Abstract: In a microwave heating apparatus, the fundamental TE10 mode of the standard waveguide (5) having a standard rectangular cross-section is fed into an elongated heating cavity (2) having an enlarged rectangular cross-section in which the shorter side of the standard waveguide is enlarged to a length which can accommodate the desired width of a board (8) to be heated. A pair of lateral slots (25) is provided parallel in the opposite enlarged walls (11) of the heating cavity (2) to form a track for the board (8) to travel across the cavity. As the initially longer sidewall (11) of the standard waveguide is unchanged, the fundamental mode is not affected but the electric field is uniformly distributed along the width of the board (8) traversing the electric field and the cavity. As a result, wider products can be heated and a more uniform heating pattern can be achieved.

Abstract: The invention relates to a microwave waveguide element for matching a standard waveguide input port to an enlarged waveguide output port. In the waveguide element, a plurality of intermediate waveguide segments is cascaded in the propagation direction of the microwave energy to first split the waveguide element into two symmetrical waveguide branches and then combine the branches at the output port. Thus, the width of the waveguide element is gradually enlarged and the input port is matched to the output port. The intermediate waveguide segments are preferably dimensioned such that respective characteristic impedances are approximately matched with each other for the fundamental mode.

Abstract: The invention relates to squeeze pressing of a laid-up veneer assembly having glue applied as glue stripes. The pressing in the method is subjected to the assembly as two uniform fronts advancing in opposite directions from the central area of the assembly. A press for implementing the method comprises press plates to be pressed together, at least one press plate being equipped with a sub-pressing plate extending as an arch at the central area of the press plate to the press opening.

Abstract: The invention relates to a microwave waveguide element for matching a standard waveguide input port (31) to an enlarged waveguide output port (37). In the waveguide element, a plurality of intermediate waveguide segments (B-E) is cascaded in the propagation direction of the microwave energy to first split the waveguide element into two symmetrical waveguide branches (34,36:34?,36?) and then combine the branches at the output port (37). Thus, the width of the waveguide element is gradually enlarged and the input port is matched to the output port. The intermediate waveguide segments are preferably dimensioned such that respective characteristic impedances are approximately matched with each other for the fundamental mode.

Abstract: In a microwave heating apparatus, the fundamental TE10 mode of the standard waveguide (5) having a standard rectangular cross-section is fed into an elongated heating cavity (2) having an enlarged rectangular cross-section in which the shorter side of the standard waveguide is enlarged to a length which can accommodate the desired width of a board (8) to be heated. A pair of lateral slots (25) is provided parallel in the opposite enlarged walls (11) of the heating cavity (2) to form a track for the board (8) to travel across the cavity. As the initially longer sidewall (11) of the standard waveguide is unchanged, the fundamental mode is not affected but the electric field is uniformly distributed along the width of the board (8) traversing the electric field and the cavity. As a result, wider products can be heated and a more uniform heating pattern can be achieved.

Abstract: The invention relates to squeeze pressing of a laid-up veneer assembly having glue applied as glue stripes. The pressing in the method is subjected to the assembly as two uniform fronts advancing in opposite directions from the central area of the assembly. A press for implementing the method comprises press plates to be pressed together, at least one press plate being equipped with a sub-pressing plate extending as an arch at the central area of the press plate to the press opening.

Abstract: A pressing apparatus for continuous pressing of panels, which apparatus consists of two pressure chambers juxtaposed with a vertical clearance. Each of the chambers occupying a platen in a sealed sliding contact to the vertical inner side walls of the chamber. The mutual distance of the platens define the clearance. A transport band is in sliding contact to the platen of each chamber. The chambers are pressurized. The platen edges in contact with the band are provided with a seal having a protrusion directed towards the middle area of the platen, and means are provided to exert and maintain a pressure in the volume defined by the platen, the band and the seal.

Abstract: An apparatus for heating a board product containing glued wood is disclosed. The apparatus includes a heating chamber through which the board product passes. The board product passes through a heating field in the heating chamber provided by means of microwave energy applied perpendicular to the board plane. The clearances between respective side edges of the board and side walls of the heating apparatus are filled by slide pieces made of a material that has a small loss tangent and a low dielectric factor. The slide pieces correct the form of the heating field affecting the board plane.

