The present invention applies to the field of waste compacting apparatuses in mechanical type recycling processes. More in detail, the invention relates to a compactor for compacting waste such as plastics, glass or aluminum.

As known, the process of mechanically recycling plastics consists in mechanically processing plastic waste, which, following such a process, become raw material for the production of new objects made of polymeric material. The process of mechanically recycling plastics starts with the step of separate collection by product type or, otherwise, of multi-material collection, in the case of two or more product types, or even of unsorted collection of all waste fractions. Following the collection step, a selection step is performed on the plastic waste from municipal solid waste, such a bottles, flasks and other plastic packaging. A compacting step, a shredding and grinding step, and finally a densification step then follow, ending with a last extrusion step.

The step of compacting the material allows to reduce the volume of the waste if it must be accumulated before being subjected to grinding or sent to different processing systems. Currently, the step of compacting the plastic waste is performed by means of the known compacting mills, the latter consisting of a loading compartment in which two or more rotating rollers are present, provided with a plurality of radial metal tools, which have the purpose of compacting the plastic waste and considerably reducing the volume it occupies.

A first example of known mill is described in European Patent application EP1690596A1 (Franzoi MetalMeccanica Sri), August 16, 2006 (2006-08-16). Such a type of mill is provided with a pair of counter-rotating parallel axis shafts on which a plurality of grinding wheels and a plurality of spacer elements are alternately keyed.

A further type of known compacting mill is disclosed in United States Patent US4009838 (Tashman Philip), March 1 , 1977 (1977-03-01). Such a type of apparatus consists in a compactor for solid waste, such as glass, plastics and metals. Similar to the first type of apparatus, such a compactor comprises a pair of counter-rotating shafts, each having a plurality of pairs of tools alternating with spacer elements. Furthermore, the tools used in such a compactor consist of a central portion and a single lobe which develops radially from said central portion.

The mills of known type for compacting plastic waste have some drawbacks. In particular, when compacting rigid materials, such as plastic bottles provided with their respective closing cap, problems of feeding the plastic waste frequently occur because the compacting rollers cannot "engage" the bottles which tend to escape also because of their rigidity. The aforesaid rigidity occurs because the bottles, by containing air therein and being closed by the closing caps, will .elastically respond to a compressing and compacting action by the revolving rollers.

A further problem of the compacting mills for plastic materials of known type is the impossibility of removing possible paper labels present on the outer surface of the bottles or plastic containers simultaneously with the step of compacting.

The glass recycling process comprises instead a first manual or mechanical picking operation. This is followed by a subsequent step of crushing the waste glass and then a sieving step. The purpose of the picking step is to eliminate large-sized foreign bodies, i.e. fragments of ceramics, porcelain, stones and plastics. Furthermore, magnetic bodies and metal bodies are eliminated using electromagnets or neodymium magnets. Additionally, light bodies, such as paper, aluminum, wood and non-ferrous metal bodies (aluminum, lead, copper) and opaque bodies, are removed by means of a suction process or by means of automatic machines.

The step of crushing the glass waste is performed by means of appropriate crushing mills consisting of at least one pair of crushing discs between which the waste is crushed in order to reduce its volume and subject it to the subsequent processing steps.

Finally, the aluminum recycling process comprises the following steps. A first step of separately collecting and selecting the waste, followed by a first picking step, either manual and/or by means of the bias of an electromagnet, by means of which it is possible to separate mixed metals, cans and ferromagnetic metal bodies, which are subjected to a further check. A suction system collects the aluminum and plastics: appropriate induced current separators make the non- ferrous materials "jump" into specific motorized stores by means of the action of a magnetic field. Finally, the aluminum waste deprived of the totality of polluting waste is subjected to a compacting and pressing step and then bound to be available for the subsequent processes, such as melting, for making new goods.

It is a fundamental object of the present invention to provide a waste compacting apparatus which solves the drawbacks of the waste compacting apparatuses of known type used in the recycling processes, and more in particular provides a highly flexible apparatus which can be used for compacting any type of waste, such as for example plastics, glass and/or aluminum.

In particular, it is the main object of the present invention to provide a compacting apparatus for waste, in particular plastic material waste, such as for example bottles made of "PET", which allows to obtain a volume reduction of the waste either greater than or equal to 80% of the initially occupied volume. It is another object of the present invention to provide a compacting apparatus _, for waste, including plastic material waste, which allows to compact plastic bottles, provided with the respective closing cap, detennining the expulsion of the cap itself following the compaction, with the advantage of obtaining waste of uniform size and shape.

It is another object of the present invention to provide an apparatus for compacting waste, in particular plastic material waste, in which there are no problems related to the step of feeding the plastic waste, and which is capable of firmly "engaging" the bottles provided with the respective closing cap, which otherwise tend to escape the compacting rollers in the apparatuses of known type.

