Special and Comprehensive Review

• XU Qijun,WANG Xiaolong,LIU Min,LI Zhichao,YAN Xuelong,QIN Nianrong and HUA Runjia
• Performance Evaluation and Application Progress of Bio-based Polyamide 56 Dipped Cord

• 2024 Vol. 44(4): 0195-0201

  [Abstract](109)

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• Abstract:The research was conducted on the properties of bio-based polyamide 56（PA56） dipped cord and its application was introduced.The results showed that PA56 dipped cord had good heat resistance，fatigue resistance，adhesion and dynamic mechanical property.Using PA56 dipped cord as reinforcement material for the cap ply of steel-belted radial tire，the performance of tires produced from Q-grade to Y-grade had reached the level of tires produced using traditional petroleum based polyamide 66 dipped cord，and had the effect of reducing carbon emissions.

• CHEN Renquan,WANG Jun,JIA Chunhui,TANG Ming,ZHOU Lei and SUN Xiangyang
• Study on Tangential Harmonic Force of High-speed Uniformity of Passenger Car Radial Tire

• 2024 Vol. 44(4): 0202-0204

  [Abstract](112)

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• Abstract:The tangential harmonic force values of high-speed uniformity of passenger car radial tire were studied.The results showed that the amplitude of the first harmonic of tire tangential force（TFV1H） increased with the increase of tire speed and showed a geometric growth trend.The relationship between tire TFV1H amplitude and speed could be represented by a power function model.The two coefficients of the power function model for different tires were different，but they had a good linear relationship.The relationship between tire TFV1H amplitude and speed could be determined as a power function model with only one undetermined constant.

Structure Design

• LIU Jie,XU Wei,WANG Jun,MA Lihua,DONG Kang,JIAO Dongdong and LIU Junjie
• Design on 255/45R19 104W New Energy Vehicle Tire

• 2024 Vol. 44(4): 0205-0208

  [Abstract](135)

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• Abstract:The design on 255/45R19 104W new energy vehicle tire was introduced.In the structure design，the following parameters were taken：overall diameter　707 mm，cross-sectional width　270 mm，width of running surface　222 mm，arc height of running surface　7.33 mm,，bead diameter at rim seat　486 mm，bead width at rim seat　236 mm，and maximum width position of cross–section（H₁/H₂）　0.92.The tread pattern design adopted a five variable pitch，pattern depth　7.3 mm，block/total ratio　72.47%，and mumber of pattern pitches　88.In the construction design，the following processes were taken：adopted 2 layers of 1670dtex/2 polyester cord for carcass，2×0.30ST steel cord for belt，1400dtex/2 nylon 66 cord for crown strip，and using one-stage building machine to build tires and nitrogen vulcanization process to cure tires.The test results of finished tire showed that，the inflated peripheral dimention，strength，bead unseating resistance，high-speed performance and durability of the tire all met the corresponding national standards or design requirements.

• LIU Kun,WANG Jun,LUO Baoyu,WANG Chaohua and LIU Wenguo
• Improvement of High-speed/Durability Performance of Light Truck and Bus Tire

• 2024 Vol. 44(4): 0209-0213

  [Abstract](127)

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• Abstract:The testing principle and method of the high-speed/durability performance testing of the tire was introduced，the common failure modes and stresses on different areas of light truck and bus tire were analyzed，and measures to improve high-speed/durability performance of the tire were proposed.The failure modes of the tire in high-speed performance and durability performance tests were relatively similar，but the failure areas of the tire in high-speed performance test were more reflected in the shoulder，while those in durability performance test were more reflected in the bead.Reasonable profile and material distribution were beneficial for maintaining good high-speed/durability performance of light truck and bus tire.Thinning of the tread/sidewall and increasing the thickness of the ply coating could effectively improve the high-speed performance of the tire.Measures such as using 2-layer carcass cords for reverse wrapping，using low hardness apex，applying adhesive reinforcement film，and using carcass cords with thick adhesive coating were all beneficial for improving the durability performance of the tire.

