Surface Treatment

Solvent Technology

Introduction

Solvents can be used in many types of applications where the quality of the results is an extremely high priority. The compatibility between the solvent and the material to be cleaned is of utmost importance and must be respected, and it is imperative to identify the affinity between the solvent itself and the polluting material that has to be removed; as an example perchlorethylene is an excellent agent to remove oils, fats or a mixture of both from metals. Regarding the solvents themselves, it is extremely important to use them correctly in order to guarantee normal stability, efficiency while fully respecting the environment.

1. Technology

The main characteristic of our machines is the airtight seal of the processing chamber, which, together with the vapour sensors, ensures absolute absence of any dispersed emissions (not channelled). These washing units operate according to the following steps:

WASHING CYCLE: The system either rotates the basket or the support to facilitate the removal of solid waste and the drying process that follows. This is a sequential washing method that utilizes hot-cold-solvent vapour types of solvents which can also allow the possibility of adding an immersion phase (optional) that can eventually be combined with a strong mechanical action (forced water-jet drive, ultrasounds, etc.).

DRYING CYCLE:This is a closed circuit hot air system with condensation of the solvent vapours which is achieved through the use of a low temperature refrigeration unit. The length of the drying cycle varies according to the type of materials processed. The possible vacuum type drying system ensures shorter times and yields the best results when processing items that have hollow spaces, dead holes or that are extremely small. The reduction of the residual concentration is achieved through an active carbon recycling unit, which is regenerated with hot air (also in a closed circuit system).

RECYCLING:In order to maintain the maximum purity of the washing liquid that comes into contact with the surface of the parts and guarantee consistent results, a water separation process (which removes the humidity present on the parts or that is possibly introduced through the outside each time the door is opened) plus a filtering process (which separates the solid polluting materials) and finally a distilling process (which separates all the polluting materials that are soluble in the solvent and from the liquid used in the process) all come together to ensure that the solvent always remains at levels of peak performance.

2. Benefits

A drastic reduction of solvent used benefits the environment tremendously (emissions are reduced up to 98% compared to traditional systems), which then generates substantial financial benefits (taking as an example manufacturers of small mechanical parts and comparing this installation to a traditional type, the consumption – and consequent savings on chemical products – is in the ratio of 1:15).

3. Characteristics of Drying Systems through Air Circulation

• 1 Hot solvent storing tank
  
• 1 Cold solvent storing tank
  
• 1 integrated still tank to constantly regenerate the solvent
  
• Water condensation system for the distilling phase
  
• Condensation system complete with refrigeration block for the drying phase
  
• Electric or steam heating system
  
• Centrifugal pump system for solvent circulation
  
• Filtering system to filter processing residues at 200 µm
  
• Completely computer controlled washing process