Determine surface target first, then compare abrasives
Abrasive material, shape, particle size, and hardness affect impact pattern, cleaning action, and surface profile. Selection should be based on realistic rust, scale, coating requirements and workpiece geometry, while adhering to applicable blast wheel and circulation system requirements. Existing processes cannot be replaced just because an abrasive is cheaper.
The functional characteristics of round steel shot and angular steel grit are different. Whether to use them alone or in proportion should be confirmed by the equipment and consumables plan. Media suitable for compressed air blasting cannot be thrown into wheeled shot blasting equipment without checking, nor can the particle size or hardness be directly increased in pursuit of a rougher surface.
The new material specification is not equal to the actual particle size at runtime
After the abrasive circulates, it gradually wears and breaks, and at the same time, oxide scale, dust and other impurities are mixed. The combination of particle sizes being used in the equipment is called the working mix and it is directly involved in cleaning. The original packaging particle size only describes the new material being replenished and cannot represent the state after hours or days.
| object | What should be recorded | Problems to avoid |
|---|---|---|
| New material | Material, grain size, hardness, batch and supply specifications | Different specifications are mistakenly mixed or batches cannot be traced |
| working mix | Specifies sampling locations, screening results, contamination and moisture status | Only look at whether the silo is sufficient, not the effective granularity |
| Separating waste | Scrap composition, abnormally large particles, or loss of usable abrasive | Misplacement of qualified abrasives, or fine powder not effectively discharged |
Feed and separator settings should be controlled jointly
The frequency and quantity of feeding materials are determined according to equipment operation and quality requirements to avoid significant fluctuations in the working mixture caused by feeding a large amount of new materials at one time. Check the label and drying status before replenishing materials, and record the corresponding surface results after changes. The actual operation and allowable adjustment range are subject to the equipment manual.
The separator does not discard all small particles uniformly. Its task is to maintain the abrasive state required by the program and to remove material that is not suitable for continued circulation. When adjusting, you should check the sampling and waste materials, rather than changing the settings based on more dust or less abrasive.
If the surface is abnormal, investigate based on evidence
| phenomenon | Check direction | Review method |
|---|---|---|
| Decline in cleanliness | Whether the effective abrasive, supply, coverage and actual incoming material have changed | Keep representative parts and operating conditions and compare them item by item |
| The outline is thicker or thinner | Working granularity, media mix, operating parameters and measurement methods | Cross-checking of screening and profile measurements |
| Sudden increase in consumption | Leakage, carryover, separation misalignment, and batch changes | Also check the recycling path and waste composition |
| Abnormal stains appear on the surface | Incoming oil pollution, abrasive pollution and storage environment | Isolate the source of pollution and re-inspect after processing according to the process |
| Abrasive agglomeration or unstable flow | Moisture, contamination, material accumulation and abnormal recovery and transportation | Stop and isolate for inspection according to the manual, and force feed materials without failure |
Cost comparison should use qualified workpieces as the denominator
When comparing consumable costs, use the same product mix, surface requirements, and conforming output, recording new material additions, changes in available inventory, scrap, and carry-out losses. Comparing only purchase unit prices will miss changes in cleaning cycles, rework and wearing parts.
Records for each batch or shift can be established: scope and quantity of workpieces, working hours, replenishment and abnormal losses, inspection results and maintenance matters. There is no need to commit to a uniform kilogram/ton first; only by forming a record of the same conditions can we judge whether replacing the media will really improve costs.
Perform the same inspection process before and after changing the abrasive
- Confirm the compatibility of the new specifications with the equipment and consumables data, and check the impact on wearing parts and separation systems.
- Keep representative part results, working mixes, and operating records under original operating conditions.
- Handle residual materials, supplementary materials and necessary settings in accordance with the approved method, and do not mix materials at will.
- Check cleanliness, contours and specified contaminants using the same measurement method.
- Update the process card and inventory identification after passing the test, and continue to observe consumption and surface stability.
These dates show the proposed editorial schedule for this preview; they do not represent previous publication.