Blow Molding
During World War II,molding process started to be used for the production of low-density polyethylene vial. In the late 1950s, with the birth of high density polyethylene and the development of molding machine, molding technology was widely used. The hollow container’s volume is up to thousands of liters and some production has adopted computer control. Plastics applicable to molding include polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyester (PET) etc., and hollow containers made from them are widely used for industrial packaging containers.
Blow Molding
Blow molding, also known as hollow molding, is a rapidly developed plastic processing method. Place the tubular plastic mold preform made from thermoplastic resin extrusion or injection molding while it is hot (or heated to a softening state) in the bisected mold, and close the mold with immediately passing into the compressed air within the preform so that the plastic mold preform is inflated closely to the mold internal wall, then after cooling and de-molding, all kinds of hollow products are produced. The manufacturing process of the blow film is very similar to hollow plastic blow molding in principle, but it does not use a mold, and from the point of view of the classification of plastics processing technology, molding process is usually included in the extrusion.
According to making method of mold preform, molding can be divided into extrusion molding and injection molding, the newly developed multi-layer co-extrusion molding and stretch molding.
Multi-layer co-extrusion blow molding is a molding method of multi-layer composite products. It uses two or more kinds of plastic or use two or more extruders to cooperatively extrude multi-layer molding preform, then make the preform Inflate in the mold cavity by compressed air to produce blow molding products with multi-layer composite structure. This process is called multi-layer co-extrusion blow molding.
Injection blow molding adopts injection molding process to inject molten plastic into injection mold so as to produce tubular preform with bottom and the tube preform wrapped in hollow cavity core with microporous surrounding wall; then while it’s still hot place the cavity core and the wrapped hot preform into hollow blow molding mold; then pass into the compressed air from the core bar pipe so that the tube preform are blown-molding closely to the inner surface of blow molding mold; finally after packing and colling molding, extrude compressed air and open the mold to remove the product.
Stretch blow molding, also known as biaxially oriented blow molding, is a molding method that produce thermoplastics by extrusion or injection process into mold preform, then after thermostat process with the preform in the high-elastic state of the polymer, carry out axial mechanical stretch and then make circumferential stretch with compressed air to produce biaxially oriented containers.
It is a process where a liquid plastic is forced through a pipe and through a die. The end result is a hollow 3D shape which can be blown into many different shapes.
it is a manufacturing process in which the part to be made is shaped into the desired form by blowing hot air or gasses into it. This heating process can be by injection or extrusion. During this process, gases find their way through fine holes in the heated material and will force into it at high speeds. This allows for a lot more pressure that would otherwise not be possible without the holes. The end result is a very tight fit between surfaces with as little give as possible, making it an ideal blowing method for many high-pressure purposes.it is a manufacturing process that specializes in making candy, marshmallows and other sweets. In the process of molding, a liquid is blown into a hollow tube filled with powdered material. The pressure of the air causes the wet material to fill cavities formed in the object being created.
it is a manufacturing process in which very high-pressure air is used to form thermoplastic material into a shape. molding has become the preferred method of forming plastic parts due to its productivity, speed and cost effectiveness.it is a manufacturing process to produce plastic sheet. The plastic sheet can be used directly or as a coating for other plastics, like molded parts.
it is the use of high pressure and hot gas to create a substance that can be formed into a specific shape. This can be done by heating air through an internal nozzle. The concept was first developed in Belgium in 1875 by Émile Bock in order to create chocolate bars, though the technology was not widely used until the late 1880s.