LJF service commitment

Air Filter Services: From Quality Control
to Packaging and Shipping

Quality control, warranty support, export packaging, shipping documentation
and quotation service for industrial air filtration customers.

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Clear communication · Reliable quality · Fast response

Service coverage

Support at every stage of your air filter order.

From incoming material inspection to final shipment, LJF coordinates the commercial and technical details that help keep product quality, delivery and after-sales expectations clear.

Quality Control

Inspection before production, during production and before shipment, against the confirmed product requirements.

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Warranty & Claims

Product warranty guidance and a documented claim-review process supported by technical and order information.

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Export Packaging

Packaging designed around filter dimensions, deformation risk, moisture exposure and the selected shipping method.

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Shipping & Documentation

Trade-term coordination, loading-port arrangements and the commercial and technical documents required for export.

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Samples

Sample evaluation support for dimensions, structure, materials, workmanship, performance and packaging requirements.

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Quotation Service

Clear quotations based on product specifications, customization level, quantity, trade term and delivery requirements.

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Quality control process

Four inspection checkpoints before shipment.

Quality control follows the approved sample, drawing or confirmed technical specification. Materials or finished products that do not meet the requirements are held back for review instead of being released automatically.

01

Raw Material Inspection

Incoming materials are checked according to the product type and confirmed specification.

  • Media specification and thickness
  • Basis weight, density and appearance
  • Frame material and dimensions
  • Batch consistency and accessories
02

In-Process Inspection

Key production details are checked while the order is being manufactured.

  • Dimensions and pocket count or depth
  • Media direction and bonding
  • Frame structure and sealing
  • Appearance, labels and customized details
03

Finished Product Inspection

Depending on the product, finished goods may be checked by sampling inspection or full inspection.

  • Appearance, dimensions and structure
  • Media, frame and workmanship
  • Quantity and packaging
  • Performance or pressure-drop requirements where applicable
04

Pre-Shipment Inspection

Before shipment, product and packing information is reconfirmed against the order.

  • Model, quantity and labels
  • Packaging and shipping marks
  • Carton and pallet quantity
  • Customer information and shipping documents

Production control: materials that do not meet the confirmed requirements are not released for production.

Warranty & claim support

Warranty principles, product coverage and claim review.

LJF provides reasonable quality assurance for its products. Because actual filter service life depends on operating and application conditions, warranty coverage focuses on manufacturing and material defects rather than the normal service life of consumable filters.

01 · Warranty principle

Manufacturing and material defects are covered.

Actual service life is affected by dust concentration, airflow, temperature, humidity, installation method and equipment conditions. Guaranteeing an exact service-life period would therefore be misleading.

For customized products, special-performance products or project orders, the final technical agreement, approved sample, quotation and sales contract shall prevail.

02 · Product coverage

Warranty coverage by product category

Coverage is assessed against the confirmed product specification, intended application and normal operating conditions.

01

Pocket Filters / Bag Filters

Warranty mainly covers manufacturing-related issues such as abnormal frame condition, workmanship defects, incorrect assembly or obvious material defects under proper storage and normal operating conditions.

02

Panel Filters

Warranty covers manufacturing-related defects involving the frame, filter media fixing, product structure and workmanship.

03

Spray Booth Filter Media

This includes ceiling filter media, intake filter media and paint arrestor filter media. Warranty mainly covers material defects, incorrect specifications and manufacturing defects existing before use.

04

HEPA / High Efficiency Filters

For filters with specified performance requirements, quality assurance is based on the confirmed efficiency grade, testing requirements and technical standard stated in the order. Specific warranty periods can be confirmed according to product type and application before order placement.

03 · Exclusions

Items Not Covered by Warranty

The following situations are generally not covered by warranty:

  • Incorrect installation
  • Incorrect installation direction
  • Operation above the designed airflow
  • Long-term exposure to excessive temperature, humidity or corrosive environments
  • Use in an application for which the product was not designed
  • Continued use beyond the normal replacement cycle
  • Human damage
  • Damage caused by third-party logistics or transportation
  • Unauthorized modification, disassembly or secondary processing
  • Improper storage causing moisture, deformation or contamination
  • Damage caused by equipment failure
  • Normal dust loading and pressure-drop increase during use
  • Failure to follow agreed technical or operating requirements
Consumable-product note:

Air filters are consumable products. Normal dust accumulation, pressure-drop increase and replacement due to service life are not normally considered product quality defects.

04 · Quality claim support

Quality Claim Review

To help us investigate complaints efficiently, please provide as much of the following information as possible.

Initial response Normally within 1 working day

Information to Provide

  • Order number or invoice number
  • Product name and model
  • Quantity affected
  • Product batch information
  • Detailed description of the issue
  • Clear photos and videos
  • Product label photos
  • Carton and packaging photos
  • Installation photos
  • Actual operating conditions
  • Date of receipt
  • Date when the issue was discovered
Note:

For issues involving filtration efficiency, pressure drop or other performance data, relevant test reports or test conditions may also be required where necessary.

The more complete the information, the faster we can analyze the issue and propose a solution.

Complaint Handling Process

Customer Feedback Evidence Collection Initial Review Technical Analysis Root Cause Evaluation Proposed Solution Customer Confirmation Corrective Action Case Closure

After complete information is received, our sales, production and quality teams review the issue.

Standard cases receive an initial solution or explanation as soon as possible. Cases requiring product testing, batch traceability or technical verification may take additional time. Customers will be updated during the investigation.