It is another object of the present invention to provide a compacting apparatus for waste, including plastic material waste, which is capable of removing possible paper labels present on the bottles or plastic containers which are subjected to the step of compacting simultaneously with the step of compacting.

It is a further object of the present invention to provide a compacting apparatus for waste, in particular glass waste, in which glass bottles can be crushed using the same compacting tools adopted for compacting the plastic material.

It is a last further object of the present invention to provide a waste compacting apparatus in which aluminum waste can be pressed and compacted using the same compacting tools adopted for compacting plastic and/or glass waste.

These and further objects are achieved by the waste compacting apparatus of the present invention described below, in a preferred non-limiting embodiment of further developments in the scope of the patent, with the aid of the accompanying drawings which show the following figures:

Fig. 1 is an axonometric view of the waste compacting apparatus;

Fig. 2 is an axonometric view of a compacting rotor;

Fig. 3 is a front view of a compacting rotor;

Fig. 4 is a section side view of a compacting rotor;

Fig. 5 is a plan view of a compacting tool;

Fig. 6 is a side sectional view of a first embodiment of the apparatus;

Fig. 7 is a side sectional view of the apparatus of a different embodiment;

Fig. 8 is an axonometric view of a waste compacting apparatus provided with compacting rotors with a single series of compacting tools;

Fig. 9 is an axonometric view of a waste compacting apparatus provided with compacting rotors with a double series of compacting tools. With reference to the accompanying figures, the waste compacting apparatus is indicated by reference number 1 as a whole. The apparatus comprises a compacting chamber 3, which contains at least two parallel axis compacting rotors 4 therein. Furthermore, in order to allow the introduction of the waste to be compacted into the aforesaid chamber and the subsequent extraction following the process, apparatus 1 is provided with means 2 adapted to introduce the waste to be compacted into the compacting chamber 3, and means 9 adapted to extract the waste following the compacting process.

The compacting chamber 3 is delimited by a frame 10 which consists of a plurality of section bars 1 1 , reciprocally assembled by means of welding or mechanical joining, and by a plurality of side closing plates 12 forming the lateral containing sides. One opposite pair, 12a and 12b, of the aforesaid side plates is provided with appropriate housings and thus configured so as to constrain bearings 7, which form the element adapted to constrain and support the compacting rotors 4 to frame 8.

Apparatus 1 comprises means 2 adapted to introduce the waste to be compacted into the compacting compartment 3. With reference to figure 6, means 2, in a fust embodiment, consist of at least one pivoting hatch 14 positioned in raised position with respect to the plane containing the axes of the compacting rotors 4. The waste, such as plastic bottles, glass or cans, can be introduced through the aforesaid, appropriately sized hatch 14. Such a configuration is particularly useful if the compacting apparatus 1 is used for compacting small volumes of waste and if the operation of the apparatus is not of the continuous type. Multiple hatches 14 may be used if introducing multiple bottles simultaneously is desired.

In a different embodiment, means 2 consist of a conveyor belt 15 positioned in raised position with respect to the plane containing the axes of the compacting rotors 4.

Such a configuration is adopted in the case of large volumes of waste to be processed and continuous use of the apparatus, such as in case of use in waste recycling plants. A photocell 16 is included in both configurations of means 2. Such a photocell 16 is operatively connected to the means adapted to move the rotors 21 , in particular to their control unit or control PLC 17, and has the purpose of detecting possible intrusions, either voluntary or not, of bodies different from the waste to be compacted into the compacting chamber 3, and thus inhibiting the rotation of the compacting rotors 4. For example, the use of such a photocell 16 allows to block the operation of the rotors 4 if the limb of a user of apparatus 1 is involuntarily introduced into the compacting chamber 3.

With reference to the accompanying figures, apparatus 1 further comprises means 9 adapted to extract the waste following the compacting process of the compacting chamber 3. In a first embodiment, the means 9 consist of a collection tank 18, which is positioned under the plane containing the compacting rotors 4 and is provided with a weighing element, such as for example an electronic scale 1:9, for weighing the compacted waste contained therein. Such a configuration is useful when it is required to weigh the waste before it is intended for other processes, treatments or is sold compacted.

Following the weighing process by means of the electronic scale 19, the control unit 17 will emit weight-related data by displaying it on monitors or printing it on paper.

In a different embodiment, means 9 consist of a conveyor belt 20 in case of continuous process. In such a configuration, the conveyor belt is arranged under of the plane containing the rotors 4, to allow the waste to fall by gravity and be transported on the aforesaid conveyor belt 20.

With reference to the accompanying figures, the waste is compacted by at least one pair of compacting rotors 4a and 4b. Each compacting rotor 4 consists of a shaft 42 and a plurality of compacting tools 5 and spacer rings 6.

