News overview and blog about products

Stay up to date with the latest developments within Hecht Technology and the industry. In this overview, we share practical insights, technical innovations, market trends, and company news. From containment solutions and process optimization to project updates and events – here you will find relevant knowledge and current affairs for professionals in high-containment and powder handling.

Lifters and handling systems for powders: the complete guide

Lifting systems determine whether your operators work safely and ergonomically with drums, big bags and containers, or whether you risk back and shoulder injuries, product loss and downtime. In pharmaceutical, chemical, food and battery production, staff lift loads every day that far exceed the ergonomic limit without assistance. This pillar shows how HECHT lifters automate powder and drum handling, which safety standards apply and how to combine ergonomics with containment.

Why lifting systems are indispensable

A drum of powder easily weighs 50 to 200 kg, a big bag 500 to 1000 kg. Tilting, lifting or emptying by hand is physically demanding and error-prone. Lifting systems take over that load, position the product accurately above a discharge point and prevent spillage. The result: less absenteeism, higher throughput and a reproducible process that does not depend on the physical strength of the operator.

Types of lifters for powder and drum handling

The right lifter depends on your load type, height and process step.

  • Drum lifters: lift, tilt and empty drums in a controlled way above a mixer or hopper.
  • Big bag lifters: hoist and position big bags for dust-free emptying, often with a discharge station.
  • Container and IBC lifters: dock to IBCs for charging process installations at height.
  • Mobile lift tables and column lifters: bring products to working height and bridge level differences in the line.
  • Vacuum lifters: lift sacks and packages without mechanical clamping force, ideal for varying formats.

Ergonomics as a design principle

Ergonomics is not a side issue but a design requirement. Good lifting systems bring the discharge point to the correct working height, eliminate reaching and bending and let the operator steer with minimal force. Match the operating height, tilt angle and speed to the task. A lifter that follows ergonomic guidelines measurably lowers the risk of musculoskeletal complaints and keeps your people deployable longer.

Integration with containment and dust-free working

Lifting and containment belong together. For active or hazardous powders you couple the lifter to a dust-free discharge, for example via a liner, a docking station or a split butterfly valve. This prevents the lifting moment itself from causing dust emission. Combine the lifter with a closed transfer to secure operator protection and ergonomics in a single action.

Safety, ATEX and standards

Lifting systems fall under strict safety rules. In zones with explosive dust the lifter must be ATEX-compliant, with spark-free design and correct grounding. The Machinery Directive and requirements for safe loading, emergency stop and fall protection also apply.

  • ATEX: spark-free, certified design for dust explosion hazard zones.
  • Machinery Directive: CE conformity, risk assessment and safe operation.
  • Load safety: validated maximum working load, overload protection and stable pick-up.
  • GMP/EHEDG: hygienic design and cleanable surfaces for pharma and food.

Material and hygienic design

In pharma and food the hygienic design determines suitability. Choose stainless steel 316L, crevice-free welds and surfaces that comply with EHEDG and GMP. This prevents product build-up, eases cleaning and keeps cross-contamination out. For corrosive chemicals you select materials resistant to the specific medium.

Return on investment and total cost of ownership

For procurement, more counts than the purchase price. Factor in the saving on absenteeism, the higher throughput and the lower product loss from spillage. A lifting system that speeds up changeover and eliminates manual steps often pays for itself within a few years. Moreover, automating handling lowers the risk of costly process errors and recalls.

Frequently asked questions about lifting systems

What load can a drum lifter handle?

That depends on the configuration, but standard drum lifters handle drums up to around 200 kg; heavier configurations are available to specification.

Are lifting systems suitable for ATEX zones?

Yes, provided you choose an ATEX-certified, spark-free design with correct grounding for zones with explosive dust.

How do I combine lifting with dust-free working?

By coupling the lifter to a closed discharge via a liner, docking station or split butterfly valve, so the lifting moment causes no dust emission.

Do lifters comply with GMP and EHEDG?

