Hand-Assembled Footwear

Hand-Assembled Footwear
The footwear industry is an important outlet for rubber. Hand-assembled footwear is one of its products.
Although this method is labour intensive, it still has its advantages in that it allows for greater flexibility in changing product design without the need for acquiring new and sometimes expensive equipment. Some all-rubber industrial and Wellington boots and canvas-topped sports shorts are still made by this method.
A pair of all-rubber industrial boots may consist of 40 rubber or rubberized fabric component parts, each prepared and cut to the required shape prior to assembly. These parts consist of the outer rubber leg, outer rubber vamp, fabric leg lining, fabric vamp lining, insole, toe and heel reinforcements, foxing strip, sole and heel.
The calendered sheet for the production of outsoles is produced on a four roll calendar where the fourth roll is engraved with the necessary sole pattern. Any required sole design and thickness is obtained by changing the fourth roll.
The component, freshened by a solvent wipe or thin rubber solution, are assembled in a specified sequence, tightly on the metal last and then thoroughly rolled to ensure good bonding.
For canvas-topped footwear, the fabric components are die cut and machined together to form the upper, and on to which eyelets and heelpieces have been fitted. This is lasted on to the last, and the necessary rubber components attached.
Vulcaniation is carried out in a large cylindrical autoclave heated mternally by steam coils fitted in the base and around the sides. The boots or shoes are loaded on to carries and wheeled into the autoclave. Immediately the autoclave doors are closed, air, at a pressure of some 3kg/cm2, is admitted to offset any blistering of blowing of the outer rubber parts. The temperature gradually rises to 135oC, where it is then maintained for the remainder of the vulcanizing period, which is normally 60~65min, in total.
Because of the different thickness of rubber components and the hot-air method of vulcanization, the compound need to have a plateau-type curing system to avoid degradation. Accelerator system based on thiazoles with TMTD as a booster have been proved effective.



New Words and Expressions
1. footwear 鞋类
2. outlet 排水口，出口
3. labour 劳动，劳动大众
4. intensive 强烈的，加强的
5. expensive 昂贵的，花钱多的
6. boot 靴子，（美国）长筒靴
high boots (英国)长筒靴
Wellington boot 长筒靴，高筒鞋
7. canvas topped 布面
8. sports shoes 运动鞋
9. rubberized 涂胶的，挂胶的
10. prior 早先的，更重要的
prior to 在……之前
11. leg 腿，腿统
12. vamp 鞋面，鞋帮
13. line 镶里子，衬里
leg lining 统里
14. insole 中底
outsole 大底
15. toe 趾，脚趾，足尖，鞋头
toe reinforcement 护趾布
16. heel 脚后跟，鞋（袜）后跟
heel reinforcement 护跟布
17. foxing 沿条，围条（胶鞋）
foxing strip 沿条，围条
18. sole 脚底，鞋底，袜底
sole pattern 大底花纹
19. engrave 雕刻，刻上
20. freshen 使新鲜
21. wipe 涂刷
22. specify 指定，详细说明，列举
23. sequence 连续，序列，顺序
24. tight 紧紧的
25. last 鞋楦
继续，维持，套
26. thoroughly 彻底地，充分地，完全地
27. bond 契约，债券，联结
28. die 硬模，冲模，钢型
die out 冲切
29. upper 鞋帮，鞋面
上部的
30. eyelet 鞋跟
31. heelpieces 护跟布
32. attach 加上，帖上，系上
33. coil 圈，盘，盘管
34. immediate 立即，紧接的
35. admit 允许，进入
36. offset（offset, offset, offset, offsetting） 抵销，弥补，去除，注销
37. blister 气泡，鼓泡
38. blow 发泡，鼓泡
39. total 总计的，完全的
40. plateau 高原，高层，由线的平稳段
a plateau-type curing system 平坦型硫化体系
41. degradation 降解
42. thiazole 噻唑类
43. bootster 第二促进剂