Ejector Pin Marks. 8,233 17. A sufficient quantity of these pins is required to ensure that the green component can be removed without distortion or cracking. How to Eliminate Ejector Pin Marks in Injection Molding Avoid excessive injection of melt. The causes thereof comprise: puff1000. 409. puff1000. Having said that, sometimes you need to weigh your choices. Three Gold Stars. Bissyboat.

That electric toothbrush trick is clever. The basic choices are to either fill, sand and buff the affected area or find a way to mask the defect so that it won’t show on your completed model. Raised pin marks arent as bad, I could learn to live with these, albeit with some counseling and a bit of sandpaper. Ok, so you decide you want to get rid of the ejector pin marks and/or sink marks.

I have two loads that are shooting MOA, they are max book loads of RL19 and H4350.

Velocity is book as well, low 3000 fps. Ejector pin marks are maddening - especially when they are in hard to deal with places! I will appreciate your comments or ideas! Shorten dwell time. They are evil and they must be destroyed. In injection molding process, ejector marks is a concave or a convex on the surface. I'm developing a load for my Win70 in .300WSM with the Barmes 175gr LRX. 409. Lots of good suggestions here, but this is supposed to be a relaxing hobby (yea, right). It never did it with the 22-250 barrel, but now that it's a 243Ackley, it does it consistently with fireforming loads. Reduce injection pressure and dwell pressure. At Plastopia, ejector pin marks are showed on our DFM report, and you will need to confirm them before tooling. ejector marks injection molding Cause of ejector mark. Thanks for explaining and clarifying the difference between the two things Ratch. Samples are stick in the mold under force of ejector system, it will create holes on products. As a natural consequence, witness marks where these ejector pins were located are evident. They are the circular marks caused when the ejector pins push against the plastic to eject the piece from the mould :mad: Bissyboat. Reduce injection rate, optimize the design of the feed system and realize a sound mold filling. Factors that cause ejector pin mark 1. Post Apr 11, 2005 #1 2005-04-11T09:59.

Figure 2.2 shows a typical ejector pin blemish.

Filling. Ejector pin marks are much more common. I have a Howa that continues to gouge the rims even though I have taken it apart and filed the extractor a couple times.

I am working on an air pressure expulsion mechanism for plastic injection molds, to avoid the use of ejector pins and eliminate or reduce the ejector pins marks. However, recessed ejector pin marks, these are another story. They are bad, very bad. If you send us an assembly drawing along with the part, it will help us to avoid to put the marks on cosmetic surfaces. Extractor marks typically a gouge on the case head and ejector marks usually dents on the necks as thrown from a gas gun. Can you eliminate ejector pins marks? The only issue is every 3-4 brass I get slight ejector cut-out marks on the brass.

It has always bothered me in the past, but you … Ejector pins are required to remove the green component from the tool. I would like to know other possible solutions to reduce the marks when you eject the parts from the cavity. During ejection, white ejector mark usually appears on the plastic parts in contact with the ejector pin and such ejector mark will easily crack during actual use of the products. Ejector pin marks usually refer to the glossy or white imprints on the surface of a injection molded product, as well as the different levels of glossiness – dark or shadow, without convex or concave – visible directly opposite to the ejector pin location. 8,233 17. Do you have a hard bolt lift? Post Jul 05, 2013 #2 2013-07-05T08:33.