HECHT lifters are available in stainless steel 316L with crevice-free, hygienic design that meets GMP and EHEDG for pharma and food.

What does a lifting system deliver?

Less absenteeism through ergonomics, higher throughput, less product loss and a reproducible process, lowering total cost of ownership.

Related guides

Tailored advice from HECHT

Want to know which lifting system fits your load type, working height and containment requirements? HECHT engineers lifters that combine ergonomics, safety and dust-free working. Request a no-obligation consultation and receive a proposal tailored to your line.

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Screw conveying for powders

Screw conveying is one of the most reliable methods for moving powders and bulk materials in a controlled way. A rotating screw inside a closed trough or tube pushes the product from inlet to outlet at a constant, dosable rate. For engineers, buyers and QA in pharma, chemical, food and the battery industry, screw conveying offers a robust, low-dust and highly controllable solution. HECHT designs screw conveyors and dosing screws tailored to your product, capacity and hygiene requirements.

How screw conveying works

A screw conveyor consists of a helical screw shaft rotating inside a housing. The rotation moves the product axially towards the outlet. Through speed control, the screw acts as both a conveyor and a precise dosing device. This makes screw conveying ideal for processes that require a constant, adjustable mass flow.

Because the product is fully enclosed, dust emission stays minimal and the working environment remains clean and safe.

Types of screw conveyors

The right design depends on product, capacity and layout.

  • Trough screw — open or closed trough, suited to larger volumes and horizontal transport
  • Tube screw — fully enclosed tube, dust-tight and suitable for inclined transport
  • Dosing screw — short, precise screw for gravimetric or volumetric dosing
  • Shaftless screw — for sticky or fibrous products without a central shaft
  • Vertical screw — for conveying powders upward in compact layouts

Precise dosing with screw technology

Screw conveying excels at dosing. Coupling the rotation speed to a weighing system creates a gravimetric dosing screw that holds the mass flow within tight tolerances. This is critical for recipe formulation, continuous production and filling of critical ingredients.

  • Volumetric dosing — constant speed delivers a fixed volume per revolution
  • Gravimetric dosing — feedback from weighing corrects density variations
  • Loss-in-weight — continuous weighing of the supply hopper for maximum accuracy

Product-friendly conveying

Not every powder tolerates the same handling. Break-sensitive granules, sticky substances and segregation-prone mixtures call for an adapted screw design. The pitch, profile and speed of the screw determine how gently the product is moved. HECHT matches the geometry to the break sensitivity and flow properties of your product.

Containment and operator protection

For highly active powders, a closed screw system is an effective containment strategy. Combined with split-butterfly valves at inlet and outlet, the product stays isolated from the environment and operator exposure is limited. Depending on the OEB band, seals, bearings and feed-throughs are validated for leak-tightness, verified to SMEPAC.

Hygienic design: GMP and EHEDG

In pharma and food, a screw conveyor must be fully cleanable. GMP and EHEDG-compliant designs have polished surfaces (Ra ≤ 0.8 µm), no dead zones and disassembly-free CIP/WIP cleaning. Stainless steel 316L and FDA-compliant seals prevent cross-contamination between batches and product changeovers.

ATEX and safety

For combustible powders, the screw conveyor must be ATEX-compliant. Earthing, spark-free bearings, temperature monitoring and correct zoning prevent ignition. For oxygen-sensitive products such as battery powders, the system can be run inert with nitrogen.

Frequently asked questions about screw conveying

What is the difference between a conveying screw and a dosing screw?

A conveying screw moves large volumes; a dosing screw is optimised for accuracy and delivers a controlled mass flow.

What accuracy does a gravimetric dosing screw achieve?

With loss-in-weight weighing, accuracies within a fraction of a percent are achievable, depending on product and capacity.

Is screw conveying suitable for sticky products?

Yes, with a shaftless screw or an adapted pitch; HECHT selects the geometry based on the flow properties.

Can a screw conveyor operate dust-free?

