The production process of the mini pleated HEPA filter

28/07/2020

    HEPA filters are divided into high-efficiency air filters with partitions and high-efficiency air filters without partitions. Relatively speaking, the filtration efficiency of high-efficiency filters without partitions is slightly better. However, the production difficulties of HEPA filters without partitions are relatively more complicated. The following introduces the production process of HEPA filters without partitions for reference only.

    One: picking

    1. Confirm the required materials and quantity based on the order form.

    2. According to the production order, the production department will be sent to the warehouse by a special person. The warehouse will issue a requisition form and sign according to the total amount of each material in the order. After the requisitioner signs and is approved by the production director, the warehouse can deliver goods.

    3. Determine the required raw materials and quantities according to the order, and place them in the corresponding position in the workshop and arrange them neatly.

    Two: cutting

    1. The hardware is blanked according to the specifications described on the list, including profile blanking and guard net blanking. The profile has no poor oxidation or scratches; the blanking tolerance of aluminum is 1170+0-2*570+0-2mm. When lowering the aluminum material, the 45-degree angle must be accurate, and when the aluminum angle is lowered, ensure that the angle aluminum must be vertical and not a parallelogram. The angle aluminum length tolerance is 65+0-1mm. The size of the protective net is 139+0-1*112+0-1mm, and the meshes are arranged horizontally.

    2. The filter element is unloaded in the high-efficiency workshop, and the folding and forming origami refers to the "Operation Guide for Origami Machine Without Partition". The filter material has uniform glue lines and equal fold distances. The surface of the origami is free of fluff, no damage, flat, no dirt, no filter material. Inclined, the height of the filter material is 52mm, and the number of folds is 39-41.

    Three: clean up

    1 After cutting the hardware, use an air gun to blow clean the aluminum chips, place them in the corresponding position in the workshop and place them neatly, and paste the labels. The quality department will sample the semi-finished products to see if they are qualified and add labels.

    Four; frame

    1 The framing personnel assembles the qualified profiles under the hardware according to the regulations. The four corners of the outer frame are not nailed, and the angle aluminum can be connected directly.

    2. Efficient assembly to level and shape the protective net. The surface of the protective net has no unevenness, no rust, no break, no bad oxidation.

    Four: assembly

    Use a blade to cut the filter element to the required size. Assemblers cannot leave long nails. The filter element must be cut neatly and without burrs.

    Put the protective net and filter material into the profile frame and fix the four corners with masking paper.

    Five: potting

    Polyurethane AB glue is used, and the connection between the side and the bottom edge is not misaligned after the glue is poured. The diamond-shaped net is fixed with a bead to keep it beautiful.

    2. A: B glue, the glue mixing ratio is A: B=1: 2.5, the glue is stirred evenly, and the mixing time is not less than 1 minute. After the glue is poured, the diagonal must be measured and placed on a clean and flat table. Fasten the protective net with a bead, and make sure that the glue flows evenly and there is no pile after the glue is injected.

    Six: clean up

    1Tear off the masking paper at the four corners of the filter.

    2 Use a blade to carefully remove the plastic block on the surface of the outer frame. There should be no glue stains on the protective screen of the frame and no debris in the filter element.

    3. Use a rag with a small amount of detergent to wipe the glue stains on the surface of the outer frame. When cleaning, pay attention to no scratches, no glue stains on the aluminum surface, and no damage to the filter material.

    4. Use a polishing tool to polish the four corners of each filter. After polishing, pay attention to the four corners without burrs.

    Seven: sticking tape

    1 Use a special integrally formed sealing tape to be pasted on the air outlet surface of the filter. The sealing strip must be pasted neatly and not beyond the filter frame.

    2. Clean up and vacuum. When vacuuming, it should be 2cm away from the surface of the filter to prevent damage to the filter material.

    3. After cleaning, place it in the corresponding position of the inspection room and place it neatly.

    Eight: Detection

    1 The products to be inspected and the inspected products are placed separately and neatly.

    2. Check whether the finished product is qualified. Place unqualified products in zones and deal with them according to regulations.

    3. The probe of the detection instrument is 2-3cm away from the surface of the filter and scans progressively at a constant speed of 4-20m/s along the direction of the print. Others are tested for leaks in accordance with the national standard GB13554. The number of dust passing through the upstream of the filter is not low. At 3.0*104, the sampling count of particles ≥0.5μm downstream does not exceed 3.

    4. Label the qualified products.

    Nine: Packaging

    1 Products that pass the inspection are sent to the outer packaging workshop. Inner packaging is required in accordance with the production order. Cardboards or other shock-proof items are stored in a carton. The finished product is packed in a PE bag, labeled and certified.

    2 Carry out the outer packaging, paste the shipment inspection form, and stick the tape neatly, try to keep it at 5cm.

    Ten: Storage

    1 Put the packaged products in the corresponding position and neatly in the workshop. Put the cardboard on the ground to prevent moisture.

    2 The finished products are stacked according to the filter paper folded in the vertical direction, not flat.

    3. The products stacked on the pallet must be wrapped with stretch film to prevent slipping during transportation. For ease of transportation, the stack height should not exceed 3 layers.

    4. Send the products that will pass the factory inspection to the warehouse and issue the warehouse receipt.