Hi all, I wanted to see if I could injection mould a cheap little plastic dust pan at home. I was successful in making a concrete mold by using a taped plastic prototype and clay. Turns out that the Smooth-on.com product smooth cast 45 does form the cast, but, it takes way to long to make each piece enough to make any money selling the final pieces. With that in mind, I figured I would try to make a home made injection mould by welding soft iron sheets together. I use the Harbor Frieght sheet metal shears, as well as a chop saw, and they all worked well enough for me to cut the proper sized pieces. The only problem is that the Low Density Poly Ethelyne ( LDPE ) is Way too viscous to flow into any metal form that I make. You will see from the video that even though the melting point of LDPE is 248 F, it does not easily flow into the mould without high presure. If anyone has any suggestion, please feel free to let me know how I can make an injection mold piece at my house.

Hi all, I wanted to see if I could injection mould a cheap little plastic dust pan at home. I was successful in making a concrete mold by using a taped plastic prototype and clay. Turns out that the Smooth-on.com product smooth cast 45 does form the cast, but, it takes way to long to make each piece enough to make any money selling the final pieces. With that in mind, I figured I would try to make a home made injection mould by welding soft iron sheets together. I use the Harbor Frieght sheet metal shears, as well as a chop saw, and they all worked well enough for me to cut the proper sized pieces. The only problem is that the Low Density Poly Ethelyne ( LDPE ) is Way too viscous to flow into any metal form that I make. You will see from the video that even though the melting point of LDPE is 248 F, it does not easily flow into the mould without high presure. If anyone has any suggestion, please feel free to let me know how I can make an injection mold piece at my house.

Injection molds usually require extremely high pressures for form plastic. After I looked at some injection mould machines, I found that they are usually rated by the volume of molten plastic and a certain number of tons of pressure. I found some injection mold machines which were rated for 4 oz of molten plastic and 65 tons of pressure. I wanted to see I I could possibly bypass the pneumatics and press the two halves of the mold by hand and still manage to form a cast. It turns out that it really is possible to form a part at home even by pressing the mould halve manually. If nichrome wire is used to heat the mold while it is being pressed, it is actually very doable.