Analysis of the whole process of roller chain welding preheating in the production of silicone breast stickers

Analysis of the whole process of roller chain welding preheating in the production of silicone breast stickers

Introduction
In today’s fiercely competitive global market, silicone breast stickers, as a beauty product favored by female consumers, have a growing market demand. For manufacturers engaged in the production of silicone breast stickers, it is crucial to ensure the stability of product quality and the efficiency of production. As a key transmission component in production equipment, the preheating link of the roller chain plays an important role in the welding process. This article will deeply explore the specific operation of roller chain welding preheating in the production of silicone breast stickers, aiming to provide useful reference and reference for relevant practitioners.

1. The importance of roller chain welding preheating
Improve welding quality: Preheating can slow down the cooling rate after welding and effectively prevent the generation of cracks. Appropriately extending the cooling time in the range of 800-500℃ is conducive to the escape of diffused hydrogen in the weld metal, avoiding hydrogen-induced cracks, and at the same time reducing the hardening degree of the weld and heat-affected zone, and improving the crack resistance of the welded joint.
Reduce welding stress: Uniform local preheating or overall preheating can reduce the temperature difference between the parts of the welded workpiece, that is, reduce welding stress, and then reduce welding strain rate, which is conducive to avoiding welding cracks and improving the overall performance and stability of the roller chain after welding.
Adapt to complex working conditions: During the production of silicone breast stickers, the roller chain may be subjected to different degrees of impact and tension. Sufficient preheating can enable the roller chain to better adapt to these complex working conditions in the subsequent use process, reduce damage caused by stress concentration, and extend its service life.

2. Preparation before preheating of roller chain welding
Clean the surface of the weldment: Use professional cleaning tools, such as wire brushes, solvents, etc., to thoroughly remove impurities such as oil, rust, oxides, etc. in and around the roller chain welding part to ensure the cleanliness and dryness of the weldment surface, so as to facilitate the smooth progress of the welding process and improve the welding quality.
Check the equipment condition: Perform a comprehensive inspection and maintenance of the welding equipment, including welding power supply, control box, heating tools, etc. Ensure that the performance indicators of the equipment are normal, the heating elements are not damaged, the electrical connection is reliable, and it can meet the requirements of welding preheating.
Select the preheating method: Select the appropriate preheating method according to the material, size, production site conditions and other factors of the roller chain. Common preheating methods include flame heating, electric heating, induction heating, etc. Flame heating is suitable for large roller chains or situations where the site conditions are relatively simple; electric heating can accurately control the preheating temperature and is suitable for occasions with high preheating temperature requirements; induction heating is fast and efficient, but the requirements for equipment are relatively high.
Prepare temperature measuring tools: Prepare accurate and reliable temperature measuring instruments, such as infrared thermometers, thermocouple thermometers, etc., so as to monitor the temperature of the weldment in real time during the preheating process to ensure that the preheating temperature meets the process requirements.

3. Specific operation steps for roller chain welding preheating
Determine the preheating temperature: The determination of the preheating temperature should comprehensively consider the chemical composition, welding performance, thickness, degree of constraint of the welded joint, welding method and welding environment of the roller chain base material. In general, for roller chains with larger thickness, poorer material and higher degree of constraint, the preheating temperature should be appropriately increased. For example, for some alloy steel roller chains, the preheating temperature may need to reach 150-300℃ or even higher; while for carbon steel roller chains, the preheating temperature can be relatively low, generally between 50-150℃.
Set the heating area: Determine the preheating heating area according to the structure of the roller chain and the welding process requirements. Usually, the heating area should include the weld and the area within a certain range on both sides of the weld. Generally, the two sides of the weld are required to be no less than 3 times the thickness of the weldment and no less than 100mm, so as to ensure that the welded joint can be heated evenly, reduce the temperature gradient and reduce the welding stress.
Start heating: Preheat the roller chain using the selected heating method. During the heating process, the heat source should be kept as stable and uniform as possible to avoid local overheating or uneven heating. At the same time, closely observe the temperature changes of the weldment, use temperature measuring tools to measure the temperature in real time, and keep records.
Insulation treatment: When the temperature of the weldment reaches the preset preheating temperature, it is necessary to carry out insulation treatment for a period of time to make the temperature distribution inside the weldment more uniform and further reduce the welding stress. The insulation time should be determined according to the size, material and other factors of the roller chain, generally between 10-30 minutes. During the insulation process, continue to use the temperature measuring tool to monitor the temperature to ensure that the temperature is not lower than the preheating temperature.