Abstract: A pressing apparatus for continuous pressing of panels, which apparatus consists of two pressure chambers juxtaposed with a vertical clearance. Each of the chambers occupying a platen in a sealed sliding contact to the vertical inner side walls of the chamber. The mutual distance of the platens define the clearance. A transport band is in sliding contact to the platen of each chamber. The chambers are pressurized. The platen edges in contact with the band are provided with a seal having a protrusion directed towards the middle area of the platen, and means are provided to exert and maintain a pressure in the volume defined by the platen, the band and the seal.

Abstract: The invention concerns an apparatus for heating a board product (1) containing glued wood. The apparatus comprises a heating chamber, through which the board product (1) passes. The board passes through a heating field in the chamber provided by means of microwave energy applied perpendicular to the board plane. The clearance between the both edges of the board (1) in the proceeding direction of the board, and the wall of the heating apparatus (3), respectively, is filled by a slide piece (2, 2?) being made of material having a small loss tangent and a low dielectric factor. Said slide pieces correct the heating field form affecting in the plane of the board.

Abstract: The invention relates to a continuously operating press for pressing planar products. The press comprises facing platens (7, 7′) between which the product (1) to be pressed is passed in order to subject the same to compression. The press further includes slat elements (2, 2′) introduced as a continuous line of adjacent slat elements between the product (1) being pressed and both ones of the press platens (7, 7′) so as to make the slats to travel with the product being pressed and to slide along the press platens, the surface of the slats facing the platens being provided with a tray recess.

Abstract: The invention relates to an apparatus for hot-pressing a planar product in a process using microwave heating. The apparatus comprises a constant-volume, box-like microwave resonant cavity divided into two opposed subcavities by an elongated gap suitable for passing therethrough the product (1) to be heated. The product is guided through the gap by conveyor belts (2, 2′) of microwave-transparent material. The subcavities are delineated from the conveyor passageway gap by parallel walls of microwave-transparent material, each one of them sealed so as to form a wall of its own subcavity. At least one of the subcavities is pressurized, whereby the sealed wall of the pressurized subcavity is designed to yield under the pressure applied into the subcavity in a direction perpendicular to the product (1) to be pressed.

Abstract: The invention relates to an apparatus for hot-pressing a planar product in a process using microwave heating. The apparatus comprises a constant-volume, box-like microwave resonant cavity divided into two opposed subcavities by an elongated gap suitable for passing therethrough the product (1) to be heated. The product is guided through the gap by conveyor belts (2, 2′) of microwave-transparent material. The subcavities are delineated from the conveyor passageway gap by parallel walls of microwave-transparent material, each one of them sealed so as to form a wall of its own subcavity. At least one of the subcavities is pressurized, whereby the sealed wall of the pressurized subcavity is designed to yield under the pressure applied into the subcavity in a direction perpendicular to the product (1) to be pressed.

Abstract: The invention relates to a continuously operating press for pressing planar products. The press comprises facing platens (7, 7′) between which the product (1) to be pressed is passed in order to subject the same to compression. The press further includes slat elements (2, 2′) introduced as a continuous line of adjacent slat elements between the product (1) being pressed and both ones of the press platens (7, 7′) so as to make the slats to travel with the product being pressed and to slide along the press platens, the surface of the slats facing the platens being provided with a tray recess.

Abstract: The invention relates to an apparatus for removing solid material, particularly for removing finely divided solid material created in a filtering process from a pressurized space, the apparatus being provided with members for feeding the treated material to a process taking place in a pressurized space, as well as for removing the products created in said process from the pressurized space. According to the invention, in a discharge station (4,25) connected to the pressurized space (2,22), there are provided discharge apertures (8,28) for the solid material (5,24) to be removed from the pressurized space (2,22). The discharge apertures (8,28) are provided with at least one adjusting member (9,29) in order to adjust (11,31) the quantity of the material located in the discharge station (4,25) and to be removed from the discharge station (4,25).