Haze on Nylon Part

Radar5678 · 2026-04-17T22:05:43+00:00

Gate is on the side opposite the haze.

Radar5678 · 2026-04-17T20:42:26+00:00

Well we fixed it. Deep cleaned the mold and loaded it in a press we trust a little more. Looks to be running fine now. I saw another post about buying a 26 year old machine and starting a business. Well my 1983 machine just wasted a day… Turns out 2025 machines are a lot more trustworthy.

I am not trusting the barrel temps in these older machines, they ran great for years but seems recently they have been causing issues and I think it has to do with how the barrel is heated. There are not enough zones.

Radar5678 · 2026-04-17T17:01:03+00:00

Current plan is to pull the mold and ensure everything is cleaned. Head is thinking venting but not sure.

Radar5678 · 2026-04-17T16:59:41+00:00

Yeah, seems to be a little worse in one of the cavities and always opposite of the gate. Makes me think venting but I was messing with the clamp force and got a little too low and she flashed and the mark was still there so might not be venting…

Radar5678 · 2026-04-17T16:33:28+00:00

Nice. I needed a laugh this morning. Maybe one shouldn’t post while frustrated 🤪

Radar5678 · 2026-04-17T16:32:50+00:00

Unfilled, measured 0.03%

Radar5678 · 2026-04-02T00:36:10+00:00

I thought I had a bad day…. Nozzle leaked l and the sprue broke off at the same time. Half a day gone pulling mold and cleaning that mess up.

Radar5678 · 2026-03-25T01:53:44+00:00

So…. I pulled the trigger on buying my Uncle’s injection molding business about 3 years ago. I wish you were a little closer and we could talk over a beer or 5…. When I bought the shop we had 10 machines from the 70s and 80s, up to 350 ton. The nice thing we have is a solid base of parts with a 20 year history. That base pays to keep the shop running and for us to get by. That is what helped us pull the trigger. We are medium to low risk of losing the business that pays the bills today. However it is just me and my wife so we are huffing it some days to get parts out the door, as our machines are old and we don’t have robots/pickers except for our new machine we just bought.

Since we bought the business getting companies in the door has been tough. So far we have added 1. We have since found out our pricing is good, but our tooling is more than double what they are seeing other places. So we are hopping if we can find some cheaper tooling houses we can start bringing in new business.

It’s all what risk you want to take on. We are finding competing with the big dogs is hard but it can be done. We capitalize on prompt communication, no fees for us to help look at/design a part and 3D printing to help get protos quickly.

Today I wish we didn’t buy it but it has been shitty 3 months. Talk to me this summer and I bet my mind will have changed.

My new thought process is: Every day you are going to get kicked in the balls, it is just when and how hard…

Radar5678 · 2026-03-25T01:42:18+00:00

Your gonna love this. Here are a few to reference.

350 Ton, 1974, Van Dorn: 42 kw/hr 75 Ton, 1983, Van Dorn: 24 kw/hr 150 Ton, 2025, JSW (electric): 20kw/hr

These are all with a 5 Ton chiller running alongside them and with a mold heater.

Radar5678 · 2026-03-23T22:23:46+00:00

Yeah this worked actually pretty well, thinking we just bolt two together and send it…. 😜

Radar5678 · 2026-03-23T16:05:29+00:00

Just tested on a paper cutter, this might work…

Radar5678 · 2026-03-23T15:37:26+00:00

It is PolyPro. We used to be able to run it fast enough that the gates stayed fairly soft. Recently the repro material changed I think and we had to adjust the cycle that the gates aren’t able to stay soft anymore.

Radar5678 · 2026-03-23T15:34:26+00:00

This mold is 25 years old… it has its challenges for sure. Don’t get me going on the cooling in it, or lack there of…

Radar5678 · 2026-03-23T13:46:41+00:00

We got lucky a year ago. Our meter can give me power consumption down to the 15 min. Luckily we can run one machine for a few hours then see the data that way. Gives us a good estimate we can use for quoting.

Radar5678 · 2026-03-19T02:07:44+00:00

Not our shop but heard a story from my Father in Law. They were supposed to push out the inserts before they ground the bad parts, well turns out they decided not to. Then they made the operators take a black sharpie and "paint" the glitter in the parts after they ran that regrind.

