scholarly journals The accuracy of holes drilled in the side surface of plywood

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 117-129
Author(s):  
Maciej Sydor ◽  
Tomasz Rogoziński ◽  
Kinga Stuper-Szablewska ◽  
Karol Starczewski
Keyword(s):  
Phenol Formaldehyde ◽  
Adhesive Layer ◽  
Dimensional Accuracy ◽  
Side Surface ◽  
Drilling Machine ◽  
Geometric Accuracy ◽  
Hole Axis ◽  
Birch Veneer ◽  
Made In ◽  
Nominal Position

Dimensional accuracy of machining translates into susceptibility to defects in assembly of furniture elements. In the initial drilling phase, the tip of the drill may slip due to the properties of the workpiece, which may result in inaccurate machining. Taking this into account, it was decided to investigate this phenomenon for drilling in the side of the plywood board. Samples for testing were made of 18 mm thick, 13 layer birch-alder plywood, covered with melamine film, glued with phenol-formaldehyde glue. With the use of an industrial dowel drilling machine, 30 holes in each of three examined layer were made. All holes were made parallel to the layers – on the side of the plywood board, and their axes were located in three adjacent layers: the birch veneer layer, the adhesive layer, and the alder veneer layer. Two types of geometric accuracy of holes were analyzed: the distance between the real center of the hole and the nominal position and also the inclination of the hole axis from the nominal axis. The holes made in the adhesive layer showed approximately twice larger deviations compared with the holes made in two adjacent layers of veneer. There was no significant relationship between the deviations of the angle of holes axis and the inaccuracies in the position of their centers. Main conclusion: When drilling in the side surface of the plywood board, less accurate holes are obtained if the hole axis is located in the adhesive layer, and there is more accuracy if the hole axis is located in the veneer layer.

In Implementing a Metal 3D AM Machine

2018 ◽  
Vol 786 ◽  
pp. 356-363
Author(s):  
Tero Jokelainen ◽  
Kimmo Mäkelä ◽  
Aappo Mustakangas ◽  
Jari Mäkelä ◽  
Kari Mäntyjärvi
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Dimensional Accuracy ◽  
Acceptance Test ◽  
Aisi 316L ◽  
Laser Melting ◽  
Geometrical Accuracy ◽  
Machine Performance ◽  
Geometrical Features ◽  
Made In

Additive Manufacturing (AM) does not yet have a standardized way to measure performance. Here a AM machines dimensional accuracy is measured trough acceptance test (AT) and AM machines capability is tested trough test parts. Test parts are created with specific geometrical features using a 3D AM machine. Performance of the machine is then evaluated trough accuracy of test parts geometry. AM machine here uses selective laser melting (SLM) process. This machine has done Factory acceptance test (FAT) to ascertain this machine ́s geometrical accuracy with material AISI 316L. Manufacturer promises accuracy of ±0.05 mm. These parts are used as comparison to AT parts made in this study. After installation two AT parts are manufactured with AM machine. One with AISI 316L and one AlSi10Mg. Dimensional accuracy of geometrical features on these parts are then compared to FAT part and to one another. Machines capability is measured trough two test parts done with material AlSi10Mg. Two of the test parts are done at the same time using same model as the FAT. Parts are printed without supports and with features facing same directions. Features of these parts were then evaluated. Another test to find out AM machines capability was to create part consisting of pipes doing 90˚ angle resulting in horizontal and vertical holes. Dimensional accuracy and circularity of holes was measured. Through these tests machines capability is benchmarked.

scholarly journals An in-vitro study to evaluate the accuracy of dies obtained from dual arch impression trays using addition silicone impression material and tray combinations

2015 ◽  
Vol 12 (2) ◽  
pp. 111-117
Author(s):  
P K Parajuli ◽  
S George ◽  
V Shenoy
Keyword(s):  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Acrylic Resin ◽  
Simultaneous Recording ◽  
T Test ◽  
Impression Material ◽  
Tooth Preparation ◽  
Made In ◽  
Plastic Trays

