How To Clean Forming Fabric ?

Concept of Cleaning Forming Fabric

"Only clean forming fabriccan produce high-quality paper"

Our primary goal is to remove all impurities from the pulp before forming fabric enters the headbox, but it is difficult to achieve this. Therefore, it is very important to adopt various cleaning methods to efficiently clean the forming fabric in the papermaking process system. The main cleaning methods are as follows:

1. Cleaning of high pressure shower pipe: High pressure needle nozzle, fan-shaped nozzle, paper web peeling spray pipe

2. Water and gas mixed cleaning: Use JET cleaner

3. Chemical cleaning:Acidic cleaning agent, alkaline cleaning agent, maintenance of forming fabric

Cleaning Method of High Pressure Shower Pipe

High Pressure Needle Nozzle Shower Pipe

Suggested installation location: preferably at the guide roller. Do not install it on the tension roller;

Single layer or composite layer forming fabric installed on the back (wear surface) of the forming fabric;

Double or triple layer forming fabric installed on the front of the forming fabric (paper surface)

The best flushing effect is to install it on the front of the forming fabric, and the flushing water is directly flushed onto the roller for use.

Technical Parameters of High Pressure Shower Pipe

Nozzle size: 0.8-1.2mm, 1mm is optimal

Nozzle spacing: The stroke for distances of 66100 and 200mm is 200mm; the stroke for distances of 75150 and 300mm is 300mm.

Distance between nozzle and forming fabric: 100-200mm for optimal cleaning effect

Cleaning water pressure: maximum not exceeding 30 bar (above 30 bar will damage the forming fabric)

Fan-shaped Nozzle Showe Pipe

The best location is at the guide roller

Do not place at the tension roller

For all formed mesh designs, the spray direction is from the reverse side towards the formed mesh

Technical Parameters of Fan-shaped Nozzle Showe Pipe

Water pressure: around 6 bar

Fan angle: 60

Distance between nozzle and forming mesh: 90-100mm

Nozzle spacing=100mm

Paper Web Peeling Spray Pipe

Assist in cleaning the network department

Spray direction: The jet flows along the tangential direction of the roller surface into the clamping area between the forming fabric and the rotating roller, just in front of the rotating roller surface in the clamping area

Spray pressure p: 10-15 bar

Distance between sprinkler pipe and forming fabric: 100-300mm (depending on the diameter of the pipe and specific conditions)

Nozzle spacing: 50-200mm (depending on spray distance and water consumption)

Water Quality Requirements

The maximum high-pressure water for the needle nozzle is 30ppm (only for fine fibers and fillers)

The maximum flushing water for the fan-shaped nozzle is 100ppm (only for fine fibers and fillers)

The spray water for peeling the paper web is 500-1000ppm

Using white water or even clean water may clog the nozzle

JET Cleaner Method

Function: Cleaning and maintenance of forming fabric, edge cleaning, and peeling of paper webs and edges.

Advantages: Thoroughly cleaned, uniform, safe, and free of streaks. In special circumstances, high-pressure cleaning is not necessary. The forming fabric is kept clean during the return journey and does not produce water mist, which can maintain a clean and dry production environment and reduce downtime.

Chemical Cleaning Method

Requirements for cleaning agents:

Rapid response time;

Has no corrosive effect on polyester and polyamide materials;

Easy to use and safe;

Environment protection.

Different products available for selection in the market:

Alkaline cleaning agents are used to remove organic pollutants such as resins, rosin, organic esters, etc;

Alkaline solvent mixture reacts faster than pure caustic products;

Acidic cleaning agents are used to remove inorganic pollutants such as calcium carbonate, chalk, etc;

Acidic solvent mixture with dual effects of removing organic and inorganic deposits;

Neutral cleaning agent, with limited cleaning effect.

Alkaline cleaner

Alkaline cleaning agents such as IMBONAL are widely used and efficient foaming cleaning agents.

This type of product has different concentrations and can be used as required without causing damage or chemical degradation to the forming fabric. Highly concentrated alkaline cleaning agents are very dangerous and must be tested before use,

For viscous deposits from waste paper or deinked pulp, using solvent based alkaline cleaning agents such as IMBELITUW/A or UW/SOH yields excellent results. Solvent based cleaning agents pose no harm to the forming mesh

Note: Solvent based cleaning agents are not foam based cleaning agents and only have a slight tendency to foam, but can be used with foam based cleaning equipment.

Acidic cleaner

Due to lack of experience, many forming fabric are prone to damage in the following situations: sulfuric acid, hypochlorous acid, or highly acidic cleaning agents. Polyamide is very sensitive to acid, and high acidity or prolonged contact with acid can be particularly dangerous.

We must strictly follow the supplier's recommendations. If there are any doubts, in order to reduce risks, it is recommended to conduct experiments using molded nets in the laboratory. If the formed mesh is severely contaminated by inorganic sediments, cleaning once is generally not enough and may require two times.

Note: Acidic cleaning agents are prone to foaming, so special attention should be paid to cleaning equipment and wearing protective clothing.

IMBELITU acidic foaming cleaning agent is commonly used.

Maintenance of Forming Fabric

We recommend using low-pressure fan-shaped nozzles for spraying, without requiring the spray pipe to swing. If it can swing, the effect will be better. The optimal installation position is in front of the breast roller; For the double mesh former, both forming fabric need to be installed in front of the spray pipe in the clamping area. Directly spray on the front of the forming fabric. If the paper machine conditions do not allow it, spraying on the back will affect the effect.