PP board (polypropylene board) duct is a ventilation duct system commonly used in corrosion-resistant and chemical-resistant environments. It is widely used in chemical, laboratory, electroplating, sewage treatment and other industries. The construction process of PP board duct needs to be strictly carried out in accordance with the specifications to ensure its sealing, strength and service life. The following is the main process flow of PP board duct construction:

1. Construction preparation

Material preparation:

• PP board: Select the appropriate thickness (usually 3mm~10mm) according to the design requirements.

• PP welding rod: The same material as PP board, used for welding.

• Flanges, brackets, bolts and other accessories.

Tool preparation:

• Hot air welding gun, extrusion welder, cutting tools (such as circular saws or curved saws), grinders, measuring tools (tape measures, levels), etc.

Technical preparation:

• Be familiar with the design drawings and understand the direction, size and connection method of the duct.

• Develop a construction plan and clarify the construction sequence and quality requirements.

  
  

2. PP plate air duct production

Layout and cutting:

• Layout on the PP plate according to the design drawings, and mark the unfolded size of the air duct.

• Use cutting tools (such as circular saws) to cut the PP plate according to the marked line to ensure that the cut is smooth and burr-free.

Sheet bending:

• For the part that needs to be bent, use a hot air gun to heat the PP plate, soften it, and bend it to the required angle.

• After bending, it needs to be cooled and shaped to ensure that the shape is stable.

Welding preparation:

• Grind the edges of the cut and bent plates to ensure that the welding surface is flat and clean.

• Check whether the welding rod meets the requirements and ensure that it is consistent with the material of the PP plate.

3. PP plate air duct welding

Hot air welding:

• Use a hot air welding gun to weld the joints of the PP plate.

• During welding, the temperature of the welding gun is controlled at 250℃~300℃, and the welding rod and the plate are heated at the same time to ensure that the welding is firm.

• The welding speed is uniform to avoid cracking of the weld due to overheating or overcooling.

Extrusion welding:

• Extrusion welding can be used for thicker PP plates or welds that require higher strength.

• Use an extrusion welder to fill the molten PP material into the joint to form a uniform weld.

Weld inspection:

• After welding, check whether the weld is uniform, free of bubbles and cracks.

• If necessary, use a grinding tool to trim the weld to ensure a smooth surface.

4. Duct assembly

Flange connection:

• Install the PP flange at the end of the duct, and the flange and duct are fixed by welding.

• Sealing gaskets (such as rubber gaskets or PP gaskets) need to be added to the flange connection to ensure sealing.

Duct splicing:

• Splice the prepared duct sections according to the design drawings, and use bolts to fix the flange connection.

• Pay attention to the horizontal and vertical degree of the duct during splicing to avoid twisting or tilting.

Bracket installation:

• Install the bracket or hanger according to the direction and weight of the duct.

• The bracket spacing should meet the requirements of the specification, usually 2m~3m.

• Rubber pads or PP pads need to be installed between the bracket and the air duct to avoid direct contact and wear.

5. Air duct installation

Positioning and fixing:

• Determine the installation position of the air duct according to the design drawings, and use a level and measuring tools to ensure installation accuracy.

• Fix the air duct on the bracket, adjust the position and tighten the bolts.

Connecting equipment:

• Connect the air duct with the fan, filter, exhaust port and other equipment to ensure that the interface is sealed.

• Use sealant or sealing tape to perform secondary sealing treatment on the connection.

Inspection and adjustment:

• After installation, check the overall horizontality, verticality and sealing of the air duct.

• Adjust the bracket or hanger to ensure that the air duct is stable and does not shake.

6. System test

Air leakage test:

Use smoke or pressure test equipment to check the sealing of the air duct to ensure that there is no air leakage.

Repair the leaking parts and re-weld or seal them if necessary.

Operation test:

Start the fan and check the operation of the air duct system to ensure that there is no abnormal vibration or noise.

Test whether the air volume and wind speed meet the design requirements.

7. Construction precautions

Welding quality:

Welding is a key link in the construction of PP board air ducts. The welding temperature and speed must be strictly controlled to ensure that the welds are firm and defect-free.

Material protection:

PP boards are easily affected by ultraviolet rays. Sunshade or protective measures must be taken when installed outdoors.

Avoid collision with sharp objects to prevent damage to the air duct.

Safety measures:

Wear protective equipment (such as gloves and goggles) during construction to avoid burns or inhalation of harmful gases during welding.

Safety belts and scaffolding are required for high-altitude operations to ensure construction safety.

Environmental requirements:

The construction environment temperature should not be too low (generally not less than 5℃) to avoid affecting the welding quality.

Avoid construction in humid or heavily polluted environments.

8. Maintenance and care

• Regularly check the welds and joints of the air ducts and repair them in time if problems are found.

• Clean the inside of the air duct to avoid dust or debris affecting the ventilation effect.

• For air ducts installed outdoors, regularly check whether the protective layer is intact.

Through the above process, PP board duct can meet the requirements of corrosion resistance and chemical resistance, and is suitable for various special environments. During the construction process, it is necessary to strictly follow the specifications to ensure the quality and performance of the duct system.