Possible Solutions

Technical explanation Usage recommendation Replacement Reshipment Rework Compensation in the next order Partial refund Refund Other mutually agreed solutions

The final solution is determined based on the verified cause and actual loss.

Packaging & product protection

Packaging matched to the filter, route and handling risk.

LJF designs packaging according to product type, dimensions, quantity and shipping method. Carton quantity, carton dimensions, pallet dimensions, gross weight and net weight are confirmed in the quotation, packing list or order documents.

Standard Export Packaging

Common options are selected according to product structure and order quantity.

PE bagsWoven bagsExport cartonsPalletsWooden casesStretch filmCorner protectorsPacking straps

Compression Protection

Reinforcement options help reduce deformation during stacking, loading and transport.

Reinforced cartonsInternal dividersLayered packingCorner protectionPallet packingWooden casesReinforced straps

Moisture & Clean Protection

Long-distance sea shipments and high-efficiency filters can use additional sealing and dust-control measures.

PE moisture-proof bagsIndividual bagsSealed outer bagsWaterproof pallet wrappingDust-proof packingInternal cushioning
Shipping & export documents

Trade terms, loading arrangements and documents in one flow.

The final trade term and loading port depend on destination, order volume and shipping method. They are clearly stated in the quotation or sales order.

Trade Terms & Loading Ports

LJF supports common international trade terms and coordinates orders produced in South China from suitable major ports.

EXWFOBCIFCFRDDPOther agreed Incoterms
Order confirmationMaterial preparationProductionQCPackagingShipment

Export Documentation

Depending on the order and destination, LJF can provide the relevant commercial, export and technical documents.

  • Commercial invoice and packing list
  • Sales contract
  • Certificate of origin where applicable
  • Product specification and technical data sheet
  • Inspection documents
  • Shipping marks, labels and packing information
  • Bill of lading documents
Samples & quotations

Start with the right product details.

Complete dimensions, performance requirements and commercial information help LJF assess feasibility, confirm the sample schedule and prepare a quotation without unnecessary back-and-forth.

Sample Service

The sample charge depends on product type, dimensions, quantity and customization requirements.

  • Customer normally pays international courier cost
  • Sample dispatch time is confirmed before sample production
  • Sample fee may be deducted from bulk-order payment subject to agreed conditions
  • Sample evaluation can cover dimensions, structure, materials, workmanship, performance and packaging

Quotation Service

For air filters, please provide the product type, L × W × D, efficiency grade, media, frame material and quantity. Clear standard product inquiries are normally quoted within 1 working day.

  • Quotations have a limited validity period
  • Common currencies: USD and EUR
  • Payment terms depend on order value, customization level, cooperation history and trade term
  • Final transaction terms are confirmed in the Proforma Invoice or Sales Contract
LJF service commitment

A clearer standard for international filter orders.

Product specifications, pricing, production lead time, packaging, shipment and after-sales responsibilities should be clear from the beginning of each inquiry.

Clear CommunicationRequirements, lead times and responsibilities confirmed in writing.
Reliable QualityInspection checkpoints aligned with the approved specification.
Flexible CustomizationProduct, packaging and label requirements discussed around the application.
Stable SupplyProduction and material planning discussed before order confirmation.
Fast ResponseService inquiries and complete quality claims reviewed promptly.
Frequently asked questions

Air filter service FAQ

Answers to common questions about quality control, warranty, claims, packaging, shipping, samples and quotations.

What quality control steps does LJF follow?

LJF carries out raw material inspection, in-process inspection, finished product inspection and pre-shipment inspection. Materials that do not meet the confirmed requirements are not released for production.

What does the LJF product warranty cover?

The warranty mainly covers manufacturing defects and material defects under proper storage, installation and normal operating conditions. Specific coverage is confirmed according to product type and application.

What is not covered by the warranty?

The warranty normally excludes incorrect installation, misuse, operation above the designed airflow, unauthorized modification, improper storage, third-party transport damage, equipment failure and normal dust loading or pressure-drop increase during use.

What information should I provide for a quality claim?

Please provide the order or invoice number, product model, quantity, batch or lot information, issue description, clear photos and videos, packaging photos and relevant operating conditions so the case can be reviewed efficiently. When filtration efficiency, pressure drop or other performance data are involved, relevant test reports or test conditions may also be required.

How are filters packaged for export?

Packaging options include PE bags, woven bags, export cartons, pallets, wooden cases, stretch film, corner protectors and packing straps. Compression, moisture and dust protection can be added according to the product and shipping route.

Which shipping terms and documents are available?

Common trade terms include EXW, FOB, CIF, CFR and DDP. Depending on the order, LJF can provide commercial invoices, packing lists, contracts, certificates of origin, product specifications, technical data sheets, inspection documents, labels, packing information and bill of lading documents.

How does LJF handle sample fees?

The sample charge depends on product type, dimensions, quantity and customization requirements. The customer normally pays the international courier cost, and the sample fee may be deducted from a bulk order payment subject to agreed conditions.

What information is needed for a quotation?

For an air filter quotation, please provide the product type, length by width by depth, efficiency grade, filter media, frame material and required quantity. Clear standard product inquiries are normally quoted within 1 working day.

Need service support for your filter order?

Share your product details, order information or delivery requirements with LJF. Our team will review the next practical step with you.

Contact LJF