温敏型胶体对玉米淀粉3D打印固化性能的影响

Effect of Temperature Sensitive Colloid on 3D Printing and Curing Properties of Corn Starch

目的:利用温敏型胶体的相转变特性,辅助实现淀粉在打印过程中的成型固化,并揭示不同种类胶体-淀粉体系的固化性能变化规律。方法:将不同比例的温敏型胶体(低酰基结冷胶、明胶、κ-卡拉胶)与玉米淀粉进行复配并测定其流变性能,通过打印圆柱及空心球模型、测试产品力-位移曲线、温度扫描流变、全质构分析及微观结构观测评估体系可打印及固化性能。结果:结冷胶和卡拉胶在2%~4%添加量,明胶在0%~2%添加量时,体系具有适宜的流变性能及良好的可打印性能。添加4%结冷胶及4%卡拉胶的产品表现出显著的塑性,固化效果较好;添加明胶的打印产品无显著塑性,打印产品不固化。结冷胶-淀粉混合体系的固化温度在35~43℃之间;卡拉胶-淀粉混合体系的固化温度在30~40℃之间,随着胶体含量增加,固化温度上升,固化速度加快。而随着明胶含量增加,固化温度从25℃下降至20℃以下且固化速度减慢。4%低酰基结冷胶产品具有更致密的凝胶网络,硬度高于4%κ-卡拉胶产品。明胶对硬度、弹性都有削弱作用,但使粘附力大幅提高。结论:适宜含量的低酰基结冷胶和κ-卡拉胶能够实现淀粉的成型固化,且卡拉胶固化性能优于结冷胶,而明胶则无辅助固化能力。

Objective:To assist the molding and curing of starch in 3D printing,and to reveal the change law of curing properties of different hydrocolloid-starch systems based on the phase-change characteristics of temperature-sensitive hydrocolloids.Methods:Three hydrocolloids,low-acyl gellan gum,gelatin,andκ-carrageenan,respectively,were mixed with corn starch at different ratios for evaluating their rheological properties.The printability and curing performance were evaluated by printing cylinder and hollow sphere models,testing force-displacement curves,temperature sweep rheology,whole-texture analysis and microstructure observation.Results:When gellan gum andκ-carrageenan were added at 2%~4%and gelatin at 0%~2%,the system had suitable rheological properties and good printability.The products with 4%gellan gum and 4%κ-carrageenan showed remarkable plasticity and better curing effect.Whereas the products with gelatin was not significantly plastic and cured.The curing temperature of gellan gum-starch system andκ-carrageenan-starch system were between 35~43℃and 30~40℃respectively,meanwhile,the curing temperature and speed increased with the increase of hydrocolloids content.However,as the gelatin content increased,the curing temperature decreased from 25℃ to 20℃ and the curing speed slowed down as well.The products with 4%low-acyl gellan gum had a denser gel network,which was harder than that with 4%κ-carrageenan.Gelatin weakened the hardness and elasticity,but greatly increased the adhesion.Conclusion:Appropriate low-acyl gellan gum andκ-carrageenan contributed to the molding and curing of starch,and the curing performance ofκ-carrageenan was better than that of gellan gum,while gelatin had no auxiliary curing ability.