Recent content by DragonForge

@ Pud "As stated above, jetting. Gate too small, (should be min. 75% of max part thickness) wrong position (best max section of part), ideally gated against an obstruction." Does the fact that there are 3 gates have a bearing on this? The weld (cold shut) lines would suggest too cold a tool...

@ onerynorsk "Regarding what looks like burn marks near the ejector pin line in the middle picture, where is it in relation to the whole part? You may need more venting. Are there other areas with similar marks?" The 3 pictures are at the 3 gates - I should have made this more clear. The...

Sorry guys, I should have been a lot more clear on this. There are actually 3 gates along the length of the blade. They can be seen here: http://img338.imageshack.us/img338/6840/imagesix.jpg I am not sure how that affects what has been said so far? We are able to fill the mould with only the...

I do know that the material is dried before moulding. However, I do not know if this has been done thoroughly enough. Perhaps this is where the problem "may" lie. The factory have been moulding for over 20 years so I would suspect they are drying it correctly.

Link doesn't seem to work but image can be found here: http://imageshack.us/photo/my-images/195/bladeyt.jpg/

Thanks for all the help so far with this! Just one more question if I may? I have attached an image of where the material is going through the gates. The blade has fissures at these points and other blemishes. I am informed that this is just part of the moulding process when using this material...

"My tip is you have slight variations in degree of crystalisation, probably from mould temperature variations from side to side from shot to shot." This will certainly be looked into further - Thanks! "You could try rethinking cooling channel plumbing stratergies to get more uniform...

"I believe he is spot-on regarding the variation in crystallisation temp, otherwise you would see more uniformity. Two other things that have not been touched on, is your material being dried thoroughly and are you using any regrind?" Ah, I shall have this looked in to as well. Thanks! We are...

Thanks for the suggestions so far chaps! Greatly appreciated. Ornerynorsk, I like the idea that it may be moulded in stress causing this - I will set up an experiment along the lines of your methods and see what comes of it. Just so I am clear on this, the pat was heated to around 250 F, it...

The blades are produced 1 at a time and are all coming from the same mould. The blades taper along both planes 54mm wide x 16mm thick to 20mm x 8mm along a 1200mm length. As such they do not cool uniformly (the narrow end cooling much more quickly). The jigs do hold them straight until they...

Hello Chaps I posted here back in 2010 and got some really helpful advice. I am hoping somebody here can help with my latest problem. We produce injection moulded sword blades for the martial arts industry. We are now using an Impact Modified nylon with fantastic results. It is much...

Brillaint Harry! Thanks for the info - I'll contact them today.

Hi Pat Thanks for all the suggestions. We will certainly try some of them. I'll have a chat with the materials supplier and see what's viable based on price and availability.

Pud wrote "Where are you located - Demon has assumed you are in the USA?" We are based in the U.K. - North Wales.

Harry wrote "Why not use a toughened nylon? There are even glass filled versions of the stuff. No break Izod.Google long fibre filled materials - if your feed point is down the handle end you should get a real stiff sword (no innuendos, gentlemen thank you!)Want heavier? Try acetal.Cheers Harry"...