A closed tube screw with the right seals operates virtually dust-free and is suitable for containment up to high OEB bands.

How is a screw conveyor cleaned?

Via CIP or WIP, or for fast product changeovers through an easily disassembled design, depending on your hygiene requirements.

Related guides

Tailored advice from HECHT

A screw conveyor that suits your product starts with an analysis of your powder, capacity and dosing requirement. HECHT designs, tests and supplies screw conveying that is reliable, low-dust and hygienic, and integrates seamlessly with your dosing and filling systems. Contact us for a conveying analysis and a tailored proposal.

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Powder transport: methods and systems for powders

Powder transport is the artery of every production line that works with bulk solids. How you move powders between dumping, mixing, dosing and packaging determines your throughput, product quality and dust emission. For pharma, chemical, food and the battery industry, the choice between pneumatic and mechanical transport is a strategic decision. This pillar explains which transport principles fit when, how to secure containment and ATEX, and where the value lies for process and cost.

The role of powder transport in your process

Transport connects all process steps. A well-chosen system moves powder in a closed manner, without segregation, product degradation or dust loss. The wrong system causes blockages, quality loss and exposure. Because transport is often the throughput bottleneck, the right choice directly delivers returns in capacity and reliability.

Pneumatic versus mechanical transport

The two main principles differ fundamentally in how they move powder.

  • Pneumatic transport: moves powder via an air stream through closed pipes, ideal for dust-free, hygienic and flexible routing over distance and height.
  • Dilute phase: high air velocity, suitable for non-friable, free-flowing powders.
  • Dense phase: low velocity, high density, ideal for friable, abrasive or segregation-sensitive products.
  • Mechanical transport: screw conveyors, trough chains and elevators for short, robust routes with high capacity.
  • Vacuum transport: closed and dust-free, popular in pharma for low to medium flow rates and easy cleaning.

Product characteristics drive the choice

The powder dictates the system. Particle size, density, moisture content, abrasiveness, friability and flow behaviour determine whether pneumatic or mechanical transport fits and in which phase. Hygroscopic or friable powders call for dense phase or vacuum transport to prevent degradation and segregation. Abrasive materials such as battery powders place extra demands on wear-resistant piping and low velocities.

Containment and dust-free transport

Closed transport is the simplest route to containment. A well-sealed pneumatic or vacuum system keeps powder entirely inside the pipe, so operators are not exposed and the room stays clean. For active pharmaceutical ingredients you couple transport to dust-free loading and discharge points via liners, docking stations or split butterfly valves. This keeps the whole chain, from source to destination, closed.

ATEX and explosion safety

Many powders form an explosive dust/air mixture. Transport through pipes also generates static charge. ATEX-compliant design is therefore not an option but a requirement.

  • Zone classification: match the design to the dust explosion zone inside and outside the installation.
  • Grounding: ensure grounding of all conductive parts to prevent spark formation.
  • Explosion protection: where needed, apply pressure relief, suppression or isolation.
  • Inert transport: use nitrogen to keep the oxygen concentration below the limit.

Hygiene, GMP and cleaning

In pharma and food, cleanability determines suitability. Choose stainless steel 316L, crevice-free construction and surfaces that comply with GMP and EHEDG. Vacuum transport is favoured because it is dismountable and easy to clean, supporting CIP or fast changeover. Secure batch separation and traceability to rule out cross-contamination.

Capacity, energy and total cost of ownership

Procurement weighs throughput against energy consumption and maintenance. Pneumatic transport is flexible but more energy-intensive; mechanical transport is efficient over short distances but less flexible in routing. Calculate the full picture: investment, energy, wear, cleaning and downtime. A system matched to your product and flow rate prevents blockages and recovers quickly, lowering total cost of ownership.

Frequently asked questions about powder transport

When do I choose pneumatic and when mechanical transport?

Pneumatic transport suits distance, height difference and dust-free requirements; mechanical transport suits short, robust routes with high capacity.

What is the difference between dilute and dense phase?

