I. Preparation Before Application: Accurate Diagnosis and Solution Design
The effective use of textile auxiliaries begins with meticulous preparation, not simple addition.
1. Fabric and Target Analysis:
It is essential to clearly identify the fiber composition of the fabric to be treated (cotton, polyester, blends, etc.), its structure, and the status of previous processes (such as bleaching and dyeing). Simultaneously, clearly define the finishing objectives: is it to achieve softness, waterproofing, wrinkle resistance, or a combination of multiple functions? Different objectives correspond to completely different auxiliary selections and process routes.
2. Scientific Selection and Blending of Auxiliaries:
Based on the diagnostic results, select targeted auxiliaries. Emphasis should be placed on checking their ionic nature (anionic, cationic, non-ionic) to prevent charge conflicts with residual auxiliaries on the fabric or other auxiliaries used in the same bath, which could lead to precipitation. Complex functions often require the blending of multiple auxiliaries; **small-scale compatibility tests** must be conducted to verify their stability and synergy, avoiding mutual cancellation of effects.

II. Core Application Process: Precise Control of Process Parameters
This stage is crucial in determining the finishing effect and requires systematic control of various parameters.
1. Working Solution Preparation:
Follow the principle of "dilute first, then add." Most auxiliaries need to be fully diluted with an appropriate amount of warm water (at the temperature specified in the instructions) before being slowly added to the mixing tank, and continuously stirred until uniform. Directly pouring in high-concentration stock solution can easily lead to localized aggregation and uneven effects.
2. Application and Liquor Pick-up Rate Control:
Whether using the immersion method (such as for yarns and garments) or the padding method (such as for continuous fabrics), temperature, pH, and time must be precisely controlled. The key indicator is the liquor pick-up rate (the percentage by weight of the working solution carried by the fabric), which directly affects the amount of auxiliary attached. This needs to be kept stable and consistent through roller pressure or dewatering rate to ensure uniformity of effect in batch production.
3. Subsequent Fixing Treatment:
Most auxiliaries (such as resins, waterproofing agents, and some softeners) require subsequent baking (setting) to complete the cross-linking reaction or firm attachment. The temperature and time requirements of the process must be strictly followed.  Too low a temperature or insufficient time will lead to poor performance and lack of wash durability; too high a temperature may cause fabric damage or decomposition and yellowing of the auxiliaries.

III. Effect Verification and Production Optimization
Application completion is not the end point; continuous optimization must be achieved through closed-loop management.
1. Standardized Effect Evaluation:
After the fabric has fully regained its moisture balance, the effect is evaluated from multiple dimensions, including subjective hand feel assessment, physical performance tests (elasticity, tear strength), functional tests (waterproof rating, UV protection index), and wash durability tests. Standards are established, and data changes before and after treatment are compared.
2. Process Recording and Adjustment:
Detailed records of process parameters, auxiliary batches, and environmental conditions for each batch are kept. When fluctuations in effect occur, the cause can be traced back – is it an auxiliary problem, a process deviation, or a difference in fabric batches? Precise adjustments are made based on data and records to form a stable production process.

Conclusion: The efficient application of textile auxiliaries is a systematic engineering process that spans the entire "diagnosis-design-control-verification" process. Its core lies in precision – precisely understanding the substrate and requirements, precisely controlling every process parameter, and achieving closed-loop optimization through scientific evaluation. Only in this way can the chemical potential of the auxiliaries be stably and efficiently transformed into excellent and lasting functions and quality in the fabric.