On the use of a PASSIVE-REACTOR for the Infusion Process wth Phenolic Resin Matrix, composite parts ……..

ABSTRACT: A manufacturing-system for the Infusion-process producing advanced composites with phenolic-resin matrix in which toxic formaldehyde fumes are produced, then are neutralized within the system by the use of a Passive Reactor.

BACKGROUND:

1.Field of Invention ~ The invention described herein relates to the development of an advanced mfg-system for the INFUSION process in the production of phenolic, resin-matrix composites. In the phenol-aldehyde reaction the by-products are water-vapor and some amounts of free-formaldehyde. The ‘formaldehyde’ fumes appear as a colorless gas and are highly toxic. Historically the fumes are vented to atmosphere by industry; this places toxic fumes in the workplace and creates a very un-healthy environment. In the State of California, the CAL/OSHA agency has set a TWA (Time Weighted Average over an 8-Hr day) for free-formaldehyde of 0.75ppm intakewhile the American Conference of Governmental and Industrial Hygienists has lowered it’s stated TWA to 0.3ppm. Little effort has been expended by industry to date, to develop a mfg-system in which formaldehyde fumes are eliminated from the workplace; thus…very little processing of phenolics are employed in the US composites industry at present.

2. Description of Related Art ~ US patent No. 6,362,275 is the most-recent patent which addresses the reduction of formaldehyde fumes. This art claims to ‘somewhat’ reduce fumes produced in the process by the introduction of amino-acids into the reaction. This chemical modification of the reaction is a step in the right direction but falls far-short of reducing the level of toxic gas to a safe level in the workplace. Other patents in recent years have addressed the reduction of such fumes by means of a chemical additive, but to an even lesser-effective level.

SUMMARY OF THE INVENTION:

My approach to the problem of eliminating toxic formaldehyde fumes, produced as a by-product in the phenol-aldehyde reaction lies not in the in-effective method of chemical-additives as with most prior art, but in the direct approach of ‘Capture & Control’ as mandated in pending federal legislation . ( the MACT ACT ) My unique approach is that of incorporating a Passive Reactor which when used with the Phenolic-Infusion process for composites, effects the dual-function of Capture & Control wherein… a) the vacuum-bag forms a hermetic-seal over the part being produced and thus… ‘captures’ all emitted fumes and …….. b) ‘controls’ the fumes by reducing the formaldehyde to yield water-vapor and a small amount of Carbon Dioxide. ( CH2O > CO2 + H2O ) thus leaving a safe workplace. (see schematic animation below)

The fumes are drawn thru the system by means of the in-line vacuum-pump. In this process, the fumes pass thru the Passive Reactor. The unit is loaded with a surface-treated Zonolite, used as the internal flow-media. As the fumes are drawn thru the unit, the media collects the target fumes thru both absorbtion and adsorbtion . When the fumes contact the media, they are chemically reduced. This reaction reduces the free-formaldehyde content to an approximate level of 2 to 3 parts per billion; a level which will not even register on industry scanning-instruments and leaves the workplace entirely safe. This method of ‘Capture and Control’ is far superior to other approaches to the hazard in the workplace.