Seeking Technology To Bind Polyester (PET) to Polypropylene (PP)

• A material
• A technology

The SpecialChem Client has developed a new application where one of the PP part is replaced with a PET-film (which is much more chemical resistant). But due to the difference in the chemical structure, their current adhesive technology is not able to bind PP to PET.
The SpecialChem Client is looking for a material that will create excellent adhesion between an amorphous polypropylene structure and a heat sealable polyester film (APET, coex OPET, coated OPET, or possibly some other chemical resistant barrier film).

The annual volume estimate for the material is based upon the use rate of the current solution of 7-15 mg (dry weight) per part. We will produce 1.5 to 2.0 billion parts per year, so that equates to 10M to 30M kg (dry weight) per year.

• The technology solution must permanently bond polypropylene (PP) structure and polyester films (PET):
  • Once applied and dried on the PET surface, must be dimensionally stable and not run, sag or melt during handling/conveying at up to 150°C (ring and ball test, ASTM D36).
• PP and PET materials are clamped together to facilitate the bonding.
  • Estimated strains on the weld interface are in the range of 80 lb/in².
• PP and PET materials can also be heated to facilitate the bonding
  • The heat is applied via conduction from a metal layer underneath the PET. It is necessary that the coating does not degrade or have an adverse reaction to a Radio-Frequency field that is 20-60 MHz.
• Dispensing system via narrow-diameter (0.3 to 2 mm) nozzle.
  • Existing dispensing system requires a 2300 to 3600 cP material. We can use either water-based, solvent based compounds or 100% solids liquid material. Our current compounds are around 50-70% solids. After the compound is applied it is dried for 40-60 sec at 90-140C. This drying time is a bottleneck and a shorter dry time will be a critical differentiator.
  • Hot melt-style dispensing systems can also be a method for 100% solid thermoplastic compounds. Melt flow is typically 43-49 cubic mm per minute.
  • These values are given for guidance on what would be the easiest dispensing method, but there is significant flexibility available to accommodate other conditions.

• A water-based, solvent-based or 100% solids (thermoplastic or curable liquid) material.
• Any chemistry is must meet FDA indirect contact requirements, or has the potential to meet FDA requirements.

• Materials that may give off-flavors or odors.
• Materials that contain BPA.
• Materials that are halogenated or contain CONEG heavy metals or create other compliance issues.

• Ready-to-use solutions

• Industry: Consumer Packaging
• Annual Revenue: $5 Billion USD
• Years in Business: >100 Years
• Headquarters Area: USA

• Buying