technical plastic injection

31
Aug

DIGI-REC 4.0 (optimización del impacto ambiental en inyección de plásticos)

Concluido el proyecto Europeo  DIGI REC 4.0, cuyo número de expediente es AEI-010500-2020-191, donde ZATEC ha participado junto con el Centro Español de Plásticos (CEP), ItanInnova y Citsalp,  exponemos a continuación un resumen y conclusiones del mismo.

PRESENTACIÓN 

Este proyecto tiene como objetivo principal maximizar la reciclabilidad de materiales plásticos empleados en procesos de moldeo por inyección, lo que implica maximizar la reducción de su impacto medioambiental, favoreciendo la circularidad del plástico y facilitando la producción energéticamente limpia. 

Los fabricantes de piezas de plástico normalmente utilizan material reciclado proveniente de sus propias piezas de rechazo y/o ramales, pero no conocen en qué proporción pueden mezclarlo con el material virgen sin comprometer (i) las características mecánicas del producto y (ii) la procesabilidad de la fabricación de las mismas. Un exceso de material reciclado puede suponer un empeoramiento en las características mecánicas del producto a fabricar y por otro lado puede generar problemas de procesabilidad en las máquinas de inyección que den lugar a defectos dimensionales o estéticos. Por miedo a ello, normalmente se emplea menos material reciclado del que sería posible. 

Por este motivo, el reto que ha sido abordado en este proyecto es la investigación experimental de la variación de propiedades de un material plástico con el reciclado, y la introducción y utilización de técnicas digitales que permitan conocer cuál es la cantidad máxima admisible de material reciclado que el producto y el proceso son capaces de admitir. 

OBJETIVOS 

los objetivos específicos de este proyecto son:

Establecimiento de procedimiento para la recuperación de desechos en planta y regranceado posterior para dosificación precisa de mezclas de material virgen con distintos porcentajes de material reciclado. 

Investigación de la procesabilidad de las diferentes mezclas realizadas para garantizar que la introducción de material reciclado es inyectable con las mismas garantías que el material virgen. 

Estudio de las propiedades mecánicas y físico-químicas del nuevo material obtenido, (material reciclado), para comparar con las del material virgen y análisis de los posibles cambios físicos en el material reciclado tales como transiciones térmicas y/o aparición de subproductos de oxidación (degradación). 

Ajuste de modelos para digitalización de los materiales reciclados, habilitando su uso en simulaciones del proceso de inyección con las diferentes mezclas de material reciclado en pieza de componente final. 

Creación de herramienta (basada en simulaciones de elementos finitos) con la que se pueda maximizar la cantidad de material reciclado garantizando la óptima procesabilidad en máquina de inyección 

Verificación en planta industrial de los porcentajes máximos de reciclado a conseguir. 

METODOLOGÍA 

Para ello, en el proyecto se ha seguido el plan de trabajo mostrado en la siguiente ilustración:

CONCLUSIONES 

Para el material seleccionado en este estudio (polipropileno con talco), inicialmente se preveía que podría existir una degradación evidente durante el reciclado que provocara una merma de propiedades, lo que conllevaría tener que alcanzar un compromiso entre la cantidad que se reintroduce, las propiedades que se obtienen y los cambios en el proceso de inyección que fuera necesario efectuar. 

Sin embargo, las investigaciones experimentales realizadas en el proyecto DIGI-REC han mostrado que, si se recicla en condiciones adecuadas, las propiedades del material permanecen muy estables. De hecho, el resultado fundamental ha sido que el material 100% reciclado prácticamente tiene las mismas propiedades que el virgen, con lo cual podría reintroducirse en cualquier porcentaje en el proceso de inyección. 

A la vista de este resultado se decidió ampliar la investigación y simular ciclos de reciclado para comprobar si se aprecia acumulación de degradación. Los resultados obtenidos en relación a las propiedades relacionadas con la procesabilidad (viscosidad, pvT, CTE, …), para hasta seis ciclos de regranceado, mostraron sólo ligeros cambios. El análisis de las propiedades mecánicas, en este caso realizadas hasta doce ciclos de reciclado, tampoco mostraron una merma apreciable. Esta investigación confirmó nuevamente la estabilidad de las propiedades de este material con el número de ciclos de reciclado. 

