Abstract: A device for ascertaining the corrosiveness of a plastic melt, including a housing having a cavity to be filled with plastic melt; a first electrode made of a first material and a second electrode made of a second material, the first electrode and the second electrode each having a contact surface toward the cavity, the standard potential of the first material being higher than that of the second material, and the first electrode and second electrode additionally being connectable to each other via a measuring element for determining an electric current and/or an electric voltage between the contact surfaces.

Abstract: The present invention provides a heating unit capable of easily and inexpensively adjusting total impedance based on tire mold size so that a power source can be used at a high power factor, and a tire heating apparatus using the same. A ferromagnetic metallic member 10a heats a tire mold M1 by heat conduction. An induction heating coil C1 is disposed on the side of the ferromagnetic metallic member 10a opposite the tire mold M1 to induction-heat the ferromagnetic metallic member 10a by generating magnetic field lines. A nonmagnetic conductor 30a is disposed on the side of the induction heating coil C1 opposite the ferromagnetic metallic member 10a to shield the magnetic field lines generated by the induction heating coil C1. A heating unit 100a including these elements heats the tire mold M1 storing a tire.

Abstract: A loose mixture formed of one or more solid inert materials and a hardenable resin dissolved in an organic solvent, in particular the remainder of the initial mix used for the manufacture of conglomerate stone sheets, is rendered inert by means of dielectric heating at a frequency of less than 300 MHz. A plant for implements a method where a loose mixture is formed of one or more solid inert materials and a hardenable resin dissolved in an organic solvent, in particular the remainder of the initial mix used for the manufacture of conglomerate stone sheets, is rendered inert by means of dielectric heating at a frequency of less than 300 MHz.

Abstract: A tube apparatus is provided to detect successful or failed tube operations. The tube apparatus includes jaws mounted for movement with respect to one another between (1) a first position spaced from one another and (2) a second position selected to perform a successful tube operation. A sensor is positioned to detect when the jaws have moved into the second position, and a timer is electrically coupled to the sensor for determining the time delay before the jaws have moved into the second position, wherein a time delay up to a predetermined time limit indicates a successful tube operation and a time delay exceeding the predetermined limit indicates a failed tube operation.

Abstract: FIG. 1 depicts a full view of the picnic table backrest. It shows the backrest, the bars that wrap around the bench to keep the back rest stable and the latch on the back of the rest that keeps the rest from slipping out. FIG. 2 shows a close up view of the latch on the rear of the backrest. The bar that holds the latch swivels upward to latch on to the top part of the backrest. This keeps the backrest from slipping out and also holds it in place so it doesn't shift while your sitting.

Abstract: A dielectric tube sealer is provided with first and second jaws oriented along a jaw axis and positioned to receive a tube portion in a space therebetween. The first jaw is fixed and is coupled to a radio frequency generator. The second jaw is movable with respect to the first jaw along the jaw and is coupled to ground potential. The second jaw is mounted on a single shaft. At least a portion of the shaft extends along a shaft axis that is substantially parallel to, but spaced from, the jaw axis.

Abstract: A desk top sealer includes three compartments for housing a solenoid assembly, a power supply and a circuit board, respectively. A source of air flow flows into an initial compartment and is channeled through apertures in brackets forming the two remaining compartments for cooling purposes and is exhausted from each compartment through a base. The circuit board, upon actuation, provides RF energy to a fixed ceramic/metal jaw to heat and weld plastic tubing clamped to the fixed jaw by a movable jaw at ground potential. The movable jaw is guided during translation by a pair of rods extending from a face plate, which rods also prevent rotation of the movable jaw about its axis of translation to maintain the movable jaw in alignment with the fixed jaw. The movable jaw is relatively massive to serve as a heat sink for the heat of the tubing being welded and includes a substantial surface area to dissipate to the ambient environment any heat buildup that may occur.

Abstract: A fixture for use with a radio-frequency welding press includes an independent electrode that is not attached to a platen of the press and which is used to register directly on flexible material workpieces to locate and hold workpieces during a welding operation. The invention also includes shuttles that slidably move welding fixtures to respective positions beneath and laterally away from press platens so that welding and workpiece removal and loading operations can be performed simultaneously on fixtures mounted to respective shuttles. Methods and alternate embodiments are disclosed.

Abstract: In odd-numbered current-supplying periods of a plurality of current-supplying periods constituting a gross current-supplying time, a control unit 42 allows continuous switching actions of only a first set of switching elements at an inverter frequency, with a second set of switching elements remaining OFF. In even-numbered current-supplying periods, the control unit 42 allows continuous switching actions of only the second set of switching elements at the inverter frequency, with the first set of switching elements (24, 28) remaining OFF. As a result of this, a secondary circuit of the power supply apparatus allows a secondary current i2, namely a fusing current I having a substantially trapezoidal current waveform to flow in a positive direction in the odd-numbered current-supplying periods, and to flow in a negative direction in the even-numbered current-supplying periods.

Abstract: A method of preheating a polymer plate by dielectric heating by applying a radio frequency voltage to a laminate in the direction of its lamination through electrodes; a method of producing a laminate, comprising dielectric heating a polymer plate by applying a radio frequency voltage to a laminate in the direction of its lamination through electrodes in a state where the laminate is housed in an annular container encompassing the surfaces of the laminates, and pressing the laminate in the direction of its lamination at least after completion of the application of the radio frequency voltage; and an apparatus for producing the laminate.

