Adhesive Puzzle: Can You Help?

One of the fun parts of writing for Design News is hearing readers’ requests for help. I got a doozy in a meeting last week. The requirements are listed below. If you have a though, put them in the comments, or write me directly at doug.smock@reedbusiness.com.

This documents the objective, and criteria pertaining to bonding a neoprene product to an aluminum surface whereby once bonding is completed, the product is readily functional.

Objective

The objective is to identify an adhesive system; tape type or film, hot melt, 2-part system, contact cement or a cement in liquid form which will be applied to a neoprene rubber product in a plant environment, and then the product shipped to a customer who will apply the product to aluminum. The product must be operational within 1-3 hours after the bonding process has started. It requires approx one hour to bond the part. The customer may install the product immediately, or it may be in inventory of a period of time.

The aluminum will be cleaned, and can be washed with solvents, or may be wiped with an alodine solution prior to joining. Wipe-on type primers or adhesion enhancers may be applied to the aluminum by the customer as part of the bonding process.

The adhesive must be strippable; parts will be replaced periodically.

The adhesive system, preparation procedures, bonding procedures and storage procedures must be identified. Stripping procedures must be identified.

Any suggested adhesive systems will be evaluated thoroughly.

Description

The adhesive system will be applied to flat neoprene rubber textured surfaces in the plant using determined manufacturing procedures. The adhesive may be covered with a removable liner. The part will be rolled, bagged, and then placed in a box for shipping. The part will be shipped to the customer. The customer may install it one day, or may keep it in inventory for a period of time. The maximum shelf life must be determined. Once the customer installs the part, it must be operational; within an approx 1 –3 hour period from the time the work begins. The adhesive may not be at full strength at that time, but must be at least strong enough to function without failure.

Tie-in layers may be added to the bond side of the product in the plant to allow for adhesive systems not directly compatible with neoprene to be considered.

Operational Conditions

Physical Requirements

            Rolling Peel                           2”/ min                        40 lb/in

            Dynamic Lap Shear              2”/min             115 PSI

            Dynamic Stitch Seam Test              2”/min             40 lb/in

                        (Customer’s test)

            Static Dead Load Lap Shear          9 lbs/sq in for 96 hours, max allowable creep of 0.010”

Static Dead Load Stitch Seam       9 lbs/sq in for 96 hours, minimal creep allowed

                        (Customer’s test)

            Fatigue Stitched Seam                    9 lb loading at 3 cycles/minute for 8 hours, minimal creep                                   (Customer’s test, 10 seconds loaded, 10 seconds unloaded)

Product Testing

            Install rubber parts on aluminum structure, wait 1 hour, and initiate cycle test

Temperature Range

            Survival Temperature Range:          –60 F thru 160 F

            Operational Temperature Range:   -22 F thru 140 F

Environment

            Storage:                     Ambient temperature and humidity

            Operational:   External environment. 

Note: The edges of the product and adhesive will be sealed with a rubber-based sealer.

The above physical properties are a guide, and are the minimums as observed with current adhesives in this application. They are not a specification, and may be varied. The true test is the product operational performance. The customer will test and certify that the adhesive system selected performs satisfactorily in this application.

Action

Identify an off the shelf products for this application, or identify a vendor who will mix an adhesive to meet these requirements.

Determine the procedures, shelf life, and time between application to the product and customer installation for the selected adhesive.