Lubrication-Free Plastic Solutions For Food Processing
Tuesday, August 6th, 2019 | 1753 Views
For movement purposes, specially optimised plastics can be used in many different ways in the food and packaging industry.
Although high-performance plastics used to be overlooked as suitable materials for machine components, they are now a standard feature of equipment used in many branches of industry. They are successfully coping with many different challenges, especially in the case of food processing equipment where metal solutions are not an option due to corrosion and the need for lubrication. But their potential has by no means been exhausted. New materials and improved designs are increasing quality, helping to accelerate processes and lowering costs. Today, for example, motion plastics specialist igus supplies energy chains based on Hygienic Design guidelines and abrasion-resistant plain bearing components for a wide range of solutions used in the food, beverage and packaging industry.
Special customer requests are often the driving force for new innovations at igus. More than 50 years ago, company founder Günter Blase built up the company by asking customers about their greatest problems in the area of machine design, problems that he wanted to solve with plastic. This approach in the search for solutions continues to lead to new products every year. They all have one thing in common: they are developed on the basis of high-performance plastics, which are used for moving applications and increase the service life of machines while reducing the customer’s costs.
For the R 081 thermoforming packaging machine of Multivac, the first e-chain from igus designed in accordance with Hygienic Design guidelines is used. (Source: igus GmbH)
An example for the food industry is the TH3 plastic energy chain, which was developed on the basis of concrete enquiries received during the IFFA 2016 trade fair in Frankfurt and from Multivac, the packaging machine specialist. The requirements for a special energy chain intended for use with food processing equipment are clear: it must not only be safe and avoid product contamination but must also be capable of being cleaned effectively. The new TH3 e-chain, the result of requirements of the food industry, is impressive. In the specification sheet for this product, the main focus for igus is on the following criteria, which were determined after an analysis of the market requirements:
- A design based on the Guidelines for Hygienic Design
- An open design for efficient and easy cleaning
- Rounded edges allowing liquids to run off
- Good resistance to chemicals
- FDA-conformity and EU-conformity of the materials used, if possible
- Blue as the desired colour for plastics in the food industry
igus will offer the chain made of FDA-/ EU-compliant and chemically resistant material in blue with two inner heights and five different inner widths. The up to five fixed interior segments for individual filling make it possible to lay cables and hoses separately from each other in order to leave enough space for cleaning.
As in the case of all its energy chains, igus also supplies the new TH3 as a ready-to-install, harnessed product with no minimum order quantity. The chains, called ‘readychains’, are filled with (harnessed) cables and hoses by igus and, on request, are supplied in complete form and installed directly on site. Given that igus is not only the manufacturer of plastic energy chains but also of chainflex cables specially developed for movement in e-chains, users can have confidence in these safe and reliable systems from a single source.
igus now supplies a wide range of drylin stainless-steel components specially for the food industry. (Source: igus GmbH)
Know-how regarding materials enables solutions for nearly all applications
In addition to energy supply systems, igus supplies plain bearing components made of high-performance polymers, which have already been used successfully in very different versions in all possible applications in the packaging, food and beverage industry for many years. This is possible due to the more than 30 years of experience with special plastics for moving applications as well as the many years of cooperation with the industry. An iglidur plain bearing from igus is based on thermoplastic polymers that ensure good basic resistance to wear. Fibres and filling materials increase the bearing’s mechanical load-carrying capacity. Due to years-long research and development, igus can now offer plain bearing materials that comply with EU regulation 10/2011 and the requirements of the FDA (Food and Drug Administration) for recurring contact with food. Examples are the blue materials iglidur A160 and iglidur A181. Due to their high wear-resistance, low moisture absorption and resistance to chemicals, both are especially suitable for applications involving direct contact with food. Like all iglidur materials, they do not require any external lubrication as solid lubricants are embedded in the plastic. These are in the form of millions of microscopically small particles in tiny chambers in the material. From these chambers, the plain bearings release tiny amounts of solid lubricants during movement. This is adequate to sufficiently lubricate the immediate surrounding area.
Every iglidur material has further unique properties in addition to being optimised in terms of friction and wear. For example, iglidur A181 on stainless-steel shafts, which are used in food processing equipment mainly for reasons of corrosion, has an outstanding coefficient of friction in applications involving pivoting and rotating movements. What is special about the cost-effective all-round FDA material iglidur A160 is its good chemical resistance, which also makes it resistant to aggressive cleaning agents. In addition, igus supplies tribo-tape in two thicknesses, 0.5 or 1.0 millimetres. As this liner can be glued on, it offers great freedom with regard to design and the lining of sliding surfaces that are subjected to severe levels of stress. The liner is characterised by its low price as well as its high wear resistance, and is also FDA-compliant. Today, igus supplies tribo-tape made of iglidur A160 with a width of up to half a metre and cut to the required length (available from stock). Cutting the liner to size individually in order to ensure that the geometry is correct is especially easy. igus also offers a cutting service. It is only necessary to upload the 3D data of the desired shape in the form of a DXF file to the website and then igus prepares the parts on the basis of these data – no minimum order quantity.
Bearing solutions with a wide variety of geometries
In addition to classical plain bearing bushings that igus also supplies as tape or as bar stock for further machining, igus supplies even further special plastic solutions for the food industry. As the safety standards for the protection of consumers are extremely high, the demand for detectable materials in food processing machinery is always great in this industry. In the framework of its ball and spherical bearing series, igus offers products that are made of detectable plastics. This guarantees that no detectable plastics enter the production chain in the event of failure or misuse. Today, the special high-performance plastic, which can be easily traced with standard metal searching techniques, is to be found in selected products of the igubal series, as well as in swivel joints and clevis joints, flange bearings, spherical bearings and pillow block bearings. Both the housing and the spherical balls are made of the detectable plastic. This characteristic is sought after in other areas of bearing technology. For example, the xiros M180 is a lightweight polymer ball bearing, whose material is also detectable and, what’s more, is especially resistant to various media. On the basis of its xiros polymer ball bearings, igus also offers all-round solutions in the form of guide rollers, each one consisting of two ball bearings and one tube, which are used in film storage devices of labelling machines of the company Krones.
Thanks to its plastics expertise, igus is also able to offer maintenance-free linear guides for the food industry. The reason is that, in contrast to conventional ball circulating guides, these drylin linear axes do not have to be lubricated as liners made of iglidur materials are used between rail and carriage. In this context, igus now supplies a wide range of stainless steel components specially for the food industry. For example, in the case of the new toothed belt axis kits of the type drylin ZLW. Here, the widths and rail distances of the ready-to-install axes can be combined depending on the requirements in each case. Except for the toothed belt and the liner, the axis has a very open design and is completely made of stainless steel. An extremely long service life is possible if used in combination with liners made of iglidur E7.
In order to be able to guarantee this service life and make it calculable for all products – energy chains systems and plain bearings – igus operates a test laboratory covering an area of 3,800 square metres. In very different tests here, plain bearing components of all kinds in different lifting and pivoting movements as well as energy chains and cables of all sizes are moved on travels of up to 240 metres or at temperatures down to -40 °C and brought to the limits of the stress that they can bear. Every year, igus also carries out not only 1,000 customer-specific tests in its test laboratory but also more than 4,000 tests of its energy chains as well as over 12,000 tests of its plain bearing products. The results of all tests are fed into a database, on the basis of which igus provides its customers with around 40 different web tools such as the online product finder and the service life calculator, doing so free of charge and without registration. Users are therefore always able to find the most suitable solution that improves the technical performance of their equipment while reducing costs, and can rely on tested and safe components in their machines and systems.