This Technical Bulletin reviews the general operating parameters common to EnviroStrip® wheat starch media applications. EnviroStrip media is a highly reliable and efficient coating removal technology, when proper process guidelines - combined with appropriate safety precautions - are used.
Extensive production experience has shown that a broad particle size range in the working media mix is essential for optimum performance of EnviroStrip. Media replenishment (adding new media to the production mix) can be done manually by the operator, or blast equipment can be designed to automatically replenish at regular intervals. In order to optimize performance, it is recommended that new media be fed into the production mix often and in small amounts.
For applications on metal surfaces, a media mix comprising 12 through 100 mesh (U.S. Std.) in size is recommended.
For applications on composite surfaces, a media mix comprising 30 through 100 mesh (U.S. Std) in size is recommended.
EnviroStrip wheat starch media is available in three standard mesh sizes. Product Data Sheets for each media mesh size are available:
- EnviroStrip Plus: This media is ground to a broad particle size range and is recommended for start-up and production purposes. This media is the fastest stripping material out of the drum and provides good recycle life. It can be used on both aluminum and composite substrates.
- EnviroStrip 12/30: This media is intended as media replenishment for a production mix or systems already using EnviroStrip Plus. The EnviroStrip 12/30 mix requires several cycles of use before it reaches its maximum stripping performance. Used primarily for aluminum alloy stripping applications, it offers the longest recycle life.
- EnviroStrip 30/50: This media is intended as media replenishment for a production mix or systems already using EnviroStrip Plus. It is used for composite stripping and adhesive de-flash applications.
EnviroStrip wheat starch media is preferably used in specially designed equipment, or any light abrasive blasting system (e.g. plastic media) fitted with appropriate modifications. Dry stripping with wheat starch media is performed in hand cabinets, blast rooms and full-scale (hangar) aircraft de-paint operations. ADM can assist you in specifying equipment.
Contaminants from Coatings Removed
The paint or coating material being removed may contain hazardous ingredients such as chromium, lead, or cadmium metals. Since such contaminants become part of the starch media dust waste, this dust waste material may be hazardous to personnel and the environment.
Users should investigate and fully understand the applicable safety regulations and environmental laws concerning dust contamination and exposure. User personnel and the working environment should be protected with the appropriate personnel protection and engineering controls.
ADM has issued several studies that report the ignition properties and explosibility data of EnviroStrip wheat starch media (e.g. ADM/ CANMET reports, parts I & II). These studies show that EnviroStrip wheat starch media, when purchased in 12/30, 30/50 or Plus sizes, is not explosible. These products cannot be ignited. It is only the dust produced from the breakdown of these products after blasting (material at a size less than 120 mesh size US Std. or < 0.125 mm) that is ignitable at a given concentration in the presence of a high energy source.
The overall conclusion, based on a hazard assessment performed by independent research laboratories (Woodward Clyde Company and Chilworth Technology Inc), clearly shows that EnviroStrip wheat starch media and its corresponding dust is less hazardous than that of Type V plastic media. Thus the equipment recommendations used for light abrasives such as plastic media are more than sufficient for the starch media dry stripping process.
Technical reports on the ignition characteristics of EnviroStrip wheat starch media can be obtained from ADM upon request.
The information contained herein is correct to the best of our knowledge. The recommendations or suggestions contained in this bulletin are made without guarantee or representation as to results. We suggest that you evaluate these recommendations and suggestions in your own laboratory prior to use. Our responsibility for claims arising from breach of warranty, negligence, or otherwise is limited to the purchase price of the material. Freedom to use any patent owned by ADM or others is not be to inferred for any statement contained herein.