Background: Dual-arch impression technique allows the simultaneous recording of  tooth preparation, opposing anatomic tooth and maxillomandibular relationship. The  accuracy of reproduction of this easy and quick technique, however, has not been  studied in detail in past. Objective: To compare the accuracy of the impressions  made by using the same impression material in dual arch plastic trays, dual-arch  metal trays and acrylic resin custom trays. Methods: The dies obtained from the  addition silicone impressions made in dual-arch plastic trays, dual-arch metal trays  and full arch acrylic resin custom trays were compared for the dimensional accuracy  with the prepared typodont tooth as a control. Student’s paired t-test and unpaired  t-test were used for the data analyses using the Statistical Package for Social Studies  (SPSS) version 11.5. Results: The dies obtained from all the impression combinations  showed increased dimension (acrylic resin custom trays 9.4 mm±0.048, dual-arch  plastic trays 9.5 mm±0.035, dual-arch metal trays 9.41 mm±0.017) as compared to  the dimension of control (9.39 mm±0.007). Conclusion: All the tray-impression  material combinations showed variable accuracies. Full arch acrylic resin trays  resulted in greatest accuracy whereas dual-arch plastic trays the least accuracy.Health Renaissance 2014;12(2):  pp: 111-117

Rheology of latex films bonded to wood: influence of cross-linking

Holzforschung ◽  
2006 ◽  
Vol 60 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Francisco López-Suevos ◽  
Charles E. Frazier
Keyword(s):  
Phenol Formaldehyde ◽  
Adhesive Layer ◽  
Wood Adhesive ◽  
Water Soluble ◽  
Cross Linking ◽  
Sample Type ◽  
Master Curves ◽  
Latex Films ◽  
Adhesive Interaction ◽  
Tan Δ

Abstract Parallel-plate rheological analysis was conducted on two types of cross-linking poly(vinyl acetate) latex films: dry freestanding films, and dry films bonded directly to wood (composites). For each sample type, three levels of cross-linking were used: (1) little or no cross-linking of unaltered latex; (2) substantial cross-linking through AlCl3 catalysis of N-methylolacrylamide co-monomer; and (3) greater cross-linking from a phenol-formaldehyde resol additive, in addition to AlCl3 catalysis. Simple thermal scans revealed a strong wood/adhesive interaction; wood increased the base polymer T g by ∼5°C in all adhesives. Relative to the simple thermal scans, time-temperature master curves provided more insight and information about the wood/adhesive interaction. Storage modulus and tan δ master curves both indicated that wood retarded adhesive cross-linking. Using time-temperature superposition, a segmental coupling analysis demonstrated that wood actually narrowed the breadth of the glass transition, or reduced segmental coupling. Cross-linking influenced segmental coupling, but in a fashion that was dependent on the presence or absence of wood. Wood-induced reductions in cross-linking and in segmental coupling were attributed to the diffusion of water-soluble reactive compounds away from the adhesive layer and into the bulk wood. Time/temperature equivalence provides a sensitive means to detect interactions between wood and viscoelastic adhesives.

scholarly journals Accuracy of Ceramic Mould Filling with Liquid AlSi9 Aluminium Alloy in the Process Using Back-Pressure

2013 ◽  
Vol 13 (1) ◽  
pp. 73-76
Author(s):  
A. Karwiński ◽  
R. Haratym ◽  
R. Biernacki
Keyword(s):  
Dimensional Accuracy ◽  
Back Pressure ◽  
Suction Pressure ◽  
Capillary Phenomena ◽  
Mould Filling ◽  
Alsi Alloy ◽  
Surface Microgeometry ◽  
Special Pattern ◽  
Investment Process ◽  
Made In

Abstract The paper presents the effect of suction pressure exerted on the liquid AlSi alloy when it is introduced into a ceramic mould made in the investment process and the results compared with data obtained on gravity poured castings. The study used special pattern sets and ceramic moulds made with the alternately applied soluble silicate binder and ethyl silicate. Additionally, self-supported moulds based entirely on the Ekosil binder were used. In the analysis of castings, the following parameters were examined: a linear dimensional accuracy, the state of surface microgeometry and the possibility of metal penetration into a complex ceramic mould, allowing also for the presence of capillary phenomena. In the process of casting with back-pressure, the pressure values of 500 hPa, 600 hPa and 700 hPa were applied in the chamber where the ceramic mould was located, with the temperature of the said mould kept at a level of 150 ± 10°C.