A pesar de la poca influencia encontrada en las propiedades de material, se completó el proceso inicialmente previsto de digitalización del material y la creación del gemelo digital del proceso de inyección de la pieza demostradora. Los ligeros cambios en propiedades como la viscosidad, pvT o CTE provocan según las simulaciones del proceso de inyección realizadas también pequeños cambios en la calidad estimada de la pieza. No obstante, a nivel metodológico se completó el estudio y el desarrollo de la herramienta para su aplicación a futuro a otros materiales que puedan ser más susceptibles a sufrir degradación durante el reciclado. 

Desde un punto de vista de la metodología desarrollada, la digitalización de los materiales reciclados y la generación de gemelos digitales del proceso, se prevé aporte notables beneficios para otros materiales que sufran mayor degradación, ya que permite aunar en una herramienta ágil los requerimientos de procesabilidad y calidad dimensional de la pieza para maximizar el porcentaje de material reciclado reintroducido. 

27
Jul

Considerations of design about injection molding

Many times we receive a drawing with demanding tolerances, a 3D design that turn on all alarms, for example  big accumulation of mass, with paralelism, perpendicularity or flatness in raw materials like polyamide with high percent of glass fiber. By this reason, we think it is necessary to bear in mind some considerations about design of  injection molding based on more than 25 years of knowledge, that probably it could be of help.

In ZATEC we can advise to customer collaborating in this first phase of design, checking the feasibility analysis to optimize the design of piece, according to adequate raw material depending onf inal application and our process of injection molding, to reduce the investment if it is possible. As you can read as follow, we have remarked some examples about it:

Thickness

although sometimes it is not possible to avoid changes of thickness, is very important to have homogeneus thickness without sudden cahnges always it will be possibe. An irregular thickness could generate problems like deformations due to differences of shrinkage in the mentioned thickness, or sink marks in the opposite face.

Sharp Edges,

the sharp edges are stress concentrations (Kc) weakening the piece. Although we can do radii in some areas could complicate the mold, also we improve the design considerably.  It is necessary to take acocunt the big accumulation of mass in the perimeter when we round this area. A good example is a plastic part like a box, and the barrel efect.

Nerves

If we want a rigid piece, it is better to add nerves like reinforcement than increase the thickness. It is very important to bear in mind the crosses of nerves due to possible accumulation of mass, that as you know, this accumulation can generate asthetic defects. In areas with flat surfaces, besides of mentioned nerves, it is necessary to take account the cooling in mold with variations of temperatute, location and size of injection gate(s) and the chosen of adequate engineering plastic based on final application.

Towers and spigots

It should be designed to avoid big accumulation of mass, bubbles… theredore the important consideration is the difference between exterior radius and inner radius.

considerations about design of injection molding

Threaded

if it is possible, avoid the thread’s pitch too thin.  In case of female thread, avoid the fillet ends up to final of piece by possible breaks. In case of  male threads demolded by sliders, can be stopped at height of union line, avoiding if it is possible the problem of wear. As we have mentioned, is important to avoid the sharpd edges with weak mechanical properties, by this reason a good option is to reduce them.

Parts with Inserts

The inserts must not weakening the around material, by this reason the optimum thickness of around material of insert, it must be verified. The shrinkage of plastic on the metal can generate an overflow. This overflow could be removed, doing a ribbed uniform and crossed in the insert part.  Based on our knowledge, it is recommended to heat the insert before injectioning.

If we can help you with a project of plastic part, based on our expertise of engineering plastics and injection molding, do not hesitate to contact us like company of technical plastic injection located in Muel, Zaragoza (Spain), where we can collaborate actively with our customers.

24
Dec

ZATEC wishes you Merry Christmas

ZATEC wishes to all peopele who is in contact us, directly or indirectly, Merry Christmas and a Happy New Yeear .                           

This 2020 has been a complicated year, but we should look ahead, improving each day and adapting  to this new scenario with Covid-19.

We would like to thank the effort of our workers, the support from all suppliers and specially to customers that continue trusting in Zatec despite of Covid situation.