Dilute phase uses high air velocity for free-flowing powders; dense phase uses low velocity for friable, abrasive or segregation-sensitive products.

How do I keep powder transport dust-free?

With a closed pneumatic or vacuum system and dust-free loading and discharge points via liners, docking stations or split butterfly valves.

Is ATEX always necessary?

For most organic and metal powders, yes. You assess the dust explosion properties and apply zone classification, grounding and explosion protection.

Which transport suits battery powders?

Abrasive battery powders require low velocities, wear-resistant piping and often inert transport to limit degradation and explosion risk.

Related guides

Tailored advice from HECHT

Want to know which transport principle fits your powder, flow rate and layout? HECHT engineers closed transport systems that combine containment, ATEX and throughput. Request a no-obligation consultation and receive a proposal tailored to your process.

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Vacuum deaerators for powders

When powders are filled, poured or conveyed, they entrain air. That trapped air makes the product fluffy, unstable and hard to dose — and causes dust, overflowing packs and weight deviations. A vacuum deaerator removes that air under negative pressure, so the powder becomes compact, stable and reliably processable. For engineers, buyers and QA in pharma, chemical, food and the battery industry, deaeration is the key to consistent fill density and reliable dosing. HECHT designs vacuum deaerators tuned precisely to your product and process.

What a vacuum deaerator does

A vacuum deaerator extracts the air trapped between powder particles. The powder passes through a vacuum chamber or a perforated surface surrounded by negative pressure, drawing off the air while a filter retains the powder. The result is a deaerated, more compact product with a higher and more consistent bulk density.

This solves a persistent problem: fluffy powder that settles over time, leaving packs underweight or doses inconsistent.

Why deaeration matters

Trapped air causes a series of process problems that deaeration directly addresses.

  • Consistent fill density — deaerated powder fills reproducibly, without after-settling
  • Accurate dosing — a stable bulk density makes volumetric dosing reliable
  • Less dust — compact powder generates less dust during transfer and filling
  • More compact packaging — more product per pack volume, lower transport cost
  • Better flow properties — deaerated powder behaves more predictably

Operation and efficiency

A vacuum deaerator's efficiency depends on residence time in the negative-pressure zone, the depth of the vacuum and the filter area. A fine, compressible powder requires a deeper vacuum and longer residence time than a coarse, granular product. HECHT dimensions the deaerator based on particle size distribution, compressibility and the required throughput, so you gain maximum density without slowing the process.

Inline deaeration in the process chain

A vacuum deaerator works best as an integrated step, not a standalone device. Placed before the filling or dosing stage, it continuously supplies deaerated powder to the filling line. Combined with screw or vacuum conveying, it forms a closed, dust-free chain from storage to packaging, in which every pack receives the same density and weight.

Containment and operator protection

Because deaeration takes place under negative pressure, no dust escapes to the environment — air is drawn inward instead. This makes the vacuum deaerator suitable for containment applications. The extracted air is cleaned through HEPA filtration before leaving the system. For highly active substances, the design is validated to the relevant OEB band and verified to SMEPAC.

Hygienic design and ATEX

In pharma and food, the deaerator is fully CIP/WIP-cleanable, with smooth 316L surfaces and no dead zones to GMP and EHEDG. For combustible powders, the system is earthed and built ATEX-compliant, with correct zoning and explosion-safe components. For oxygen-sensitive battery powders, deaeration can take place under nitrogen.

Frequently asked questions about vacuum deaerators

What problem does a vacuum deaerator solve?

It removes trapped air, making powder more compact and keeping fill density and dosing consistent, without after-settling in the pack.

For which powders is deaeration worthwhile?

Fine, compressible and fluffy powders benefit most; coarse, free-flowing products contain less trapped air.

Does deaeration slow down my process?

When correctly dimensioned, deaeration runs inline at production speed and the process need not stop.

Is a vacuum deaerator suitable for containment?

Yes. Because it works under negative pressure with HEPA filtration, it is suitable for highly active substances up to high OEB bands.

