This news article was originally written in Spanish. It has been automatically translated for your convenience. Reasonable efforts have been made to provide an accurate translation, however, no automated translation is perfect nor is it intended to replace a human translator. The original article in Spanish can be viewed at Incorporación de residuos naturales para la fabricación de juguetes

The technological Institute of the toy (Aiju) is developing a project on natural waste in plastics

Incorporation of natural waste for the manufacture of toys

Ana Ibáñez García, Asunción Martínez, Ana Sánchez Reche02/12/2008

In recent years, under the premises 'oil crisis', 'sustainable development', 'conservation of non-renewable resources', 'waste minimisation', 'environmentally friendly materials with the environment', etc., has increased the interest for the development of plastic composites reinforced with natural fibers obtained from renewable sources.

In this context, the Technological Institute of the toy (Aiju) has developed a project funded by Social work CAM on the incorporation of natural waste plastic materials whose main objective is the incorporation of shell of almond, renewable natural residue, to formulations of plastic materials in order to obtain a material with new propertiesmechanical, environmental, etc., for the manufacture of toys looking wood, innovative and differentiated, with a few additional properties not present on the market.

These natural reinforcements ensure a total recyclability as they decompose easily without presenting any type of toxic waste. The incorporation of this natural reinforcement incorporated into plastic formulations greater rigidity and tensile strength and lower resistance to impact.

Figure 1. (Whole, b) crushed, (Fotografía_de_la_cáscara_de_almendra:_a) c) powder.

The toy industry

Normally, for the manufacture of toys are used materials such as wood, textiles, and metal; However, the component star is plastic. The polyolefins, the polystyrenes and plasticized PVC are recurring materials, as well as some technical polymers, such as polycarbonate or polyamide for some components and parts.

Toys are usually a relatively short life cycle and are discarded after few years. This problem is compounded the difficulty of disassembly. For this reason, is necessary research and innovation in the juguetero sector, to improve the products and adapt them to current requirements of sustainability. The incorporation of almond shells allows to reduce the cost of the final product due to the partial replacement of the plastic material and on the other hand, from the development of different ecological plastics, which do not come from oil, new values are entered to the toys and their users, such as respect for the environment and natural resources.

Description of the work plan

The project has basically been on the one hand to obtain compounds plastic with a proportion of almond shell and on the other hand, analysing the feasibility of these formulations using different techniques of processing processing (extrusion and injection) to obtain prototypes of toys.

This has been necessary to a process of selection of plastic materials, study of their compatibility with the shell of almond, the preparation of different formulations of composite with different percentages of shell of almond and its physical and mechanical characterization.

Microphone: Microphone basis injected with the retrieved composite material.

Products used

The plastics used in this work have been: polyethylene of high density (Rigidex HD 5218) and polystyrene impact-resistant (PS6541).

Used almond shell has been the 'marcona' variety. The entire supplied skins are trituraron for their incorporation into formulations of HDPE and PS to reach a size of particle to submit not difficulties of passage through the mouthpiece of the extruder and facilitate the process of mixing (Figure 1).

For the preparation of these formulations are added an compatibilizador agent (Polybond 3009).

Experimental conditions

• Mixture of thermoplastic resins with feathers

The mixture of thermoplastic resins and compatibilizante agent with the almond shell was conducted in an extruder with main entrance for material base and side for reinforcement. The outgoing rows of the extruder is subsequently proceeded to grancear. Mixtures of composites obtained is dried before the process of injection to 80 ° C for 72 hours.

• Injection of thermoplastic reinforced with almond shell

In order to analyze the effect of the shell of almond as reinforcement of plastics, is injected test tubes of tensile, flexural and impact. The temperature of the injection process was 190 and 200 ° C in the case of the formulations with HDPE and PS respectively.

Fig. 2. Variation of the module by Young and tension with the content of shell materials injected with HDPE almond.

Results

He has been the characterization of mixtures obtained with HDPE and PS to study its physical and mechanical properties using different experimental techniques.

He was the study of the (mass loss) breakdown of both materials containing in shell almonds from 45 per cent depending on the temperature. The temperature increased at a speed of 20 ° C/min.

It notes that approximately up to 230 ° C the loss of mass is approximately 3 per cent of the total. This loss is due to the evaporation of the moisture and other volatile impurities. Then, from 230 to 380 ° C occurs the greatest loss of mass. In this temperature range, the almond shell breaks down and lose their properties. Based on these results, it was decided that mixtures were processed at temperatures as low possible and always lower at 220 ° C.

In order to see the spread of dust from shell of almond in the matrix, was a scanning electron microscopy.

Shows that by increasing the percent of almond shell hardness increases slightly since this variety of almond has a very hard shell. Also density increases with the content of shell, as well as the temperature of softening, indicating that the burden slightly reinforces the material. Fluidity index decreases, however the incorporation of the shell makes the mixture more viscous and flows less than the material without charge. Vary the content of shell of almond in the formulations yields a significant increase in the modulus of elasticity that the incorporation of almond to HDPE husk, increases the rigidity of the material. It notes that resistance to rupture of materials with almond shell is also higher than the HDPE without strengthening, and the resistance value obtained is similar with shell between 15 and 45 percent content.

Table 1. Properties of HDPE with different percentages of almond shells.

Conclusions

Studies have shown the possibility of mixing and processing through conventional, such as extrusion and injection methods, made up of plastic with peel of almond in proportions of up to 45%. The incorporation of shell of almond, renewable natural resource to formulations of plastic materials shows good perspective from the technical and economic point of view.
The visual appearance of the resulting outputs of this partial substitution has been similar to the wood, with the advantage that, unlike this one, the almond composites can transform plastic, that is, without having to modify the production lines.
On the other hand, through the use of the almond shells intended this waste a significant new use at industrial level.
Commercial applications of the products developed are very broad, from decorative objects, outdoor furniture, elements of game in playgrounds, containers of objects and games table, etc.

The incorporation of a 15 per cent of almond shell obtained an increase in the modulus of elasticity. However, an increase of the content of almond up 45 percent shell causes a slight decrease from the rigidity of the material, still below the PS without load. It also notes that the strength of materials with almond shell is greater than the PS not reinforced.

The impact resistance decreases with the addition of almond shells increased the rigidity with respect to the plastic material only. This behavior can be improved through the use of additives to improve this property. In order to demonstrate the feasibility of processing, are injected prototypes of toys (Figure 8), which corresponded to an already existing in the market piece, made of another material.