We know the essential is invisible to our eyes, by this reason we want to wish you a Merry Christmas and mainly a good health in this new year 2021.

20
Apr

Situation in Zatec about COVID-19

Today is the star theme in the Tv news with current alarm state communicated by the Spanish Government.

Several weeks ago, we saw this situation far away in China and his quick spread have been the same in Spain or even further. In Zatec we read each day bad news due to temporal closure of companies, mainly in automotive market due to mentioned COVID-19.

Internally in ZATEC, we have taken several safety measures and continue analyzing future proposals from workers to avoid, if it is possible, the quick spread, keeping the security in our facility:

  • Maximum 3 workers in each costume (male and female), to respect the minimum distance between workers of aboout 1 meter in the change of shift.
  • Maximum 1 worker in the break cofee area.
  • Of course,  clean the hand with soap more times than usual. Mainly after/before clocking in.
  • More cleanliness in switches, handles, knobs….
  • To use glovees according to each workstation.
  • Flexibility in the shifts, prioritizing the workers with sons and dependent family members.
  • There will be not visits,  from Zatec to Customers/suppliers and from out to Zatec. Except to in execptional cases like repairs with the adequate safety measures.
  • The last point is very important to transporters. The drivers must not enter to warehouse.
  • Bear in mind the possibility to work from house with portable PC in depending on some cases like office.

Anyway, besides of sanitary point of view, that obviously this is the most important, this situation COVID-19 is producing an elevated economical impact in the industry. In fact, there iare some examples in automotive like Seat, VW, Nissan, PSA, Ford, Mercedes… and therefore several companies like Tier-1 1, similar than a house of cards  which is collapsing. Everything is connected.   This is a chain.  Nevertheless in Zatec we continue working 24 hours/ 5 days per week due to we have not positive cases of Covid-19 and we hace still customers working despite of this complicated situation. They need our plastic components of injection molding but we understand this situation could be different tomorrow, waiting the next news about this pandemic.

By this reason we are evaluating our situation in each moment to analyze the best option for our customers and workers day to day.

There are a lot of type of customers, and the critical point at this moment is the direct communicationin both directions to help us like “partners” and not only like acomercial relationship.  Sometimes, there are plastic parts in the transport without posibility to download in the destination due to temporal closure of some companies and this is other unnecesary extra problem. We expect this situation finished as soon as possible but we understand there is a long way to walk, yet. Then, we will adapt at this new moment, and we will continue working to improve and supplying plastic parts of injection molding for different markets like Automotive, being more flexibles in our production based on our know how.

We wish you good healthy to enjoy of working again, with at least relative normality.

28
Feb

Corporate Social Responsability in Zatec

Beyond of certificated and applied standards of our sector or sectors that we are working, for example the IATF-16949 of Automotive market, in Zatec like an injection molding company of technical parts in enginerring plastics, we have a target to develop year on year the Corporate Social Responsability Area grouping all good practices that we are doing or we will do based on sustainable development objectives. By this way, we will contribute with our effort about it.

RSC-Quiero trabajar ahí

Therefore, our interest groups are customers, supplier, social enviroment, enviromental and of course, the workers. In this context Zatec is implementing an ambitious plan of good practices integrated in our everyday and strategy. Considering the satisfaction of our customers like target, supplying plastic parts of high added value according to customer’s requirements, as priority.

Bearing in mind the last paragraph, this year Zatec has made important steps in humans resources to improve the satisfaction of our employees. For example, the birthday present, labor and family conciliation if it is possible, checking their happiness in the job and hearing a proposals to continue improving. Zatec has collaborated with Serlog, an specialized company of  Human Resources like  guide improving the work atmosphere.

Other example that is a source of pride is the Campaign of Pencils and Smiles, collaborating with Automotive Cluster of Aragon, where we are partners, and donating academic materials for children in emergency situation.

In short, it does not mean a simple whitewash, it means to improve our productivity, motivate and retaining talent, giving an important added value to our workers. In fact, this year we have achieved the stamp of Social Responsability in Aragon-RSA(our region in Spain). We expect this year will be only the beginning.

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