Fuse manufacture

As described above, industrial fuses, mainly Bickford, which are modified for firework use have become popular recently in Japan. But a few manufacturers produce fuses by hand by the old method or for special use as in dark fuses. 

The processes were described in Lancaster s book on page 247-249. 

By this process the moisture or solvent contained in raw materials, compositions and half finished pieces is driven out. The most important problem is the drying of compositions which have been shaped into stars, particularly those pasted in more than one layer. 

The ultraviolet rays in sunshine generally cause chemical degeneration of materials. Dr.Osada studied this problem in firework materials(see.13.1). However in practice there is no chance of such long exposure of these materials in the sun as there was in Dr.Osada s experiment, and perhaps it is not necessary to worry unduly about this kind of degeneration in ultraviolet light. The fact remains however that direct sunshine is not good chemically for various materials. 

The degree of rise in the temperature during drying in the sunshine depends mainly on the sun s intensity, but it is affected also by the colour or the nature of the surface of the dried pieces. Fig.73 shows examples on a clear day in midsummer in Tokyo. According to the curves the available maximum temperature is 66°C for the black stars and 59°C with the silver stars. The temperature of the stars rises to the maximum at noon. This time is earlier than that of the maximum room temperature which occurs at 1 3 o clock. (On some days the maximum temperature of the stars occurred at 11 o clock.) Until about 2 o clock the temperature of the black stars is higher than that of the silver stars, but after that time the position reverses so that the silver stars are higher. 

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Fuse manufacturers catalogues give suggested fuse sizes for all 415 V motors. However, the following parameters all affect the fuse rating ... 

Counter. In fuse manufacture, to wind on textile yams in a direction opposite to a previous spinning process. 

These are not to be confused with Bickford fuse or safety fuse manufactured by the same company, which consists of a central thread surrounded by a core of black powder enclosed within a tube of woven threads, surrounded by various layers of textile, waterproof material, sheathing, etc. This is miner s fuse, and is everywhere known as Bickford fuse after the Englishman who invented the machine by which such fuse was first woven. The most common variety bums with a velocity of about 1 foot per minute. When the fire reaches its end, a spurt of flame about an inch long shoots out for igniting black powder or for firing a blasting cap. 

Excipient Calcium stearate (Fused) Manufacturer Witco Corporation Voltage 15 kV... 

Fuse manufacturers will usually offer advice on the most appropriate fuses to be used in a particular installation. 

It should be noted that when the melting time exceeds about 0.1 sec the corresponding arcing time is less than 0.01 sec. Therefore for times above 0.1 sec it may be assumed that the melting or pre-arcing time is in fact the clearance time. The fuse manufacturers normally give curves for the... 

A fuse manufacturer replaced a 30 min epoxy used in a heat cure process to assemble stainless steel inserts into phenolic holders. By utilizing an aerobic adhesive bonding process, the assembly was complete in 30 s at room temperature. The resulting increase in productivity more than offset the higher adhesive cost. A cyanoacrylate bonding process was even faster, but did not resist aging in a moist atmospheric environment or pass a drop test for impact resistance. 

It occurs in many natural glycosides. It can be prepared by fusing resorcinol with NaOH and is manufactured from trinitrotoluene via trinitrobenzoic acid and triaminobenzene. 

Cera.micA.bla.tors, Several types of subliming or melting ceramic ablators have been used or considered for use in dielectric appHcations particularly with quartz or boron nitride [10043-11 -5] fiber reinforcements to form a nonconductive char. Fused siHca is available in both nonporous (optically transparent) and porous (sHp cast) forms. Ford Aerospace manufactures a 3D siHca-fiber-reinforced composite densified with coUoidal siHca (37). The material, designated AS-3DX, demonstrates improved mechanical toughness compared to monolithic ceramics. Other dielectric ceramic composites have been used with performance improvements over monolithic ceramics (see COMPOSITE MATERIALS, CERAMIC MATRIX). 

The abrasive industry is highly competitive and many small companies worldwide successfully compete by specializing in a particular segment of the business, eg, disk wheels, mounted points, and mbber wheels. Costs in the fused abrasive industry are primarily in materials and electric power. Thus manufacturers seek out plant sites having the lowest power costs. Costs for coated abrasive manufacturers are capital and labor intensive and they seek out sources of low cost labor. 

Generally, soluble materials are more effective as micronutrient sources than are insoluble ones. For this reason, many soil minerals that contain the micronutrient elements are ineffective sources for plants. Some principal micronutrient sources and uses are summarized below. In this discussion the term frits refers to a fused, pulverized siUceous material manufactured and marketed commercially for incorporation in fertilizers. Chelates refers to metaHoorganic complexes specially prepared and marketed as especially soluble, highly assimilable sources of micronutrient elements (see CHELATING agents). 

There are two principal PVC resins for producing vinyl foams suspension resin and dispersion resin. The suspension resin is prepared by suspension polymerization with a relatively large particle size in the 30—250 p.m range and the dispersion resin is prepared by emulsion polymerization with a fine particle size in the 0.2—2 p.m range (245). The latter is used in the manufacture of vinyl plastisols which can be fused without the appHcation of pressure. In addition, plastisol blending resins, which are fine particle size suspension resins, can be used as a partial replacement for the dispersion resin in a plastisol system to reduce the resin costs. 

Other Food. Tartaric acid is also used ia the manufacture of gelatin (qv) desserts and ia fmit jellies, especially ia pectin jellies for candies where a low pH is necessary for proper setting. It is used as a starch modifier ia starch jelly candies so that the product flows freely while being cast. It is used ia hard candy because its melting poiat permits it to fuse iato the "glass" and does not contribute to moisture. 

Hard-burned magnesias may be used in a variety of appHcations such as ceramics (qv), animal feed supplements, acid neutralization, wastewater treatment, leather (qv) tanning, magnesium phosphate cements, magnesium compound manufacturing, fertilizer, or as a raw material for fused magnesia. A patented process has introduced this material as a cation adsorbent for metals removal in wastewater treatment (132). 

Laminates. Laminate manufacture involves the impregnation of a web with a Hquid phenoHc resin in a dip-coating operation. Solvent type, resin concentration, and viscosity determine the degree of fiber penetration. The treated web is dried in an oven and the resin cures, sometimes to the B-stage (semicured). Final resin content is between 30 and 70%. The dry sheet is cut and stacked, ready for lamination. In the curing step, multilayers of laminate are stacked or laid up in a press and cured at 150—175°C for several hours. The resins are generally low molecular weight resoles, which have been neutralized with the salt removed. Common carrier solvents for the varnish include acetone, alcohol, and toluene. Alkylated phenols such as cresols improve flexibiUty and moisture resistance in the fused products. 

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