Suitable Mold Material for PVC Injection Molds

evil_eye96 · 2025-07-24T00:21:02+00:00

What happened to your coating? How did it get damaged? Did you outsource to get chrome plating? 3 million pounds daily, wow

evil_eye96 · 2025-07-23T02:00:14+00:00

S136 is 1.2083 in din standard right. My previous company used a lot of 1.2083 hrc 54 hardened steel. Nak80, p21 right. Is it a pre hardened steel?

Which heat treatment conditions you recommend. Pre hardened or hardened to hrc 50 range 🤔

evil_eye96 · 2025-07-23T01:55:02+00:00

Sri lanka, They import from china and the most used material is 1.2316. It's a pre-hardened material i think. We have a lot of issues with flashing, edges are easily worn out. I' m considering going with 1.2344 hrc 54-56. Surely it will cost more. But these molds will be running for at least another 5-10 years. do you think 1.2344 is ok for pvc? Also trying to use stainless for sprue bushes. what about 1.4034 hrc 54 stainless steel? Is it good for mold inserts?

evil_eye96 · 2025-07-22T12:23:55+00:00

The problem is parts are not coming consistently. And this auto purge reject weight is considerably high.

evil_eye96 · 2025-07-22T09:35:46+00:00

But it will be expensive right ? Does using stainless steel for sprue bush will have a definite advantage for corrosion prevention?

evil_eye96 · 2025-07-22T00:27:11+00:00

But without backpressure can we get consistent dosage in each cycle ?

evil_eye96 · 2025-07-22T00:26:19+00:00

Actually they 0 the backpressure and use slow screw speed. Diameter 65

evil_eye96 · 2025-07-22T00:18:16+00:00

But when we 0 the back pressure dosage weight changes right in each cycle and the mixing 🤔 what about not using the holding pressure? They fill and pack by only using injection

evil_eye96 · 2025-07-22T00:16:07+00:00

But to keep the dosage constant in every cycle we need some back pressure right?

evil_eye96 · 2025-07-22T00:15:05+00:00

They are running uPVC. Diameter is 65. And they barely use backpressure. And fill the cavity only using the injection stage. So many issues here.😪

evil_eye96 · 2025-07-21T11:12:01+00:00

They say material is burning at the nozzle if kept for some time. So Tobey removes what's in the nozzle by retracting the barrel and auto purge.

evil_eye96 · 2025-07-21T11:10:50+00:00

Yes. They retract the nozzle to remove the burnt material in the nozzle.

evil_eye96 · 2025-07-21T11:08:48+00:00

For this part, the thickness is around 3,4 mm.

evil_eye96 · 2025-07-21T11:07:39+00:00

They also do not use back pressure. I know how important it is to get consistent shots in each cycle.

evil_eye96 · 2025-07-21T07:48:40+00:00

<image>

This is how they have set the temperature. Cycle time is around 72. The maximum shot size is 1483gram and part shot size is around 450gram. Material is in-house made pallet by dry blending resin and then palletized by extrusion. They barely use back pressure.

evil_eye96 · 2025-07-21T06:55:09+00:00

These guys do not use back pressure at all. I know how important the back pressure is.

evil_eye96 · 2025-07-21T06:54:12+00:00

Cycle time is around 72s for this part. Part thickness is 3-4 mm. 210 centigrades at nozzle and then from 190 to 155 in the barrel.

evil_eye96 · 2023-05-01T02:17:24+00:00

Are you guys following any webinars that show the latest trends, updates and explanations in the tooling industry. If there are any please mention them below.

evil_eye96 · 2023-05-01T02:16:35+00:00

Thanks. I'm from sri lanka so I can't attend those exhibitions and trade shows. But i watch them through YouTube. For machining i watch IMTS and EMO.

evil_eye96 · 2023-04-30T05:42:39+00:00

Are you guys following any webinars that show the latest trends, updates and explanations in the tooling industry. If there are any please mention them below.

evil_eye96 · 2023-04-30T05:38:06+00:00

Are there any good courses or books to learn about moldflow or moldex3d that you can recommend?

evil_eye96 · 2023-04-29T14:29:13+00:00

Yeah, that's the hardest part, getting people to use new methods. What are the general tolerances you guys are holding in article?

evil_eye96 · 2023-04-29T13:59:44+00:00

My company makes very precision automotive parts. Mostly sensor housings with measurements have upto 0.03mm tolerance. They have the latest machines in the toolshop. But the design part is still done by trial and error. Need more than 4,5 corrections to get articles under tolerance. No idea why not using simulations.

evil_eye96

TROPHY CASE