I have to agree. I do chemical cleaning in my resist stripper. We have to use EDPM rollers at the entrance and exit. Even then we have to change these out every 2500 hours. We have two sets so we can have one set out to be recoated. Chuck Brummer, ACUSON Joe, Boy do I know how you feel. I had this problem in a former (job) life. The original rollers were polypro which leaches in acid solutions, like peroxide sulfuric. We had to go to EPDM rollers, I think, in the acid and acid rinse modules to get away from this. It took months to figure this one out. My suggestion is get with the equipment supplier and get a material which would not leach out in an acid environment. If your equipment supplier cannot answer this, check with your process chemistry supplier for an answer. Good luck. Dave Sullivan Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: FAB: chemical-clean roller marks Author: [log in to unmask] at ccmgw1 Date: 12/4/96 3:59 PM This sounds like an easy one, but it's got us in a quandary. The process is traditional peroxide-sulfuric chemical clean for innerlayer cores prior to cut-sheet-lam (including a phosphoric-based acid cleaner/chromate remover). The equipment is a new, horizontal conveyorized line (wetted materials are: polypro, PVC, CPVC, EPDM, 304ss, 316ss and...). The problem: conveyor rollers leave visible "tracks" on the layers which subsequently fail water-break test within 2 seconds on a clean coupon. The original roller material was 'santoprene' - a neoprene/polypro hybrid. Other mold trials from the manufacturer have produced samples made of PVC (soft vinyl), hypalon and rigid polypro, all of which leave marks to varying degrees. We have tried various lab-scale leaching procedures on each of the new roller material samples: 10% sulfuric (no effect), 15-20% NaOH (leached out an oily residue - a plasticizer, we're guessing), toluene (no effect), 50% sulfuric (basically complete destruction) - all samples still produced tracks. Even after grinding a wheel down about a millimeter, the residue persisted. In the past, I have only seen previously used horizontal equipment retrofitted for use as chemical clean lines with resulting matte pink, uniform layers. Is it possible that in those cases, the wheels were already 'broken in' after years of use elsewhere? If we enter into production, will the marks eventually (gulp) disappear? Are we being too finicky? Has anyone encountered and overcome a similar situation on a new chem-clean process with new equipment? Responses from equipment gurus out there is certainly welcome... J Felts, PC World, Toronto [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** Received: from by ccmgw1.cacd.rockwell.com (SMTPLINK V2.11) ; Wed, 04 Dec 96 15:59:16 cst Return-Path: <[log in to unmask]> Received: from stealth.cacd.rockwell.com (stealth) by mailserv with ESMTP (1.39.111.2/16.2) id AA175356761; Wed, 4 Dec 1996 15:59:21 -0600 Received: by stealth.cacd.rockwell.com; id PAA08081; Wed, 4 Dec 1996 15:58:41 -0600 Received: from ipc.org(168.113.24.64) by stealth via smap (V3.1.1) id xma008073; Wed, 4 Dec 96 15:58:35 -0600 Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) id PAA17091; Wed, 4 Dec 1996 15:51:03 -0800 Resent-Date: Wed, 4 Dec 1996 15:51:03 -0800 Received: by ipc.org (Smail3.1.28.1 #2) id m0vVOdI-0000WFC; Wed, 4 Dec 96 15:13 CST Resent-Sender: [log in to unmask] Old-Return-Path: <[log in to unmask]> Date: Wed, 04 Dec 96 15:50:40 EST From: "joef" <[log in to unmask]> Message-Id: <[log in to unmask]> To: [log in to unmask] Subject: FAB: chemical-clean roller marks Resent-Message-Id: <"wYMXh2.0.v3Q.rbUfo"@ipc> Resent-From: [log in to unmask] X-Mailing-List: <[log in to unmask]> archive/latest/8246 X-Loop: [log in to unmask] Precedence: list Resent-Sender: [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************