Chapter 2: Rubber Materials and Products used in Contact with Food
2.1 Polymers Used in Food Contact Rubbers
As part of the FSA project FS2219 an extensive review of the food industry was carried out by consultants at Rapra Technology Ltd in order to obtain information on the types of rubber used in the food industry. All the major sectors of the food industry were surveyed. Some examples are given below:
Brewery and soft drinks
Abattoir and meat processors
Vending machine dispensers
Food canning and the preserves industry
A relatively large range of rubber types were found to be used in a wide variety of rubber products (see Section 2.3). One of the most important criteria that is used in selecting a particular rubber for a specific end-use application is its temperature resistance, although other properties such as chemical inertness, the physical properties of the resulting product (e.g., tensile strength, abrasion and tear resistance) and the types of additives that have to be incorporated into it to achieve the desired processing and final properties are also considered. The most important classes of rubber used in the food industry are reviewed below.
2.1.1 Natural Rubber (i.e., cis-1,4-polyisoprene)
Food contact natural rubber product compounds are mainly used for gloves, can sealants, teats and soothers, although it is coming under pressure from synthetic polyisoprene and other rubbers (e.g., thermoplastic rubbers and silicones) due to the increasing incidence of protein allergies. In food processing equipment natural rubber products will be found in belting and hosing products, sometimes in blends with...