Industrial shredder for plastics. Shredders for shredding (recycling) plastic

Most polymer materials are chemically inert and not biodegradable.

There is also, but its share in world production is very small.

The durability of polymers has back side– waste, including industrial waste, must be disposed of.

Landfilling or burning plastics causes irreparable harm to the environment. Therefore, polymer manufacturers and solid waste disposal enterprises are mastering recycling.

This is a set of activities, the diagram of which as follows:

• waste collection and sorting;
• processing into secondary raw materials;
• production of final products.

In this article we will talk about plastic shredders.

Polymer processing is impossible without shredders and crushers. They are used for grinding, that is, obtaining pieces of a given size.

Fraction size- one of the key technical parameters equipment, and it determines how costly the next stage of processing – granulation – will be.

In some industries, technology allows for the mixing of plastic chips into the feedstock. Here the uniformity of grinding, the absence of dust and too large pieces plays an even more important role.

Types of shredders and crushers

Manufacturers and equipment suppliers are often faced with a client’s request to select a universal shredder or crusher that will work with all types of plastics and produce almost finished granulate.

This task is practically impossible, because polymer materials differ in a number of parameters:

• physical and mechanical properties - strength, impact strength, friction coefficient, softening temperature;
• structure - they are solid, fibrous, cellular, composite;
• shape and dimensions.

In addition, consumers do not always understand the purpose and operating principle of the equipment. To avoid confusion, we note that both machines stand next to each other in a complete production line: the shredder performs the primary grinding of waste, and the crusher does the secondary. Their designs may be the same.

The division into two stages is carried out to optimize production. For example, grinding a thick-walled 200-liter barrel to the required size will require either a high-power drive or a high time investment.

Two-stage crushing allows reduce energy costs And increase processing speed.

Some manufacturers make machines that combine a shredder and a crusher. For example, international group TRIA companies have developed a series of combines for processing large blocks and thick-walled blow moldings. However, they are not suitable for working with small-sized waste - , -.

Crushing equipment differs in design, operating principle and type of material being processed.

Processed materials and methods of exposure

All recyclable materials can be divided into three types:

1. Film— polypropylene, acrylic, polyethylene and PVC films are highly elastic. To grind them, you need cutting or tearing installations.
2. Small and thin-walled— these include PET containers, small canisters for fuels and lubricants, plastic pipes. Shredders should be equipped with stronger blades or teeth.
3. Large and thick-walled— sprues, profiles and molding defects are crushed by impact, squeezing or abrasion.

The dimensions of the loading window, hopper, filling system, actuator and profiling sieve depend on the dimensions of the waste. Feeding can be done manually using belt conveyor or lifting machine.

Some types of machines are integrated into the production lines of enterprises, others are installed separately.

There are a number of solutions on a trailed chassis, such shredders delivered to the temporary work site. Many manufacturers offer their customers modular designs with a set of options that allow the same mechanisms to be used in different conditions.

Operating principles of shredders

There are three types of shredders depending on the principle of operation:

• shock action;
• compressive;
• cutting and tearing.

Impact shredders, or hammer crushers, are often used in mining and processing plants, are also used to destroy polymers.

They fit for working with gates and large waste made of fragile plastics. The advantages of such machines include high productivity and the ability to work with hard-to-grind materials.

However, they have significant flaws:

• large mass of the frame— some models can only be installed on a prepared reinforced concrete base;
• high rotation speed in combination with hinged hammers make the mechanism a source of noise and vibration.

Compression devices—jaw and cone crushers—are designed for grinding the largest wastes. However, they are not able to cope with viscous polymers such as ABS plastic or polyurethane.

The machines are equipped with a powerful drive; electric motors and hydraulic cylinders are used as power units.

Cutting and breaking shredders, or rotary shredders, are equipped with knives and teeth. They are suitable for grinding most types of polymer waste. Among the manufacturers' offers models for industrial use can be found, medium and small businesses.

