What I did at work

[Don-Wi]

Tuesday and Wednesday I machined and polished these blocks. Today I welded them together after it was surface ground and prehetaed in the oven for 4 hours.

It's a block used in the process of making sandwich bags I think, and I've made several dozen of these throughout the years at work. The surface I polished is an internal passage that plastic flows through and goes through some die plates. Made of 4140 prehard.

I left it in the oven for post heat and shut it down when I quit for the day. Tomorrow it comes out and then we start machining off the excess weld and adding more holes and features to the outside of the block, then it gets some wire edm work, more welding, machining, surface grind the entire outside of the block, and nickel plating to finish it all off. If I do my welds good and all the seams match up right, you can't see where the weld is. Once in a while there are a couple pits that give it away, but man are they pretty once complete! I think it holds up to around 20,000 PSI once on the machine.

I polish the flow surface to about between a 3-7 finish, and it takes about 3-4 hours to do one half start to finish all by hand. All 6 side get machine work done, and one side gets some weld and more machining after EDM to fill in some spots that inevitably and unavoidably get cut out from the wire process.

I'm not sure how many hours are involved in one of these welded assemblies, but it's quite a few. If we keep on it, it takes us around 1 1/2 weeks once started on it to get it out the door for plating.

Donovan from Wisconsin

 

[Anonymous-0]

4140 is Chrome-Moly. Must need to be super strong.
What rods did you use and do you have to worry about
getting it too hot when welding?

 

[Hendrik]

Very nice work; typical tool and die making.
Is it a mould for extrusion?
Worked in plastics processing, mainly injection moulding, for many years. PVC and high level engineering plastics such as PEEK are the most demanding to process.
Strength, rigidity, heat resistance, corrosion resistance and wear resistance are very important, hence the high alloy steel.

 

[Don-Wi]

That's exactly what it's for Hendrik. I'm not sure if it's part of what makes the zipper for the ziplock bags, or what exactly it does, but it's got something to do with sandwich bags and similar product. I used Weld Mold Company's 210T alloy filler rod, made specifically for alloys like 4140. In the past I've typically used plain ER70S2 or ER70S6, but as I go through the rods we have in inventory and figure out what they are, I try to use more application specific rods, and order some more as we go.

For many years there wasn't any one specific guy who was put in charge of the weld area, so it was extremely disorganized. As time went on I pressed my way into the weld area and got a little more company paid training with a few other guys and I finally was told that that area was my baby and to take care of it. I've identified several of the tool steel rods that we've got, but some just has absolutely no markings so it's difficult to ID those. I typically burn those off on non-critical jobs and see how the welds turn out to see what properties they do have Some is in boxes from vendors that don't even exist anymore, and they've been around for atleast 10-15 years, if not more. The company just celebrated 20 years a couple weeks ago.

In our shop we work with lots of different tool steels. S7, 4140, D2, A2, H13, Vanadis 4 (that manure's what came from Roswell I think....) as well as other alloys like Ampco bronze. We manufacture a wide variety of products for different industries. About 1/2 our work is trim tools for foundry. Very interesting work, and after being there for 4 1/2 years, I still enjoy going to work most days.

Donovan from Wisconsin

 

[Bret4207]

I will never look at a simple sandwich bag the same way again!

 

[Eric in IL]

Oh, how I hated polishing !

It really made the hours drag by for me.

Still cringe at the sight of the Gesswein name.

 

[Don-Wi]

I don't think there are many guys who truly love to polish, but as seldom as I do it, it isn't so bad. I hadn't machined one of these in a few years as I had been moved to larger machines. Another guy quit so i get to fill in for the mean time.

As bad as polishing is, I really like jobs like this because not everyone can do it, and it's very rewarding to see the finished product.

Donovan from wisconsin

 

[jon f mn]

That's a very interesting project and certainly
above my pay grade. Thanks for sharing.

 

[RickieBlue]

Looks very nice but I would not have the patience to do that. My Dad used to polish cavities in molds to + or - .0002 and he was a stickler for details in his home life also..Sometimes he would use toothpicks and diamond dust to clean up areas in the molds. I guess it takes a special person to do this. Great job! Thanks for sharing..it scratched my mind on precision.

 

[Spook]

I used to work in a shop that had guys who specialized in finishing dies. They were called die barbers. Nice job, btw.

 

[David G]

Nothing that fun for me.

We do factory automation. We are building a new plant for Intel, rebuilding 3 others, working on a natural gas compressor station and a Heinz soup plant.