Precise and efficient sorting of good parts and sprues
Screw separators from MTF Technik are the ideal solution for simple and automatic sorting of production goods of different sizes. They are used in particular in plastics processing or in the die-casting industry for the separation of injection moulded parts and sprues.Separation is achieved by a rotating screw located above a fixed plate.
The smaller parts slide under the screw, while the larger parts are transported to the side. Thanks to the individual adjustment of the screw geometry, the separators can be precisely adapted to your requirements. The wide range of adjustment options for speed and inclination, combined with the stable bearing of the screw, ensure optimal separation results.
The screw separators are ideal for inline operation directly behind the production machine, where the material to be separated is fed in batches, e.g. via a conveyor belt. They can be designed either on a separate base frame or as an attachment to conveyor belts.
With their robust designand high efficiency, they are the ideal addition to a wide range of production processes and relieve your employees of manual sorting tasks.
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Why should you choose MTF Technik?
Customised product manufacturing
Special solutions
Comprehensive service
Expertise for over 50 years
Patented technologies
Advantages of MTF Technik Screw separators
Double-sided mounting of the separating screw for precise separation gap
Height of the separator gap can be conveniently adjusted using knurled nuts adjustable
Efficient drum motor drive with its own speed control
Scraper above the screw conveyor for targeted part feed
Flexible and adjustable spikes for loosening the material to be separated.
Quick conversion to different part combinations
The screw separators in detail
Precise separation of materials
Precise separation of materials
Screw separators are used to sort material of different shapes and sizes. They are typically used in plastic injection moulding or die casting for aluminium or zinc to separate finished parts from sprues.
The material to be separated is fed into the screw separator in measured quantities, usually directly after each production cycle. The material falls onto a flat sheet metal plate above which a rotating screw roller is mounted at a defined distance. The smaller parts slide through this gap under the screw body, while the larger parts are transported to one side by the threading action of the screw.
The screw separators from MTF Technik are available either as attachments for a conveyor belt or as stand-alone units on their own base frame. They have a sturdy drip tray on which the separating screw is mounted and guided on both sides. This allows the separation gap to be adjusted precisely using knurled nuts.
The drive is provided by an efficient DC drum motor with a power output of only 30W and its own control system, which allows the rotational speed to be set in 15 steps between 8 and 140 rpm. The motor is integrated directly into the screw roller and therefore requires no additional installation space.
The screw base can be supplied in various materials and screw heights. Spikes made of flexible material are embedded in the base and can be adjusted in length. These ensure that the material to be separated is continuously loosened, thereby improving the separation result.
A flexible scraper made of polyester material mounted above the screw ensures that parts fed into the separator do not jump over the screw but are directed into the separation area.
The design of the screw separators can be customised to the respective separation task if required.
We would be happy to provide you with personal advice for your individual requirements.
Questions and answers about Screw separators
Are the snail separators available in different sizes?
Yes. The screw separators from MTF Technik are available in two separation lengths of 600 mm and 800 mm. The length used depends on the feed width of the part stream and the separability of the parts. The more difficult the parts are to separate, the longer the screw length must be.
Can the screw separator attachments from MTF Technik also be mounted on conveyor belts from other manufacturers?
Yes. Since the screw separator attachments have their own drum motor drive, they can generally be used independently. To mount them on a third-party conveyor belt, all you need to do is create the connection in the form of round steel mountings to which the attachment can be fastened.
Why is it so important that the screw is mounted on both sides?
The separation gap between the screw and the discharge plate can only be adjusted precisely if the screw body is securely supported and guided on both sides. If the separating screw is supported on one side only, there is a risk that it will start to wobble. This makes precise adjustment impossible and impairs the separation result.
What are the spikes on the separating screw for?
The spikes are pulled through the material to be separated with each rotation of the separating screw. At a sufficiently high rotation speed, the spikes throw the separated material up slightly and loosen it. This prevents large pieces from covering the screw and blocking the separation gap for smaller pieces. Loosening the separated material gives the small pieces a better chance of falling through the separation gap.
Can a screw separator also be used to separate components?
Depending on the part geometry and production volume per unit of time, screw separators can also be used to separate parts. The screw is used to first align the components in a row. The spikes help to break up any accumulations of parts. The pitch of the screw then pushes the components along the screw body, where they fall individually to the side of the support plate. At this point, the components can then be counted, for example by a frame light barrier, or transferred individually to a downstream device.
It is important for the function that the parts cannot become entangled and that there is sufficient time for the separation process. In addition, the parts must be able to be transported safely through the screw profile. We would be happy to carry out tests with your sample parts and evaluate whether separation is possible in your application.
Why is a flexible scraper mounted above the separating screw?
When the components are fed onto the separator, e.g. falling from a conveyor belt, they may bounce off the support plate and jump over the screw. Here, the scraper acts as a flexible barrier for the material to be separated and ensures that it is guided precisely in front of the screw to undergo the separation process.
In addition, parts can become caught between the individual threads of the screw or between the threads and the spikes, which would then be pulled along by the rotary movement of the screw body. The flexible polyester material releases the entanglement, scrapes off the parts and guides them specifically to the separation process.
Doesn't the screw have to be covered for safety reasons?
No. The drive used is designed to stop easily if clothing or body parts are pulled in. In addition, the screw is mounted so that it only pulls in the direction of the drain plate under its own weight. This means that if something gets stuck, the screw can move upwards unhindered, preventing any points of entrapment. This eliminates any risk to occupational safety.
How do you optimally adjust a screw separator?
The aim is always to set the separation gap as wide as possible, i.e. the setting should always be based on the larger part. The screw body must therefore be set high enough above the drain plate so that the larger part does not slip through the separation gap.
The speed of the separator should then be adjusted so that the spikes can perform their function optimally and the separated material is loosened and barriers of parts are avoided in front of the separation gap. At the same time, however, the spikes must not cause too much turbulence. Otherwise, there is a risk that the thread flanks of the screw will not be able to transport enough of the large parts to the side.
For larger components with rounded shapes, it may be necessary to adjust the inclination of the discharge plate to a steeper angle so that the parts press more strongly against the screw profile due to their weight and can thus be transported away more easily to the side.
The correct setting of the separating devices has a significant influence on the quality of the separating process.
Can the screw separators also be used in die casting?
Yes. In this case, the screw body and the drain plate are usually made of stainless steel.
Can screw conveyors also be used in clean rooms?
Basically, yes. The actual operation of the separator does not generate any significant emissions. Depending on customer requirements, the screw body and/or the drain plate can be made of stainless steel for this application. The customer must then assess whether harmful emissions are generated by the sliding and transport process of the parts.
We are happy to provide loan equipment for on-site testing.
