The hygienic design of food machinery plays an important role in controlling food safety。 However, if this concept is applied in a general way without considering the hygienic design of equipment components, there is a risk that bacteria can grow and spread within bearings, says Davide Zanghi, head of SKF's Hygienic Design office。
Hygienic design should consider the adverse effects of specific factors (such as corrosion, lubricant leakage, cleaning and automatic drying) on food safety, and apply appropriate design principles to solve the problem。 In essence, it is a design concept that adopts specific principles。 Just as ergonomic design focuses on the physiological needs of the user, hygienic design focuses on preventing food contamination。
The European Alliance for Sanitary Engineering and Design (EHEDG) aims to promote the safe food production capacity of its members, including equipment manufacturers, food companies and research institutions, by raising standards for sanitary engineering design, and SKF has been a member of EHEDG since 2006。 In November 2016, the alliance held its biennial World Congress in Denmark, where SKF once again highlighted its long tradition of applying these design principles。
Design Principles - Treat bearing assemblies with care
In general, the EHEDG guidelines consider that bearings are prone to retention of food particles and water, so bearings are considered to be a potential breeding ground for bacteria。 The general advice is to ensure that bearings are kept away from food contact areas。
This recommendation is very much in line with the latest guidelines for the hygienic design of belt conveyors in the food industry，In this area, EHEDG focuses on two major challenges in safe food production: how to avoid contamination of food by improperly designed processing equipment，And how to improve food safety without raising the operational costs of cleaner production and hygiene。 In fact, the main concern in the hygienic design of the whole system is the system and main components (such as belts);However, bearings and bearing units are often not paid enough attention to。
However, even if the bearings are not in direct contact with the food area, they are often near the food and have high-pressure water or dry cleaning systems。This way, if there are bacteria present, it has the potential to become airborne and contaminate food。
In order to minimize the risk of contamination, sanitary design principles should be fully considered when designing bearings。 And one of the most important principles that make up sanitary design is the ability to clean effectively。 This is actually quite easy to understand, but in practice it is often not easy for bearings and bearing units。 First, the product should be made of non-corrosive and non-porous materials (such as stainless steel) or composite materials, and the shape is easy to clean, and the trapped water can be automatically drained。 The bearing unit should have a filler base to avoid leaving gaps for bacteria to grow。
In general, the use of materials such as elastomers, composites and greases should comply with food safety directives and regulations。 In all cases, leakage of grease into food during operation should be avoided as much as possible。
The best approach is that the bearing unit is equipped with an efficient end cap that prevents contaminants and clean liquids from entering the bearing cavity while allowing frequent visual inspections。
Other relevant areas include:
Avoid metal-to-metal contact between the cell assembly and the attached surface
Supplementary lubrication should be avoided whenever possible
Long service life under very demanding handling and cleaning systems
The hygienic design is fully suitable for food production and packaging machinery。 However, bearings are only one of many problem components, and solving the bearing problem is only the first step in improving the overall risk strategy。
Hygienic design should consider the adverse effects of specific factors (such as corrosion, lubricant leakage, cleaning and automatic drying) on food safety, and apply appropriate design principles to solve the problem。 In essence, it is a design concept that adopts specific principles。 Just as ergonomic design focuses on the physiological needs of the user, hygienic design focuses on preventing food contamination。
The European Alliance for Sanitary Engineering and Design (EHEDG) aims to promote the safe food production capacity of its members, including equipment manufacturers, food companies and research institutions, by raising standards for sanitary engineering design, and SKF has been a member of EHEDG since 2006。 In November 2016, the alliance held its biennial World Congress in Denmark, where SKF once again highlighted its long tradition of applying these design principles。
Design Principles - Treat bearing assemblies with care
In general, the EHEDG guidelines consider that bearings are prone to retention of food particles and water, so bearings are considered to be a potential breeding ground for bacteria。 The general advice is to ensure that bearings are kept away from food contact areas。
This recommendation is very much in line with the latest guidelines for the hygienic design of belt conveyors in the food industry，In this area, EHEDG focuses on two major challenges in safe food production: how to avoid contamination of food by improperly designed processing equipment，And how to improve food safety without raising the operational costs of cleaner production and hygiene。 In fact, the main concern in the hygienic design of the whole system is the system and main components (such as belts);However, bearings and bearing units are often not paid enough attention to。
However, even if the bearings are not in direct contact with the food area, they are often near the food and have high-pressure water or dry cleaning systems。This way, if there are bacteria present, it has the potential to become airborne and contaminate food。
In order to minimize the risk of contamination, sanitary design principles should be fully considered when designing bearings。 And one of the most important principles that make up sanitary design is the ability to clean effectively。 This is actually quite easy to understand, but in practice it is often not easy for bearings and bearing units。 First, the product should be made of non-corrosive and non-porous materials (such as stainless steel) or composite materials, and the shape is easy to clean, and the trapped water can be automatically drained。 The bearing unit should have a filler base to avoid leaving gaps for bacteria to grow。
In general, the use of materials such as elastomers, composites and greases should comply with food safety directives and regulations。 In all cases, leakage of grease into food during operation should be avoided as much as possible。
The best approach is that the bearing unit is equipped with an efficient end cap that prevents contaminants and clean liquids from entering the bearing cavity while allowing frequent visual inspections。
Other relevant areas include:
Avoid metal-to-metal contact between the cell assembly and the attached surface
Supplementary lubrication should be avoided whenever possible
Long service life under very demanding handling and cleaning systems
The hygienic design is fully suitable for food production and packaging machinery。 However, bearings are only one of many problem components, and solving the bearing problem is only the first step in improving the overall risk strategy。