How much density gain is achievable?

That depends on the product and its compressibility; for fluffy powders, significant improvements in bulk density are possible.

In-depth articles on vacuum deaerators

Related guides

Tailored advice from HECHT

Struggling with fluffy powder, varying fill weights or dust at the filling line? HECHT's specialists analyse your product and process and dimension a vacuum deaerator that delivers consistent density, accurate dosing and a dust-free, safe working environment. Contact us for a product analysis and a tailored proposal.

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Safe powder sampling: the complete guide

Sampling is a critical but underrated risk point in powder processing. Every time you draw a sample, you open a closed process, precisely where containment is most vulnerable. For pharma, chemical, food and battery production, safe sampling means taking a representative sample without operator exposure, cross-contamination or product loss. This pillar explains how HECHT sampling systems sample safely, representatively and GMP-compliantly, and which technique fits your OEB target.

Why sampling is a risk point

QA and QC require samples for identity, content and homogeneity. But opening a drum, pipe or mixture exposes the operator to dust and breaks the closed chain. For active pharmaceutical ingredients or toxic powders that is unacceptable. Safe sampling resolves the tension between the analytical need for a sample and the requirement of a closed, protected process.

Representativeness as the first requirement

An unsafe sample is a problem; a non-representative sample is one too. The golden rule of sampling is that the sample must represent the whole batch. Take samples at the right location and depth, at multiple points and moments, and prevent segregation while drawing. A wrongly taken sample leads to incorrect release decisions, recalls or rejected batches, no matter how well the lab analyses.

Techniques for safe sampling

The right technique depends on the medium, the process step and your containment target.

  • Sample thieves/spears: draw powder at various depths from static bulk in drums or containers.
  • In-line samplers: automatically take a sample from a moving powder stream or pipe without opening the process.
  • Closed sampling systems: take samples via a sealed port, ideal for high containment.
  • Glovebox and isolator sampling: for the highest OEB classes, keeping the operator fully separated from the product.
  • Single-use samplers: disposable samplers that eliminate cross-contamination and cleaning.

Containment and OEB classes

The required containment determines the system. For low-active substances a sealed port suffices; for high-potent APIs a closed or isolated system is needed.

  • OEB 3-4: closed sampling ports with liners or sealed interfaces.
  • OEB 5 and higher: glovebox, isolator or single-use sampling with validated disconnection.
  • Validation: confirm containment performance with SMEPAC measurements to demonstrate operator protection.

GMP, cross-contamination and traceability

Under GMP, sampling must be reproducible, documented and free of cross-contamination. Single-use samplers eliminate cleaning between samples and rule out product-bearing surfaces. Secure traceability of sample, batch and time, and use contact materials that comply with USP/EU requirements. A validated sampling procedure prevents deviations during audits.

ATEX and explosion safety during sampling

Opening a powder process in an ATEX zone requires extra care. Samplers and ports must be spark-free and grounded, so static charge causes no ignition. At high explosion risk you take samples under inert gas or via a closed system that limits oxygen ingress. Match the design to the zone classification of the installation.

Integration into the process flow

Sampling works best as a fixed part of the process, not as a separate action. Place sampling ports at logical points: after mixing for homogeneity, at receipt for identity and at discharge for release. Couple the sampler to your existing docking and liner interface, so sampling does not break the closed chain but fits into it.

Frequently asked questions about sampling

How do I take a representative powder sample?

By sampling at multiple points, depths and moments and preventing segregation while drawing, so the sample represents the whole batch.

Which sampling technique suits high-potent substances?

For OEB 5 and higher you use glovebox, isolator or single-use sampling with validated disconnection to rule out operator exposure.

How do I prevent cross-contamination during sampling?

With single-use samplers or validated cleaning, per-sample traceability and contact materials that comply with GMP and USP/EU.

Is sampling possible in an ATEX zone?

Yes, provided you use spark-free, grounded samplers and at high risk work under inert gas or via a closed system.

