Solvent bonding thermoplastics with cyclohexanone mixture
Solvent bonding thermoplastics with cyclohexanone mixture
(OP)
We routinely bond PVC tubing to thermoplastic components using solvent. We use primarily cyclohexanone and dichloromethane. We have been experiencing some issues with cracking when bonding PVC tubing to polycarbonate components. We have identified that the cyclohexanone is the chemical which is causing the issues as it relieves molded in stress from the plastic part. Cyclohexanone is used in the mixture as a lubricant to allow the plastic tubing to be easily inserted into the plastic part. This assembly is done manually.
I am wondering if anyone can provide some help identifying another solvent that could take the place of the cyclohexanone in our mixture.
I am wondering if anyone can provide some help identifying another solvent that could take the place of the cyclohexanone in our mixture.





RE: Solvent bonding thermoplastics with cyclohexanone mixture
See htt
RE: Solvent bonding thermoplastics with cyclohexanone mixture
From memory both recommend dichloromethane. I think acetone is also suitable.Acetone certainly works with PVC.
PC is exceptionally bad to aromatic hydrocarbons and most chlorinated hydrocarbons.
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: Solvent bonding thermoplastics with cyclohexanone mixture
If I read right, you add the cyclohexanone as a lubricant. Could you use a water-based lubricant? That would have the best chance to work and not ruin the PC. Try for example polyethyleneglycol in water or other water-based lubricant.
Chris DeArmitt PhD FRSC CChem
RE: Solvent bonding thermoplastics with cyclohexanone mixture
Could you please expand a bit? What grade of PC are you using? And are you flexible PVC tubing? DEHP? DEHP-Free? if so which plasticizer does your tubing has?
RE: Solvent bonding thermoplastics with cyclohexanone mixture
We are using Bayer's RX1805 Medical grade PC with flexible DEHP PVC tubing. I am checking on the plasticizer. It is a material sourced from Poly One and extruded at Colorite.
RE: Solvent bonding thermoplastics with cyclohexanone mixture
RE: Solvent bonding thermoplastics with cyclohexanone mixture
When bonding two dissimilar materials you will probably get much poorer adhesion strength. The reason is that dissimilar polymers do not mix on a molecular level 99 times out of 100. So the chains will not mix and entangle with each other across the bond.
Chris DeArmitt
Plastic Training Webinars since 2003
visit: www.plastictraining.com
RE: Solvent bonding thermoplastics with cyclohexanone mixture