1643
The second approach is where the parts above are used in a secondary furnace cycle to burn off the polymer and cause the metal particles to sinter together .
 machine or equipment: furnace; material: polymer; material: metal; manufacturing process: sinter
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 machine or equipment: furnace; material: polymer; material: metal; manufacturing process: sinter