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Abstract. This paper presents results of tensile tests carried out for specimens made of the selected group of the filament materials. As a manufacturing technology FDM 3D printing method was chosen. The selected group of the filament materials involved the group of wood, PLA, ABS, PET, PMMA and ASA. Herein, it should be noticed, that technical data sheets that are delivered by filament materials producers include data that are valid for only one specific printing direction. This printing direction is deliberately selected, in such way that ensures the best material characteristics. Therefore, received during the research results allow to make comparison between a catalogue data and data obtained in the printing process. It aids both mechanical designer and product manufacturer at the stage of the printed product mechanical properties shaping. The selection of the materials subjected to the tensile testCurrently, a vast variety of materials is available on the market. This group of materials is called filament. Filament is a thermoplastic material. It is wound on the spool in the form of a thin wire. Typically, the spool contains 1 kg of a material. In our case, 1.75 mm diameter filament was used. Manufacturers of the filament are constantly trying to surprise clients with new materials. A few years ago, only ABS or PLA were in the offer. Nowadays, these materials are the basis of FDM technology and they are the most popular. Newer and newer materials are commercially available. For example, materials with admixtures of wood or chalk, which were created for design applications. On the other hand, the impact of the industry has demonstrated a need for materials for engineering applications, such as ABS, ASA, Nylon, PET, PMMA or rubber. Above the basic properties of the selected materials are given.3DGO Wood is a product name of the material made by 3DFilamenty Company. The original name of this filament is LayWoo-D3 or LayWood and it was created by Kai Parthy from CC-Products Company [1]. This filament consists of 60% of PLA which is the base of this filament and 40% of wooden powder which is an admixture. The material has a wood *

A condition for achieving a high potato tuber yield on an early harvest is to provide plants with good growth conditions. In modern horticulture, plant growth stimulants have been gaining increasing importance. This study examined the effect of dose (0.2 dm 3 ha-1 or 0.4 dm 3 ha-1) and date (leaf development stage-BBCH 14-16, tuber formation stage-BBCH 41-43, leaf development stage and tuber formation stage) of Tytanit ® application (8.5 g Ti in 1 dm 3) on the growth of very early-maturing potato cultivars ('Lord', 'Miłek'). Following the Tytanit ® application, the plants were higher and produced a greater aboveground biomass and tuber weight, however, the leaf weight ratio (LWR) and leaf area ratio (LAR) were lower than in the cultivation without the growth stimulant. Tytanit ® had a greater effect on the leaf weight ratio (LAR) and tuber weight for the 'Lord' cultivar. Tytanit ® dose had no effect on the plant growth. A double Tytanit ® application resulted in a reduction in the length and weight of stems and tuber weight. The date of Tytanit ® application had no effect on the weight of leaves. The leaf area ratio (LAR) was the highest when Tytanit ® was only applied in the tuber formation stage, and the leaf weight ratio (LWR) was the highest when Tytanit ® was applied twice. A positive correlation was found between the tuber weight and the LWR and LAR.

In the paper a classical model of failures is considered in that successive failure-free times are supposed to have Gamma distributions and are followed by exponentially distributed times of repairs. It is assumed that parameters of these distributions, in general, change with time. Basing on information about the number of failures and failure-free times in a number of periods of the same duration in the past, three different methods of estimation unknown parameters of the model are proposed. Next, predictions of the most important reliability characteristics are found.