Blow Molding Machines
Blow molding machines are used by millions of people around the world to produce soda, water, cleaning products, and more. It is a highly energy-efficient process that uses low and high-density plastic materials to create hollow forms known as parisons.
It requires air pressure to inflate and cool the plastic. The inflated plastic is then ejected from the mold.
Extrusion
Blow molding is a versatile manufacturing process that is used to create plastic bottles and containers. It is a three-step process that involves parison extrusion, moulding, and product ejection. Blow molding machines automate and streamline these processes, making them ideal for high-volume production.
The extrusion capability of a blow molding machine begins with the plastic pellets that are fed into a barrel that uses both frictional and shear force to melt the resin. blow molding machine The melted plastic is then forced through an extruder die that has different sections that serve distinct purposes. Once the preform is formed, it is inflated with air to form the final hollow plastic part.
After the melted plastic passes through the extruder, it’s collected in an accumulator head and pushed out by a ram piston or cylinders depending on whether intermittent or straight extrusion is being used. The accumulator’s capacity dictates the amount of molten plastic that is pushed out at one time.
The accumulator’s shape determines the size and profile of the parison. When the accumulator reaches its set capacity, the ram pushes it through the die that defines the neck and bottom of the final product. The compressed air from the ram’s piston or cylinder forces the parison to expand against the mold cavity walls and conform to their shape. This forms the neck and bottom of the product as well as a thin strip of excess material known as flash.
Injection
Injection blow molding is a high-production technology that is used for making containers, packaging, and industrial applications. It involves melting down plastic resin and forming it into a preform, called a parison (for extrusion blow molds) or injection stretch blow mold (ISB). Then the parison is placed inside the product mold, and pressurized air is blown through it until it expands to match the shape of the mold. When the plastic cools, it is ejected from the mold.
In order to operate the machine correctly, it is important to carefully examine and maintain each component of the system. In addition, it is a good idea to use a sample of the plastic material being molded to make sure that it is clean and has no hard objects. After the process is complete, the machine should be shut down, cleaned, and lubricated.
Injection blow molding can be used to manufacture a wide range of products, from liquid bottles and food cans to car parts and tanks. It is also capable of creating a wider range of container sizes, allowing manufacturers to produce more varieties of their product lines. Unlike other plastic processing techniques, injection blow molding can be used to create containers with a thicker neck or bottom and still meet industry manufacturing specifications. This makes it a good choice for making larger, more complex containers that require precise tolerances.
Capabilities
A blow molding machine creates hollow plastic products by inflating a heated tube of melted resin called a parison until it takes the shape of the mold cavity. It is a versatile manufacturing process that supports the production of bottles, containers, drums and other hollow plastic products. Several different types of blow molding machines are available, each suited for specific production requirements and applications.
The primary differences between blow molding and injection molding are that the former is used to produce hollow plastic objects, whereas the latter produces solid plastic objects. Blow molding can use a wider range of materials than injection, as long as they are thermoplastics that don’t degrade upon heating. Some common examples of blown-moldable plastics include HDPE (high density polyethylene), LDPE (low density polyethylene), PETG (polyethylene terephthalate glycol), PP (polypropylene) and PC (polycarbonate).
One of the most significant developments in blow molding technology is energy efficiency. The emergence of new electric drives and energy recovery systems for heat, compressed blow molding machine factory air and cooling help reduce the amount of power needed to operate the machine. This lowers operating costs and energy consumption, which in turn enables greater sustainability.
Wilmington Machinery, for example, recently introduced an all-electric eight-station rotary blow molding machine that can produce calibrated bottles in various shapes and sizes ranging from 8 ounces to 4 liters, including small specialty bottles for cosmetics, miniature spirits and pharmaceuticals. It is compatible with single-, dual- and triple-parison die heads for monolayer and multilayer bottles.
Applications
Blow molding machines are essential for industrial manufacturing, as they help producers produce glass or plastic bottles cheaply and in large quantities. They work by melting and blowing a hollow tube of plastic known as a parison into a mold, creating a plastic product with an internal void. This process allows manufacturers to produce a wide variety of bottle shapes and sizes.
The most popular type of blow molding material is polyethylene, which offers a good balance of mechanical and chemical properties. It is easy to work with and possesses desirable qualities like high-density, odour and tininess resistance, good electrical insulation properties, high fluidity at low temperatures, and good water barrier characteristics. Other popular materials for blow molding include polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS) and other thermoplastics.
The two main types of blow molding processes are extrusion and injection blow molding. With the extrusion blow molding process, the plastic is melted and forced through an extruder barrel into a shape that mimics the final product. The resulting parison is then clamped into a mold, which is blown with air pressure to create the finished container. Extrusion blow molding produces larger products with shorter cycle times than injection methods, but it is not suitable for thin-walled containers or bottles with handles. This type of molding is best used for specialty products such as wide-mouthed jars. After a product is molded, it goes through a trimming process to remove excess plastic. This can be done manually or automatically using a spin trimmer, which uses titanium-nitride coated blades to provide longer life and better cutting performance than standard stainless steel.
