Лесотехнически Университет

Резюме

The upholstery with inner spring units, is composed of materials, which have various stress-strain behavior under load. In the work is studied softness and behavior of structures composed of different combinations of upholstery materials. The type of the innerspring unit, materials and thickness of the upper layers are changed. As criteria for evaluation of the specimens are used coefficients of softness and requirements for general deformation of the structure of the upholstery for seat and back elements. Conclusions are made and recommendations for their application in the structure of upholstered furniture.

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3D geometric model of one-seat frame for upholstered furniture was created by the CAD system Autodesk Inventor Pro^®. A linear static analysis was carried out with CAE system Autodesk Simulation Mechanical^â by the method of finite elements (FEM) simulating light-service loading of the frame.

The orthotropic material characteristics of pine solid wood (Pinus Sylvestris L.) for the rails and particleboard (PB) for the side plates are considered in the analysis. Corner joints in the framewith staples and PVA glue were considered. FEA was performed with regard to laboratory establishedcoefficients of rotational stiffness of used staple corner joints in the frame – case butt joints and end to face butt joints.

As a result, the most loading construction part of the frame with staple corner joints is established – the rear upper rail of the seat where the maximum values for linear displacements,nodal rotationsand stresses are received due to the nature of the applied loading.

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The presented study is the result of a laboratory testing under bending stress by collecting arms by corner butt joints with 2 staples type М1/40 of Scots pine (Pinus sylvestris L.) members and boards (OSB, PB, PW) to determine the deformation behaviour of the joints.

The aim of the study is to establish the stiffness coefficients by examining the influence of the material, the reinforcement by means of a triangular wood member and the type of joints on the deformation behaviour of butt joints by staples.

The results obtained could be used as a basis for future research to predict the deformation behaviour of furniture constructions as well as to find their application in the design of skeletons of upholstered furniture.

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In this paper, the absorption properties of wood materials from Scots pine (Pinus Silvestrys L.), which are widely used in flooring and wall linings, have been experimentally studied. The frequency-dependent sound absorption coefficient (αp) was determined in octagonal frequency bands with an average geometric frequency of 100 Hz to 2000 Hz. The tests were carried out using an impedance tube, according to the requirements of BDS EN ISO 10534-1:2006. The obtained results are of a particular interest from both scientific and practical point of view, given that the sound absorption coefficient has a decisive impact on the reverberation time. The latter is the main acoustic parameter of a room depending on its intended purpose.

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Joints made with staples and gusset plates are widely used in the wood frame construction of various types of furniture, due to the quick and easy production and the availability of simple technology. In this regard, their good knowledge of bending loads would help furniture designers in the design process. The investigation aims to summarize the data from the specialized literature on the values of parameters characterizing the behavior of joints with staples and gusset plates of details in wood frame, as well as to establish the influence of some key factors such as the detailed thickness, the angle between wood details of the joints, thickness and type of material of the gusset plates on their strength and stiffness under bending load.

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The strength of bonding between protective-decorative coatings and the surface of wood materials, plays a major role in the durability of the wooden products, exposed to atmospheric conditions in the open area. This article analyzes the effects, that has the protective-decorative coatings, like durability of the natural oils and synthetic lacquer products used for protective layer of wood and the surface condition, after stay under the environmental impacts. To achieve this aim, an experimental stand was built according to standard EN 350:2016 and mounted in the territory of Yundola, Velingrad municipality. By the determined 12 months under review time period it is followed the change of surface of different types of natural oils and synthetic lacquer products used for protection of wood exposed to open area. The change in color is reflected, the damage to the surface of the used protective-decorative coatings, the mold formation, and the moisture resistance of the protective coatings. The results are analyzed and graphically presented. 

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This work presents one of the first systematic, ISO-aligned assessments of PVAc-bonded joints in laboratory-made hemp shive particleboards, benchmarked directly against industrial P2 particleboard under identical processing conditions (adhesive type and spread, surface preparation, and three nominal pressing pressures). By holding all bonding variables constant and varying only the substrate and pressure, the study isolates the effect of the substrate on shear strength. It offers actionable data for furniture construction with emergent hemp-based panels. 
The key achievement is a consistent approximately 45% increase in PVAc shear strength for hemp shive panels across the tested pressures, with mean values rising from 1.23 to 1.53 N/mm², compared to 0.68 to 0.83 N/mm² for P2 (ISO 6237:2017). This result demonstrates that hemp shive particleboards can deliver markedly stronger adhesive joints without changing adhesive type or application rate, directly supporting their use as a higher-performance alternative in PVAc-bonded furniture assemblies. The observed variability at the highest pressure level highlights a practical optimization window for balancing pressure with adhesive spread and substrate permeability.