HOW IS A QUALITY MEMBRANE MADE?
WE EXPLAIN THE KEY FACTORS BEHIND PRODUCING THE IDEAL MEMBRANE FOR YOUR FILTRATION PROCESS.
For the filtration of wine, beer, juices, soft drinks and beverages, it is essential to use first-class, high-performance filtering elements.
IT ALL STARTS WITH THE SEARCH FOR MATERIALS AND THE CHECKS
With 100% in-house production starting from high quality, certified raw materials, DANMIL filtration cartridges have a unique, stand-out design, guaranteeing an excellent regeneration performance and full compatibility with different detergents.
DANMIL filtering elements are manufactured from polymers produced in-house in polyethersulfone, polypropylene and PTFE. DANMIL prefilters have a β-ratio 5000 retention rate and can be customised on request, assembling up to six different layers.
The technical staff also carries out integrity tests and continuous checks throughout the production process to ensure high performance and microbial retention, both of which are essential features in obtaining a quality product.
DANMIL ensures maximum flexibility, offering tailor-made solutions which can fulfil any customer application requirement.
FILTER CARTRIDGES: HOW CAN QUALITY BE RECOGNISED?
Filtration is a complex process: its quality depends on numerous variables which are linked to the product being filtered. What are the features which make a prefiltration element capable of fulfilling its purpose correctly, guaranteeing the microbial stability of the beverages?
To understand this aspect, we will give you a detailed look at the production process of our filtering elements: a journey into the world of DANMIL to enable you to recognise the features behind a top-quality filter cartridge.
An important factor is sustainability. In light of our Group’s commitment to environmentally-friendly development, DANMIL filtering products are made of recyclable components.
PLEATING WITH HIGH QUALITY STANDARDS
The machinery which makes the folds in the membrane is fitted with fixed pleating units to guarantee even pleating which is, therefore, consistent throughout the production process.
It is essential that every fold is exactly the same as the others to guarantee the perfect formation of the filter pack.
The pleating of DANMIL polypropylene cartridges is specific and ideal for backwashing.
The heat sealing of the membrane allows the polyester and polyethersulfone layers to be fused together, thus guaranteeing an excellent seal during the sterilisation and regeneration processes.
Given that the automated systems have been designed to achieve a superior production performance, they subject the cartridge to significant stress, caused by the chemical regeneration combined with high flow rates and temperatures. This type of sealing, therefore, guarantees the end user a better performance and prolonged durability.
COSNTRUCTION OF THE CARTRIDGE ELEMENTS
All the components of the DANMIL cartridge are assembled in-house to guarantee the highest quality and complete control over the production process. This is combined with the complete traceability of the DANMIL 10-inch modules which bear the code, batch and micrometre measurement.
So, let’s take a closer look and examine the elements which make up the cartridge:
- The DANMIL tip: it is solid which prevents the accumulation of water or wine and eliminates the risk of microbial problems due to residue.
- The DANMIL ring: it is not fused inside the adaptor. This is an important aspect which prevents the problem of by-pass caused by the different expansion properties of plastic and steel. For this application, DANMIL, together with our Group, has developed equipment borrowed from precision mechanics which eliminates any risk of micro-cracks during insertion. Furthermore, in keeping with our commitment to sustainable development, the conformation of the DANMIL ring is ideal for the environment because it allows the materials to be separated and recycled.
- The protective cage: DANMIL has developed a special design for the protective cage to ensure resistance to sterilisation cycles and high hourly flow rates. The most significant innovation lies in the use of offset intervals between the various openings, which ensure elasticity during sterilisation and the cooling of the cartridge, thus preventing it from breaking.
- The inner core: the central inner core support is reinforced, and thanks to its size, adds stability and resistance to the filter element.
SEALING AND JOINING OF THE CAGE, MEMBRANE AND END CAP
The sealing and joining of the cage, membrane and end cap is another fundamental and specific step in the process: the membrane is inserted into the 10-inch module, leaving a calculated space between the membrane and the cage, to avoid any kind of friction during the heating and cooling phases in the sterilisation and sanitisation processes.
For a perfect join of the end elements, DANMIL uses an infrared system, which avoids direct contact between the sealing point and the heat source, thus ensuring perfect alignment. The 10-inch module is then inserted inside the operating machine where two steel plates are heated by induction which, in turn, heat the ends of the module and two end elements to be joined. After this, the steel plates retract and the end elements are brought together and sealed.
Thanks to all these precautions, DANMIL ensures an impeccable fusion of the three elements - membrane, cap and cage - so the resulting cartridge is perfect from all aspects.
COSTRUCTION OF THE 30-INCH FILTER ELEMENT
The same infrared sealing system is used to produce the 30-inch models. With this technology, a perfect assembly of the individual modules (20”-30”-40”) is ensured, thus avoiding micro cracks and by-pass. This operation is performed by inserting a stainless steel guard on the individual 10-inch filter element to avoid any deformations during the sealing phase.
INTEGRITY TEST ON ALL THE MEMBRANES
All the membranes are tested twice: the first time in the 10-inch format and then, in the final assembly in the 20-, 30 or 40-inch version.