Abstract: A prepackaged food sterilizing apparatus for sterilizing a prepackaged food P has a high frequency generator 71. A high frequency is supplied from the high frequency generator 71 to the prepackaged food P to sterilize the prepackaged food P by dielectric heating. The apparatus includes a food loading container 2x constituted by a pair of opposing electrodes 20 consisting of a lower electrode 210 and an upper electrode 220 to which the high frequency is supplied and an annular insulator 23 interposed between the opposing electrode pair 20. The food loading container 2x has at least one food loading chamber 21 in which the prepackaged food P is loaded with an inner shape thereof substantially equal to an outer shape of the prepackaged food P.

Abstract: A heating apparatus for heating a prepackaged food, is provided with a heater which heats a prepackaged food, an enclosure which defines an airtight chamber operable to accommodate the prepackaged food, and a pressure controller which controls the inside pressure of the airtight chamber. The heater includes a pair of electrodes which are arranged face to face, and an electric power source which supplies a high frequency electric power. The inside pressure of the airtight chamber is controlled in response to an expansion of the prepackaged food being heated to prevent the packaging container from breaking out.

Abstract: A novel dielectric heater including a RF source having a first impedance, a parallel plate mold having a second impedance, and an impedance network, matching the first impedance to the second impedance, connected to the RF source and the parallel plate mold. The impedance network may be connected in series with the RF source and the parallel plate mold. The RF source may include a RF terminal and a common terminal, the impedance network may include a first terminal, connected to the RF terminal, and a second terminal, and the parallel plate mold may include a first plate, connected to the second terminal of the impedance network, and a second plate, connected to the common terminal of the RF source. In an alternative embodiment the novel dielectric heater includes parallel plates divided into a number of series-connected cells. The series cells lower the capacitive component, and may be configured such that an impedance of the parallel plate mold approximates an impedance of the RF source.

Abstract: Radio frequency power for melting, sealing and welding plastic tubing compressed between a pair of manually or automatically actuated electrically conducting jaws of a hand held or fixed base tubing sealer is regulated by a pulse width modulator controlling the duty cycle of applied constant voltage pulses. A predetermined change of impedance of the tubing during compression and melting is detected to regulate the power applied and to ensure a weld of predetermined physical parameters. On completion of the weld, a first timer is reset and a further weld may be made. In the event of impedance mismatch, a second timer inhibits further application of power and resetting of the first timer. The use of the pulse width modulator enhances conservation of power and accommodates portability of the tubing sealer through use of rechargeable batteries as the power source.

Abstract: Method and apparatus employing radio frequency electric energy for heat sealing of laminated packaging materials, particularly aseptic packaging materials, that include facing contiguous layers of thermoplastic material, including first and second seal jaws having respective working surfaces. The working surface of the first seal jaw is defined by a plurality of working faces of alternating layers of electrically conductive and electrically nonconductive materials.

Abstract: Process for automatic connection, at the moment of pressing, between a source (26) of electric current and the metal parts (35), connected in series, of the piles (30) of packages (31) for making plastic laminates to permit electric endothermic heating, there being placed in the pressing machines (10), at those parts which will come in contact with the ends (36,37) of the pile (30), metal contact sheets (20,21) connected to the source (26) of electric current.

Abstract: A method of forming a raised image of preselected pattern onto the surface of a fabric material by first laminating a thin film of vinyl onto the surface of the fabric and underlying the fabric with a thin layer of vinyl. A heated die of the image to be formed is then caused to be impressed in a highly forced engagement against the laminated film, while RF energy is applied to the die platen for a controlled time period. The die and image are permitted to cool in place after which the die is removed and any extraneous vinyl particles permeated during the heated engagement can be easily brushed from the fabric surface while the image pattern remains.

Abstract: The invention relates to an apparatus for the generation of smoothness in paper. The paper (1) is thereby supplied to the rolls (2) of the smoothing mechanism with a moisture distribution which is characterized in that the moisture content in the inner layers of the paper is substantially smaller or at least as large as in the outer layers. This can be achieved with the aid of a dielectric paper web heating device (3) which is positioned in front of the rolls (2) of the smoothing mechanism. Through the invention less energy is to be required for the same smoothness values and a lower reduction in volume is to take place.

Abstract: An insulating sleeve retains heat in the plastic of a flexible plastic medical tube when the plastic of the medical tube is dielectrically heated by a radio frequency tubing sealer. The heat retained by the insulating sleeve permits additional melting of the plastic of the medical tube after a seal has been formed. The additional melting results in forming an easily tearable web between the segments of the medical tube in the same operation as the sealing operation. The medical tube is selectively sealed without forming the easily tearable web by using the radio frequency tubing sealer without the insulating sleeve.

Abstract: A process for obtaining long, continuous, thermoplastic welds on large structures. A series of tabs are used in pairs and especially in alternating, overlapping pairs to obtain resistance heating of a strip material placed in the bond line. The resistance of the tabs is less than that of the strip material. Conducting braid-tubes afford continuous welding when the bond line is curved. Alternatively, an electromagnetic field is used to take advantage of the induction heating. A wide susceptor is used to weld a current conducting substrate while avoiding bulk heating of the substrate. The unexpected property of current-conducting braid-tube susceptors, in which induction heating takes place at the center rather than at the edges of a flattened braid-tube susceptor, is used to obtain long continuous curved welds.