Reduce Squeak and Rattle
A simple, low-cost solution to increasing long-term structural rigidity has helped a European vehicle manufacturer reduce squeak and rattle and improve five year warranty performance.
As vehicles age, the heat affected zone around spot welds can develop micro cracking that leads to increased flexing of the body. This in turn leads to reduced dynamic performance and increased squeak and rattle from trim components. This latter can result in customer dissatisfaction and expensive warranty claims, even in vehicles less than three years old.
3M was approached by a vehicle manufacturer looking for a low cost solution to this issue so that customer satisfaction could be increased and longer warranties could be offered cost-effectively. Traditional work-around solutions (additional spot welding or TIG welding of the Body-in-White supplemented by new reinforcing components) had already been rejected due to the increased cost and manufacturing complexity.
3M’s solution is to supplement the existing spot welds with 3M Body-in-White Structural Adhesive. As well as providing a fastening that will not deteriorate significantly within the normal vehicle life expectancy, the adhesive reduces stress concentrations around welds and therefore minimises the development of microcracking. The result is significantly greater retention of body stiffness with time and a reduction in both immediate and long-term squeak and rattle.
In this application, the vehicle manufacturer was also able to remove several spot welds in locations where poor access required additional weld cleaning due to the welding head angle creating unwanted spatter. This created a further cost saving and reduction in process complexity.
The success of this programme has led the vehicle manufacturer to specify 3M Body-in-White Structural Adhesive to supplement spot welding for a new vehicle structure now in development. As well as allowing cost to be taken out of the body assembly process, the additional stiffness has allowed trim engineers to reduce the gaps between components, increasing the perception of quality. The number of barrier components (compliant foams) used at critical trim interfaces to reduce squeak and rattle has also been reduced, creating further savings in materials and processes.
Quick solution – 3M’s adhesives can solve issues quickly and cost effectively without changes to vehicle design or tooling.
Mixed materials – 3M’s adhesives can attach mixed materials including steel, aluminium and composites.
Reduced materials requirement – reduction in stress concentrations allows down gauging and the reduction or elimination of reinforcements.
Reduced energy consumption – 3M’s adhesives use less energy than welding and 3M adhesives applied with induction heating typically require feed temperatures 50oC lower than competitor adhesives.
Improved sealing – excellent gap filling properties can eliminate the need for additional sealants or for costly tooling changes.
Simple surface preparation – resistance to oil and moisture is high, so most surfaces require no special preparation.
Zero read-through - there is no damage to the reverse surface so the need for additional finishing or trim is eliminated.
Very fast assembly strength – 3M’s unique pre-cure process gives very fast assembly strength (can be immediate with induction heating), allowing squeeze out and spillage to be easily cleaned and giving assemblies sufficient strength to be moved without compromising assembly accuracy.
High dwell time - the time between assembly and bake can be up to seven days, allowing batch manufacture and manufacture at alternative locations without risk of assembly distortion
Film alternative – 3M Body-in-White structural adhesive can also be supplied as a film in pre-cut shapes optimised for each application
- Body-in-White reinforcement,
- Body-in-White primary fixing,
- Subframe structures,
- Closure assembly,
- Module assembly,
- Hinge washers.
Challenge us to save you money
3M’s cost-down and manufacturing specialists can undertake a line-walk review with you to identify manufacturing and cycle time reductions as well as potential quality improvements and other cost down opportunities.
to put us to the test!
Back to Automotive News