out of it. It's pretty deep, about 1/8" deep by 1/4" wide. Along with that, tons of scratches. Can someone confirm that this is the cause of my specks?

[rickbatey]

What color were the specks? Blue I believe? I'd say that was from the resin as many light colors have some blue added to offset the yellowing that can occurr when melting.
Now you do need to fix the problem; what does the barrel look like? I'd expect some damage since the screw was so bad. You could opt to have the screw welded and chromed again. Or contact someone for a replacement. I can get you the names of some folks that should be able to help for a good price.
Rick.

[manimaste]

Dear,

Better you can see your machine manual,they may given you the exact details off pulling the screw with all the details like LH thread and other details.

mani