Study On The Device For Testing The Uniformity Of Wood-composites Mat

To test the uniformity of composites-mat formed by cotton-stalk, traditional methods used complicated and high-tech device, which often needed professional worker and was not economical. To solve this problem, this thesis designed a new on-line non-destructive testing device for testing the uniformity of composites-mat formed by cotton-stalk. This device took air current as testing medium, used wind speed sensor as main testing tool and made use of MCU as control unit. Next, marked the mat defects by colored adhesive from spray devices. And then, the mat defects were added corresponding quantity of cotton stalk to reach the aim of even distribution. Finally, it enhanced the uniformity of wood-composites mat, which made some prime foundation for the large-scale industrial production of cotton-stalk composites.Based on elaborative analysis about the structure of cotton-stalk mat and the theory of mechanical design & control, this thesis designed a new device, which had more advantages, such as simple structure, stable function and low cost, for testing the uniformity of composites-mat formed by cotton-stalk. While, the main content of this thesis and some conclusions which this thesis got were summarized as follows.(1) This thesis studied the two different structures of cotton-stalk mat formed by both random forming and parallel forming, and the characters of two types mat when air-current got through them. As a result, the feasibility of this method was proved from both qualitative and quantitative sides by testing the distribution of air-current under mat, ascertained further design direction, at the same time, supplied key parameters for the design of overall and partial structure.(2) According to GB/T21723-2008 wheat/rice-straw particleboard, the specification of the cotton-stalk mat was decided as 1200mm×2400mm.(3) This thesis accomplished the work of mechanism design and key parameters select. This testing device consisted air-current supplying, drive and convey mechanism, test and control mechanism, spray and mark mechanism as well as square steel pipe support & fix mechanism. The key facilities included YE-B3-28-200-200-S low-speed motor, JS-II-6A axial-flow fan, DB(s)2/2.8-58-54 chain-conveying belt, WA-101-101P spray gun, anemometer and AT89S52 Micro-control Unit, etc. Based on the installation dimension of all kinds of facilities, the outline dimension of the testing device was determined as (L×W×H) 6000×1600×1520~1600.(4) The control system of the testing device was designed and produced. In this section, several usual testing methods and devices, as well as their advantages and disadvantages were compared, what is more important is that a new air-speed & temperature testing system was developed on the hardware of DS18B20 data temperature sensor and AT89S52 MCU, which could acquire 8 wind-signal once at a same time on the whole width of the cotton-stalk composites mat, it also had the digital display function and alarm prompt function.(5) Based on the software of Pro/Engineer Wildfire2.0, this thesis completed the 3D solid design of the whole testing device. Thanks to the powerful design and develop functions of Pro/E software, all the facilities and mechanisms were accomplished and assembled according to the operating principle.