Forum Replies Created
– Which should be the thickness of the metal sheets to use? 3 mm or 4 mm
– Should the mold need to be structured? what do yo mind?
– Do the parts need to be CNC cut? yes is better but most expensive
– and any further detail that could help me to make a good mold.
what are the units in te drawing?
You have to decide the thinknes of the product and how much plastic are you going to use
Its too importan the release angle for the compression depends of the mould 10 to 20 °
the distance of the mould with the flake(before heating) the botton and the top enter to the oven
If you can make a lining of teflon to the mould you are going to save a lot of headaches
@s2019 Stan you’ve right, but I forgot to explain that I would be missing the way to retain the plastic while it warms up, the people of @preciousplasticusa designed a knife valve system to avoid threading and unscrewing a plug before the injection. Maybe combining one of these designs we would avoid threaded connections.
hello people I was thinking the same. The threaded connection takes a lot of time so I was thinking of a quick coupler connection. Like the one in the picture Tell me what you think
Has there been any progress?
@chenkus al comenzar a trabajar con plastico hay mucho de prueba y error. Vas variando temperaturas, cantidad de materiales, tiempos de calentamiento y esto hace que cuando realices las compresiones los moldes sufren algunos esfuerzos. Con espesores de 3 a 4mm los moldes son mas rígidos y no se deforman tanto.
Saludos y cualquier cosa seguimos chateando
what type of plastic do you work? at what temperature do you set the oven?
First you have to disarm the shredder and straighten the blades. When you assemble the box you have to mesure the distance betwenblades on the top and the botton of the box and adjust the screw to have the same mesure (around 148mm) and it does not have to be very tight. Some materials have different tolerances which you have to realize. It is important that when you arm the shredder the friction between the blades is minimum
Hi @imuh for PS and Other 7 I dont use mould realese. For PP i use a little bit but you could avoid using.
For HDPE i need a lot of mould realese.
Do you have any suggestion ? MAybe you can share the variables of a typical compression like type of plastic (Example:cups), temperature, time,etc
Thank you for share your experience 🙂
Hello @ehugler ! Some things that I learned using the outside compression:
1.The mould of the bowl has to be very well polish. Used grinder disk.
2.PS(5)-PP(6)-And ohter (7) are the best plastic for this technique
3.Alignment and parallelism are important to avoid imperfection.
4. When you are compressing do it very slowly to avoid over flow
5. HDPE (for me) is the worst plastic for this technique many time stick in the bowl and other time make bubbles (Im still try to improve with this material because i have a lot of and the most beutifull bowls of colors are of hdpe)
6.The best mould realase is Mirror Glaze Meguiar`s and alternative i used silicone spray
7. If you mould need 350 gr you have to put 400 gr and never compress the mould to the end, live 5 mm between the upper and lower bowl
8. After compressing i wait 5 minutes and decompress the mould and put to colling in a place with wind (the dilation of the plasticand the steel make easy to unmould
I wait your answer
Maybe you can weld a sheet of carbon steel in the out side to give de mould more recistence. Its going to be like a coating of stanle steel
like a folder that contains all the precious plastic molds
Hello in the Bazar preciousplastic sells de coins!!! Here the direction
Hola!!!! lo dejo entre 45 a 50 minutos y luego de la compresión lo dejo enfriar hasta temperatura ambiente, esto hace que se contraiga y sea fácil desmoldarlo.
Hi @dplasto @nickchomey thank you for your answer-I havent solved the problem yet im going to try what you told me.
I compress the plastic at 210°C and I use a mesh of 8 mm hole
I usually use pp and hdpe and the residence time is about 40 minutes and the plastic is all reade melted
Im going to polish and use some mould release
Thank you guys