FIELD OF THE INVENTION

The invention relates to a method as defined in the preamble of claim 1 for utilizing waste energy in connection with the manufacture of a paperboard product .

BACKGROUND OF THE INVENTION

Different kinds of methods and tools are known in the prior art for manufacturing and shaping paperboard products from paperboard.

It is known that the manufacture of paper- board products produces waste energy, e.g. dissipated thermal energy. Waste energy may be produced during breaking of a drive motor which is part of the manu ^¬ facturing line. The energy being produced can be conveyed to a brake resistor, dissipating the energy as waste heat.

OBJECTIVE OF THE INVENTION

The objective of the invention is to disclose a novel method for utilizing waste energy.

DESCRIPTION OF THE INVENTION

The method according to the invention is characterized by the features set out in the claims.

The invention is based on a method for uti ^¬ lizing waste energy. In the method, waste energy pro ^¬ duced during braking of at least one drive motor which is part of a paperboard product manufacturing line is recovered, and the waste energy is used for heating in connection with the manufacture of the paperboard product . In this connection, waste energy is intended to mean any waste energy which is produced during braking of a drive motor. Preferably, the waste energy is thermal energy.

Typically, the energy produced during braking of a drive motor is conveyed to a brake resistor which dissipates the energy as heat, producing waste energy. In the present invention, this waste energy is utilized in heating, e.g. in the heating of a tool of a paper- board product manufacturing line.

A paperboard product manufacturing line is in ^¬ tended to mean, in this connection, any manufacturing line for forming and/or shaping a paperboard product. The paperboard product manufacturing line comprises one or more drive motors. The paperboard product manufactur ^¬ ing line comprises one or more tools for manufacturing the paperboard product. The paperboard product is formed by means of at least one or more tools on the paperboard product manufacturing line. The tool may have been se ^¬ lected from the group of a die cutting tool, a cutting tool, a creasing tool, a shaping tool, a finishing tool and their combinations. The tool is used, e.g. driven, by means of at least one drive motor on the manufactur ^¬ ing line. Shaping the paperboard material into a product is important in terms of formation of the paperboard product, and it is preferably done by means of a shaping tool .

A paperboard product is intended to mean, in this connection, any paperboard product which is formed from any paperboard. The paperboard may have been formed from any fibre-based source material, such as wood-based or plant-based source material or fibre-based composite source material or combinations thereof. The source material may be material formed from so-called fresh raw material, such as wood- or plant-based material, pulp, fibres or the like, or alternatively recycled material, such as pulp, fibres or the like, or their combinations. In one embodiment, paperboard is a paper product formed from several fibre-based plies. In one embodiment, pa ^¬ perboard is a thick paper product formed from one fibre- based ply or sheet-type material. Paperboard may be any paperboard, cardboard or other such thick paper which may have a grammage of 170 to 600 g/m ² .

In one embodiment, the waste energy is used in heating a tool or part of a tool of the paperboard product manufacturing line. In one embodiment, the waste energy is used in preheating a tool or part of a tool of the paperboard product manufacturing line. In one embodiment, the waste energy is used in heating a shaping tool or part of it. In one embodiment, the waste energy is used in heating a female tool element of the shaping tool.

In this connection, a tool is intended to mean any tool or part of it. As the tool it is possi ^¬ ble to use any tool known per se or part of it. In one embodiment, the tool is a shaping tool, a die cutting tool or other suitable tool for use in the shaping of a paperboard product. In one embodiment, the tool is a forming tool or a shaping tool. In one embodiment, the paperboard material is shaped by means of a shaping tool which comprises a female tool element and a male tool element, of which tool elements one is moved rel ^¬ ative to the other tool element. Preferably, the tool comprises at least one heating means for heating the tool or part of it.

In this connection, shaping of the paperboard product is intended to mean any shaping, processing, forming or pressing to shape or their combinations for providing the shape of the paperboard product, preferably by means of a shaping tool.

In one embodiment, the waste energy is used in preheating a paperboard web. In one embodiment, the drive motor is selected from the group of a drive motor producing the force for die cutting the paperboard product, a drive motor pro ^¬ ducing the force for forming the paperboard product and their combinations. In one embodiment, the drive motor is a drive motor producing the force for die cutting the paperboard product. In one embodiment, the drive motor is a drive motor producing the force for forming the paperboard product.

In one embodiment, the waste energy is utilized in connection with a tool heating means, e.g. on a heat ^¬ ing resistor.

In one embodiment, the brake resistor of the drive motor being used is a heating resistor of a heat- ing means of a tool, preferably a shaping tool. The waste energy is recovered by means of the heating resis ^¬ tor. In one embodiment, the heating resistor contains thermally conductive material, e.g. liquid, wax-type or other suitable heat-retaining material. In one embodi- ment, the heating resistor is disposed in a suitable space in connection with the heating means, e.g. in the oil space of the heating means.

In one embodiment, temperature adjustment is controlled by means of a control device in connection with heating the tool. In one embodiment, temperature adjustment is controlled by means of a thermostat in connection with heating the tool. In one embodiment, ex ^¬ cess heating energy is conveyed to a secondary brake re ^¬ sistor .