scholarly journals IMPROVING STRENGTH INDICATORS OF FSF PLYWOOD BY USING MODIFIING ADDITIVES TO BINDING AGENT

2020 ◽  
Vol 10 (1) ◽  
pp. 124-135
Author(s):  
A. Fedotov ◽  
Tat'yana Vahnina ◽  
Sergey Kotikov
Keyword(s):  
Tensile Strength ◽  
Active Sites ◽  
Water Resistance ◽  
Phenol Formaldehyde ◽  
Adhesive Layer ◽  
Strength Properties ◽  
Production Costs ◽  
Modifying Additives ◽  
Anhydrous Magnesium Chloride

Improving the production process of FSF waterproof plywood has been relevant since the beginning of its pro-duction. Only the criteria for improving the quality of plywood products are changing. At the present stage, the costs of improving the quality of plywood cannot be compensated by an increase in prices. Reduction in production costs is required. A rational way to improve operational properties is to reduce pressing temperature and introduce modifying additives that increase adhesive and cohesive strength of phenol-formaldehyde binder. The problem is that when press-ing temperature is reduced to 150 °C or lower, phenol-formaldehyde binder does not reach the resite stage. It negatively affects the strength and water resistance of FSF plywood. It was decided to use modifying additives in the adhesive composition to bind free methylol groups of the oligomer and increase the number of active sites in the curable phenolic binder network. The strength properties of FSF plywood with the use of nine modifying additives have been investigated. The consumption of modifiers varied in the range of 0.25-1.5% in increments of 0.25%. Pressing was carried out at a temperature of 120 °С. An improvement in the tensile strength of plywood when shearing on the adhesive layer was found to be 5-15% (in comparison with control samples without the addition of a modifier) when aqueous solutions of hexavalent aluminum chloride, anhydrous magnesium chloride, eight-zinc zinc sulfate, sulfosalicylic acid, dimethylglyoxime with a different proportion of additives were used as modifying additives to phenol-formaldehyde binder. Tensile strength under static bending of plywood is also increased when using modifiers with different proportion of additives

scholarly journals Shear Strength of Tack Coat on Flexible Pavement and Composite Pavement

2018 ◽  
Vol 4 (2) ◽  
pp. 121
Author(s):  
Tampanatu P. F. Sompie ◽  
Syanne Pangemanan
Keyword(s):  
Shear Strength ◽  
Adhesive Layer ◽  
Flexible Pavement ◽  
Concrete Pavement ◽  
Direct Shear ◽  
Rigid Pavement ◽  
Tack Coat ◽  
Directorate General ◽  
The Right ◽  
Made In

Tack coat is a thin layer that spread on the surface of existing pavement or concrete pavement. The function of this layer is as an adhesive layer needed to give adhesive power between the existing pavement course and new pavement course or with the concrete pavement, therefore created one strong unity and would bond both, in order to withstand the sheer strength caused by the vehicle load on top of it. Strong adhesiveness of the tack coat course will add sheer strength between the interfaces of the pavement courses. Strong adhesiveness is gained from the asphalt mixed with solvent, therefore created the right viscosity level of the tack coat solution. This research was aimed to measure the sheer strength of tack coat by using modified direct shear asphalt samples. The research method used was by using gauge to measure the sheer strength of tack coat on asphalt sample which was the modified direct shear. While the samples were consisted of 2 types, the asphalt solvent sample as a model of flexible pavement course of AC-WC pavement type with optimum asphalt content of 6.1%, and concrete solvent sample as a model of rigid pavement. These samples were made in briquette form, made with Marshall Mould with 4 inches diameter. The tack coat solvent was made in three solvent variations, which was referring to the standard of the Directorate General of Highways. From this research, it could be concluded that the highest shear strength for flexible pavement was reached on the tack coal solvent mix composition of 30 pph and composite pavement of 15 pph. Tack coat spread rate of 0.25 l/m2 gave highest shear strength on flexible pavement and composition pavement of 0.35 l/m2. Balance was reached on flexible pavement on tack coat variation of 30 pph and 50 pph; while on composite pavement, balance was reached on tack coat solvent variation of 15 pph and 30 pph. This modified direct shear sample could be a method to measure shear strength of tack coat on flexible pavement and composite pavement.

scholarly journals Incremental sheet forming of thermoplastics: a review

2020 ◽  
Vol 111 (1-2) ◽  
pp. 565-587
Author(s):  
Hui Zhu ◽  
Hengan Ou ◽  
Atanas Popov
Keyword(s):  
Process Parameters ◽  
Flexible Manufacturing ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Metallic Materials ◽  
Processing Conditions ◽  
Geometric Accuracy ◽  
Significant Progress ◽  
Research Directions ◽  
Made In

