Suppression of Surface Waviness Error of Fresnel Micro-Structured Mold by Using Non-Integer Rotation Speed Ratio in Parallel Grinding Process

Fresnel micro-structured lenses are widely used in the field of modern optoelectronic technology. High-precision Fresnel micro-structured mold is the key technology to achieve its large-scale replication production. Focusing on the surface waviness error of Fresnel micro-structured mold machined by parallel grinding process, this paper conducted theoretical modeling and experiment research. Based on the grinding kinematics theory, the simulation models of the surface waviness topography and the circular waviness profiles of the ground Fresnel micro-structured mold were developed, considering the combined influence of the non-integer rotation speed ratio and other grinding parameters. A series of grinding experiments were carried out to verify the proposed simulation models. The influence of a non-integer rotation speed ratio and a wave-shift value upon the surface waviness error of the ground Fresnel micro-structured molds were analyzed. Both the simulation and experimental results proved that choosing the non-integer rotation speed ratio and a proper wave-shift value could greatly reduce the surface waviness error and improve the surface quality and uniformity.

VIBRO-CENTRIFUGAL UNITS FOR COMPLEX PROCESSING OF TECHNOGENIC MATERIALS

The article deals with the problem of complex processing of technogenic anisotropic materials. The direction of production activity, which requires the creation of special equipment for selective exposure at each stage of the technological process, is determined. A description of the devices of aggregates that have a basic crank-slide scheme of the mechanism for performing various technological functions is presented: grinding, classification, thin and ultrafine grinding, homogenization, agglomeration, etc. A brief description of patent-protected designs of vibro-centrifugal units is given: centrifugal grinding and mixing unit, centrifugal unit with parallel grinding blocks, vibration-centrifugal granulator, vibro-centrifugal unit of combined action. The design features of the vibro-centrifugal unit of combined action intended for complex processing of technogenic fibrous materials in two ways are considered. One of the developed technological options for the implementation of the vibration-centrifugal combined effect on the material is described in detail, in which, according to the single-branch variant, the processes of deagglomeration of technogenic fibrous materials in the first chamber, grinding and mixing of the components of the composite mixture in the second chamber and micro-granulation of the mixture with fiber fillers in the third the camera. The results of the analysis of the kinematic scheme of the basic crank-slide mechanism are presented and a system of equations for determining the position functions of the points of the mechanism links is obtained, the characteristics of speed and power parameters in individual units of the unit are defined. Taking into account the identified advantages of the vibro-centrifugal unit, the directions of its use for complex processing of technogenic materials are determined.