Plastic molds for resin
EXTRUSION or AIR PRESSURE MOLDING: consists of pouring the plastic in granules (pellets) into a hopper so that it enters a hot tube (oven), the molten material is pushed by a screw (worm) to the mold that has the desired shape and then air is injected so that it sticks to the walls of the mold. It is used to manufacture hollow objects (bottles, jars, …).
INJECTION molding is similar to the previous one, but it does not use air, but introduces the molten plastic into a mold (plastic injection). It is used to make solid objects without hollows inside.
By VACUUM or THERMOCONFORMING or HOT DEFORMATION, a thin sheet of plastic is placed on a mold, by means of a radiator the plastic is heated so that it adapts to the shape of the mold, finally the vacuum is made so that it adheres and adjusts completely to the mold. It is used to make trays, plates, buckets, masks, ……
Molding by PRESSING the crushed components are introduced into a mold. A “core” presses the mixture while it is heated and softened. The piece obtained is left to cool in the mold until it hardens.
Hot forming plastic
The melt forming and molding process is a procedure for manufacturing parts without loss of material and is performed by melting the material and pouring it into molds that reproduce the shape of the part. It is also known as casting or pouring and is mainly applicable to the manufacture of metal parts, plastics, glass, cement, etc.
The mold is a container with a cavity in which a material is introduced in a molten state which, when solidified, takes the shape of the cavity. It is then left to cool for the necessary time until it solidifies and is removed from the mold. The molds, in general, consist of two pieces, perfectly coupled.
The working method starts by obtaining a wax, plaster or wood model of the part to be manufactured. A mold is built on this model, which will be made of sand or metal. When the original piece is hollow, it is also necessary to manufacture cores, which are the pieces that occupy the interior holes in the mold.
How to melt plastic to make bricks
Repairing plastic items can be confusing for someone who has never done it before. There are no parts to replace (usually), no nuts to tighten, just repair the material itself.
Plastic can be easier to work with than you might imagine. With some heat and some pressure, many items can be fixed quite simply. So, before you resign yourself to tossing a broken piece of plastic into your recycling garbage can, here are some techniques you can use to repair plastic.
If you have two separate pieces of plastic that need to be joined together or if they have a crack, then you’ll need some plastic welding. The basic idea is to apply heat to the edges that are joined to melt the plastic until it is liquid enough to blur the edges. Additional plastic can be melted into the groove to create a stronger bond, but depending on the situation, this may not always be necessary.
If your part has a large enough hole, you will need to resort to creating a plastic patch. The answer to this particular problem seems to have been best addressed by kayakers. Using a heat source (preferably a heat gun), soften the edges of the hole and the section of plastic you’ll use as a patch and carefully place it to make sure the hole is completely covered. This gets very hot, so you’ll need gloves. Once the patch is in place, you can use a hot metal spoon or trowel to smooth the edges.
Melt plastic in a homemade way
Hello I work in a plastics factory and I comment that polyethylene is melted at a controlled temperature between 150 and 220 ° C depending on the PE low density melts at 150 – 180 º and high at 200 – 230 º generally bottles, jars, drums etc.. are made of low density PE but not the soft drink bottles that are made of PET and glass bottles (shiny) of PP (polypropylene) as for the molding, is as minibuda says, is injected under pressure, the other way is by blowing, but for this you need a piuco to create a sleeve.