Material·Compounding

• CONG Minghui,XU Yi,LI Chao,CUI Xiao,ZHOU Pengcheng and DONG Lingbo
• Effect of Relative Molecular Weight of NR on Properties of Carcass Compound of Truck and Bus Radial Tire and Its Rapid Characterization Method Evaluation

• 2024 Vol. 44(4): 0214-0219

  [Abstract](104)

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• Abstract:The effect of relative molecular weight of natural rubber（NR） on the properties of the carcass compound of truck and bus radial tire was studied，and different methods were used to characterize the relative molecular weight of NR.The results showed that the relative molecular weight of NR was positively correlated with the Mooney viscosity of the compound，and negatively correlated with the Mooney scorch time and tackiness of the compound.The comprehensive physical properties of RSS3 vulcanizate were the best，while the comprehensive physical properties of 10# standard vulcanizate were the worst.There was a strong correlation between the relative molecular weight of NR within a certain range and the H extraction force of the vulcanizate.The initial plasticity value and Mooney viscosity of NR could only roughly represent the relative molecular weight of NR，while complex viscosity could effectively represent the relative molecular weight of NR.

• ZHAO Xiangshuai,LIU Huaqiao,GU Peishuang,WEI Jianxin and ZHU Jiashun
• Effect of Highly Modified Solution Polymerized Styrene Butadiene Rubber on Performance of Electric Vehicle Tire Tread Compound

• 2024 Vol. 44(4): 0220-0222

  [Abstract](115)

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• Abstract:Using the tread formula of electric vehicle tire in production as the basic formula，different grades of solution polymerized styrene butadiene rubber（SSBR） were used for equal replacement，the effect of SSBR microstructure on the curing characteristics，physical properties and dynamic mechanical properties of the tread compound were studed.The results showed that under the premise that the properties of the compound were equivalent，the double-end functionalized SSBR with higher vinyl content had lower hysteresis loss，resulting in lower rolling resistance of the tire.

• LIU Wenguo,DONG Kang,ZHAO Xiaodong,CHEN Yating,WANG Lufei,XU Jingjing and LIANG Xue
• Application of Silane Modified Liquid Polybutadiene Rubber in Silica Filled Tread Compound

• 2024 Vol. 44(4): 0223-0227

  [Abstract](121)

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• Abstract:The apread compound was studied.The results showed that using ST-E 60 in equal amounts to replace cyclohexane oil，the Mooney viscosity of the compound decreased，Mooney scorch time was prolonged，theF_LandF_max were decreased，the t₉₀plication of silane modified liquid polybutadiene rubber Polyvest EP ST-E60（referred to as ST-E60） in the silica filled t was shortened，the Payne effect was weakened，and the dispersibility of silica improved.The wear resistance of the vulcanizate improved，the rebound value increased，and the dynamic heat build-up decreased.The larger the amount of silica used in the tread compound formulation system，the more significant the improvement effect of ST-E60 on the properties of the compound.

• WANG yandong and CHEN Yimin
• Application of Highly Dispersed Zinc Oxide ZX-G905 in Tread Compound of All-steel Radial Tire

• 2024 Vol. 44(4): 0228-0231

  [Abstract](103)

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• Abstract:The application of highly dispersed zinc oxide ZX-G905 in the tread compound of all-steel radial tire was studied.The results showed that the zinc content of the highly dispersed zinc oxide ZX-G905 was only 50% of that of indirect zinc oxide.Replacing indirect method zinc oxide with equal amount of ZX-G905 in the tread compound，the vulcanization characteristics，physical properties and aging resistance of the compound were equivalent，and the actual amount of zinc oxide could be decreased，and the environmental pollution was reduced.