Common designs

Shredders for plastics are made according to three different kinematic schemes. They are:

1. Single-shaft. The rotor rotates in a working chamber, or stator. The raw material is fed through the loading window, and the crushed material, under its own weight, exits through the profiling sieve. There are also machines with forced pneumatic unloading. One of the main elements of a single-shaft shredder for medium and large waste is a hydraulic press plate. It presses pieces of plastic against the rotor and ensures that they are captured by teeth or knives. Single-shaft designs are suitable for primary grinding of high-hardness polymers.
2. Twin-shaft. Systems with two rotors differ more high degree grinding. On the loading side, the shafts rotate towards each other. The gripping conditions in a two-rotor machine make it possible to do without a pre-presser. High torque allows you to process waste from soft elastic plastics, elastomers, and rubber goods.
3. Four-shaft. The system includes two main (cutting) and two auxiliary (feed) shafts. Such machines are designed for crushing large-sized waste, including hollow waste: cans, barrels, cans. The knives of the feed rotors are spaced apart, but have a positive overlap with the knives of the working shafts, and therefore also participate in the grinding process.

The largest demand for plastic recycling use rotary shredders and crushers.

They achieve the required crushing depth with high productivity, are easy to operate and do not require high maintenance costs.

Grinding is performed with knives attached to the rotor and stator. For light and thin plastics, machines with a high rotation speed are used, for solid and large waste - with a low one.

Depending on the type of plastic, knives of the following designs are used:

• disk;
• straight;
• oblique;
• V-shaped;
• cascading.

Highly specialized machines

The largest share of waste in the production of polymer film comes from the edges. To crush it and remove it from the work area specialized installations have been developed.

Venti Oelde produces a range of industrial burst fans. There are no counterknives in their design, and the edges of the blades have a sawtooth shape. Fine teeth grab the edge and pull it until it breaks, and the crushed waste is directed by air flow into the receiving hopper.

Shredding of polyethylene films and extruded polystyrene foam is accompanied by heating of the material itself and the knives.

To avoid material sticking, crushers are equipped with water cooling systems. However, some manufacturers self-heating is used to obtain agglomerate– the processing stage following grinding.

They are high-speed (≥1200 min -1) crushers that produce dense balls with a diameter of 3 – 15 mm. If the initial raw material did not contain impurities, the agglomerate is sent for reuse without additional processing.

Equipment performance: industrial and mini

You need to choose a plastic shredder for specific tasks taking into account its performance.

Using the example of the ATLASMASH LLC family of shredders, it can be seen that the spread of this parameter is 50 – 3500 kg per hour.

The consumers of such installations are enterprises not involved in recycling.

WS line – medium performance models designed for commercial application. WN – industrial shredders designed for high level downloads.

It is also worth paying attention to machine drive power. The most productive models consume up to 160 kW/h electricity.

Plastic shredder prices

Approximate prices for polymer shredders from various companies are presented in the table:

Most manufacturers of shredders and crushers for plastic do not lay out prices for their equipment, but make a commercial offer at the request of the client after studying all his needs.

For example, installing a cooling system or a cyclone filter can lead to a significant increase in the cost of equipment.

A decision on the advisability of purchasing a shredder or crusher should be made only after calculations and consultations with an economist and the manufacturer.

Sometimes a mini crusher will be enough. In cases where the amount of polymer waste does not reach 1 ton per year, the optimal solution would be take mobile shredder for rent or enter into a collection agreement, removal and disposal with a specialized company.

Results

Crusher and shredder are indispensable devices in plastic processing. The right shredder will give you a good start and make it as cost-effective as possible.

In contact with

Twin-shaft shredders are used for crushing materials (plastic, wood, metal) and are used on such objects as:

• waste sorting complexes;
• lines for processing and procurement of recyclable materials;
• manufacturing enterprises.

A twin-shaft crusher is a device equipped with two rotating different sides rotors. Knives are installed on the shafts. There are various options for knives, for example, knives can be disk type and removable knives on a shaft. The knives on the shafts are located in such a way as not to touch each other and crush the material caught between them. The number of knives depends on the performance of the shredder and the type of material to be crushed. In disk-type shredders, when sharpening, it is necessary to remove the disks for sharpening. In a shredder with removable knives, the knives are removed and turned over to the sharp side for further use. The shredder design may include an output conveyor with an installed metal catcher.

