Thank you for contacting 3M for your bonding and adhesives needs. I am guessing this is a one time need and would suggest you go to your local home store or order online an aerosol can of Spray 90 as this would be a very good option. It will have very good bond strength to both of your substrates. I would also suggest beforehand you do a little test with the HDPE because there different forms of this and it may bond well. Also make sure both of your substrates are clean and dry before bonding them.
Please do not hesitate to contact us if you have additional questions.