Nappy production plant

• What was needed: lubrication-free drylin®-set Easy Tube, RJUM linear plain bearings, spindle linear units, hybrid bearings from the drylin® W-programme
• Requirements: High load on linear technology due to frequent changeovers with continuous operation almost 365 days a year, high levels of dirt and dust, contamination due to friction effects
• Sector: Textile industry
• Success for the customer: Today, drylin® linear bearings are used for quick and reliable changeovers. They are lubrication and maintenance-free, insensitive to dust and dirt, corrosion-free, durable, quiet and lightweight.

Nappies are manufactured in what is known as a one-step process. This means that all the required raw materials are available in the form of rolls or powders and are combined and packaged in a single process step to create the end product. ONTEX MAYEN GmbH is the market leader in the field of private label hygiene products. It offers a wide range of products for the baby, feminine and adult hygiene sectors. At the Mayen site, baby nappies in all sizes and variations are produced exclusively on a total of eleven lines and sold almost worldwide.
The nappy manufacturer serves many customers. It must therefore guarantee system safety and flexibility in production and packaging. Every order or size change results in changeover times or adjustments. There are typically four size changes a week per line, which equates to over 200 size changes a year. But the requirement profile goes even further. This is because the systems run around the clock, seven days a week. This means that they are in continuous operation almost 365 days a year. Due to the high process speed, high dynamic loads are also applied to the systems. These are up to 600 m/min.
Due to the process, the ambient temperature in the production hall tends to be warm. However, there are no extreme temperatures. Superabsorbents and cellulose are processed, which cause a relatively high amount of dirt and dust. Superabsorber also behaves in a similar way to sand, so that soiling occurs due to friction effects. To summarise, it can therefore be said that the systems and the machine elements installed in them are subject to extremely high loads. Nevertheless, they must function absolutely reliably under all circumstances.

Today, drylin® linear bearings are used for quick and reliable retooling. They are lubrication and maintenance-free, insensitive to dust and dirt, corrosion-free, durable, quiet and lightweight.
Among other things, the drylin® Easy Tube system is used (see pictures 1 - 3 below). The slides, torque support and trapezoidal lead screw nut of the particularly compact linear unit for light adjustment tasks are made from a special high-performance polymer plain bearing. This guarantees freedom from lubricants combined with a low coefficient of friction and very good wear behaviour.
RJUM linear plain bearings replace recirculating ball bearing components in various areas. They are based on highly wear-resistant polymers and are particularly robust and economical.
However, other products are also used in the systems:

Position adjustment
drylin® linear bearings primarily realise positional adjustments such as in the area of the adhesive application points. The adhesive application head is moved reliably via linear guides.

Packaging and visual inspection
Spindle linear units or tables (Figures 4 - 6) prove their worth in the packaging environment or for optical inspection and quality assurance. They are often equipped with spindle clamping to prevent unintentional rotation, position indicators for reliable position adjustment and hand wheel.

Material loading cranes
Another special feature of the systems are material loading cranes, which bring the heavy raw material rolls to the machine (Fig. 7). Hybrid bearings from the drylin® W-programme are used to move the overhead cranes. They offer a combination of gliding and rolling. The coefficient of friction is minimised, adjustment and drive force are kept as low as possible.