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Demand of Thin Walled Plastics Products Continues to Increase
Time: 2017-08-19
When designing and moulding plastic products, product wall thickness is a key consideration. While thicker walls offer greater strength, the downside is warping can be more prevalent when the plastic cools in the mould. To combat this and in their quest to reduce unit costs, many engineers and designers go in the opposite direction, keeping parts as thin and lightweight as feasible.
The advantages of plastic thin wall moulding are clear. A lower moulding weight means reductions in raw material and shipping costs. Meanwhile, due to faster cooling times, cycle times are much faster. This enables mass-production moulders and converters who dominate the thin walled market space significant productivity gains - so important in today's competitive plastics environment. 
It is not just packaging moulders that benefit. In the automotive industry, lighter components help to reduce on-the-road weight; that means more mpg and fewer carbon emissions. While producers of electronic and telecommunication devices, as well as medical equipment manufacturers are continually pushing the boundaries for thin-walled parts. So how thin are we talking? As a general rule, thin walled components are characterised as being less than 1mm in thickness for portable electronic parts and 2mm or less for large automotive parts. For food packaging containers found in retail and catering outlets, thin wall thicknesses is typically less than 0.6mm.
According to industry research compiled by AMI Consulting (2016), approximately 43% of the European thin wall packaging market is dominated by the top 10 converters. As predicted several years ago, consolidation between thin wall moulding specialists continues throughout Europe, with SME moulders combining to strengthen their market offering. To successfully succeed in the thin walling arena, injection moulders need to examine every potential application to ensure that the selection of materials, machine and tooling give the optimum blend of speed, quality and consistency. Providing the injection moulding machine can withstand the higher stresses and injection pressures, switching to thin wall moulding is feasible.
Hydraulic machines designed for thin-wall moulding applications frequently have accumulators driving both injection and clamping cycles. Today's all-electric and hybrid electric/hydraulic models are designed to withstand higher stresses and speeds in a 24/7 production environment. At Sumitomo (SHI) Demag, the company's hybrid El-Exis SP machine is the system of choice for many thin wall moulding specialists. The El-Exis SP range of hybrid moulding presses is designed for high-speed thin walling production. Incorporating a number of innovative mechanical and software features, the range typically achieves between 3% and 5% more productivity than other machines on the market. When fast production speeds and frequent changes are required, machine versatility is vital.
Moulders must also take into account the flow of the material and how far it has to travel within the mould tool. Faster filling and higher pressures are required to drive molten plastic material into thinner cavities to prevent it freezing off between shots. This may involve making modifications to gating arrangements within the mould. With many contracts involving millions of mouldings every year, a tailor-made system can deliver the precision and cycle time needed to achieve a rapid return on investment and sustainable growth. You should also consider longer-term plans, factoring in the likelihood of needing to integrate robotics and labelling technology into your thin wall processes.  High-level engineering, automation, operational, communication and IT skills are equally essential. 
Moreover, operator skills and experience are important for production efficiency. Sumitomo (SHI) Demag places great emphasis on pre-installation training and familiarisation, in addition to on-going structured process optimisation courses. Catering to this demand, Sumitomo (SHI) Demag opened a new training facility in Daventry and launched a new 'Machine & Process Appreciation' UK training programme.
The number of moulders is shrinking, but the volumes of thin walled plastics parts being produced have increased exponentially. With sustainability consumption being a key priority across the packaging, automotive and electronic supply chains, lightweight plastics offer a combination of superior functionality, strength, shatter resistance and barrier properties. These factors will continue to drive demand for thin walling in the future.
Source: www.packagingeurope.com