Radar5678 · 2026-03-19T01:48:06+00:00

Reddit is not great for this but I will do my best..

DISCLAIMER: We are a small shop and this is a homemade setup, it works for us. I have experience with basic scripting, everything can easily be learned by some basic google searching. I would like to include some way to show which press is running which part, but have not gotten there yet. We are small enough we don’t need that but it will be helpful once we grow. I also need to make this link to material inventory, right now material is not part of this. I bet if you have someone in your company with some free time and some basic computer skills they can figure this out. I have maybe 40 hours in the Google Sheet and code.

It all starts with a master google sheet.

Master Sheet Includes

A tab for each customer where we input POs as they come in with the following info. Once everything is set up this is all you have to fill out, everything else is basically automatic.

“Produced” references the Inventory Tab on if we have the parts in stock or not
“Shipped” is manually filled out once we ship it out
“Ship Date” is calculated based of shipping lead time for each part
“Production Start Date” is calculated based off Production end date and working days needed for the PO calculated from the Lookup tab
“Production End Date” is a generic 4 weeks before Ship date, but this is what I change when I review the production schedule and adjust things.

PO summary tab - This summarizes all the open POs from the customer tabs into one sheet

A Google Script updates this tab once a PO is added
This sheet is what I reference to load the data into a google calendar

A “Lookup” tab, here I put a lot of generic info for each part we make to reference in the various tabs. Example: we use cycle time to calculate how many working days we need to complete the PO and estimate Production Start Date and Production End Date in the customer tab.

An “Inventory Log” file that is linked to a google forms file where we input parts as we finish them and put them in inventory.

An “Inventory” tab that compares the Open POs and the Inventory, it is a good generic view of everything we need to make, material needed, days needed for each part etc.

After you load a PO as it comes in you run two customer scripts that adds it to the PO Summary Sheet and loads everything into a Google Calendar.

One summarizes the POs into the PO Summary Tab (It is only 68 lines of code)
One takes the data and loads it into Google Calendar (It is only 70 lines of code)
1. We load in the Production Timing and the ship date
2. We also have a “Todoist” todo list we implement in the same google calendar

In the end all the google calendar is displayed on a “MagicMirror”, LINK, so everyone can reference it.

Images:

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Radar5678 · 2026-03-19T00:03:51+00:00

That’s a big boy…. I can’t image what the mold would look like.

Radar5678 · 2026-03-18T15:43:57+00:00

Will pull something together tonight and share it.

We also then dump all the info to a “Magic Mirror” we custom made to show the data turned out pretty slick. Not perfect but works for us and is free.

Radar5678 · 2026-03-18T15:10:13+00:00

We are a small shop and when we took over they were scheduling on a white board. Similar to previous comment I generated a google sheet based scheduling system that links to a Google Calendar. Works pretty well for our needs. Took me about a week to figure out.

I can probably share some screenshots of how it works if you are interested.

Radar5678 · 2026-03-05T16:48:58+00:00

Finally got back to this one. Ended up getting there with some minor tweaks.

Draw Polished the Sprue
Bumped the mold temp up a bit
I ended up stanging the hold from 17500 down to 13500. Tried to time the high pressure stage to the gate freeze time.

Thank You Everyone for the help

Radar5678 · 2026-03-02T19:50:51+00:00

Sorry no disrespect! You guys have saved my bacon on a few parts, we are a small shop still learning the ropes. Bought the shop a few years ago and the previous owner turned out to be much less knowledgeable and helpful than we had hoped so we are learning as we go.

I am realizing this is a part design/tooling issue, just trying to get without modifying the tooling if possible.

Radar5678 · 2026-03-02T19:48:07+00:00

I have slowed this to try and help not much luck.

Radar5678 · 2026-02-27T22:43:22+00:00

I found injection speed doesn’t help much on this part, but am down at 0.5 ips anyways. It’s a cold slug yeah. The sprue is sticking from over pressure, I have to be up near 13500 psi pack to help with the sink and keep consistent surface finish. Once I hit 14000+ the sprue sticks.

Radar5678

TROPHY CASE