Home > MacroLetter > 4.1 - Winter 1998 > Developing The PVdC Extrusion Coating Line

Developing the World's First PVdC Extrusion Coating Line

Coating substrates with PVdC for improved property is done by today by a gravure coating process using latex or solvent base coating. The disadvantage of this process is the limited thickness that can be applied in one pass. A number of coating passes are required to achieve the desired film thickness.

Another problem with gravure coating is that coatings thicker than 35 microns (1.4 mil) or 60 GSM (g/m) have a tendency to crack when flexed. This creates minute passages for moisture or oxygen, diminishing the barrier properties. New demands for longer shelf life in the medial, pharmaceutical and food packaging industries make it necessary to apply a thicker coating of PVdC than is practical with latex.

To address these problems, Macro Engineering proceeded to develop the world’s first PVdC extrusion coating process. The new Macro PVdC extrusion coating process eliminated the above mentioned problems associated with latex and solvent coatings—namely, micro cracking.

What makes it possible to extrude PVdC?

• Price control of the extrusion process
  
• Eliminating any dead or slow flow areas in the extruder and die
  
• Streamlining the die for maximum velocity
  
• Using materials that are highly resistant to corrosion
  
• Precise temperature control
  
• Newly developed PVdC resin

To achieve the above, Macro had to develop new die, extruder, process and controls technology. Dow chemical played a significant role in developing new resins with better processing characteristics and heat stability. The result is a process that is easier and safer to operate and control. The line can be shut down and restarted without the problem of degradation, or the need to take the die apart. In fact, die cleaning is required only once or twice per month.

With every PVdC extrusion coating line, Macro Engineering provides complete technical knowledge and operator training. The equipment performance is guaranteed.