Can I sample without opening the process?

Yes, with in-line or closed sampling systems that sample via a sealed port without breaking the closed chain.

Related guides

Tailored advice from HECHT

Want to know which sampling system samples representatively, safely and GMP-compliantly at your OEB target? HECHT engineers closed sampling solutions that combine containment and representativeness. Request a no-obligation consultation and receive a proposal tailored to your process.

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Filling systems for powders

Filling is the final, critical step in powder processing: this is where the product is transferred into bags, drums, big bags or containers at the right weight and without dust. A good filling system combines accuracy, speed, hygiene and operator protection. For engineers, buyers and QA in pharma, chemical, food and the battery industry, the filling strategy determines product quality, throughput and the safety of the working environment. HECHT designs filling systems tuned to your product, packaging format and containment requirements.

What a filling system must deliver

A reliable filling system doses the correct weight, fills dust-free, protects the operator and keeps pace with production. These requirements often conflict: fast filling generates dust, accurate filling costs time. A good design balances them by aligning dosing, deaeration and containment.

The choice of system follows from the product, the packaging format and the required accuracy and capacity.

Filling formats and packaging

Each packaging format calls for its own approach.

  • Bag filling — open or valve bags, manual or (semi-)automatic, for 5–50 kg
  • Big bag (FIBC) filling — bulk packaging up to 1,000 kg and beyond, with deaeration and compaction
  • Drum filling — for powders and granules in steel or plastic drums
  • Container filling — IBCs and process containers for closed transfer
  • Bottles and small packs — accurate dosing of small quantities in pharma

Accurate dosing during filling

Fill accuracy determines whether you deliver under- or overweight — both cost money. Gravimetric filling with integrated load cells corrects during filling and holds the weight within tight tolerances. A coarse/fine dose (fast fill, then top-up) combines speed with precision. HECHT couples the dosing screw or valve to the weighing system for reproducible fill weights.

Dust-free filling and deaeration

During filling, powder displaces air, which wants to escape carrying dust. Dust-free filling requires closed fill heads, extraction at the fill point and deaeration of the pack. A vacuum deaerator before the fill head supplies compact, deaerated powder, so the pack settles less and dusts less. The result is a clean working environment and a consistent fill weight.

Containment and operator protection

For highly active powders, filling is the moment of highest exposure risk. Containment filling systems use split-butterfly valves, continuous liners or isolator technology to minimise operator exposure.

  • OEB 1–2 — local extraction and closed fill heads often suffice
  • OEB 3–4 — split-butterfly valves and continuous liner for closed transfer
  • OEB 5 — isolator or glovebox with validated, SMEPAC-verified containment

Hygienic design and ATEX

In pharma and food, fill heads and product-contact parts are fully CIP/WIP-cleanable, in 316L with smooth surfaces and no dead zones to GMP and EHEDG. For combustible powders, the filling system is earthed and built ATEX-compliant; for battery powders, filling can take place under nitrogen.

Frequently asked questions about filling systems

What fill accuracy is achievable?

With gravimetric filling and coarse/fine dosing, accuracies within a few tenths of a percent are achievable, depending on product and packaging.

How do I fill dust-free?

With closed fill heads, extraction at the fill point, pack deaeration and a vacuum deaerator that compacts the powder beforehand.

Which filling system suits highly active substances?

Depending on the OEB band: split-butterfly valves, continuous liner or isolator technology with SMEPAC verification.

Can one line handle multiple packaging formats?

Yes, with interchangeable fill heads and stations a line can handle bags, drums and big bags, depending on the design.

How fast can I fill?

Capacity depends on packaging format, dosing principle and accuracy requirement; HECHT dimensions to your required throughput.

Related guides

Tailored advice from HECHT

Looking for a filling system that fills your product accurately, dust-free and safely into your packaging? HECHT's specialists analyse your powder, packaging format and OEB band and design a filling line that combines quality, throughput and operator protection. Contact us for a filling analysis and a tailored proposal.

