Improving the fire retardancy of extruded/coextruded wood-plastic composites

The main objective of this thesis is to study the impact of different mineral fillers and fire retardants on the reaction-to-fire properties of extruded/coextruded wood-plastic composites (WPCs). The impact of additives on the flammability properties of WPCs is studied by cone calorimetry. The studied properties are ignition time, peak heat release rate, total heat release, total smoke production, and mass loss rate. The effects of mineral fillers and fire retardants were found to vary with the type of additive, the type of additive combinations, the amount of additives, as well as the production method of the WPCs. The study shows that talc can be used to improve the properties of extruded WPCs. Especially ignition time, peak heat release rate and mass loss rate were found to be improved significantly by talc. The most significant improvement in the fire retardancy of coextruded WPCs was achieved in combinations of natural graphite and melamine. Ignition time, peak heat release rate and total smoke production were improved essentially. High increase in smoke production was found in samples where the amount of ammonium polyphosphate was 10% or higher. Coextrusion as a structural modification was found as a promising way to improve the flammability properties of composite materials in a cost-effective way.

Marks of Fire, Value and Faith. Swords with Ferrous Inlays in Finland during the Late Iron Age (ca. 700–1200 AD)

This study explores swords with ferrous inlays found in Finland and dating from the late Iron Age, ca. 700–1200 AD. These swords reflect profound changes not only in styles and fashion but also in the technology of hilts and blades. This study explores how many of these kinds of swords are known from Finland, how they were made and where, what their status was in Late Iron Age Finland, and where the Finnish finds stand in accordance with other areas of Europe. The various methods included measuring of the finds and statistics. The main method of revealing the inlaid marks was radiography due to its non-destructive nature. In cases where inlays were visible without radiography, their details were inspected via microscopy. To study the materials and manufacture of inlaid swords, a sample of them was metallographically analysed to determine the forging technologies and nature of used materials. Furthermore, the manufacture was also studied with experimental approaches. As a result, a catalogue of 151 swords with ferrous inlays was created. This number is relatively high compared with other European countries, although systematic studies have been conducted in only some countries. The inlaid motifs were classified into five distinct categories to help the classification. To summarize, almost every documented inlaid sword was unique in some respect including measurements, inlaid motifs and materials of blades and inlays. Technological variation was also present, some blades being poorer and some of higher quality in spite of the inlaid motifs. Misspelt inscriptions as well as letter-like marks were common in Finland and also in Scandinavia. Furthermore, the provenance of iron and steel used in some blades hints at Scandinavian ores. The above observations, along with the experimental results indicating the existence of multiple alternative techniques of inlaying, suggest that these swords were manufactured locally in Scandinavia, most likely in imitation of Continental European models. Inlaid swords were valued partly for their assumed functionality in combat, as evidenced by damage on some examined blades, or they were valued for their inlays, which could have had fashionable or symbolical meanings bound to local beliefs.

Toimintamalli asuinkiinteistö öljyvahingon hoitamiseksi

Pienkiinteistöjen öljyvahingot ovat viime vuosina lisääntyneet. Tämän työn tarkoituksena on luoda öljyvahingon torjuntaan ja jälkihoitoon osallistuvalle urakoitsijalle toimintamalli asuinkiinteistön öljyvahingon hoitamiseksi. Mallin halutaan erityisesti kuvaavan öljyvahingon hoitoon osallistuvien viranomaisten ja muiden tahojen vastuita ja velvollisuuksia. Työn tavoitteena on myös tunnistaa pienkiinteistöissä tapahtuvat öljyvahinkotyypit sekä niille altistavat riskitekijät. Öljyn päästäminen ympäristöön sekä öljyn käsittely ja varastointi niin, että siitä aiheutuu öljyvahingon vaara, kielletään laissa. Vahinkojen torjumiseksi on annettu määräyksiä muun muassa öljylämmityslaitteistojen turvallisuutta koskien. Asuinkiinteistöjen öljyvahingot liittyvät yleensä öljysäiliön täyttötilanteisiin. Vahinkojen syynä on usein säiliön ja sen varusteiden puutteellisuus tai huono kunto. Asuinrakennusten lämmitykseen käytetään kevyttä polttoöljyä. Maahan joutuessaan polttoöljy imeytyy sora- ja hiekkamaahan nopeasti, jolloin vaarana on öljyn kulkeutuminen pohjaveteen ja vesistöihin. Asuinkiinteistön öljyvahingossa öljyä joutuu usein myös rakenteisiin. Öljyvahingosta tulee ilmoittaa aina hätäkeskukseen. Vastuu öljyvahinkojen torjunnasta kuuluu alueelliselle pelastustoimelle. Torjuntatoimiin osallistuu usein myös urakoitsija. Jos vahinkokohdetta ei torjuntatoimin saada kunnostettua, alueellinen ympäristökeskus voi määrätä puhdistamisesta vastuussa olevan selvittämään pilaantuneen alueen laajuuden ja puhdistamistarpeen sekä toteuttamaan mahdollisen kunnostuksen. Pilaantuneen maaperän kunnostus voidaan toteuttaa massan vaihtona tai paikan päällä maata kaivamatta. Likaantuneiden rakenteiden saneerausta tarvitaan sisäilman hajuhaittojen poistamiseksi. Öljyvahingon kustannukset voivat nousta hyvinkin suuriksi. Ensisijainen vastuu niistä kuuluu vahingonaiheuttajalle.