PVC is an extremely versatile plastic with excellent properties and a good price-performance ratio. It is therefore not surprising that more than 20 million tonnes of PVC are processed worldwide every year - often in the form of flooring, bottles or even window profiles. But for the production of high-quality PVC, numerous fillers, stabilisers, plasticisers or even colour pigments have to be mixed safely and true to formulation. This is where AZO comes in: with our solutions for automated raw material handling, we are able to feed any raw material to the right mixing line at the right time, in the right quantity.
S-PVC is one of the most frequently used PVC variants and is required in large quantities. Due to its good flowability, this raw material does not pose any particular challenges. However, it is important to transfer the PVC powder from the silo into the process safely and with high accuracy.
With our AZO suction weighing systems, you no longer have to worry about this. Our systems offer you maximum flexibility, consistent product quality and enable quick recipe changes - all with high dosing and weighing accuracy. In combination with the AZO plant control, you always have a complete overview and control of your raw materials.
Chalk or E-PVC, in contrast to S-PVC, are poorly-flowing and require appropriate solutions in raw material automation. Our AZO discharge systems are ideal for this task.
By fluidizing with air or other gases, for example, the flow behavior of the raw materials can be significantly improved. The fluidizing gas can be introduced either selectively via nozzles or membranes, or over a large area via funnels lined with permeable textiles. The gas loosens the product and reduces the wall friction forces through the resulting air cushions, so that the raw material begins to flow.
Titanium dioxide is also known as "whitener" and is used, among other things, in the production of window profiles. The raw material is not easy in two respects: Firstly, it is both cohesive and adhesive and thus tends to adhere strongly to surfaces and has poor flow properties. Secondly, it is respirable and has been classified as a potential carcinogen by the European Union. For the safe and efficient handling of titanium dioxide, a number of precautions must therefore be taken in raw material automation.
The use of vibratory trays with built-in ventilation can prevent the powder from sticking and allow it to be discharged. The deposition of powder in pipelines can be circumvented by using hose systems. Due to the flexibility of the hose and appropriate mounting, there is constant slight movement, which ensures that any deposited material flakes off again.
The protection of the operating personnel is made possible by special feeding stations. Big bag discharging stations or sack discharging stations equipped with a glove box allow the containers to be opened and emptied into the downstream process without bringing the personnel into contact with the product.
Numerous additives, such as stabilizers, pigments, fillers or plasticizers, which have to be used in the production of PVC-based plastics, are highly flammable and explosive. Thus, explosion protection is a top priority in raw material automation in order to realize both product and operator protection. Starting with the product feed, if possible under inert conditions, this extends to pneumatic conveying and feeding into the mixer.
At AZO, we are familiar with these requirements and are able to ensure system safety through ATEX-designed plants.
When producing a dry blend, the temperature remains below the softening temperature of the plastic powder. This maintains the flowability of the powder and reduces production costs. The above list of raw materials must therefore be conveyed into a mixer and homogenised there. However, since homogenisation itself generates heat, we at AZO use heating-cooling mixers to ensure that the softening temperature is not reached or even exceeded. In doing so, it is important to meet the requirements of all raw materials used.
In addition, our AZO production control system enables constant monitoring and control of the entire production process, so that you have an overview of your raw materials at all times.