4. Precautions after preheating of roller chain welding
Prevent weldment contamination: During the preheated roller chain welding process, the weldment surface should be prevented from being contaminated by oil, moisture, impurities, etc. Operators should wear clean gloves and use clean tools to operate to ensure a clean welding environment.
Control welding parameters: Strictly control welding parameters such as welding current, voltage, welding speed, etc. in accordance with welding process requirements. Reasonable welding parameters can ensure the stability and welding quality of the welding process, and also help to avoid overheating of weldments or welding defects.
Interlayer temperature control of multi-layer welding: During the multi-layer welding process of the roller chain, the interlayer temperature after each layer of welding should be strictly controlled so that it is not lower than the preheating temperature. If the interlayer temperature is too low, the performance of the welded joint may be reduced and the risk of welding defects may be increased. The interlayer temperature can be maintained by appropriate heating measures or by adjusting the welding process parameters.
Slow cooling after welding: After welding, the roller chain should be cooled slowly in the air to avoid welding stress and cracks caused by rapid cooling. For some special materials or roller chains with higher requirements, appropriate post-weld heat treatment measures such as dehydrogenation treatment and tempering can also be taken to further improve the performance and quality of the welded joint.

5. Common problems and solutions
Uneven preheating temperature: Possible reasons include uneven distribution of heat sources, improper placement of welds, and insufficient heating time. The solution is to adjust the position and angle of the heat source to ensure that the heat source can evenly cover the heating area; check the placement of the weldment so that its distance from the heat source is moderate and uniform; appropriately extend the heating time to ensure that the weldment can be fully heated.
Preheating temperature is too high or too low: If the preheating temperature is too high, the weldment may be overheated, the metal grains may be coarsened, and the quality of the welded joint may be reduced; if the preheating temperature is too low, the preheating effect cannot be achieved, and welding defects cannot be effectively prevented. The solution is to determine the preheating temperature strictly in accordance with the process requirements, and use accurate and reliable temperature measuring tools for measurement and control. If the preheating temperature deviates, the heating power or heating time should be adjusted in time to make the temperature reach the range required by the process.
Inaccurate temperature measurement: Factors such as low accuracy of the temperature measuring tool, incorrect temperature measuring position, and poor contact between the temperature measuring tool and the weldment surface may lead to inaccurate temperature measurement. To ensure the accuracy of temperature measurement, a temperature measuring tool with qualified quality and high accuracy should be selected and calibrated regularly; the temperature measuring position should be reasonably selected, and generally a representative position on the weldment surface should be selected for measurement; when measuring, ensure that the temperature measuring tool is in full contact with the weldment surface to avoid affecting the measurement results due to poor contact.

6. Case Analysis
Take a silicone breast patch manufacturer as an example. During the roller chain welding process, the factory often encountered problems such as welding cracks and insufficient strength of welding joints due to insufficient attention to the preheating link, resulting in low production efficiency and a high rate of defective products. Later, under the guidance of technical personnel, the factory strictly followed the above-mentioned roller chain welding preheating operation steps for production, including carefully cleaning the weld surface, accurately selecting the preheating temperature, uniformly heating the weld, and strictly controlling the insulation time. After a period of practice, the quality of roller chain welding has been significantly improved, defects such as welding cracks have been significantly reduced, the defective rate of products has been greatly reduced, and the production efficiency has increased by about 30%, bringing considerable economic benefits to the enterprise.