Can anyone tell me what factors increase the gloss level of textured parts? Especially glass filled nylon!

Hi Chris , This is Bhaskar, I have moulding GF nylon for over 20 years. Firstly your material should be preheated well preferably in dehumidifying oven temp 120 c. The mould should be hot 60-80 c . the machine ( screw) does matter the gloss. The temp you keep should not be low, it will cause dull finish. some experimentation with speed & pressure will take you to desired results.Please let me know if this helped you.

Chris, it is a fine line between higher temperature and degradation from the increase. But that will increase gloss, and as Bhaskar mentions, drying and preheating is most important. I would run recommended resin temp. and step up in increments of 5C until desired gloss is obtained. May be a plastifier additive available from an Arkema/Clariant type of company that also may boost gloss surface finish.

Thanks to all, I'll try your suggestions and let you know the results soon.

Hello Chris,
We did some 13% and 30% glass filled nylon with a light texture recently and the thing that effected gloss the most was mold surface temperature. The recommendations for mold surface temperatures between 100- 120C seem correct. To maintain these surface tempuratures and still have a decent cycle time usually requires the use of oil cooled tooling instead of the common water cooled tooling.

The high gloss is the result of a resin rich surface skin with little glass at the surface. The high mold surface tempuratures allow this to happen by keeping the skin soft enough that the flow of the resin in the core of the part will "pull" the fibers away from the non flowing skin. as the part fills. Others think that this happens more during the packing process...

Regards,

Pat