Industrial twin-roll crushers are used for processing metal products, wood, plastic, industrial waste, rubber products, bottles, branches, tree stumps.

Buy a twin-shaft crusher for wood, plastic, metal and rubber products

When ordering a twin-shaft shredder, you must first consult with the manager of Netmus LLC to obtain the exact specifications for the equipment, and the price will also be calculated. Industrial shredders are manufactured individually to achieve maximum performance in accordance with production tasks (for example, shredding plastic or wood, producing wood chips). Correctly selected industrial shredder will last long years. The quality of equipment manufactured in Europe to the highest standards is beyond criticism.

Throughout our lives we have to deal with different polymers. They have been used for the past several decades to make the most various products, beginning plastic containers and ending with parts for space construction. In just one year on the planet produced about 180 million tons of plastic for various purposes.

A significant part of them are polymers that do not decompose and are unable to be disposed of. All this cannot but influence environmental situation and often leads to environmental disasters. But processing polymers is not such a technologically difficult task. Moreover, they can be used to make useful things. Recycled plastic is virtually indistinguishable from virgin polymer and has virtually the same performance characteristics.

Types of crushing devices

The whole variety of devices for plastic processing can be presented in the form of several groups according to the purpose and design of the main working elements.

Depending on the device and application of the crusher for plastic waste There are the following types:

• Crushers-grinders of plastic of great thickness and strength, reminiscent in design of cabinet-type elements and window profiles.
• Shredders of small thickness waste, designed for processing bottles and other items, in the design of which cascade-type shredders are the main working unit.
• Cutters for polymer film waste that work on the same principle as regular scissors.

Upon closer examination of the design of plastic shredders, among their many options, we can distinguish shredders for shredding plastic, designed for processing certain types of polymer waste:

• Rotary crushers for plastic. It is this type of shredder that is most often used for recycling plastic waste. Available in two versions - high-speed for grinding fragile products and low-speed, designed for recycling durable plastic products.
• Crushers equipped with a roller material feeding mechanism.
• Cone devices in which the process of recycling raw materials occurs by passing it between two cones.
• Hammer devices. Designed for processing hard plastics. All work is done by rotating hammers on hinges.
• Jaw units. Waste is disposed of by applying pressure to the raw material with corrugated steel plates.

Low-speed devices with a power of about 10 kW cope best with the task of recycling thick polymers. At the same time, they can easily recycle the most durable, thick types of waste without even pre-treatment. Often low-speed crushers are used for the first coarse crushing stage. At the next stages, high-speed units are already used. This combined approach to raw material utilization increases the overall productivity of the crushing complex to the required levels.

Designed for recycling polymers equipment is produced by both Russian manufacturers and foreign companies. Quite a lot of units for crushing plastic are presented from Chinese manufacturers, which not only can be purchased at attractive prices (not higher than 250 thousand rubles), but also have good performance characteristics and high reliability.

Scope of application

The main users of plastic shredders are:

• Organizations engaged in the production of polymer products.
• Companies whose scope of activity includes the collection and subsequent disposal of secondary raw materials.
• Manufacturing enterprises engaged in the production of plastic items for various purposes.

As a result of recycling defective products, as well as other types of industrial plastic waste, a continuous supply of recycled plastic is ensured, from which new products can be made that have the necessary consumer benefits. properties. The process of reusing defective products and recyclable materials allows manufacturing enterprises save considerable amounts Money for the production of plastic products. Thanks to this, the cost of finished products is reduced.

Organizations involved in the processing of used plastic products cooperate directly with companies that are direct manufacturers polymer products. Therefore, the sale of recycled plastics can bring very significant profits to the enterprise.

Operating principle of plastic crushers

Recycled plastic raw materials, which are most often presented in the form of bottles and film fragments, have a heterogeneous composition, which requires the use of different processing methods. After all, these wastes may have different strength characteristics, viscosity and fragility.

