Analysis of thermomechanical properties and the influence of machining process on the surface structure of composites manufactured from metal chips with a polymer matrix

Nowadays, the dynamic development of the entire market of composite materials is noticeable, which is very often associated with the need to use waste or recycled materials in their production. In the process of producing composites themselves, the easy possibility of shaping their mechanical and thermomechanical properties becomes apparent, which can be a big problem for materials with a homogeneous structure. For the tests, samples made of a combination of acrylic-phenolic resin with fine aluminum and brass chips were used. The tests were performed for composite samples produced by pressing. This paper presents the results of the DMTA method of the conservative modulus and the tangent of mechanical loss angle of the composite, a detailed stereometric analysis of the surface after machining, roughness parameters and volumetric functional parameters were performed. For the tested samples, changes in the values of the conservative modulus and the mechanical loss coefficient were recorded, which indicated significant differences for the composite with brass chips in relation to composites with aluminum chips. In the case of the composite with aluminum chips, slight changes in the conservative modulus were recorded in the glass transition phase and the elastic deformation phase at different frequencies. In contrast, for composites with brass, slight changes were recorded in the entire range of the course of the conservative module as a function of temperature when different excitation frequencies were applied. In relation to the polymer matrix, a significant increase in the value of the conservative modulus of composites was recorded in the entire temperature range of the test. Significant differences were recorded in the study of the surface of composites in the case of using different materials obtained after machining as fillers. The dependences of the amplitude parameters of the surface after machining the sample made of phenolic-acrylic resin prove the poor performance properties of the surface. The use of chips in the composite significantly changed the surface geometry.Web of Science1417art. no. 350

In-process protection of wood composites: An industry perspective

Wood-based composites are commonly used as construction materials. In many of these applications, there is a potential for fungal and insect attack (e.g. millwork, sheathing, exterior siding, and decking). Traditional pressure, spray, and dip treatments suitable for solid lumber typically cannot be employed to treat wood-based composites. In-process application of preservative formulations, however, has proven to be a feasible option. Inorganic borate systems, particularly zinc borate, have an established commercial track record. Their success as an in-process preservative system can be attributed to meeting five basic attributes: They are relatively safe to use, have minimal environmental impact, have regulatory acceptance, are compatible with most wood composite manufacturing processes, and are economical. This chapter discusses the use of in-process preservative systems from a North American industrial perspective, and is aimed at formulation chemists who are developing biocides for inprocess treatment by the wood composite industry. This chapter is based on the oral presentation, In-Process Protection of Wood Composites: An Industrial Perspective by authors Merrick and Gnatowski at the ACS 229th National Meeting In San Diego, CA, March 16, 2005. © 2008 American Chemical Society

Rozwój konstrukcji stalowych odrzwi do rozcinek ścianowych

The article presents the development of steel frame sets produced for mining purposes by Huta Łabędy S.A., intended for securing gallery workings, and longwall development drifts in particular. In recent decades, longwall development drift support has evolved in terms of characteristics such as its shape. The initially utilised rectangular frames and typical widened ŁP frames were replaced with flat frames based on ŁP arches (ŁPKO), and subsequently with special frame sets adapted to the shape of powered support units. The intermediate frame shape obtained in this way was a compromise between the rectangular (beneficial from the perspective of longwall equipment and development) and the arching design (beneficial due to the high load-bearing parameters).Artykuł przedstawia rozwój konstrukcji obudów stalowych dla górnictwa, produkowanych przez Hutę Łabędy S.A. z przeznaczeniem do zabezpieczania wyrobisk korytarzowych, a szczególnie rozcinek ścianowych. Na przestrzeni ostatnich dekad obudowa rozcinek rozruchowych ewoluowała między innymi pod względem kształtu. Stosowane początkowo odrzwia prostokątne i typowe odrzwia ŁP z poszerzeniami zostały zastąpione przez odrzwia spłaszczone na bazie łuków ŁP (ŁPKO), a następnie przez specjalne odrzwia dostosowane kształtem do sekcji obudowy zmechanizowanej. Uzyskano w ten sposób obrys odrzwi pośredni, będący kompromisem pomiędzy prostokątnym (korzystnym z uwagi na zbrojenie i uruchomienie ściany), a łukowym (korzystnym z uwagi na wysokie parametry podpornościowe)

The evolution of steel frame sets for longwall development drifts

Artykuł przedstawia rozwój konstrukcji obudów stalowych dla górnictwa, produkowanych przez Hutę Łabędy S.A. z przeznaczeniem do zabezpieczania wyrobisk korytarzowych, a szczególnie rozcinek ścianowych. Na przestrzeni ostatnich dekad obudowa rozcinek rozruchowych ewoluowała między innymi pod względem kształtu. Stosowane początkowo odrzwia prostokątne i typowe odrzwia ŁP z poszerzeniami zostały zastąpione przez odrzwia spłaszczone na bazie łuków ŁP (ŁPKO), a następnie przez specjalne odrzwia dostosowane kształtem do sekcji obudowy zmechanizowanej. Uzyskano w ten sposób obrys odrzwi pośredni, będący kompromisem pomiędzy prostokątnym (korzystnym z uwagi na zbrojenie i uruchomienie ściany), a łukowym (korzystnym z uwagi na wysokie parametry podpornościowe).The article presents the development of steel frame sets produced for mining purposes by Huta Łabędy S.A., intended for securing gallery workings, and longwall development drifts in particular. In recent decades, longwall development drift support has evolved in terms of characteristics such as its shape. The initially utilised rectangular frames and typical widened ŁP frames were replaced with flat frames based on ŁP arches (ŁPKO), and subsequently with special frame sets adapted to the shape of powered support units. The intermediate frame shape obtained in this way was a compromise between the rectangular (beneficial from the perspective of longwall equipment and development) and the arching design (beneficial due to the high load-bearing parameters)