Fiberglass prevention

Lubricant for fiberglass prevents needle cutting polypropylene emulsion stable in resin baths,... 

Figures 7.8(a) and (b) display piloted ignition results for a metalized polyvinyl fluoride (MPVF) film of 0.2 mm thickness over a 25 mm fiberglass batting [14]. The MPVF film was bonded to a shear glass scrim (with no adhesive or significant thickness increase) to prevent it from stretching and ripping. The unbounded MPVF film was also tested. This shows several features that confirm the theory and also indicate issues.

As an example, styrene polymerizes at ordinary temperatures and the rate of polymerization increases as temperature increases. The reaction is exothermic and becomes violent as it is accelerated by its own heat. Inhibitors are added to prevent the initiation of dangerous polymerization. When the styrene is used to fabricate materials, e.g., fiberglass resin, a catalyst may be added in the manufacturing process to initiate polymerization at a controlled rate. Any unbalance of these reactions in terms of quantities or temperatures could cause hazardous fire conditions. 

Methanol tanks can be made from stainless steel, carbon steel, or fiberglass (using resins compatible with methanol). The steel tanks are welded together while the fiberglass tanks are molded around a form with the ends glued on. Some steel tanks are coated internally with an epoxy to prevent corrosion over time. The epoxies made for gasoline are not compatible with methanol and will come off the walls of the tank within a short time, causing major problems with... 

If a mechanical mixer is used, a "Zippy" style head (such as used in the fiberglass industry) has been found suitable. The speed of mixing is important, and the formation of a vortex must be prevented. Care must be taken with this style of mixer that air is not whipped in. If necessary, the mixture can be degassed for a short period at this time. 

The storage and transfer of raw chemicals requires special considerations relative to the equipment that come into contact with epoxy resins. Carbon steel is generally satisfactory for pipe and tank construction and will not rust beneath the epoxy resin. Rust occuring above the level of the epoxy and accidentally introduced into the resin may be removed by filters. Epoxy coated steel pipe, aluminum or stainless steel pipe, or epoxy fiberglass composite tubing is used to prevent rusting downstream of the filter. 

The emission measurements during this testing included N0X, smoke, particulate and PNA. N0X was determined by a non-disper-sive infrared analyzer, and smoke by the Bacharach test. Both the particulates and PNA were sampled by a source assessment sampling system (SASS). The SASS system isokinetically samples a fraction of the stack gas and traps particulates in a series of cyclones, which classify the particulate by size. Final filtration is through a fiberglass filter mounted in an oven heated to 200°C to prevent condensation of acids. In this program, the cyclones were not used, since previous work (3) had shown the particulate from coal-derived fuel oils to be small, with an average diameter on the order of 0.4 /um. The PNA which is not deposited on the particulate is collected on XAD-2 resin after the gas has been cooled to 15-20°C. PNA analyses were carried out on a combined extract from the particulate, XAD-2 resin, other condensates in the system, and the solvent rinses used to clean the SASS system. 

Finally, the humid, tropical Johnston Island climate corroded parts of the JACADS building and equipment. For example, exterior steel support beams, pipes, and pipe supports rusted and required frequent repainting, and some pipe supports had to be replaced. Also, corrosion caused significant deterioration of exterior valves, instrumentation, and electrical function boxes. Army officials stated that, because they had underestimated how corrosive the environment would be on Johnston Island, they had not initially used appropriate corrosion protection materials. To correct the corrosion problems, the Army now uses corrosion-resistant paints and fiberglass equipment covers. Also, the Army hired additional maintenance personnel to perform preventive maintenance work on the building areas and equipment most susceptible to corrosion. 

Guides to Pollution Prevention The Fiberglass-Reinforced and Composite Plastics Industry... 

There are two main types of barriers depth and screen. A depth filter retains particles both on its surface and within its matrix. Figure 37-6, p. 433, shows a depth filter made of fiberglass bonded with acrylic resin to prevent pieces from getting into the filtrate. Depth filters have a random matrix of fibers. The pore structure is irregular so they retain a variety of particle sizes. These filters are given a nominal rating, and they will retain 98% of all particles larger than that size. 

The distillation column should be well insulated to prevent loss of heat and to protect against bums. Two to three inches of fiberglass blanket insulation is good. On columns located outdoors because of size and safety, the insulation blanket will shield the column from increased heat loss due to wind currents. Exposed insulation blanket may require weather shielding to maintain its performance. 

---