Although cutting film waste is not difficult, shredding it using impact crushers almost impossible. ABS plastic, which has high thickness and strength, can be crushed only by sawing or impact, is particularly labor-intensive in this regard.

To choose the most suitable method for recycling plastic recyclables, you need to consider its thickness. It is for this reason that every grinding apparatus must have such design to process most efficiently and quickly certain type secondary raw materials.

Features of the shredder device for plastic processing

Considering that today we have to recycle plastic waste for various purposes, in order to more effectively perform this task, enterprises should be equipped with shredders a certain design. There are many types of equipment, each of which is capable of processing plastic only in a certain way.

Thus, even units with impact methods cannot cope with film, which can be easily cut. At the same time, ABS plastic is easily recycled drum kits. Due to the difference in the thickness of plastic products, companies have to use only a specific disposal method to shred each of them. This is why every plastics shredder must have certain performance characteristics.

To select the most suitable type of shredder, it is necessary to proceed from the type of plastic products that have been received for processing and recovery of secondary plastics. Most shredders easily cope with the task of shredding film, thin plastic products, as well as large plastic objects.

We make the crusher ourselves

Owners who decide to assemble a plastic shredder themselves can find a lot of options for this useful device online and choose the most suitable one. Making this device with your own hands is not so difficult - you just need to be patient and have minimum skills work. You can assemble a high-performance plastic processing unit without the use of special equipment. To complete the work you only need welding machine or a household inverter.

Tools

Each master can, at his own discretion, make changes to the diagram below, but in any case, a homemade plastic crusher will include the following required elements:

• Drive unit. Usually an electric motor is used as it. If you don’t have what you don’t need, you can go to the store and find an inexpensive model with the required power among the range offered. Crusher equipped electric drive, is also beneficial because it has a quieter operation, so it can be used not only outdoors, but also indoors.
• Circular Saw. It will be entrusted with processing functions plastic waste. Make sure you have enough drinks with different shapes teeth so that you can shred waste efficiently. Given the task at hand, it is ideal if you install at least 20 saws on one axis.
• Working axis designed for mounting saws.
• A metal profile that can be replaced with a pipe of a suitable diameter. The supporting frame and frame of the crusher will be made from it.
• Protective cover and feed hopper. To make them, you can use galvanized sheets. You will also need a special tool - metal scissors, a hammer and a vice.
• A pulley, a pair of bearings and a special belt that will support the interaction between the electric motor and the rotor.
• Different kinds fasteners - metal screws, washers and nuts.

Making a crusher

After you resolve the issue with materials and tools, you can proceed directly to the crusher manufacturing process.

The process begins with the manufacture of a cutting block. We take the axle and put the circular saws on it. Please note that the saw seat must have the same diameter as the axis. Make sure there is enough space between the improvised knives to accommodate metal washers. To ensure secure fastening of the saws, you need to put nuts on the ends. After this, you can install the axle itself on the pulley. You need to put two bearings on it, then the structure will rotate freely.

At the next stage, we begin to make the supporting frame. We take a welding machine and make a rectangular frame using a metal corner, profile or pipe. Next, you need to weld the legs to it, calculating their height in advance. Directly to the frame lay the sheet metal and weld it to the frame. You need to make a hole in the sheet, which should be the same size as the cutting block. Now you can install the engine, which we place near the knives.

After the work on manufacturing the frame is completed, we move on to the final stage of assembling the chopper. We take a protective casing, put it on the knives, and attach a hopper on top through which the raw materials for grinding will be supplied. Don't forget to make a hole in the casing for subsequent connection of the axle to the pulley. Next you need to put on special belt, which will connect the motor shaft to the cutting unit. At this point, the work of making a plastic crusher with your own hands can be considered complete.

To prevent the plastic crusher from causing you problems during operation, experts recommend drawing up a drawing at the very beginning that will allow you to get a visual representation of what your homemade crusher will look like. This will allow you to avoid gross miscalculations and discrepancies in the sizes of individual units in the future.

