What is an extrusion blow molding machine? Have you ever wondered how the bottles and gallons of packaging for all kinds of products came to be? Do you know how the bottle you drink juice from is made?
Many times these plastic bottles, jars and other containers that you package your goods in are created by a common process called extrusion blow molding.
What is extrusion blow molding ?
Blow molding, extrusion blowmoulding or EBM is a manufacturing process in which plastic raw materials are first melted in an extruder and then extruded in the form of a hollow tube called a parison. The hopper or tank of the extruder helps to hold the raw materials being produced and the augers help to mix the materials inside.
Common resins used in the process of extrusion blow molding machine are:
HDPE heavy polyethylene
LDPE light polyethylene material
extrusion blow molding machine
Many bottles and gallons, whether single-layer or multi-layer, are produced by single or multi-layer blow molding machines.
We’ll go a little deeper into the process and how the blow molding machine works, but for now, let’s review some important definitions that apply to the blow molding process.
blow molding machine mold
A mold is a set that can contain one or more holes.
A cavity is a single molding surface that creates a blow molding part. Cavitation is determined by the amount of product required as well as the size of the container being molded.
Parisons are “hollow plastic tubes” formed by extruding molten material through the die head or die of a blow molding machine.
Blowpin is a tool component that is inserted into the molten mold and parison in order to blow compressed air. The bluepin tip also helps to form the opening by either compressed air force or compression force against the material (and die neck cover), depending on the type of blow molding process used.
Flash is extra material that comes out of the mold.
How does the extrusion blow molding machine work?
The way theinjection blow molding machine works can be divided into 5 steps.
To produce a large number of single or multi-layered bottles and jars that you pack your products in or even use every day, the process first starts with the plastic pellets we mentioned earlier.
Bloomolding extrusion process was divided into 5 stages
The extruder turns each plastic pellet into a molten material with the help of a heated tank and pure force. Both temperature (frictional and external heat is used) and pressure melt the plastic.
The material is then passed through an extrusion tool to create a parison.
For molding, the parison is sealed in a water-cooled mold.
In the next step, compressed air is blown into the parison or intestine. This blown air blow the parison to the exact shape of the mold cavity, thereby forming a bottle, container or hollow part. If you’ve ever seen glass blowing, it’s a lot like it.
After the plastic has cooled enough, the mold is opened and the part or product is removed.
Types of blow molding machine
injection blow molding machine
injection blow molding machine, a core pin or rod is used during the process. First, a parison is injected into the mold cavity inserted around the rod. The parison that is formed is similar to a test tube. The core rod moves the parison to the blow molding machine where compressed air creates the final shape of the bottle. Then the rod transfers and extrudes the final product from the machine.
extrusion blow molding machine
Blowmoulding plastic extrusion machine can be continuous or intermittent. In a continuous blow molding machine, a parison is continuously fed into the mold and each form is cut by a blade during forming. The reciprocating blow molding machine ejects each new plastic from the metal mold as it cools, and only after the previous parison has been ejected is the parison inserted into the mold.
Plastic blow molds are usually much cheaper than injection blow molds and can be produced in a much shorter time. extrusion blow molding machine are suitable for smaller performances. Advantages include cost savings in tooling and shorter production times, while disadvantages typically include less wall thickness control and greater amounts of scrap material.
Stretch blow molding machine
The stretch blow molding machine combines injection and extrusion processes. The plastic is first molded into a solid preform to create a bottle opening.
After the preform is cooled, it is inserted into the stretchable plastic machine. The preform is then reheated using an infrared heater and blown into the plastic bottle with compressed air.
Advantages of extrusion blow molding machine
Compared with other machines, the extrusion blow molding machine only needs low pressure air and does not need a preform, which makes the total cost cheaper. Due to the lower pressure, the mold costs and auxiliary costs (compressor… etc.) in the extrusion blow molding machine are lower compared to the injection blow molding machine machine, and the machinery cost is also low.
Variety of products
The popularity of plastic extrusion blow molding machine has allowed engineers to try different products and designs that have led to several interesting applications. Products created using this technology are fuel tanks, baby seats, medical beds, and toys, just to name a few.
Productivity and high quality
Automation technology is used in plastic production. It has enabled a production cycle that is much faster to increase production capabilities. And automatically recycle flash without waste. Then automatically check the bottles or products to ensure the quality.
The extrusion blow molding machine can produce all kinds of products used in food and beverage, medical, manufacturing, pharmaceutical and other industries. For a diverse product family, it is enough to change only part of the mold to obtain different volumes or products with different appearance. Control parison can be used to modify weight or thickness. No need to modify the template. The ability to produce products for a variety of applications makes this process very beneficial for packaging companies.
Price and purchase of extrusion blow molding machine
The price of extrusion blow molding machine depends on the type of machine and the amount of production. A 1 to 4 liter extrusion blow molding machine costs less than a 20 liter blow molding machine, and in the same way, a 20 liter extrusion blow molding machine is cheaper than a 1000 to 2000 liter extrusion blow molding machine
Among other factors affecting the purchase price of extrusion blow molding machine , it can be mentioned whether the device is single-station or two-station. The two-station plastic body machine has much more production than the one-station plastic body machine, and for that reason its price is also higher, but if efficiency and daily production circulation are important to you, a two-station machine is more suitable for you.
What kind of extrusion blow molding machine do you need?
What kind of manufacturing process is right for your next project? Our engineers have decades of experience and know what type of material and mold is right for you. Contact us today to discuss your new plastic design or product idea and we will guide you through the manufacturing process that is best for your project needs.