【正文】 這很可能是由于重點(diǎn)放在發(fā)展過(guò)程，而不是早年在這一領(lǐng)域的發(fā)展，性能表征。本章結(jié)束時(shí)將在一些涉及微孔技術(shù)目前的研究方向。然而，對(duì)這些材料的熱情仍然很高，今天在各大洲的研究人員和商業(yè)企業(yè)在全球競(jìng)爭(zhēng)中利用的潛在好處。 無(wú)數(shù)的成本優(yōu)勢(shì)和加工優(yōu)勢(shì)，已導(dǎo)致全球快速部署的 MuCell 技術(shù)過(guò)程主要是在汽車(chē)，消費(fèi)電子，醫(yī)療設(shè)備，包裝及消費(fèi)品應(yīng)用。密度的結(jié)合減 少和功能設(shè)計(jì)，結(jié)果往往是節(jié)省材料和重量在 20％以上。誰(shuí)是制造或正在計(jì)劃使用 MuCell 技術(shù)注塑成型工藝制造零件的公司主要是有用的。 SCF的注入，它通過(guò)一個(gè)特殊設(shè)計(jì)的螺桿與聚合物混合每桶。有了正確的設(shè)備配置，模具設(shè)計(jì)和加工條件，這些微孔空洞大小和分布 相對(duì)均勻。這 25 頁(yè)的加工手冊(cè)涵蓋的過(guò)程中設(shè)置的所有方面，解決問(wèn)題，以優(yōu)化的結(jié)果。這些改進(jìn)的結(jié)果，在成型零件，而不是固體成型的非均勻應(yīng)力特性建立相對(duì)統(tǒng)一的應(yīng)力模式。 MuCell技術(shù)的微孔發(fā)泡注塑成型技術(shù)是一個(gè)完整的工藝和設(shè)備技術(shù)，有利于質(zhì)量非常高，大大降低了生產(chǎn)成本。 這項(xiàng)技術(shù) 使用 CO2作為發(fā)泡劑， 并將其注入 到注射機(jī)的塑化部分（圖 1）。一個(gè)適當(dāng)?shù)哪＞咴O(shè)計(jì)能提高生成的孔隙結(jié)構(gòu)，比如孔隙率，孔徑等，并且互相影響。 by mold A this range was35_10 mm to 19_8 mm. This change was also corresponding to thefinding in the mean pore size of foamed implants from two molds. It could be concluded from Figures 3–6 that the improved mold designof mold B could not affect the change tendency of pore structure, such asdecreased pore size with rise of the injection speed, but it could increasethe porosity and the mean pore size as well as the interconnective poresize of the foamed implants. At the same time the standard deviation of pore structure was significantly decreased. In other words the porestructure of foamed implants from mold B had a higher porosity, a largerpore size, and was more uniform than those from mold A. Figure 6. Size of interconnections of implants at different injection speeds. Figure 7 shows the parison of the maximal porosity at differentkinds of process parameter variations, including the injection speed, fromtwo molds. In every kind of process parameter variations, the maximalporosity was always obtained at a same setting value for two molds, suchas 79% and 67% at 300 mm/s by mold B and mold A for the injection speedvariation. It was observed that mold B indicated a higher maximalporosity at every kind of parameter variation. The porosity at 35% weightreduction from mold B showed a minimal elevation of ca. 6% while themaximal porosity elevation of 14% was found by injection speed variation. The differences between the maximal pore sizes at different kinds ofprocess parameter variations of two molds are shown in Figure from two molds showed the maximal pore size also at the sameprocess parameters setting in every kind of variation. The mold B hasalways a larger maximal pore size than mold A. The minimal elevation ofmaxima pore size of mold B was 14% by the plasticizing temperaturevariation, whereas the maximal elevation of pore size with value of 45%was found by the injection speed variation. Figure 7. Differences between the maximal porosity at different processing parametersfor two molds. Figure 8. Differences between the maximal pore size at different process parameters fortwo molds. Figure 7 and 8 have indicated that the improvement of the porestructure, such as maximal pore size and porosity, induced by thechange of mold design could be observed not only in variation of theinjection speed but also in all process parameters variations. Theshortened L/D by mold B led to a decreased energy loss which dominatesthe cell nucleation, during the polymer melt flow in the mold cavity. Therelative thicker implant from mold B needed also a longer cooling time,which was very important for the cell growth in the mold. Consideringthe possibility of interaction of these factors, using formulae of cellnucleation theory to predict the change of final pore morphology is verydifficult in this study, but the effects of mold design on pore morphologysuch as porosity and mean pore size were successfully observed throughthe experiments. CONCLUSION This study was intent to investigate the potential effect of the molddesign on the pore morphology. The improved pore morphology such asthe higher porosity, larger mean pore size, and smaller deviation wasfound by the foamed samples from mold B. This indicated that besidesthe effects of process parameters, the mold design, that is, productdesign has also a distinct influence on the foam behavior of foamingprocess, which has given the possibility to improve the pore morphologythrough a more suitable mold design if the process parameters arelimited. 模具設(shè)計(jì)對(duì)微孔泡沫注塑技術(shù) MuCell 生產(chǎn)的聚合物孔結(jié)構(gòu)的影響 摘 要 在這項(xiàng)研究中，兩副模具都用微孔泡沫注塑技術(shù) MuCell 設(shè)計(jì)和使用以生成具有多孔結(jié)構(gòu)的植入物。C to introduce the microcellular structure without an appreciable density change, to increase the fatigue life of a part. Due to the low processing temperatures, very little dimensional change was observed in the experiments. The tensile data for all gaspolymer systems investigated falls on one reduced plot where relative tensile strength can be plotted against the relative density, as is shown in Figure . However, energy absorption measures, such as an impact test, are more sensitive to variations from polymer to polymer, and the results cannot be generalized. Gardner Impact Strength for PVC foams [11] with relative densities of and higher. It is seen that the impact strength decreases linearly with foam density. This result is contrary to the popular belief, long held without proof, that the microcellular structure will always improve the energy absorption behavior due to the increased resistance to crack propagation offered by the micro voids [12]. Some studies have investigated the relations between the key processparameters in MuCell_ technology and produced cellular foam structure[1,5,6]. It was found that the pore morphology in MuCell_ process couldbe adjusted through varying the process parameters. However, there iscurrently no literature regarding the effects of mold design on the poremorphology by MuCell_ technology. In this study two molds were designed and used in MuCell_ process togenerate implants wit