Optimal material selection

Concerning specification, the following three factors are decisive:

• Predefined construction principle
• Rod diameter
• Material

Since construction principle and rod diameter are predefined, the material is an important criterion for the properties of the rod holder.

Today, as a rule, Polyurethane (PU) or Polyethylene (PE) are applied; older systems frequently still have rod holders made of rubber.

Optimal material selection

Depending on material, different manufacturing processes are required: Rod holders made of PU and rubber are manufactured in molding or extrusion processes; rod holders made of PE are usually produced on milling and planing machines. The type of manufacturing as well as the specific material properties have advantages and disadvantages in terms of manufacturing costs and operating characteristics.

In general, PU material for rod holders features high elasticity which, same as friction coefficient and hardness, can be optimized at minimum costs. Additional advantages are high surface quality and good resistance to mineral oils, fats, benzine, ozone and UV radiation. PE features a very low friction coefficient, resistance to hydrolysis, flexible designs, and a longer service life of the rod holder.

Thus, finding the optimal material depends largely on the individual requirements. Recently, however, there is a trend towards
rod holders made of PE.

Polyethylene rod holders

• Machining
• Low friction coefficient
• Resistance to hydrolysis
• Flexibility in design
• Ideal for special shapes
• Allows extended service life

Polyurethane rod holders

• Molding
• Adjustable hardness 55° – 97° Shore A
• High elasticity
• High mechanical and dynamic stability
• High surface quality
• Good resistance against mineral oils, fats, benzine, ozone, UV and high-energy radiation

Application example: Minimizing edge wear

Direct application of abrasive coating media results in above average edge wear of the metering rods, even if the boards are relatively thin. In the worst case, the metering rod runs only a few hours until the edges of the board sheet are no longer acceptable. Our complete metering system features adjustable contact pressure that is applied on the metering rod in the edge area: Since the length of the pressure hoses is adjustable, they can be positioned in such a way that they end at a defined point before the edge. This ensures uniform pressure distribution over the entire rod holder. However, since the pressure is reduced towards the edge, run time is considerably longer.

Variety of shapes

Whether customer-specific requirements or various coating station designs, our standard range covers all conventional requirements. But also special rod holder solutions pose no problem.

Together we can develop special shapes to suit your specific requirements. Individual consultation, comprehensive design expertise and individualised production options are the best prerequisites for achieving convincing results.