More than 90% of the valve used in North America is by precision (precision), seaquist and summit three valve factory production, the rest is mainly some special valves, they are produced by such as Newm~-Grean and bespak company, Beardg, Emson, Riker company and Coster companies. For example, a valve Newman company production can in two to three different speed on injection products, as long as the valve nozzle go to different rates of scale can be. And as independent bespak production 20mn] metered dose inhaler (MDD valve and can be used for such as self-defense aerosol products injection rate at 100 g / S valve.
1993, the 7 valve manufacturers to produce a total of 3308000000 valves, several other manufacturers did not report their output, the actual total amount of estimated up to 33. 5 - 34.o billion. Due to the valve production so much. So the formula designers can choose to a variety of high quality and low cost valves. In 1993, they ordered 300 million valves sample, used for scientific research or small batch production. Usually each batch production of thousands of products.
A variety of valve alarming in many aspects of basic types, the change of pore size (nozzle, valve stem, valve body and side hole), the choice of engineering plastics (polyacrylic acid, polyamide, polyethylene and polypropylene, inner gasket selection (class) Ding Jing rubber, styrene butadiene rubber, chloroprene rubber, butyl rubber, chlorine butyl rubber and chloroprene rubber), Australia (with chloroprene rubber gasket, gasket cutting, gluing polyethylene gasket, polyethylene, polypropylene and PET coated). Removal of different diameter, the diameter of the sprayer has the most shape, area, lenticular jet. Different tangent vortex cavity, cone and so on, the stem may be a single aperture, may also be varied. Many years ago, a valve experts estimate that his company can theoretically make 6000000000 changes in the valve, of course does not include changes in Straw length.
Because of a particular product can have several types of valves, so the formula designer first choice is to supplier and valve type, if time permits, we should select two suppliers, it ended on the manufacturing side and buy side is good. With many designers will be able to check that by carefully evaluation of the current retail market competing products or similar products by the use of the valve, so as to be able to use other advantages for the development of laboratory. Early formula had faced on the inclined push type valve and vertical reciprocating valve selection, two kinds of valves have their respective advantages and disadvantages, such as a directional side inclined push type valve well, the vertical (up and down) direction is not good; on the other hand, compared with the vertical movement of small buttons, inclined push type valve allows the user not be sprayed out of the finger tip assembly extracts. Both the two characteristics of the ideal way is to use a large nozzle or nozzles dome, although it will increase the cost, and the stem to the diameter of the tail hole distance increase, some ejection agent with low content of products appear obvious hysteresis effect.
The usual aerosol products are all spray type, so the spray type is an important feature of the sprayer. A good injection process in the whole temperature range (e.g. 12 to 32~C) in the maintained normal. Spray mist type is determined by measuring cone diameter and uniformity, from the nozzle to the spray distance from 152 to 304 mm, if spray cans marked the jet distance appropriate range, it is best to use the midpoint as detection using distance.
Detected by a variety of instruments, such as root detector. This is a with bottle shaped hole g (the rotation of the disk, but commonly used simple method is the nozzle alignment a piece of paper or other surface and at a fixed distance from the injection. For containing products of ethanol can be used for ethanol sensitive detection of paper, can also be in the product does not contain alcohol adding trace (O.5% ethanol for re testing. Some formulations division like to join the red Dyterl (DuPont products) or a small amount of other pigments to draw the outline of a jet shape, some laboratories are required to stem the alcohol sensitivity test paper or dye color to the detection of paper and stick it in the left side of the each page of this record.
Although there are few aerosol product is directly on the target surface vertical downwards jet, but of spray fog detection mostly used in this way, so as to get the shape than the horizontal jet to the circle, but with the actual situation. Horizontal jet is considered large, sometimes speed slower particles of gravity, often forming oval or flat teardrop shape, especially when compared to the long-range jet is even more so. Usually, detection should avoid injection excess.
Injection is also connected, and when the size of testing should be recorded jet shape in the horizontal direction and the vertical direction according to the size of a circle or elliptic, the scope of internal contains approximately 96% of the ejecta. Any deviation from the injection or part of the ejecta beyond the scope should be record, nozzle hole of a drop shaped or fibrous remnants should also be documented. Injection of more than a few seconds. These problems will seriously affect the spray pattern, sometimes clot is sprayed onto the target surface. Due to the jet cone diameter is usually measured in after a short injection were detected, so after a long time after the results should be detected well recorded down.
Mechanical break (MB and MBU) nozzle is used to relatively thick coarse ejecta into finer particles, are often not round and uniform cone, unless the product is very good on the pore characteristics of adaptability. A number of Q2 may appear in the middle part of the cone, or in some depressions