When you decide on choosing an electric motor, you must first understand how often you are going to use the crusher. For a device that will be subject to rare and minor loads, a low-power power drive will be sufficient. If you intend to actively use it, then you should look for a more powerful power unit with a higher number of revolutions.

Summing up

Considering the huge number of products made of polymers that humanity has to use, it is not surprising that last years Interest in devices such as a plastic shredder has grown. The main purpose of this device is to recycle plastic waste, which can subsequently be reused to make new things, which in terms of their performance characteristics will be practically no different from the original ones.

Such units are used today not only in industry, but also in the domestic sphere. However, owners do not always decide to purchase such a device. Some people have the idea of ​​making it on their own. In fact, anyone with minimal skills in working with a tool can cope with this task. Although the risk of errors cannot be ruled out, if you thoroughly prepare for the assembly process and draw up detailed diagram chopper, then in your own way functionality it will be no different from the branded unit.

Buying a plastic shredder is profitable and without headaches. Assembly, delivery, commissioning

For polymer processing, we suggest you familiarize yourself with single-rotor and double-rotor shredders. Quality equipment from good manufacturer- that's what everyone needs. And we will help you choose a plastic shredder, buy it and start using it.

• Why is a plastic shredder better than a crusher?

  The shredder works more efficiently, and most importantly, with less waste - it does not make much noise and does not leave dust behind. In addition, the size of the pieces of plastic can be completely different - the shredder can handle everything. The plastic shredder is very resistant to any type of damage - the knives and other parts do not wear out for a very long time.

• Shredder Types

  Shredders for plastic can be completely different - depending on the amount of material that is collected in your production, you can choose a shredder based on size and technical specifications. The fraction on the output hole is marked with productivity - for example, 50 mm, but the size of the hole can be changed depending on your wishes and needs. In addition, our company offers film shredders.

Positive traits

Buy a shredder, which processes plastic without additional costs, from us, and you will receive the following device:

• With minimal noise;
• Compact and convenient design;
• Ease of operation;
• High-quality and reliable knives on the rotor;
• Economical costs – minimum electricity consumption and machine maintenance;
• The design of the working chamber is suitable for processing plastics of large and small sizes.
• Highly efficient performance;
• Good price and availability of all models and spare parts of interest in our warehouse in Moscow;
• The shredder can be configured for more convenient use, as well as depending on the operating conditions that are optimized in your production.

Processing polymers is not such a complicated technological process if you have the space, specialists and a plastic shredder. Thanks to the correct adherence to the technological process, in a minimum amount of time, you can clean up a large pile of garbage and obtain a new product necessary for the production of plastic goods.

• Where is a plastic shredder used?

  The main customers of the solid waste shredder are small and large enterprises specializing in the manufacture of plastic products, companies that collect waste for the purpose of subsequent disposal, and enterprises whose activities are related to the production of plastic products.

  The process of processing used plastic and rejecting it using high-quality equipment guarantees the following advantages:

  • high productivity of granules of a certain size and shape;
  • reducing the cost of the resulting product;
  • increasing the number of sales;
  • saving costs on purchasing parts;
  • quick profit generation;
  • achieving financial independence.

  To realize your dream and develop your plastic recycling business, all that’s left is to buy a plastic shredder. We invite you to learn more about how to find us and what you need to do this.

• How to choose a shredder for LDPE?

  Choosing a high quality product is easy. To do this, you can get advice from our specialist or fill out an online application on the company’s official website. By specifying contact details, equipment requirements, managers as much as possible short time will select the unit required quality. There are several types of shredders on the market. Knowing the final purpose of the installation and the preliminary loading parameters, our specialists will never make mistakes.

Plastic recycling – one of the freest niches in Russia for doing business.

However, the issue of opening it most often depends on the cost of the equipment.

Entrepreneurs often start not with a full processing cycle with finished granulate at the output, but with the collection and grinding of polymer waste.

Even in this case, purchasing a shredder and (or) crusher may not be affordable. One of the most discussed solutions to the problem is self-production chopper

Such projects are quite feasible if two “constant quantities” are known - raw materials and product.

Both types of equipment perform the same task - crushing.