Abstract Incremental sheet forming (ISF) is a promising flexible manufacturing process, which has been tested in sheet forming of various metallic materials. Although ISF-based forming of thermoplastics is relatively new, it has drawn considerable interests and significant progress has been made in recent years. This paper presents a review of concurrent research on the emerging trend of thermoplastic-focused ISF processes. Attention is given to the processing conditions including process setup, process parameters and forming forces. The deformation mechanism and failure behaviour during ISF of thermoplastics are evaluated, which leads to detailed discussions on the formability, effect of different process parameters and the forming quality such as geometric accuracy, surface finish and other consideration factors in ISF of thermoplastics. A comparison of important similarities and differences between ISF of thermoplastic and metallic materials is made. Finally, a brief discussion is provided on the technical challenges and research directions for ISF of thermoplastic materials in the future.

Investigations on Dimensional Accuracy of Stamped Tailor Welded Blanks Under Warm Forming Conditions

2017 ◽  
Author(s):  
Vakada Venkata Naga Satya Suresh ◽  
Srinivasa Prakash Regalla
Keyword(s):  
Stainless Steel ◽  
Sheet Material ◽  
Dimensional Accuracy ◽  
Warm Forming ◽  
Thickness Variation ◽  
Geometric Accuracy ◽  
Spring Back ◽  
Tailor Welded Blanks ◽  
Tailor Welded Blank ◽  
Simulation Results

This work emphasizes on the geometric and dimensional accuracy of cylindrical tailor welded blank (TWB) components manufactured under warm forming conditions. In this work, TWB sheet material made of austenitic stainless steel (ASS 304 Grade) and deep drawing steel (IS 513 grade) materials were TIG welded before subjecting to stamping operation. Numerical simulations were validated with experimental results. Simulation results were analyzed to check the thickness variation and stress distribution within the component which otherwise would be difficult to measure experimentally. Measurements in terms of geometric accuracy gave encouraging results. The roundness and perpendicularity measurements indicated better accuracy whereas, cylindricity value has slightly improved. However, dimensional accuracy of the parts in terms of thinning, cup height and diameter has deteriorated. It was found that the spring back effect played a significant role in the deterioration of dimensional accuracy. Presence of residual stresses might be the cause for this effect; further studies are needed to address this issue.

Assessment of Sandwich Beam in Three-Point Bending for Measuring Adhesive Shear Modulus

2001 ◽  
Vol 123 (3) ◽  
pp. 322-328 ◽  
Author(s):  
Jianmei He ◽  
Martin Y. M. Chiang ◽  
Donald L. Hunston
Keyword(s):  
Shear Modulus ◽  
Sandwich Beam ◽  
Adhesive Layer ◽  
Test Method ◽  
Bending Test ◽  
Beam Specimen ◽  
Element Analysis ◽  
Three Point Bending ◽  
The Impact ◽  
Made In

A finite element analysis (FEA) was conducted to examine the feasibility of determining the shear modulus of an adhesive in a bonded geometry using a three-point bending test on a sandwich beam specimen. The FEA results were compared with the predictions from two analytical solutions for the geometry used to determine the impact of the assumptions that were made in these analyses. The analytical results showed significantly different to the values obtained from other experiments on bulk samples of the adhesive in the glassy region. Although there were some agreements in rubbery region, the negligible sensitivity of the beam stiffness to the presence of adhesive layer makes the agreements very questionable. To examine the possible explanations for these differences in glassy adhesives, sensitivity analysis was conducted to explore the effects of experimental variables. Some possible reasons for the differences are discussed, but none of these reasons taken alone satisfactorily account for the discrepancies. Until an explanation is found, the three-point bending test using a sandwich beam specimen to determine the adhesive shear modulus might not be a desirable test method, at least for the range of geometry examined in this study.

Comparison of the geometric accuracy of holes made in CFRP/Ti laminate by drilling and helical milling

2021 ◽  
Vol 112 (11-12) ◽  
pp. 3343-3350
Author(s):  
Ben Wang ◽  
Hua Zhao ◽  
Fan Zhang ◽  
Minghai Wang ◽  
Yaohui Zheng
Keyword(s):  
Helical Milling ◽  
Geometric Accuracy ◽  
Made In
Sign in / Sign up

Export Citation Format

Share Document