Size reducing, washing, separating, drying and agglomeration
Herbold, Hall 9, Booth B42
Process solutions for the treatment of plastic waste
The machine and plant manufacturer Herbold Meckesheim GmbH will be presenting tried and tested process solutions for the treatment of plastic waste in Düsseldorf in addition to its wide range of machines.
Pre-shredding
Pre-shredding is an essential process step when the feed material is too bulky to process or when it has to be coarsely broken up before sorting, visual inspection, or testing. Herbold uses shredders, granulators, guillotines, and hammer mills for pre-crushing. For example:
The demand for high-performance shredders that can process entire bales is increasing, especially when used in washing lines. Herbold will present the EWS 60/210 for the first time at the K 2019 trade fair. This shredder was developed for dry operation as well as for wet operation and has a maintenance-friendly design in addition to its high capacity. The machine is designed to be very robust and durable. In many plants, the crusher is the first stage in the process. In this stage, foreign bodies are often impossible to avoid. For this reason, some of the special features of this stage have been taken into account during its development that the company claims are unavailable in any other machines on the market. The company focuses on making a perfect wear-protected rotor that, in addition to custom knife configurations, is equipped in particular with bolted armour plating and a special grinding chamber seal. The time-consuming hard-facing of rotors is therefore unnecessary. The two-sided belt drive is low-maintenance, and to safeguard against foreign bodies, there is a clutch that prevents damage to the machine when uncrushable feed material is encountered.
The maintenance concept is tailored to ensure optimal accessibility based on ergonomic considerations. The first machines are already in use at customers in Europe, and the official product launch will take place at the K 2019 trade fair.
DWS two-shaft shredder
A new two-shaft shredder with the stator positioned in the middle will be presented as a new innovation at the fair. Due to the large surface area of the rotor, the machine is stated to have a good feed performance and to be suitable for materials that can only be fed in doses using conventional shredders such as big bags or high-volume containers.
Size reduction: Herbold granulators grind all plastic waste materials.
SB granulators with force feeding
he Herbold SB series granulators with force feeding have been used successfully worldwide for many years. “We have consciously redesigned this series of machines to enable complete horizontal charging”, stated Karlheinz Herbold, who is responsible for the technology as the Executive Director. The feed material is not fed into the grinding chamber from the top through the force of gravity as in the case of standard granulators, but by even feeding the material into the grinding chamber horizontally at the height of the rotor using screw conveyors. To accomplish this, the machine housing and feed system were completely redesigned to meet all requirements in terms of size-reduction performance as well as ease of access for maintenance purposes.
Washing, separating, and drying
he treatment of process water also plays a decisive role, especially for washing lines. Herbold now offers solutions covering this area as well. Achim Ebel, Division Manager for washing lines states: “We look closely at the planned input quantities and compositions, but at the same time keep an eye on the desired applications for the washed end products. We do not offer washing lines off the shelf – designing a solution that meets the particular requirements is a more intensive individual process performed together with the customer.”
Herbold offers tried and tested solutions for many applications including PET bottles, post-industrial and post-consumer films, post-consumer hard plastics, big bags and other monofilaments, Tetra paks and pulp waste. The following new developments from the washing line product area will be presented.
VWE 700 prewashing unit
An important component in a Herbold film washing line is the multi-stage prewashing unit, which captures coarse foreign bodies and reduces the mineral fraction, both to protect the subsequent machines. The remainder is also gently pre-washed. The type of pre-washing developed by Herbold Meckesheim has been a proven technology. Now this process step has been further optimised by increasing the throughput performance for films, optimising the flow of water, and integrating a baffle plate thickener into the unit to clean the process water. Contaminants are removed directly on the unit.
Hot washing
ncreasing quality requirements in the plastic recycling industry also require optimised cleaning stages when building a plastics recycling plant. An important step in plastics recycling is the hot washing step, which has been a major one in the PET bottle recycling process. Herbold Meckesheim has advanced this step of the process for PO films and can offer optimised temperatures and appropriate dwell times, as well as optimal cleaning results and end material quality through the use of suitable additives.
Mechanical drying
The dryers from Herbold Meckesheim are claimed to meet high quality requirements in terms of high drying efficiency and performance, good accessibility, wear-protected parts, and automatic cleaning systems. Now, the company has also implemented the principles of multi-stage vertical drying in their horizontal dryers. This improves the product output rate and the lifespans of the wear parts. Furthermore, the thermal drying process has been optimised.
Thermal drying
The two-stage thermal dryer is completely new. The flow through the coils was optimised and the heating temperature was improved in terms of energy consumption. This design is used especially in the recycling of increasingly thinner films. It is used to reach low residual moisture contents and ensure the material can be processed afterwards with as little energy as possible.
Label remover
Herbold has made numerous minor improvements, and therefore introduced a new and improved generation to the market. Based on a proven basic principle, the Herbold HLR label removers are now much more variable, states the company. This applies to the removal process as well as to the integrated separation using a classifier. They are now able to control the dwell times and intensities of the label removal process much better. To accomplish this, a series of adjustable machine parameters is used.
