摘要:
A foam generating nozzle is provided for converting a liquid containing a gas maintained under pressure in solution in the liquid, to a foam for application to a substrate. Complete foaming of the solution is accomplished prior to discharge from the nozzle. This assures in some applications complete atomization before contact with the substance to be coated.
摘要:
A foam generating nozzle is provided for converting a liquid containing a gas maintained under pressure in solution in the liquid, to a foam for application to a substrate. Complete foaming of the solution is accomplished prior to discharge from the nozzle. This assures in some applications complete atomization before contact with the substance to be coated.
摘要:
A nozzle assembly adapted with an adhesive spray gun for forming a liquid adhesive/gas solution into a foam includes a nozzle formed with a chamber having a rearward end and a forward discharge orifice which is maintained at a pressure less than that required to maintain the gas in solution in the liquid. A turbulence plate having a front surface formed with a notch is mounted to the spray gun such that the notch extends within the rearward end of the chamber. The notch is formed with at least two input ends and a turbulence zone therebetween. The liquid/gas solution is conveyed to each input end of the notch where a separate stream of solution is formed. The streams move along the notch from each input end toward the turbulence zone of the notch where they impact one another within the chamber. Agitation of the liquid/gas solution caused by impacting of the separate streams, in the presence of the reduced pressure within the chamber, results in the partial or initial formation of a homogeneous, closed cell solid foam within the chamber prior to emission from the discharge orifice.
摘要:
A powder spray coating system includes a power source and an electrical supply line connected to the power source. A spray gun sprays powder in a spray pattern onto a part. The spray gun includes an electrode which charges powder as the powder is dispensed from the gun toward the part. The electrode is connected to the electrical supply line. A first current sensing device is located in the electrical supply line measuring gun current between the power source and the electrode. An ion collector or ABI probe is mounted with the gun for collecting free ions produced by the electrode. The collector has a forward portion positioned near the spray pattern and is spaced from the electrode. The collector is connected to a ground line. A second current sensing device is located in the ground line measuring back current between the ion collector and ground. A controller is connected between the power source and the electrode to control the gun current. The controller is also connected to the first and second current sensing devices for controlling the gun current in accordance with the difference between the measured gun current and the back current. By automatically controlling the current between the gun and the part, the present invention controls the field strength and the current between the tip of the gun and the ABI probe, making unnecessary adjustment of the position of the ABI probe in order to maximize the benefits of the probe in situations where the distance between the gun and the part changes.
摘要:
A method and apparatus for dispensing liquid compositions. The apparatus includes a reservoir for containing the liquid at a low temperature, a metering device for transferring the liquid to a circulating loop at a higher temperature, a heater/mixer for coincidentally heating and mixing the liquid in the loop and means for dispensing the liquid from the loop. The invention is particularly useful for dispensing liquid adhesive and coating compositions, including thermosetting polymers, heat sensitive polymers or plastisols and other dispersed liquid systems. In addition, mixtures of polymeric liquids with other components such as gases, solvents or liquid blowing agents may be employed with uniformity of composition for dispensing foams or atomizable paints.
摘要:
Pressure vessels are disclosed for containing a foamable mixture of liquid and a blowing agent for incrementally or continuously dispensing a foam of constant foam-volume ratio. Liquid compositions having coating or polymeric solids are capable of being foamed and dispensed with the apparatus. The method and apparatus are especially advantageous in dispensing foamed coatings, paints or adhesives with superior control.
摘要:
High solids coating methods and apparatus are disclosed which eliminate many of the disadvantages associated with known coating processes. The techniques disclosed require only a minor amount of a volatile solvent to achieve atomization and application of a paint or other coating material. High solids coating compositions containing about 70-99% by weight solids are atomized and coated. This method also enables polymeric compositions having high molecular weight to be employed as coating materials. According to techniques described, liquid compositions containing film-forming solids are kept under pressure with a minor amount of a highly volatile solvent of from about 1 to 30% by weight, even as low as about 1-10% by weight, at a temperature above the normal boiling point of the solvent. Such a composition is then atomized by releasing the pressure upon a stream of the composition at a temperature above the normal boiling point of the solvent and below the minimum foam temperature at atmospheric pressure for the composition. The film-forming solids are thus conveyed with or without an external atomizing means.
摘要:
Method and apparatus for coating the interior and bottom surfaces of food and beverage cans which require protection against contact with the food or beverage content of the cans. The interior surface is sprayed with a high solids content liquid spray emitted from a pair of nozzles, one of which sprays the lower portion of the cylindrical side wall as well as the outer portion of the bottom wall and the other of which sprays the top portion of the cylindrical wall and the innermost center section of the bottom wall.
摘要:
A diaphragm assembly includes a pair of superposed flexible diaphragms adhesively secured to an annular spacer ring. The space between the diaphragms and the interior of the rings is filled preferably with de-ionized water. The resistivity of the water is monitored to detect conductivity changes upon leakage or diaphragm rupture when pumped materials or pump lubricant mix with the water. Diaphragm assembly and rupture detection methods are disclosed.