{"id":3204,"date":"2026-01-30T17:47:57","date_gmt":"2026-01-30T16:47:57","guid":{"rendered":"https:\/\/ddl.webscriptum.org\/impianto-completo-eps\/pre-espansore-discontinuo\/"},"modified":"2026-05-28T14:51:44","modified_gmt":"2026-05-28T12:51:44","slug":"pre-expander","status":"publish","type":"page","link":"https:\/\/ddl.re.it\/en\/complete-eps-system\/pre-expander\/","title":{"rendered":"Pre-expander"},"content":{"rendered":"\t\t
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Pre-expander<\/span><\/h1><\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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The batch Pre-expander is designed to expand a controlled amount<\/strong> of raw material to obtain beads<\/strong> with programmed uniform mean density<\/strong>.<\/p>

Process control and cycle repeatability make the Pre-expander a key component for the stability of the entire EPS plant.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t<\/path><\/svg>\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\tProcess control and repeatability<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t<\/path><\/svg>\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\tAutomation and operator interface<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t<\/path><\/svg>\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\tMaintenance<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
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The machine consists of a loading hopper<\/strong> which feeds in the raw material and a dosing system with scale<\/strong>, which allows the amount of material fed into the expansion chamber<\/strong> to be accurately weighed. The raw material is fed in quickly by a screw<\/strong>.<\/p>

The expansion chamber is made of AISI 304 stainless steel<\/strong> and has a specific shape: a cylindrical upper part and a conical lower section.<\/p>

This shape allows for progressive expansion of the beads<\/strong> and helps to achieve a uniform density<\/strong>.<\/p>

The chamber houses a mixer shaft<\/strong>, also made of AISI 304 stainless steel<\/strong>, driven by an electronic speed control system<\/strong>.<\/p>

The rotation speed can be optimized to suit the cycle stage, the type of raw material and the expansion conditions.<\/p>\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\t\n\t\t\t\t\t\t

\n\t\t\t\t\t\t\t\n\t\t\t\t<\/path><\/svg>\t\t\t<\/span>\n\t\t\t\t\t\t\tProcess control and repeatability<\/span>\n\t\t\t<\/div>\n\t\t\t\t\t\t
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An automatic density control<\/strong> device monitors<\/strong> each expansion cycle, thereby ensuring the repeatability and stability of the production process.<\/p>

After leaving the chamber, the expanded material is conveyed to a fluidized-bed dryer<\/strong> made of stainless steel and equipped with a steam-air heat exchanger<\/strong>, designed to prevent the beads from sustaining damage due to thermal shock<\/strong>.<\/p>

The beads are transferred to the ageing silos<\/strong> by rotary valve fan<\/strong>.<\/p>

The system includes a second expansion stage, which serves to control density and ensure process stability.<\/p>\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\t\n\t\t\t\t\t\t

\n\t\t\t\t\t\t\t\n\t\t\t\t<\/path><\/svg>\t\t\t<\/span>\n\t\t\t\t\t\t\tAutomation and operator interface<\/span>\n\t\t\t<\/div>\n\t\t\t\t\t\t
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The Pre-expander is controlled by a Siemens PLC<\/strong>.<\/p>

The human-machine interface consists of a touchscreen panel, which allows all operating parameters to be selected and stored.<\/p>

The air and steam inlets<\/strong> are automatically regulated<\/strong> as to volume and temperature throughout all the expansion stages.<\/p>\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\t\n\t\t\t\t\t\t

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The machine is designed to facilitate routine and supplementary maintenance, since it allows ease of access to components for quick replacement of parts subject to wear.<\/p>\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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Want to find out more about integrating the Pre-expander into your EPS system?<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tSpeak with a technician \t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t<\/a>\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"

Pre-expander Home The batch Pre-expander is designed to expand a controlled amount of raw material to obtain beads with programmed uniform mean density. Process control and cycle repeatability make the Pre-expander a key component for the stability of the entire EPS plant. How it works Process control and repeatability Automation and operator interface Maintenance How […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3198,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"full-width.php","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-3204","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/pages\/3204","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/comments?post=3204"}],"version-history":[{"count":16,"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/pages\/3204\/revisions"}],"predecessor-version":[{"id":3537,"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/pages\/3204\/revisions\/3537"}],"up":[{"embeddable":true,"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/pages\/3198"}],"wp:attachment":[{"href":"https:\/\/ddl.re.it\/en\/wp-json\/wp\/v2\/media?parent=3204"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}