OVERVIEW

General operating parameters common to EnviroStrip® wheat starch media applications are reviewed in this Technical Bulletin. EnviroStrip® media is a highly reliable and efficient coating removal technology, when proper process guidelines - combined with appropriate safety precautions - are used. It is currently used by major aerospace organizations worldwide.

MEDIA MANAGEMENT

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 the blast equipment can be designed to automatically replenish at regular intervals. In order to optimise 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 3 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 cutting material out of the drum and provides good recycle life. It can be used on both aluminium 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 cutting performance. Used primarily for aluminium 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 deflash applications.

PROCESS EQUIPMENT

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 depaint operations. ADM/Ogilvie can assist you in specifying equipment.

SAFETY PRECAUTIONS

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.

Explosibility Data

ADM/Ogilvie has issued several studies that report the ignition properties and explosibility data of EnviroStrip® wheat starch media (e.g. ADM/Ogilvie 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/Ogilvie 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.

TBWS-VER/09/01

Select ADM Biobased Media Series

EnviroStrip®
 (wheat starch)

EnviroStrip® XL
 (corn hybrid polymer)

eStrip ® GPX
 (starch-g-acrylic)