• Liu Huiying,Wang Yan,Xu Qi and Li Chongbing
• Optimization of Tread Compound Formula for Mud Tire

• 2024 Vol. 44(4): 0232-0235

  [Abstract](109)

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• Abstract:The tread compound formula for large-sized mud tire was optimized.The results showed that compared with normal formula compound，the modulus at 300% of optimized formula compound increased，the DIN wear was improved，and other physical properties were equivalent，the loss factor at 60 ℃ was reduced by about 20%，the compression heat build-up was reduced，and the compression burst time was prolonged.Compared with the production tire，the high-speed performance of the optimized tire improved，which met the requirements of enterprise standards.

Technology · Equipment

• CHENG Yingui and ZHANG Fujin
• Research on Factors Influencing Uniformity of Cord Fabric Thickness and Solutions

• 2024 Vol. 44(4): 0236-0241

  [Abstract](108)

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• Abstract:The factors affecting the uniformity of cord fabric thickness and solutions were studied.The results showed that by optimizating conventional process parameters（such as adjusting axis crossing values and pre-bending stresses） couldn’t effectively increase unifornity of cord fabric thickness.The fundamental reason for the saddle shaped distribution of unifornity of cord fabric thickness was the damage and deformation of the roller in the overlapping area of the bubble knife stroke，and replacing the roller was the fundamental method to solve the problem.After replacing the roller，the range uniformity of cord fabric thickness decreased from 0.20 mm to below 0.05 mm，which could meet production requirements.

• liuqing,yangwenqiang and gongchao
• Cause Analysis and Solution of Holographic Bubbles in Crown of All-steel Truck and Bus Radial Tire

• 2024 Vol. 44(4): 0242-0244

  [Abstract](117)

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• Abstract:The causes of holographic bubbles in the crown of all-steel truck and bus radial tires were analyzed and the corresponding solutions were proposed.The holographic bubbles in the crown of finished tires were generated between the belt layers and between the tread and belt layers，mainly due to the viscosity variation of the semi-finished product.Unreasonable rolling trajectory could exacerbate this phenomenon. By adjusting the viscosity of the compounds and optimizing the structure and pressing trajectory of the buildng equipment，such problems could be basically solved.

Test·Analysis

• ZHANG Weiwei,ZHANG Yongfeng and ZHANG Mengjie
• Simulation Optimization of Footprint of 215/75R22.5 All-steel Truck and Bus Radial Tire

• 2024 Vol. 44(4): 0245-0249

  [Abstract](125)

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• Abstract:Taking 215/75R22.5 all-steel truck and bus radial tire as the research object，simulation optimization of tire footprint was carried based on the experimental design method（referred to DOE）.The results showed that，with weighted shape factor（C_W） as the optimization objective，the simulated footprint of the optimized tire was basically rectangular，and the optimization effect was ideal.Crown arc height was the most significant factor affecting C_W.

• JIANG Ming
• tire X-ray image；image processing；deep learning；defect detection

• 2024 Vol. 44(4): 0250-0255

  [Abstract](99)

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• Abstract:The defects in tire X-ray images were detected automaticly by using deep learning methods based on image processing.Tire X-ray images had the characteristics of high resolution，narrow shape and small defect targets.By dividing each X-ray image into 640×640 pixels cutted，annotating each cutted region，the defective regions were divided into a training set，and the training set was histogram balanced to enhance the contrast between the foreground and background of the image.Further data augmentation was performed on the training set to improve the model’s generalization ability.Finally，the optimal weights were trained on the Faster R-CNN deep learning defect detection model.In the model inference stage，the complete X-ray image would be fed into the model，the defect range would be framed，and reassembled into the original X-ray image，and if a defect had multiple boxes，all adjacent boxes were combined into one box.The method could effectively reduce the missed detection rate of small defect targets，improve the accuracy of detection，and indirectly solve the problem of feature loss in the original X-ray image.

Domestic and Foreign News

• 赵敏
• 凯力威科技获两项实用新型专利授权

• 2024 Vol. 44(4): 0201-0201

  [Abstract](86)

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• Abstract: