SLURRY BEHAVIOUR(浆料的性能）续一

It is in the nature of the process that, at the mould build stage, slurry will be gradually used up and fresh material added (it has already been noted that there is a period of instability as the powders and binders disperse, which has a marked effect on the rheology of the slurry).

在制壳生产过程中，浆料会逐渐消耗并需要及时续补新浆料（我们已经了解到，在配浆过程中，耐火粉料和粘结剂相互润湿分散的过程中存在一个不稳定期，这对浆料的流变性能产生了显著影响）。

With the use of high shear premixing, the stabilisation time can be reduced but not completely eliminated. This implies that unless sufficient time is given for rheology adjustment after every fresh addition to the slurry, it will never behave quite consistently from one hour to the next. Some operators allow very little time to establish slurry equilibrium.

使用高剪切预混后（高速搅拌机搅拌），稳定化的时间可以变短（这里的稳定化实际上就是我们平常所说的各种配料相应需要的搅拌时间。），但不能完全没有。（意思是高速搅拌不能代替浆筒的搅拌。）这意味着每次给浆料中续加新料后，必须给予浆料足够的理论调整时间（稳定性），稳定性都不会始终从一小时保持到下一小时。（在稳定之前浆料有一个变化过程。）一些操作员允许极少的时间来建立浆料平衡。

Batch variation in raw materials is another source of variability and can only be eliminated by more stringent control of Particle distribution has hitherto been considered acceptable. Advanced equipment is available for powder characterization and an example is illustrated in Fig. 5. In considering the influence of particle size distribution on slurry behaviour, although the coarser fractions play some part in any sedimentation effect it is the submicron content of a filler that can change the slurry rheology to a remarkable degree. Because the specific surface of the filler, rather than the particle size distribution, has the most significant influence on slurry rheology, specific surface values are quite suitable as a monitor.

原材料批次变化是变异的另一个来源，且只能通过比迄今为止认为可接受的程度更为严格的粒子分布控制来消除。高级设备可用于粉料的特性分析，图5就是这样的一个设备。在考虑颗粒尺寸分布对浆料性能的影响时，尽管粗粒粉在任何沉淀效应中都起到了一定作用，但真正能显著改变浆料流变学性质的是粉料中的亚微米含量。因为粉料的特定表面积，而非粉料粒度分布，对浆料流变学性质的影响最为显著，所以粉料的特定表面积值非常适合作为监测指标。

Filler loading is an important consideration in the slurry formulation but, unfortunately, coating characteristics can be so altered by small variations in submicron particles, that they cannot be controlled if filler surface areas vary from batch to batch.

粉料添加量是粘结剂配方中的重要考虑因素，但不幸的是，由于亚微米颗粒中存在的小量变异，涂层性质会受到很大影响，以至于如果粉料表面面积积在批次间不一致，则涂层性质无法得到控制。

External influences have to a large extent been discussed in relation to the chemistry of the binders. Impurities from the filler, carbonic acid from the air, and the use of tap water, can all affect water based binders- causing them to thicken and thus upsetting the balance between filler loading and draining and coating characteristics-and can also cause further problems at a later stage in the process. Good control of water based primary coats necessitates the use of distilled or de-ionised water and close attention to raw material impurities. This applies particularly if the general usage of the slurry is relatively low, so that the natural replenishment is not being maintained. In such cases it is advisable to remove and discard some of the slurry being held, and to replenish with fresh material on a regular basis.

外部因素对粘结剂的化学性质有很大影响。粉料中的杂质、空气中的碳酸以及使用自来水，都可能影响水基粘结剂，使其粘度变大，从而打破粉料添加量、控料和涂层性质之间的平衡，并且还可能在工艺后期引发更多问题。要很好地控制水基面层涂料，就需要使用蒸馏水或去离子水，并密切关注原材料中的杂质。这一点在浆料总体使用量相对较低、自然补充不足的情况下尤为重要。在这种情况下，建议定期移除并丢弃部分持有的浆料，并用新材料进行定期补充。