In particular, the compacting tools 5, the shape of which will be described in detail below, are alternately keyed with a plurality of spacer rings 6. So, between each pair of consecutive tools 5 there will be an empty void, the axial distance of which depends on the length of the spacer ring 6. Such an empty void 43 will be occupied by the lobes 51 of the tools 5 belonging to the other compacting rotors 4 during the compacting process. So, the compacting tools 5 of each compacting rotor 4 will be keyed so as to be mutually separated and axially offset with respect to the compacting tools of the other compacting rotor 4. Such a configuration allows the free rotation of the compacting rotors 4, the shafts 42 of which have a center distance which is smaller than the outer diameter of the tools 5 without the compacting tools 5, belonging to the rotors 4a and 4b, entering into mutual contact. In particular, the lobes 51 of each compacting tool 5 may rotate in the volume 43 between two adjacent compacting tools 5 and keyed onto the opposite compacting rotor 4.

Furthermore, the compacting tools 5 are keyed in at least one series 40. With reference to Figure 4, the tools 5 are keyed in three different series 40a, 40b and 40c, the latter being reciprocally rotated by an angle a. The number of the aforesaid series 40 of tools, as the number of the compacting rotors 4, may be different and variable according to the volumes of the compacting apparatus 1.

Finally, shaft 42 is supported by a pair of bearings 7, the latter being engaged with frame 10, and the rotors are rotated by means adapted to move the compacting rotors 21. With reference to figure 2. each compacting rotor comprises at least one series 40 of compacting tools 5. Figure 2 shows a compacting rotor 4 provided with three series of tools 40a, 40b and 40c.

The series of compacting tools 40a, 40b and 40c are keyed so as to be rotated by a keying angle "a". In particular, the compacting tools 5 are provided with a central opening 55 having a square section. Such an opening is complementary to the shape of the section of shaft 42. So, it will be possible to key each compacting tool onto the shaft 42 in a rigid manner.

Due to the shape of the tools 5 and because of the keying of the series 40 at different angles, the waste, such as for example plastic bottles, will be compacted within the concavity 41 created by the series of tools 40b and cannot escape from the aforesaid cavity 41 because blocked by the tools 5 of the adjacent series 40a and 40c.

The angle extension depends on the shape of tool 5, in particular on the number of lobes. In such a configuration, given that each tool 5 is provided with three lobes 51, the offset angle between the series 40a, 40b and 40c is of 60°.

Figure 5 shows a compacting tool 5. Tool 5 consists of a central portion 50 provided with a square-section, through opening 55 for inserting, tool 5 and keying it onto shaft 4, and at least two lobes 51. In the configuration in Figure 5, there are three lobes which develop in radial direction from the central portion 50 and have a characteristic mushroom shape. Such a shape is needed to obtain the concavity 41 in which the waste will be compacted.

Furthermore, each a pair of lobes 51 has the same offset angle. In the case of three lobes

51, the offset angle between each lobe is of 120°.

Furthermore, in order to obtain the removal of paper labels from the bottles, each lobe 51 is provided with a pair of teeth 54b and 54a. The teeth 54a and 54b are positioned at the base 52 of lobe 51 in which the arm 53 ends, which joins lobe 51 to the central portion 50.

. The compacting tools 5 are preferably made of anti-wear steel and have a suitable thickness to ensure the absence of bending and deformations following the compacting process.

With reference to figure 1, the compacting rotors 4 are actuated and rotated by means adapted to move the compacting rotors 21. In a first embodiment, the moving means of the compacting rotors 21 consist of toothed wheels 210, each toothed wheel engages a compacting rotor 4 and the toothed wheels are reciprocally engaged so as to determine the simultaneous rotation of the compacting rotors 4.

The wheels 210 are actuated and rotated by means of a motor 220 of the electric type and a speed reducer 230. Alternatively, the rotation of the rotors 4 may be achieved by means of a motor of the hydraulic or pneumatic type.

Again alternatively, the compacting rotors 4 may be either independent or mechanically connected, but both configurations must be counter-rotating in order to compact the waste. The number of compacting rotors 4 depends on the size of the machine and _. on the working volumes.

The control unit 17 allows to manage the operation of apparatus 1 by means of a PLC. In particular, the control unit 17 manages the operation of the rotors 4, allows to reverse their rotation direction or to manage them autonomously _. and separately, providing different configurations of the rotation direction of the single rotors so as to support heavy material loads and ensure compacting in any condition. Finally, apparatus 1 is arranged for operating in automatic and manual mode.

The production capacity, i.e. the volumes of waste which can be processed by apparatus 1, varies as a function of various parameters, such as: type and size of the incoming waste, power of the motors, and size of the rotors.

Finally, apparatus 1 may be provided with a health or tax card reader in order to associate a specific weighting with a given user of the apparatus.