Hot-melt adhesives and devices for the automotive industry
Reactive and non-reactive hot-melt adhesives are used widely and in increasing numbers in the automotive industry. Due to the freedom of design that gluing enables, the number of glued or laminated components in the car is growing. Even dents in the paintwork can be removed with the help of hot glue.
The demand for automation and process reliability lead to fully automatic application and bonding processes. Manual gluing processes can still be found in cable assembly and the removal of dents. We offer a wide range of suitable application technologies for both application techniques.
Interior lamination
The boot of an automobile offers various applications that lend themselves to bonding with reactive and non-reactive hot-melt adhesives – the gluing of the carpet on the loading floor, lamination of the rear seats with needle felt and the lining of the side panels, for example.
Depending on the requirements and process sequences, different types of adhesives are used: These range from pressure-sensitive hot-melts and polyolefins to reactive polyurethane hot-melt adhesives.
Increased demands in the area of VOC and fogging are leading to an increased use of PUR hot-melt adhesives. At the same time, emission-optimised pressure-sensitive hot-melt adhesives will be launched on the market.
The development of PUR products is increasingly moving towards adhesives with reduced labelling through to label-free adhesives.
In the case of pressure-sensitive hot-melt adhesives, inline laminating is preferred, within the open time of the hot-melt adhesive. In the case of PUR, a pre-coating with a reactivating step during lamination is generally used.
Roof lining production
In addition to PU dispersion, reactive and non-reactive hot-melt adhesives are also used to laminate the textile-foam composite onto the carrier.
A series of assembly steps to optimise acoustics is carried out on the back of the carrier, which is not visible later. In addition to foams, many cables are positioned there, which are fixed using hot-melt adhesive. This method of fixing cables also used on car seats, e.g. in seat heating.
Decor, emblems, covers, clips
A large number of assembly bonds can also be resolved with PUR hot-melt adhesives.
Worth mentioning are:
- Decors in the central console area
- Emblems on car keys
- Emblems on hubcaps
- Fastening clips on all internal cladding and trim
Door sills
Illuminated door sills are becoming more and more popular and are being increasingly installed in car models. The environmental influences on this type of bonding have a stronger influence than with pure interior bonding. For this reason PUR hot-melt adhesives are the products of choice.
The challenge of the material combination of different plastics e.g. ABS, PC, etc. with the metallic inserts can only be met with the properties of the PUR adhesives. The wide adhesion spectrum combined with the characteristics of bonding and sealing speaks in favour of these hot-melt adhesives.
Automotive foundry
Iron foundries primarily use polyamides for the bonding of core packages in the foundry industry. BÜHNEN has polyamides in its range that are ideally suited for core packs that are to be coated (aqueous/ethanolic), and subsequently dried in a drying tunnel. Polyofins or EVA adhesives are used in aluminium foundries. The demands on the adhesives used in sand blasting or in the bonding of core packages are very high.
The hot-melt adhesives require a wide open time frame with a short setting speed. The short setting speed , combined with a high initial strength, enables rapid further handling of the cores produced using the cold-box or hot-box process. Depending on the degree of automation, glue guns or melting devices are used.
