The paper presents possibility of using biodegradable materials as parts of moulding sands’ binders based on commonly used in foundry practice resins. The authors focus on thermal destruction of binding materials and thermal deformation of moulding sands with tested materials. All the research is conducted for the biodegradable material and two typical resins separately. The point of the article is to show if tested materials are compatible from thermal destruction and thermal deformation points of view. It was proved that tested materials characterized with similar thermal destruction but thermal deformation of moulding sands with those binders was different.
The paper presents the impact of biodegradable material - polycaprolactone (PCL) on selected properties of moulding sands. A self-hardening moulding sands with phenol-furfuryl resin, which is widely used in foundry practice, and an environmentally friendly self-hardening moulding sand with hydrated sodium silicate where chosen for testing. The purpose of the new additive in the case of synthetic resin moulding sands is to reduce their harmfulness to the environment and to increase their “elasticity” at ambient temperature. In the case of moulding sands with environmentally friendly hydrated sodium silicate binder, the task of the new additive is to increase the elasticity of the tested samples while preserving their ecological character. Studies have shown that the use of 5% PCL in moulding sand increases their flexibility at ambient temperature, both with organic and inorganic binders. The influence of the new additive on the deformation of the moulding sands at elevated temperatures has also been demonstrated.
The article shows the influence of environment requirements on changes in different foundry moulding sands technologies such as cold box, self-hardening moulding sands and green sands. The aim of the article is to show the possibility of using the biodegradable materials as binders (or parts of binders’ compositions) for foundry moulding and core sands. The authors concentrated on the possibility of preparing new binders consisting of typical synthetic resins - commonly used in foundry practice - and biodegradable materials. According to own research it is presumed that using biodegradable materials as a part of new binders’ compositions may cause not only lower toxicity and better ability to reclaim, but may also accelerate the biodegradation rate of used binders. What’s more, using some kinds of biodegradable materials may improve flexibility of moulding sands with polymeric binder. The conducted research was introductory and took into account bending strength and thermal properties of furan moulding sands with biodegradable material (PCL). The research proved that new biodegradable additive did not decrease the tested properties.
Growing emission requirements are forcing the foundry industry to seek new, more environmentally friendly solutions. One of the solutions may be the technologies of preparing moulding and core sands using organic biodegradable materials as binders. However, not only environmental requirements grow but also those related to the technological properties of moulding sand. Advancing automation and mechanization of the foundry industry brings new challenges related to the moulding sands. Low elasticity may cause defects during assembly of cores or moulds by the manipulators. The paper presents the study of flexibility in the room temperature according to new method and resistance to thermal deformation of selfhardening moulding sands with furfuryl resin, containing biodegradable material PCL. The task of the new additive is to reduce the moulding sands harmfulness to the environment and increase its flexibility in the room temperature. The impact of the additive and the effect of the amount of binder on the properties of mentioned moulding sands were analysed. Studies have shown that the use of 5% of PCL does not change the nature of the thermal deformation curve, improves the bending strength of tested moulding mixtures and increases their flexibility at room temperature.