You may also contact any of your local universities where they may have pilot plant facility, providing assistance to SMEs or any companies who might be interested in doing such productions.
As a student (few years back), i had this opportunity to use samples that had gone through some of the Tetrapak machines (production units), for analysis. So definitely they are quite involved in many of liquid formulations related to dairy, soymilk, coconut drinks and others. Hopefully they may have some equipment for your purpose as well for trials. You may even get more information from them regarding the packaging and the lid variety that they offer to customers! They offer an Amazing series of lid-closing systems and packaging formats and designs.