When processing plastics This process is usually divided into two stages:

• coarse grinding - shredders are used for this;
• obtaining fine crumbs - a crusher is used for this.

The operating principle and kinematics of both units are most often the same, and they differ only in some details, for example, the size of the sieve cell, the overlap of the knives and the configuration of the cutting edges.

The process is divided into two stages to improve productivity and optimization of energy costs.

Shredder design for plastics

When choosing the design of a plastic shredder, you should pay attention to the proposals of equipment manufacturers.

It is better to take other people’s work as a basis for a project and have certain guidelines than to reinvent the wheel and end up with a non-working model.

The most popular are single- and double-shaft rotary shredders.

Single-shaft

Single shaft shredders are used for initial shredding most types of polymers.

It consists of a rotor on which movable knives (2) are fixed and a housing with fixed or stator knives (1). The raw materials are fed through the loading window from above, and the finished crumbs are poured under their own weight through the calibrating sieve (3).

The shredding process involves repeated cutting and continues until all the plastic has gone into the receiving hopper.

Rotary knives configuration selected depending on the material being processed:

1. Dovetail and slanted– for recycling and other soft waste.
2. Direct– for crushing sprues, boxes, thick-walled blow moldings, PET bottles. Such knives are often made in the form of separate segments, which are arranged in cascades. Segmentation is performed to reduce shock loads on the drive, reduce noise and vibration.

Stator knives for single-shaft polymer crushers are made solid (type P).

Twin-shaft

The rotor and stator knives on such crushers are arranged in a checkerboard pattern, and the shafts rotate in counter directions.

Low productivity machines with a small working chamber are carried out with single drive, the teeth on the rotary knives serve to capture and crush waste.

Grinding is also performed on the side surfaces (as in disc shears).

Where can I get the drawings?

You need to understand that manufacturers of equipment for shredders and crushers won't post it blueprints in the public domain.

The easiest way is to get the diagrams homemade shredder or crushers in two ways:

1. Read forums on the topic, like this. The likelihood of finding accurate and detailed drawings of plastic shredders is very low. Often, resource users recycle some unclaimed equipment from a related industry, for example, a lopper. And if a crusher is made from scratch, few people care about documenting all stages of production. However, it is worth reading the forums: analysis of discussions and other people's mistakes design will help you make a more advanced plastic shredder with your own hands.
2. Take measurements from the existing one chopper Get full information It won’t work, because the owner won’t let you disassemble a running machine. But in making your own homemade crusher Even a visual assessment will help.

Many attempts to make a crusher on their own come to a standstill because the designer tries snap to an existing node. For example, “fit” all the elements to a worm gearbox found in the garage.

An attempt to reduce the cost of a design using secondary parts, as a rule, leads to mistakes.

Initial data for design

It is better to start production with a clear definition of the tasks of the shredder, that is, you need to know the type and quantity of raw materials being processed, and the size of the output fraction.

After this, we find a model from any well-known manufacturer that fits these parameters and take its technical characteristics:

• engine power;
• loading window dimensions;
• number and diameter of rotors;
• knife configuration.

Drafting

For example, we determined that under production tasks A twin-shaft shredder with low rotor speed is suitable.

His project necessarily includes:

• engine selection by power;
• calculation of gear ratio and selection of factory model;
• determination of the diameter and length of the rotors (based on the size of the loading window);
• calculation of shafts for strength;
• selection of bearing supports.

You will need a tutorial for this.“Machine parts” for universities. You will also have to look at GOST standards for threaded connections, reference books on gearboxes, bearings, couplings and other assembly units.

When using hardware foreign production often inconsistencies arise standardization, for example, “their” retaining rings are thicker than “ours” with equal diameters.

This must be taken into account when assigning groove dimensions.

After calculations it is necessary arrange the components on graph paper or in an editor like AutoCAD, determine the dimensions of the body parts and the frame.

You need to approach this task responsibly so as not to miss anything. Sometimes the protruding head of an “unaccounted for” bolt leads to the car has to be rebuilt. After this, detailing is done - a drawing of each part separately.

