Browse Prior Art Database

Method for Preventing Carrier Bead Sticking During Cure

IP.com Disclosure Number: IPCOM000089795D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Toxen, AM: AUTHOR [+2]

Abstract

This article describes an improved process for producing carrier beads having a cured coating.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 89% of the total text.

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Method for Preventing Carrier Bead Sticking During Cure

This article describes an improved process for producing carrier beads having a cured coating.

Prior processes are known for producing a carrier bead having a cured coating over a particulate material core. In some cases the carrier beads stick together during the curing operation, and damage to the coating can occur during separation. This damage may alter the triboelectric characteristics of the carrier beads and/or limit the useful life of the carrier beads.

The improved process comprises the steps of coating the particulate material, dry tumbling the uncured particulate material with a small amount of finely divided powder material which is chemically inert with respect to the coating system so that the particulate material does not material, dry tumbling the uncured particulate material with a small amount of finely divided powder material which is chemically inert with respect to the coating system so that the particulate material does not stick together during the curing cycle, curing the coating, and removing the powder material from the coated particulate material.

A specific process, in which steel beads serve as the particulate material, comprises the steps of coating the beads with TEFLON*, dry tumbling the fresh- coated beads with about 1/2 to 1% by weight of Al(2)O(3) of 0.05 micron size, curing the beads, and sifting the beads to remove the excess Al(2)O(3). These beads exhibit substantially u...