document of maintenance and rubber injection

[simo1]

hello all,

its my first word in this forum of injection molding im from morrocco i read much thread here, i hope i can find some help, i need some document about maintenance of machine " negri bossi " and some formation about " rubber injection "

Any feedback or recommendations would be appreciated. thanks for help

[nemanja]

Hi,

What type of materialyou use, what type of tool is, is it overmold or mold. Do you have preassure limitation in molding process?

Regards,
Nemanja.

[simo1]

we use PP,PA,ABS and its simple mold , yes we have limitation in molding process, about rubber injection im new want know more about this process thanks for help

[nemanja]

Big problem with rubber mold and modl in general is that each process is diferent. Here i will try to share my expirience, and i hope will hellp you.
I generaly use TPA-SEBS im mold machine and prepare products with PA on low preassure tool. Problem of rubber like materials is that they have bad flow index, so sometime you need bigger speed, or bigger and longer holding preassure (depends of desin of mold), in some cases can even demage product, if you do overmold. thats why we protect product with PA useing preassure 4-6bar, than on machine we can go to 800bars, for good shape of final product (widouth protecting maximum preassure that we can use is 120-250 bars). Also is important to have place where air from cavitis to go out. Also one of important things is temperature and "freazing" of material. It can hapen that you have lines of "frozen" material, or even not filled space on one side, and over filled or even demaged spot on other side. There for all tools that i work with have hot-runner system.
I hope i hellp little, and if you have more specific questions i be happy to answer.

Best regards,
Nemanja.

[Working man]

I have worked with TPE and TPU. If you have thin product (about 1mm) you don`t need highly holding pressure and time. For thicker products you need longer holding time/pressure and in any case very good air gonditions in mold. You don`t need to dry TPE but some cases we have dried TPU. If you need to remould you can try to warm or plasmatize the insert.

Best regards
Anssi

[Pilot]

Hi Simo,

What do you need for Negri Bossi? user guide? drawings? hydraulic scheme? etc
Pilot