Drive design

In factory crushing plants, two methods are used to transmit rotation from the motor to the gearbox:

1. Direct drive(via coupling). Torque transmission occurs without loss, the design is compact in size. If you manage to select a ready-made geared motor, the dimensions and weight of the installation will be even smaller. However, in this case, it is necessary to provide for manual (and ideally automatic) reversing in case of jamming of the rotors.
2. Belting. Efficiency losses and relatively high dimensions are compensated by the smooth start of the mechanism. If the shredder becomes jammed, the only risk is that the belt will break or slip.

The transmission of rotation between the rotors (in the case of using one engine) is most often carried out through an open gear drive. When designing, you need to be prepared to calculate it. More likely, gears will have to be ordered.

Knives

Finding a suitable knife configuration is not difficult.

Many manufacturers make no secret of this.

Anyone interested in the question can choose the appropriate profile and change the dimensions for your rotor, make the required number of teeth.

Knives will also have to be ordered from a company engaged in waterjet, plasma or laser cutting. Afterwards you will have to grind them to the same size along the plane.

The above also applies to fixed knives. Only for them you still have to think about how to attach them to the body.

Most often, counterknives are drilled with two through holes on the sidewalls and tightened with pins through spacer bushings.

Another pair of blind holes with threads are made on the side of the body for fastening to it with bolts.

Another important question– material. This can be one of the spring (65G, 60S2, 65S2VA) or die (X12MF) steels. Anyway will have to order also literate heat treatment with control of the hardness of each finished knife.

Shafts

The standard blade mounting configuration for most manufacturers is hexagon. That is, a blank for the shaft can serve rolled profile, the ends of which are machined for bearings, gears, etc.

The optimal choice is steel 40, 45, 40X with improvement (hardening + high tempering).

Bearing units

You can use ready-made bearing units of a self-aligning design.

They “forgive” errors in the alignment of the holes, in which conventional radial bearings will warp and overheat.

However, compared to conventional bearings the cost of such units is much higher.

In addition, the dimensions of their housings often do not allow maintaining the required center-to-axle distance between the rotors.

To avoid misalignment, the sidewalls of the crusher body are used as axle boxes. The mounting holes are bored in a machine with a four-jaw spindle, placing the parts together.

If it is not possible to make a housing with coaxial holes, you can select double-row spherical bearings suitable for load-carrying capacity.

Rotors

One of the main requirements for rotors is the presence guaranteed clearance between the sides of the knives. Otherwise they will rub together, the mechanism may even jam.

The width of the spacer bushings should be larger. They also need to be sanded to the same size.

Particular attention should be paid to axial adjustment.

The design of the shafts must include the possibility displace the entire set of knives and bushings to tenths of a millimeter and reliably fix it when the side gap is uniform.

Most often, threaded parts are made on the shafts, and the position of the knives is fixed with nuts.

Assembly of finished units

For the design to be repairable, the body should not be welded.

It is better to make a bolted connection.

Then chopper can be taken apart at any time for sharpening or replacing knives.

One of the common problems with rotating mechanisms is increased vibration.

To avoid this phenomenon, it is necessary to align the actuator, gearbox and motor, i.e., align their axes.

Another reason for vibration is imbalance(imbalance) rotors. To eliminate it, you need to carry out balancing.

Useful video

We invite you to watch a video on how to implement the idea of ​​a plastic recycling business using homemade equipment:

Conclusion

Were considered not all the difficulties, which will have to be encountered in the process of designing and assembling a plastic shredder.

Manufacturing can only be called independent, since it requires a whole fleet of machines, and some units have to be purchased assembled. All the process may take months, and financial investments will be required in any case.

After developing the project “on paper” worth calculating economic efficiency Events: sum up the costs of procurement and processing, and then compare with the price of a “factory” shredder.

Those who have already had experience in manufacturing shredders believe that the idea is justified in two cases: if there are no strict time restrictions or if it is planned to establish serial production of such units. For practical plastic recycling tasks, it is usually It’s easier to choose a ready-made model.

In contact with