Sealing challenges the food and drink industry
Russ Pimblett is business development manager of FTL Technology, which offers innovative, reliable and safe engineering sealing solutions for Food Applications — including MECO seals, the full-contact soft-face mechanical split shaft seals for food and beverage process applications.
When sealing for the food and drinks industry, there are various aspects of processing equipment, machinery and instruments to be considered. These factors involve everything from ingredient preparation and storage to measuring, packing and cooking.
This range of process equipment needs to meet robust quality standards to conform to food handling regulations. Even a slight change to the ratio, temperature or operation times of ingredients and equipment can result in serious consequences for operators, or worse, the well being of end consumers.
How are you mitigating risk management?
Airborne particles are a major risk factor in food product manufacturing. A high dust concentration, when combined with turbulence and an ignition source, creates an environment conducive to combustion. This can not only cause significant material damage to process equipment, but places the health of operatives in danger.
Substances and fine powders — such as cocoa, flour and sugar — can easily create this kind of combustible environment. It is therefore imperative to reduce these hazards through control measures and the effective performance of all sealing systems. European ATEX standards are in place to regulate explosive environments of this type and must be adhered to for any sealing manufacturer in risk-heavy food process lines.
What is the impact of contamination and leakage?
Leakages and contaminated products have significant impacts on businesses, costing lots of money for the damaged equipment to be fixed and for affected products to be recalled.
Aside from material costs, there are ramifications to consider for the brand as well. The loss of a large single customer following an incident can result in strenuous times when you’re eventually retrading.
Mixing and blending ingredients which are dry, wet and/or solid often involves heat, which can in turn cause an ingredient to expand. This is a common cause of leaks in food and drink process equipment.
Contamination caused by heat, unburned products of combustion or water used in fire-fighting activities can lead to total product spoiling and contaminated equipment. A common cause of water ingress contamination is high pressure jet washing when cleaning refrigeration equipment.
The prevention of contaminant ingress is paramount to a safe and efficient food process environment. Dual seal designs, or seals with multiple stages of barrier — such as the use of a barrier fluid or purge — can help to guard against this form of contamination.
Are you meeting material compliance?
The term “food safe” is often used when looking at material suitability for food and drink applications. While the term food safe is prone to subjectivity, the most prominent quality standards on this front are regulated by the Food and Drug Administration.
The FDA is responsible for ensuring that any food or drug product available in the United States is safe, wholesome and sanitary.
CFR 21.177.2600 describes the relevant regulations for rubber articles intended for repeated use. It is pertinent when selecting materials suitable for applications where a rubber seal comes into contact with food products. The list of pre-approved materials includes silicone.
There is no guarantee that a seal made from a food safe material is safe for use in a food contact application. The method of manufacture and the exact nature of the operational environment in the application can impact the seal’s suitability for use in food contact processes.
It is vital to ensure that any seal is manufactured from FDA-compliant materials in a clean and controlled process environment to prevent contamination and ensure the end product is fit for human consumption.
Have you considered the process conditions and material finish?
When considering suitability for the process conditions we must consider factors such as size, temperature, application, media, pressure and speed (STAMPS).
Furthermore, the surface finish of materials in a sealing solution that is used in a food production environment is vital. A sealing component with a smooth surface is a key preventative measure against the build up of product, which can harbor bacteria. A smooth seal surface can also reduce the risk of product adhesion within the application.
What about hygiene and cleaning?
The European Hygienic Engineering Design Group (EHEDG) is a body set up to develop best practices for equipment intended for use in hygienic industries.
EHEDG offers guidelines on how to prevent issues such as bug traps, product build up and cleaning dead spots. When designing any sealing solution, following EHEDG’s guidance notes can help prevent the possibility of contamination.
A major factor to take into account is the requirement for clean in place (CIP) and sterilize in place (SIP). CIP and SIP expose seals to a cleaning regime that can include fluids and chemicals, hot water, steam, localized jetting, spraying and flushing. These procedures can involve aggressive temperatures and chemicals, so your choice of sealing material needs to be able to perform under these conditions.
What is your processing equipment’s duty cycle and cleaning regime? This should include obligations for any disassembly, cleaning and reassembly where CIP and SIP cannot be facilitated, Clean out of Place (COP).
Hygienic validation processes often require parts to be stripped down, removed and replaced which can take several hours (or even days) of downtime if seal designs are not split.
When working in hygienic processing industries such as food and drink manufacture and packaging, sealing challenges are very different to those in other industrial sectors. While some seal designs from other sectors may have similar design features and operate using similar principles, rarely if ever can a seal from another industrial sector be directly transplanted into a hygienic application. Special consideration on material compliance, cleaning and maintenance regimes are crucial in the development of a reliable, high performance sealing solution.