Mask-based zonal preheating apparatus and zonal preheating method thereof

Abstract

The invention belongs to the technical field of quick manufacturing equipment and particularly relates to a mask-based zonal preheating apparatus and a zonal preheating method thereof. A global heating light source and a local preheating light source are used with a base plate of a forming cylinder to heat bottom powder; a mask is arranged between the local preheating light source and the global heating light source; a local preheating zone is coated with powder to be sintered; all the local preheating light source, the mask and the global heating light source are connected with a temperaturecontroller; a temperature control probe of a temperature monitor and a thermal imager are arranged in a working chamber to detection powder temperature. The method of decreasing total working temperature of a forming cylinder and decreasing cooling pressure of the apparatus helps increase working stability and continuous operating time of zonal laser sintering equipment and allows quick sinteringfor high-melting-point powder and multiple recycling for the powder.

Description

technical field [0001] The invention belongs to the technical field of rapid manufacturing equipment, and in particular relates to mask-based partition preheating equipment and a partition preheating method thereof. Background technique [0002] SLS (selective laser sintering, selective laser sintering) technology is a rapid prototyping technology that uses laser as an energy source to sinter powder materials layer by layer into a three-dimensional entity. Polymers, metals, ceramics, etc. can all be used in SLS. In order to reduce deformation and warpage and increase laser utilization, when polymer materials are used for SLS, the materials in the powder bed are generally preheated to a temperature slightly lower than the melting point of the materials, which is the preheating temperature. Preheating temperature is an important parameter that affects the precision and performance of parts: when the preheating temperature is low, warping will occur during the forming process, ...

AI Technical Summary

Problems solved by technology

Preheating temperature is an important parameter that affects the precision and performance of parts: when the preheating temperature is low, warping will occur during the forming process, the part will be deformed, the precision of the part will decrease or it will be difficult to form; when the preheating temperature is too high, the unsintered The powder is compacted due to adhesion and cannot be recycled and reused, which greatly increases the printing cost

Especially for some special engineering plastics with high melting point (melting point ≥ 300 ℃) or aging materials, such as PEEK (polyether ether ketone), PI (polyimide), etc., the preheating temperature is high (≥ 300 ℃), And the warm-up range is narrow

On the one hand, the bearings, slide rails and other components in the forming chamber are exposed to high temperature for a long time, and the aging speed is accelerated, so that the continuous working time and long-term working stability of the forming machine are greatly reduced; on the other hand, the materials of such high melting point polymers The cost is often double or several times that of low melting point materials such as nylon and wax powder. If the unsintered powder is hardened during the forming process and it is difficult to reuse it, the production cost will increase significantly

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