Screw extruders are among the most used tools in different industries such as food industries, polymer processing, etc. Basically, a screw extruder is a machine that is used to form a plastic product to the required shape using the screw that turns. This means the small plastic pellets are carefully fed to the hopper of the screw extruder they get conveyed through this machine via a rotating screw. But how can you choose the best screw extruder? We have deep researched and came up with below helpful information on how to own the best extruder that will meet your needs and expectations.
Type of screw extruder
Twin-screw extruder and single screw extruder
Single and twin screw extruders are among the most commonly known extruders. Single and twin screw extruders are axially open-channel machines that can get regarded as drag flow pumps. Twin-screw offer counter-rotating.
The function of the single screw extruder
This extruder is used to convert slid plastic to uniform melt via the effect of pressurizing, heating and shearing to the next process. Besides, the melting procedure involves various processes such as master-batches, mixing color, re-grinding, and blending resins. And finishing must be done uniformly right in temperature and concentration where the pressure effect should be large to squeeze viscous polymer.
Overall, this type of extruder is perfect when it comes to performing the above processes with a spiral knife and barrel screw. Plastic pellets get to barrel through hopper that is then placed on one of barre, further passed via a screw and to other ends of the barrel. To maintain pressure, depth threads on the screw need to be decreased since the hopper keeps on increasing.
The principle of the twin-screw extruder
This one works on the principle of the extruder for the single-screw extruder in different processes such as melting, transport, pumping, pressurization, devolatilization, and stripping are conducted because extruders.
Catalyst Extruders
This type of extruder is used for refining crude fabrics to change them to molecular structure. This extruder type is available in different bench-top sizes in standard sizes of 8 inches, 6 inches, and 4 inches.
Food Extruders
These extruders are meant to cool and cook food that helped the food production process differently. Essentially, this screw extruder machine get rids batch cooking via consistently cooking moist, semi-moist, pre-mixed, and dry foods with high temperature, timing precision, and pressure. Once this machine is combined with extrusion cutters and customer extrusion, this similar unit is still utilized to create an unlimited variety of food pellets in different sizes and shapes. And in terms of longevity and safety, food extruders are effectively made with fabric material stainless steel to ensure less downtime and sanitary production to replace parts.
Rubber Extruders
The manufacturers dealing with materials such as silicone, rubber bales, and EPDM can agree with us that breaking this product is too hard. This extruder is specifically designed for this material based on their sizes and manufacturing requirements were controlled and improved.
Lab Extruders
Lab extruder is used to create activated carbon for water and air purification. And they have a wide range of part sizes and shapes that includes barrel, screw, auger, and die configurations. So, based on the construction need, it is in various materials such as carbon steel or stainless steel.
Application of screw extruder
Primary working principle le in the extruder. As per the spatial position of the screw, it is typically divided into two types vertical and horizontal extruders. Further, according to screw rotational speed, it can still be divided into three types over-speed extender, high-speed extruder, and standard extruder specifically. So, as per the total figure of screws present, it’s divided into screw-less extrusions such as single screw extruder, machine, multi-screw extruder, and twin screw extruder.
Screw extruder components
– Motor
– Feed Hopper
– Screw
– Pin Barrel
– Bed Plate
– Feed roll
– Gearbox
– Extruder head
– Middle barrel
– Forward cyl-support
Stage 1
Once the screw extrusion system is fully heated to a specific process at a given temperature, the motor begins while the torque and speed required by the screw are immediately supplied to it. Next, the plastic present in the hopper enters the groove part via the feeding port and under its weight on feeder thrust. Immediately, the screw rotates, and your plastic starts getting transported under the friction action of the barrel screw.
Stage 2
Whenever self-feeding ports are entered, it’s then moved forward simply because of the friction effect in the inner wall of the cylinder from the screw surface and under decreasing friction action. Now during the molding process, the fabrics are added directly from the hopper to the plastic extruder in granules or powdered form. Overall, this is the procedure of compacting, conveying, compressing, homogenizing and plasticizing to a uniform melt that gets completed. At this point, the lost solidly pelleted are effectively filled using a screw groove since the material is conveyed continuously and starts to be compacted.
Stage 3
At stage three, materials enter the compression section where plastic increases the pressure amount due to the shallow depth of the used screw groove and heat resistance that is further compacted. This is still the step in which temperature is found going up to the melting point where materials begin to melt.
Stage 4
After materials are transported, heating continues while the molten amount of material increases whereas the material amount which is not melted decreases. Right at the end of the compression section materials are transformed to a viscous flow state where the homogenization of every section is set to a uniform but not the temperature. Next, the screw quantifies determines molten material temperature. The die inside the plastic extruder heal is a unique molded part that goes through fabric that is responsible to obtain the size and geometry of certain sections. After cooling the section and all the above processes are perfectly done, the desired product can now be achieved.
Factors you should consider when choosing a screw extender?
Twin & single screw extruders
The first thing is to determine the type of pipe you require to produce. Twin-screw extruder is perfect for PVC, and single screw extruders for standard PPR and HDPE pipe.
High-quality construction, parts & components
This is another essential thing you should look into. Using quality components tends to ensure that the spare parts are accessible to guarantee high performance and allow easy servicing.
The other essential parts of the extruder machine are the barrel, screw, and gearbox, as they are subjected to extreme thermal alongside mechanical wear and tear. Therefore, using quality components is vital for any successful operation.
When it comes to different components in extruder machines, only consider the manufacturers which use high-quality components, probably from the globally accessible brand names. Also, things like electronics & pls control, equipment assembly, upstream or downstream integration options, troubleshooting, and easy operation are equally dependent and critical on the manufacturer.
Integration and ease of use
This machine is made to usually operate in a series of downstream. Thus, the integration options are vital to your extruder operation.
Track record of the success
Consider the experience and reliability of your machine. This means the machine should support you in the operating lifetime of the extruder. Overall, honest proof of the industry experience and manufacturer’s dependability is a successful and long track record.
Final word
Screw extruders are among the essential components used in different manufacturing processes. And whenever such a process is combined with cutting, feeding, de-airing, etc., it can successfully create everything. With the above guide, you will have enough helpful information to deeply understand screw extruders.
About Us
Kairong Group, headquartered in Nanjing, China, is a global manufacturing and trading company in the field of high-performance plastics and rubber processing equipment, extrusion solutions, masterbatch, and compounding, etc.
Its unit Nanjing Haisi Extrusion Company is a professional manufacturer of twin screw extruder, single screw extruder, two stage extruder,equipment for dryer and its related auxiaries. We tailor solutions from raw materials, materials processing equipment, to injection for different customers.
If you are looking for a reliable twin screw extruder manufacturer, then we are your worthy choice manufacturer, you can browse our homepage to learn more about our company and products, and if you have more questions You can contact us directly, we are happy to provide you with high-quality service and excellent products.
