NEED HELP ON PLASTIC MOLDING / CASTING

[robofights]

I NEED TO MAKE SOME PLASTIC PROTOTYPES OF A PART. THE PART IS A SIMPLE HOLLOW SHAPE THAT WILL BE EXTRUDED WHEN IT GOES INTO PRODUCTION, BUT THE TOOLING WILL COST $3K-$4K AND I DON'T KNOW IF THIS WILL BE A SELLER OR SOMETHING FOR THE ROUND FILE ON THE FLOOR NEXT TO MY DESK.

BASICALLY I AM THINKING OF CREATING A PLASTER PARIS MOLD AND INSERTING THE OBJECT INTO IT AND LETTING IT DRY, THEN SLIDE THE HOLLOW SHAPE OUT TO LEAVE A MOLD TO POUR LIQUID PLASTIC OR RESIN INTO.

ARE ANY PLASTICS OR RESINS THAT ARE SLIGHTLY FLEXIBLE AND NOT FRAGILE THAT I CAN MIX OR HEAT MYSELF TO POUR INTO THE MOLD? THESE PARTS WILL BE SUBJECT TO INTERMITTENT HOT AND COLD OF 50-110 DEGREES FAHREHEIT AND MUST KEEP THEIR SHAPE.

MANY THANKS,

JIM

 

[patprimmer]

Why are you shouting.

Polyurethane sounds possible

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[btrueblood]

Alternatively, make the mold out of a fairly flexible resin (silicone RTV or soft urethane), so that you can bend/peel the mold away from a rigid part/casting.