In one embodiment, the method according to the invention can be used in connection with a modular paperboard product manufacturing line. A modular pa ^¬ perboard product manufacturing line comprises different tool modules which are connectable to the manufac- turing line. Preferably, the modular manufacturing line comprises more than one tool module. Each work stage may have been arranged at a different module, or more than one work stages may have been combined at the same module. The work stages of the modules may have been selected from the group of die cutting, such as creasing or cutting, shaping, such as forming or form-pressing, or other suitable work stage or their combinations. In one embodiment, the modular manufac ^¬ turing line comprises a tool module provided with a shaping tool. The number of tool modules may vary de- pending on the paperboard product being manufactured. The tool modules are preferably arranged one behind another on the modular paperboard product manufacturing line. Preferably, different tool modules are ar ^¬ ranged in a suitable order considering the manufacture of the paperboard product. In one embodiment, the tool module is connected to the frame of the modular paper- board product manufacturing line, e.g. by means of guides or by means of tracks arranged in connection with the frame. In one embodiment, the tool module is moveable on the modular paperboard product manufactur ^¬ ing line. In one embodiment, the tool module is inde ^¬ pendently replaceable on the modular paperboard prod ^¬ uct manufacturing line. Preferably, the tool modules are arranged at such distance from each other as their function requires, and the distance between the tool modules can be changed. By changing the distances be ^¬ tween the modules it is possible to minimize the amount of waste material. The paperboard material is preferably fed in the form of a web to the manufactur- ing line and through the tool modules connected there ^¬ to. Preferably, each tool module can be operated inde ^¬ pendently, but the feeding of paperboard material through the manufacturing line is controlled as a whole. The paperboard material can be passed through the tool module without the module performing its work stage. In one embodiment, the electrification of the modules is arranged in such a way that each module is provided with independent electrification and, in ad ^¬ dition, current supply and the necessary bus system (ethercat) of the modular manufacturing line are ar- ranged in a common electrical system of the line. Preferably, the frame structure of the modular manu ^¬ facturing line is arranged as a unit which can be moved as one piece, e.g. in a transportation contain ^¬ er .

The method according to the invention may be utilized in connection with the manufacture of any pa- perboard product or in connection with any paperboard product manufacturing line. In one embodiment, the pa ^¬ perboard product is selected from the group of trays, dishes, containers, suchlike products and different combinations thereof. In addition, the method accord ^¬ ing to the invention may be utilized on a modular pa ^¬ perboard product manufacturing line.

By means of the invention it is possible to recover and utilize waste energy produced in connec ^¬ tion with drive motors. By means of the invention, the waste energy can be used for heating a shaping tool or part of it, such as a mould, whereby additional heat is not needed in the shaping, or is only needed to a small extent.

The method according to the invention may be implemented in industrial processes, such as on a pa ^¬ perboard product manufacturing line, easily and cost- effectively.

LIST OF FIGURES

Fig. 1 illustrates one embodiment of the in ^¬ vention for utilizing waste energy in heating. EXAMPLE S

The invention will now be described in detail by way of examples of its embodiments with reference to the accompanying figure.

Example 1

The waste energy produced during braking of a drive motor which is part of a modular paperboard product manufacturing line is recovered. The recovered waste energy is utilized for heating in connection with the manufacture of the paperboard product by us ^¬ ing the waste energy in heating a tool of the paper- board product manufacturing line, e.g. a shaping tool, or part of it.

The brake resistor of the drive motor being used is a heating resistor of a heating means of the tool, preferably a shaping tool. The heating resistor contains thermally conductive material, e.g. liquid, wax-type or other suitable thermally conductive materi ^¬ al. Fig. 1 illustrates one embodiment of the heating resistor which can be utilized in the method according to the invention. The heating resistor (1) is disposed in an oil space (2) of the heating means (3) .

Example 2

The waste energy produced during braking of a drive motor which is part of a modular paperboard product manufacturing line is recovered. The recovered waste energy is utilized for heating in connection with the manufacture of the paperboard product by us ^¬ ing the waste energy in preheating a tool of the pa ^¬ perboard product manufacturing line e.g. a shaping tool, or part of it.

As a brake resistor of the drive motor it is possible to use the embodiment of a heating resistor il- lustrated in Fig. 1 or other suitable embodiment of a resistor .

Example 3

The waste energy produced during braking of a drive motor which is part of a modular paperboard product manufacturing line is recovered. The recovered waste energy is utilized for heating in connection with the manufacture of the paperboard product by us- ing the waste energy in preheating a paperboard web before the paperboard web is conveyed to the paper- board product manufacturing line, or alternatively up ^¬ stream of a predetermined tool or process step.

As a brake resistor of the drive motor it is possible to use the embodiment of a heating resistor il ^¬ lustrated in Fig. 1 or other suitable embodiment of a resistor .

The method according to the invention is suitable, as various embodiments, for use in connec ^¬ tion with the manufacture of various paperboard prod ^¬ ucts and paperboard product manufacturing lines.

The invention is not exclusively limited to the above examples, but many variations are possible within the scope of the inventive idea defined by the claims .