How do you increase weld line strenth in GF LCP resin moldings ?

[shoobaka1]

I am looking for tips on how to increase weld line integrity when molding thin walled, long flow front parts.

Do "weld wells" that are trimed off after molding add significant strength ?

 

[ornerynorsk]

I have used "wells" in mold construction, and sometimes they help. Each part is so unique, that it is hard to throw a generic cure at the problem. If piece part design and gate location requirements are so strict as to create this problem, I'm thinking that this may be a nicely priced project ??? You may want to look at multiple gate hot runner if you can justify the cost.

 

[dhuffy]

From your description, I presume the part is some type of connector since you are using LCP. But in either case it is difficult to achieve a higher weld line strength. I would not recommend a hot runner for LCP material and this type of application, and multiple gates may only increase the number of weld lines you will be dealing with.

Some processing ideas would be to increase your injection speed and holding pressures, along with higher melt and mold temperatures. The wells you mentioned may work if the well is near the bad weldline area. The well may allow the material to "meld" instead of weld.

Good luck.
Dave

 

[shoobaka1]

The part is acually a gasket for use in a medical device. Multiple gates did, indeed, add to the problems. We are adding an overflow well to help with the weld.

Regards,

Ryan Heidenfeld
Plastics Process Engineer