Flow diagram of the UP production process

Prior to use in the process, certain raw materials need to be melted and preheated in ovens. Some installations have heated silos to keep raw materials liquid and ready to use and to avoid the emission of dust from the storage area. 

After the reaction product meets the required specifications (viscosity and functionality), it is cooled and blended in a reactive monomer, usually styrene. This step is generally performed in dilution tanks, equipped with agitation. The base resin is finished, directly or after intermediate storage, to the end formulation and specification requirements, in firushing tanks. 

Depending on the plant layout, storage facilities are available for intermediate storage and for finished product storage. Products will be filtered to specification using self cleaning filters and/or disposable cartridge and bag filters. 

Although this generic process description is used for all UP, the process will show certain differences depending on the main chemistry applied. This is illustrated in the brief process descriptions relating to the main product groups ortho- and isophthalic polyester, dicyclopentadiene (DCPD) polyesters and vinyl esters. 

Glycols and diacids or anhydrides are dosed into a batch reactor at an ambient temperature and under inert atmosphere. When heated, an esterification reaction will take place  

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