Pneumatics for food processing
Original article date: July 1999
The demands placed n machinery and equipment in the food industry are as varied as the products that are manufactured and are constantly increasing. New regulations indicate a trend towards higher quality materials and stricter hygienic design.
Hygiene regulations materials and surface properties must be observed in the food processing industry especially when parts of the machinery come directly into contact with food during production. It is important to understand the legislation affecting the food industry to ensure that the appropriate requirements and special demands of this branch of industry can be met thus avoiding unnecessary risks.
The Euro standard 93/94 EEC stipulates that the HACCP (Hazard Analysis Critical Control Point) System is to be used in food production. It is intended to be an effective and rational procedure for guaranteeing the safety of food products. Using a system of Control Points and Critical Control Points it aims to establish where controls need to be applied to avoid unacceptable health hazards as well as uncovering special biological chemical and physical hazards which might exist in a specific food processing system.
The food industry is changing ever increasingly to non-lubricated air. This means that machines will require an initial lubrication. Only appropriate permitted lubricants may be used in this initial lubrication process. In addition to the type of lubricant (eg USDA H1) the amount of lubrication coming into contact with food is also of significance as is each microbiological reaction. The addition of bactericides to the lubricant is not permitted.
Where there is a need for lubrication the exhaust air should be piped. Pneumatic components are initially greased and do not need any added lubricants. New components are developed to be leakage-free which are of great importance when aiming for a hygienic pneumatic system.
Rexroth Mecman Pneumatics has produced a selectograph for pneumatic components based on grading components according to corrosion durability hygiene class and electrical protection class. This and other guidance on selecting pneumatic systems for food processing applications are detailed in a new catalogue Pneumatics in the Food Industry nowavailable free from Rexroth Mecman.
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Directives and Standards |
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| Internat ional Standards
ISO 14159 (draft) – Machine Safety ISO 8086/1986: Hygiene Regulations for Dairies European Community Directives and Standards Hygiene Directive 93/43/EEC |
Machinery Directive 89/392/EEC This directive contains the requirements for machine safety from the design perspective and concerns the safety of the machine operators. Furthermore a series of hygiene requirements have to b fulfilled for the food industry including ease of cleaning and smooth surfaces. EN Standards for Machines used in the Food Industry prEN 1672-1 and 1672-2 USA Standards Food and Drug Administration United States Department of Agriculture (USDA) |
Definitions
Corrosion Durability Classes
1
Acid-proof and stainless steel.
Plastics such as PVC polythene PTFE silicone rubber
2
Hard chromium-plated steel
Steel such as AISI 420 430 Nickel-plated steel and brass
Chemically nickel-plated and anodised aluminium
Plastics such as polyamide 6.6 acetal rubbers urethane nitrile rubber
3
Zinc-plated steel
Bronze brass zinc
Plastics such as polycarbonate
Plain aluminium
Hygiene classes
1 Hygiene design
Smooth surface (no dangerous grooves or pores)
Rounded corners and edges
No dead spaces
Self-draining
2 Clean design
Might be some dead spaces
Self draining
3 Standard design
Dead spaces not completely avoided
Moderately cleanable
Electrical protection classes
1
High protection class IP67
2
Medium protection class IP65
- Rexroth Mecman Pneumatics
July 1999