The Design Of Hook's Mold For Velcro And Its Analysis

Velcro is an attachment device which consists of two elements each covered by an array of outgrowths or protuberances which interact or interlock with those on the opposing surface to form a bond which can be made and broken many times. The development of it's applications making it used from daily life to more widely field, such as electronics, automobile, aerospace, medical, agriculture, sports etc.Velcro industry prosperous at 1990s in China, and most of manufacturers could only produce woven and knit products what're cost high. Thus, enterprise competitiveness is far behind the developed countries.The hook of Velcro plays a vital role of the quality. The pattern of the hook geometry and the process of the hooks play important roles in the performance of the hook and loop fasteners.This article is mainly about the design of hook's mold for Velcro and its analysis. With the design of hook mold, we can lead the process development of Velcro from needle looms to plastic molding. We did some tests on both single fixing element and the whole engagement rows that related to the geometry and material properties. Thus confirms this formation mold and the plan feasibility, made the mold could apply in the actual production finally, and achieves the goal of reduces the enterprise'production cost.The article designed a new molding based on rolling production line, three-dimensional embossed theory, and the rheological theory of rolling. The new mold was substituted calender's middle roller to use in the hook's formation. And designed five groups hook geometric configuration with graphics and coordinate methods.In this paper,according to the fundamental theories of viseous fluid dynamies and polymertheology,combining the basie of theoretical research results of micro injection molding, the basice formula for filling fiow of polylmer melt during micro injection molding and lateral compressive force in rolling were constructed.Applied the new molding and the new rolling production line in the experiment, we come to a conclusion. The results showe that:using the new molding and the new rolling production line in produce the hook of Velcro is available. Desired effect could feasibility by adjusting mold roller rotational speed, the mold's temperature and the extruding machine supplies sheet material's speed and optimization the hook's shape.