How to over come the surface voids/porosity in compression molding?

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Abdelkader BOUAZIZ

Dear Suganth Velumani, there are many tips to get rid of voids, for example by applying vacuum, increase slightly mold temperature, and intermittent venting. My Regards

Suganth Velumani

Thanks, sir. What is the temperature I can maintain for epoxy resin? Abdelkader BOUAZIZ

No thanks, usually 180°C and 700 kPa with curing time of 3 min (from : https://doi.org/10.1016/B978-0-12-803581-8.02048-8), please have a look at the following documents.

https://doi.org/10.1515/polyeng-2016-0409

10.1515/polyeng-2016-0409

Doufnoune RACHIDA Rachida

Hi;

Please see the link below:

https://doi.org/10.1007/s00170-021-07838-1

My regards

There are several ways to overcome surface voids/porosity in compression molding:

Use a higher molding pressure: Increasing the molding pressure can help to fill the pores and reduce surface voids/porosity.

Use a higher molding temperature: Increasing the molding temperature can help to reduce the viscosity of the polymer and improve the flow, which can help to fill the pores and reduce surface voids/porosity.

Use a material with a lower melt viscosity: Using a material with a lower melt viscosity can help to improve the flow and reduce surface voids/porosity.

Use a material with a lower shrinkage rate: Using a material with a lower shrinkage rate can help to reduce surface voids/porosity by reducing the amount of shrinkage during the cooling process.

Use a material with a lower modulus: Using a material with a lower modulus can help to reduce surface voids/porosity by reducing the stiffness of the material and allowing it to flow more easily into the pores.

Use a material with a higher melt strength: Using a material with a higher melt strength can help to reduce surface voids/porosity by increasing the resistance to flow and allowing the material to maintain its shape during the cooling process.

Use a material with a higher surface energy: Using a material with a higher surface energy can help to reduce surface voids/porosity by increasing the wetting of the material and allowing it to flow more easily into the pores.

Use a different mold design: Using a mold with a different design, such as one with a smoother surface or a different shape, can help to reduce surface voids/porosity.

Use a different molding process: Using a different molding process, such as injection molding or blow molding, can help to reduce surface voids/porosity.