What this category’s data looks like
Business data sources for the spraying and coating field include coating supplier TDS/SDS documents, spray booth and oven operation data, colorimeter/film thickness gauge test data, environmental VOCs monitoring records, and MES system data. Document types cover coating process cards, coating batch sheets, paint mixing records, film thickness and color difference reports, oven curves, defect repair sheets, VOCs ledgers. Some documents include test reports in scanned image format. Data update frequency: batch sheets are updated per coating batch, oven and spray booth operation logs are generated per shift, and test and environmental data are collected continuously. Document fields include film thickness (unit μm), color difference ΔE, oven temperature (unit ℃), VOCs concentration (unit mg/m³), production batch number, shift information, and more.
What constraints do these characteristics impose on document parsing and chunking
The multi-source heterogeneous document structure, high-frequency update characteristics, and specific business field requirements of this category impose multiple constraints on document parsing and chunking. First, documents contain structured tables, long text descriptions, and scanned images, so mixed format parsing and retention of field units must be supported. Second, high-frequency updated batch and operation data require chunk length to fit business parameter groups, avoiding splitting associated parameters. Third, documents for tendering scenarios need to accurately match core links such as pretreatment, spraying, and curing. Chunking must retain business logic coherence and not split critical parameter associations.
FastGPT v4.17.0 supports adapting document parsing and chunking for spraying and coating scenarios via the following configuration items:
How to set the configurations
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
chunkSize | 800–1200 characters | Process parameter groups and batch-related information in coating documents usually fall within this length range, which avoids splitting critical business parameters |
chunkSplitter | Mixed semantic paragraph + fixed character | Balances parsing needs for structured tables such as coating batch sheets and long text descriptions such as oven curve instructions in coating documents, and retains content coherence |
customPdfParse | Enabled | Supports accurate parsing of multiple types of coating documents such as scanned film thickness reports and process cards with nested tables, and retains field and unit information |
PARSE_FILE_TIMEOUT_SECONDS | 120–180 seconds | Parsing large oven curve collections and multi-batch coating ledger files takes a long time, and this range covers the parsing duration of most conventional files |
UPLOAD_FILE_MAX_SIZE | 1000 MB | Historical ledger collections for a single coating batch may reach a large volume, which meets batch upload requirements |
chunkSettingMode | Manual configuration | The business logic of coating documents is clear. Manual configuration can accurately match chunking rules and avoid generic chunking from breaking parameter associations |
Three common mistakes
- After uploading multiple coating documents, the batch number fields in the parsing results are disorganized and cannot distinguish sources. The cause is that no multi-document metadata differentiation rule is configured via
customPdfParse, so the system cannot identify business associations between different files. - No matching results appear when searching for coating process parameters. The cause is that the associated parameter group of oven temperature and curing time was split during chunking, so complete business logic cannot be matched during retrieval.
- Text fields are empty after parsing scanned film thickness reports. The cause is that scanned document parsing mode was not enabled, so the system cannot recognize printed test data in images.
How to confirm the configuration is correct
- Upload a single scanned film thickness report, and check if the parsing result includes film thickness values and corresponding test date fields.
- Upload multiple coating batch sheets from different batches, and check if the parsing results label source metadata separately per file.
- Test the chunked text fragments to confirm that oven temperature and curing time parameters are not split into different chunks.
- Upload a coating ledger collection within 1000 MB, and check if parsing completes within the preset duration and no timeout errors occur.
The values listed are common starting points and should be evaluated against the reader's own samples.