Selection and Application of Wear-resistant Thermocouples for Glass Fiber Filled Plastics

Glass fiber modified plastics are utilized extensively in the manufacturing of mechanical accessories, automobile parts, and electronic structural components due to their high hardness, excellent wear resistance, and good structural strength. However, adding a significant amount of glass fiber powder to the basic materials also puts hot runner internal accessories under exceedingly difficult working conditions. Hard glass fiber particles will constantly scour and rub the surface of thermocouple probes in the high-speed flowing state of molten materials. Additionally, standard thermocouples are very vulnerable to surface wear, probe thinning, and structural deformation in a short amount of time, which can quickly cause temperature measurement performance to fail. In order to respond to such unique production settings, targeted wear-resistant specific thermocouples must be chosen.

In terms of surface treatment technology and raw material selection, wear-resistant thermocouples are improved and optimized based on traditional goods. High-strength hard alloy materials with exceptional resistance to wear and high temperatures are used to make the temperature monitoring probe and outer protective sleeve. This alloy can effectively withstand the continuous scouring and friction of high-hardness glass fiber particles in the melt flow process, prevent rapid thinning and surface scratch damage of the probe, and significantly extend the overall service life of the temperature measuring element because it has a higher surface hardness and stronger impact resistance than regular stainless steel materials. The probe's surface is coated with a high-temperature wear-resistant anti-scratch coating using a special process treatment based on a high-strength base material. This further improves the probe's surface anti-abrasion ability, isolates direct contact erosion between glass fiber and metal matrix, and significantly slows down the rate of wear loss.

Wear-resistant thermocouples use reinforced welding and thickened probe rod designs for internal structural design. Long-term material scouring and mold vibration won't cause bending deformation thanks to the thicker main body construction, which also increases overall compression and bending resistance. The temperature measuring head's welding section is welded using high-strength, high-temperature welding wire, which increases the welding point's firmness, prevents welding joint cracking and virtual connection failure brought on by prolonged alternating impact force, and sustains steady internal signal transmission performance over an extended period of time. In order to keep the internal components from loosening and shifting as a result of external impact force, the wire core structure is simultaneously fixed firmly by the internal high-density insulating filler.

Wear-resistant thermocouples also have specified matching standards for real installation and operation. Make sure the probe is fully secured in place during installation, minimize the space between the probe and the flow channel wall, prevent excessive material impact from an overly projecting position, and suitably lower the wear strength. Control the injection flow rate and melt flow speed sensibly during the production parameter debugging process to prevent excessive flow speed from exacerbating the degree of glass fiber scouring on the probe surface. Check the probe's surface wear level on a regular basis, clean glass fiber residues and surface attachments as soon as possible, and determine whether to replace new products based on the wear state.

Wear-resistant thermocouples are more expensive to buy than regular models, but their long service life and low failure rate can significantly lower the need for frequent accessory replacements, minimize downtime lost due to accessory failure, and ultimately lower overall use costs. The appropriate use of wear-resistant thermocouples can stabilize the hot runner temperature control state, guaranty the continuation of production work, and effectively guaranty the production efficiency and final product quality of high-strength modified plastic parts in the mass production of various glass fiber filled modified plastics.333