以海藻酸钠/明胶溶液为打印材料，采用3D低温沉积成形（LDM）技术在6℃成形环境下打印成线材，对比研究了挤出压力、溶液黏度和喷头速度对试验得到的和理论计算得到的挤出胀大率和挤出拉伸率的影响，确定了最佳打印参数，并探讨了在最佳打印参数下打印件的尺寸精度。结果表明：线材的挤出胀大率随溶液黏度的增加而减小，随挤出压力的增加而增大，挤出拉伸率随喷头速度的增加而增大；最佳打印参数为溶液黏度1.26 Pa·s、挤出压力80 kPa、喷头速度8 mm·s^-1，此时线材的成形效果较好，试验值和理论计算值的相对误差最小；在最佳打印参数下，基于挤出胀大率和挤出拉伸率的理论计算结果对打印件尺寸进行调整，调整后打印出的矩形件和空心圆环实际尺寸与设计尺寸的相对误差小于5%，打印精度较高。

With sodium alginate/gelatin solution as printing material, 3D low-temperature deposition manufacturing (LDM) technique was applied to print wires in the forming environment at 6℃. The effects of extrusion pressure, solution viscosity and nozzle speed on extrusion swell rates and extrusion stretching rates obtained by experiment and theoretical calculation were studied and compared. The optimum printing parameters were obtained. The dimensional accuracy of the printed parts with the optimum printing parameters was discussed. The results show that the extrusion swell rate of the wire decreased with the solution viscosity increasing and increased with the extrusion pressure increasing; the extrusion stretching rate increased with the increase of the nozzle speed. The optimum printing parameters were listed as follows:solution viscosity of 1.26 Pa·s, extrusion pressure of 80 kPa and nozzle speed of 8 mm·s^-1. With this process, the forming effect of the wire was relatively good, and the relative error between tested and theoretical values was the minimum. With the optimum printing parameters, the dimensions of printed parts were adjusted on the basis of theoretical calculation of extrusion swell rate and extrusion stretching rate. After the adjustment, the relative errors between the actual and designed size of the printed rectangular part and hollow ring were below 5%, indicating a relatively high printing accuracy.