Summary for polymer bonding Discussion
Polymer bonding in this thread centers on which thermoplastic bonds best to itself and what methods work. Brian asked whether ABS, polypropylene, or high-density polyethylene is easiest to bond and requested techniques and adhesives. The reply explains that ABS and the polyolefins (polypropylene and HDPE) behave very differently. According to the answerer, polypropylene and HDPE can be heat-fused successfully, and large HDPE pipe joints are commonly made that way, but they cannot be cemented together. Polypropylene can be heat fused like HDPE, but it cannot be fused to HDPE. ABS is described as the only one of the three that can be butt-cemented successfully, though the answerer says it takes a trick to do it well. Methyl ethyl ketone is identified as the only successful solvent for ABS, and a heavy ABS cement can be made for repairs. The answer also notes that all three can be welded, but ABS weld rod is uncommon.
Q. Which of the three following thermoplastics listed below has the best ability to be bonded to itself?
ABS, polypropylene, high density polyethylene
Please recommend some techniques and adhesives for performing this process.
Brian
– Houston, Texas
2000
Hi Brian,
Firstly, one should know exactly what you have in mind, i.e., the end use, the size … after all, you are ‘talking’ about 2 entirely different plastics, ABS and the Polyolefins. They behave differently
!
The Polyolefins … they can be fused together with great success
(pressure pipe joints now to 60″ dia in hdPe are joined this way). They cannot be cemented together. PP can be heat fused just like HDPE but you CANNOT interfuse PP to HDPE.
ABS … Possibly the only useful plastic that can be butt cemented together. For the ABS mine line fittings up to 12″ dia., all mitered joints were ‘cemented’ together. But there is a trick to doing this and making a successful bond. But
methyl ethyl ketone ⇦ on
eBay or
Amazon [affil link]
is, as far as I know, the only successful solvent for ABS. Unlike PVC, you can make a very successful ABS ultra heavy cement for patching holes in such things as ABS dingies, etc.
All of these plastics can be welded to each other but ABS weld rod is rather rare in the true chemical field as there are better acid/alkali resistant plastics such as PVC.
I hope this short summary helps you. Cheers !
Freeman Newton [deceased]
R.I.P. old friend (It is our sad duty to
advise that Freeman passed away 4/21/12)