Traditional technology for the production of electrical resistances with bare wire exposed to the air, obsolete because of the low efficiency and difficult to miniaturization, in addition to the lack of flexibility, reliability and safety.
SPIRAL-shaped resistive wire
The first technology for the manufacture of bare wire resistors exposed to the air to enable miniaturization and the resulting increase in power.
The easy availability of machines for the production of spirals, it has facilitated the spread, shifting production (especially for the consumer market) in countries where labor is less expensive. Many professional applications still make extensive use of this technology because of its flexibility, strength and solid experience. The disadvantages of this technology: the difficulty of industrialization / automation, limits in miniaturization and weight reduction, low quality consistency linked to labor.
WAVE-shaped resistive wire
It is the most current technology for the manufacture of resistors bare wire exposed to the air. The methods to give the wavy shape to the wire are varied, and there is not a common practice to all producers.
A technology now well established (Traditional Wave) allows a very limited aspect ratio h / p = 0.6 to 0.8 with consequent difficulty of miniaturization.
comparison of waves with different ratios of the form
High Wave technology, exclusive property of Gamma, allows to widen the field of work getting very high aspect ratios (up to h / p max = 2.5) universally considered excellent and to date unequaled. In addition to the above characteristic, a High Wave Technology resistor turns out to be, when compared to a similar (Spiral or Traditional Wave-shaped) resistor, easier and safer, as well as difficult to counterfeit.
The wave technology is well suited to the industrialization and automation; in this way, disengaging itself from the variables related to labor, can provide an excellent consistency in the quality of the product.
More and more business applications are converging on this technology, confirming that factors such as innovation, quality, quantity and diversity are fundamental to making the product unique.
Wire wound on insulating supports
For some applications, the resistive wire is wound on an insulating support which can be:
Lamellae micanite – when heat is transferred by contact
Support of glass or silicon – when the heat exchange by convection
The winding on the micanite lamina is then covered with layers of mica insulating material whose thickness ensures a proper electrical insulation while ensuring the proper heat exchange. Very important during this phase is the verification of the dielectric strength and the quality of the materials used, in order to ensure a perfect stability in time.
Wrapping on traditional profile / on high conicity profile
The profile of the resistance is strongly influenced by the profile of the duct and the final design of the equipment.
The tapered shape of many hairdryer, requires resistance with a high conicity profile. While the spiral technology easily adapts to any shape and size, the wave technology requires a high form factor and very sophisticated wrapping machines with numerical control.
Gamma has the best technology to wrap any form with results qualitatively irrefutable, having developed over the years many patents and dedicated equipments.
The air flow within many hairdryer has the maximum speed in the area close to the walls: a typical example is that with radial turbine.
In these devices, traditionally the resistive wire is positioned at the point of greatest air flow getting maximum heat transfer possible. Looking at the temperature trend in output can be observed that a certain amount of air outgoing centrally is not heated.
Based on these considerations, to be able to heat evenly all the air available, Gamma has developed patents and configurations with resistive wires positioned on surfaces coaxial, for impressive results.
Result not secondary, high energy saving: all the air handled is properly heated and then, at the same power, a hairdryer with coax heating technology allows the hair drying and styling in less time than a hairdryer with traditional technology (with obvious reduction in energy consumption).
Environment sensibility and Energy Saving in hairdryers
In this historic moment, in which it is growing sensibility for environment and energy saving, the challenge for the reduction of consumption of a hairdryer is not easy: on the one hand the small waste of current is hardly perfectible (only 2 % of the energy is wasted in heating the body of the appliance); on the other hand, the margins for improvement associated with the use of poorly performing Joule effect are very wide, but the solutions are still not very practicable.
The roads Gamma is driving are:
the improvement of the heat exchange (see our .: coaxial technology, which allows to have, at the same power, superior performance compared to traditional technologies)
the choice of materials, favoring the use of certified materials
miniaturization, with the consequent reduction of the material used and its environmental footprint
Ions and Cosmetics
More and more frequently, end users believe that the hair, dried in the presence of negative ions, is more soft and antistatic. Others suggest the presence of tourmaline or ceramic in the unit.
Gamma provides optimized solutions for device integration ionizers, tourmaline and ceramic into the device.
Integrated engine management: partialization of speed, Turbo mode, integration of electrical components
Through the integration of sub-circuits dedicated to the engine Gamma is able to offer additional features to meet the most demanding needs:
Managing multiple speed / mode for AC motors Universal
Easy connection for easy mounting for DC motors
Areas of USE
Resistors for SPECIAL applications The large amount of technology developed by Gamma in heating (air – by convection and radiation, fluids and solids – by conduction), together with the great experience accumulated in over forty years, have created significant impact on neighbouring application areas.
Resistors for HAND dryers In these devices the functioning is ensured by the combined effect of the heat and high air velocity.
The heating elements (with wave-shaped/spiral-shaped resistive wires) are the real heart of the device, from which descend all the final features. Here we create innovation and performance.
Resistors for HOOD dryers In the hood dryer, styling occurs through the gradual drying of the hair subjected to hot air, or for the combined effect of the hot air and infrared irradiation produced by the heating element.
The heating resistances are obtained by winding the resistive wire on suitable insulating supports, or through the insertion (in a controlled atmosphere) of a resistance in a spiral quartz tube, jointly responsible for the infrared emission.
Resistors for MANGLES and IRONS In irons and mangles, ironing plate and the boiler are heated by conduction.
The heating resistors are using the technology resistive wire wound on micanite. The windings are then covered with an insulating layer of mica whose thickness ensures a proper electrical insulation while ensuring the proper heat exchange.
Resistors for TOASTERS The heating of the bread in the toaster occurs by convection and radiation. The heating resistors are using the technology resistive wire wound on micanite. The windings are then covered with an insulating layer of mica whose thickness ensures a proper electrical insulation while ensuring the proper heat exchange. In some applications, to encourage heating by radiation, we prefer a covering layer in pure transparent mica.
Resistors for Professional and Retail HAIRDRYERS In both Professional and Retail field, a constant evolution has transformed the hairdryer in a highly refined tool, with extreme characteristics and multiple functionalities. Resistances are no longer asked simply to heat the air, we ask for more power (from 800W we have gone to over 2000W), lower weight (reduced to one-third) and smaller overall dimensions (halved).
Gamma, always been first actor of this evolution, has the ability to adapt the resistance to the needs of design and ergonomics, optimizing the different construction technologies (wave, spiral, wire wound) on the different configurations (traditional profile, high conicity profile, coaxial) and implementing additional features (devices for producing negative ions, cosmetics, integration of electrical components, integrated engine management, speed partialization, Turbo mode), all in accordance with the directives and standards (IEC, UL, CSA).
The high accuracy of our processes ensures a careful choice of materials (FDA certifications for food and for emissions UNI CEI, NF F, DIN, CEN) and an exact calibration of the quantities (= less weight) with the result of a lower environmental impact and of a reduction of CO2.