{'fraction_non_alphanumeric': 0.01936026936026936, 'fraction_numerical': 0.004208754208754209, 'mean_word_length': 5.291005291005291, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Laser Sintering of High Temperature Resistant Polymers with Carbon Black Additives

Abstract Selective laser sintering (SLS) experiments with polyetherketone (PEK) and polyetheretherketone (PEEK) powders are described. The absorption behaviour of the polymer powders has been investigated with respect to the content of carbon black as an IR-absorber in the range from 0.03 to 0.1 wt.%. Laser sintering process studies have been carried out at room temperature using a Q-switched Nd:YAG laser system. The sintering depths of single layer substrates have been determined according to the process parameters, such as laser power, scanning speed and hatch distance. These process parameters have been optimised with the goal of achieving good structural integrity of the substrate. The influence of melt viscosity has been determined by comparing PEEK powders of low and standard melt viscosity. Scanning electron micrographs show the morphology of the original polymer powders and the laser sintered specimens. On the basis of the experimental results a qualitative SLS mechanism is proposed to describe the energy transfer from the carbon black particles to the surrounding polymer powder.