Experiment § Phosphate-based inorganic adhesives
There are many types of reactive inorganic adhesives, with the two most representative categories being silicate-based and phosphate-based adhesives. Today, we are going to introduce phosphate-based inorganic adhesives are known for their heat resistance, thermal insulation, and extremely low coefficient of thermal expansion. A test specimen with a thickness of 8.3mm was exposed to a 2500℃ flame for 30 seconds, after which the material showed no significant damage (Figures 1 and 2). The central thickness was reduced to 5.4mm, losing only 2.9mm, corresponding to an average loss of 0.097mm per second. During the test, the temperature on the back side of the specimen increased from approximately 30℃ to 75℃ over the 30 seconds. After extinguishing the flame, the temperature gradually rose to about 170℃ (Figure 3). This test demonstrates this adhesive's excellent heat resistance and thermal insulation properties. TMA test results show that its coefficient of thermal expansion is only around 8ppm/℃, making it suitable for bonding with ceramic materials such as alumina (Figure 4). In addition to ceramics, this material is also suitable for bonding with metals such as SUS 304, SUS 316, and copper, with a shear adhesive strength of about 20kgf/cm². As for curing conditions, since the material uses water as a solvent, it requires 7 days at room temperature for curing. If heating is used, the curing process must follow a specific sequence: 1 hour at room temperature, 1 hour at 80℃, and 1 hour at 120℃. The temperature should be increased step by step to prevent the rapid evaporation of water, which could generate excessive bubbles and affect performance.
— Author: Dr. Yeh Cheng-Yang
Activity § Rollins College visits our factory
Rollins College recently visited our factory. To ensure smooth communication with the foreign students, we practiced spoken English with our English teachers in advance. The visit included a factory tour, an introduction to the production process, instrument operation, and DIY. After the visit, the teachers and students shared their feedback: "We gained insights into the production and application of adhesives. The products have various applications, from sports to the automotive industry. The enthusiastic employees and excellent factory environment left a deep impression on us." We are glad to have provided students and teachers from different countries with a better understanding of Taiwan's manufacturing industry.
Knowledge § What is physical aging?
When polymers undergo molding, their molecular chains do not necessarily settle in the lowest energy state. For example, if the cooling process from high temperature to room temperature is too rapid, the molecular chains may not have enough time to arrange themselves properly. When the material is left at room temperature, the molecular chains gradually move toward a lower energy state, resulting in a tighter arrangement and increased entanglement between chains. From a macroscopic perspective, this leads to an increase in density and tensile strength but a decrease in toughness. This phenomenon is known as physical aging. Physical aging is reversible—if the material is reheated and then cooled again, it will return to its pre-aging state. Due to this characteristic, materials are typically left at room temperature for several days to stabilize before measurements are taken for more accurate results.
Living § Nantou Sun Link Sea
Nantou Sun Link Sea Resort is located in Zhushan Township, Nantou County, renowned for its diverse and ever-changing scenery throughout the four seasons. Early in the year, tulips and cherry blossoms bloom, peonies and hydrangeas in the middle of the year, and vibrant maple leaves and ornamental cabbages at the year's end. Each flower season attracts numerous visitors. Departing from Yunlin, we took National Highway No. 3 to Zhushan Township. Along the winding mountain road leading to the park, we noticed various animal road signs marking the famous "Chinese Zodiac Curve." Upon arrival, we walked along the forest trails, breathing in the phytoncides and relieving daily work stress. Strolling along the stream, we reached the central Flower Exhibition Center, where seasonal flowers were in full bloom, creating a breathtaking display. The park offers a dining area serving mountain delicacies for those feeling hungry. Leaving the Center and continuing forward, we arrived at Songlong Tribe, home to the famous Songlong Waterfall. If time permits, visitors can challenge themselves to reach the park’s highest point, Tiandi Eye. The route starts from the waterfall, follows the Tian Eye Trail to Tiandi Eye, and returns via the Di Eye Trail, which takes about 1 to 1.5 hours and is suitable for hiking enthusiasts. For those feeling fatigued, shuttle buses are available to transport visitors back to the parking area. — Author: Mr. Chen Yung-Long
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