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Powder processing: the complete guide to processes and safety

Powder processing is a discipline of its own. Powders behave unpredictably: they dust, segregate, cake and form explosive mixtures. For pharma, chemical, food and the battery industry, controlling those properties determines whether a process runs safely, reproducibly and profitably. This pillar gives technical decision-makers an overview of the complete powder processing chain, from receipt to packaging, with an emphasis on safety, containment and GMP.

What makes powder processing so challenging

Unlike liquids, powders follow no fixed flow laws. Their behaviour depends on particle size, shape, moisture content, density and charge. The same powder can flow freely today and bridge tomorrow. That variability makes powder processing complex and explains why standard solutions often fail. Those who understand powder properties design a process that performs consistently.

The process steps in the chain

Powder processing is a sequence of operations that each carry their own risk.

  • Receipt and discharge: dumping sacks, big bags and drums, the dustiest part of the process.
  • Transport: moving pneumatically or mechanically between process steps.
  • Mixing and dosing: homogenizing and weighing accurately for reproducible quality.
  • Sieving and milling: adjusting particle size for flow and quality.
  • Sampling: sampling representatively for QA without opening the chain.
  • Packaging and discharge: controlled filling into final packaging or IBC.

Containment as the common thread

Throughout the chain runs one question: how do I keep powder in and the operator out? Containment means a closed process in which dust never leaves the product. You achieve this with liners, docking stations, split butterfly valves, closed transport and isolated sampling. Containment is not a separate component but a design philosophy that protects every transfer in the chain.

OEB classes and operator protection

The required containment depends on the toxicity of the product, expressed in OEB classes.

  • OEB 1-2: low activity, simple extraction and good ventilation often suffice.
  • OEB 3-4: moderately active, requires liners, closed transfer and well-engineered docking.
  • OEB 5 and higher: high-potent, requires isolators, endless liners or gloveboxes with validated disconnection.
  • Validation: confirm each containment step with SMEPAC measurements to demonstrate exposure.

ATEX and dust explosion safety

Almost every organic or metal powder can cause a dust explosion. Fine dust in the air plus an ignition source is enough. ATEX-compliant design controls this risk via zone classification, grounding of all conductive parts and, where needed, explosion protection or inertization with nitrogen. For battery powders and reactive chemicals this is an absolute design requirement, not an option.

GMP, hygiene and cleanability

In pharma and food the hygienic design determines whether an installation is usable. Choose stainless steel 316L, crevice-free welds and surfaces that comply with GMP and EHEDG. This prevents product build-up, eases CIP and rules out cross-contamination. Single-use components eliminate cleaning between batches and speed up changeover, a direct advantage with frequent product changes.

From components to an integrated system

The greatest value arises not in individual machines but in an integrated chain. When discharge, transport, mixing, sampling and packaging connect via a consistent containment and interface philosophy, the dust leaks at the transition points disappear. HECHT engineers that complete chain, so every transfer stays closed and the entire process runs reproducibly, safely and efficiently.

Frequently asked questions about powder processing

Why is powder processing more complex than liquid processing?

Because powders follow no fixed flow laws; their behaviour varies with particle size, moisture, density and charge, which often makes standard solutions fail.

What does containment mean in powder processing?

A closed process in which dust never leaves the product, achieved with liners, docking, split butterfly valves and closed transport and sampling.

How do I determine which OEB class I need?

Based on the toxicity and exposure limit of the product; the lower the permitted exposure, the higher the OEB class and the required containment.

Is ATEX necessary in powder processing?

For almost all organic and metal powders, yes, because fine dust forms an explosive mixture. Zone classification, grounding and explosion protection are then required.

How do I keep an installation GMP-compliant?

With stainless steel 316L, crevice-free hygienic design, cleanable surfaces per EHEDG and validated cleaning or single-use components.

Related guides

Tailored advice from HECHT

Want to make your powder processing safer, closed and reproducible? HECHT engineers the complete chain, from discharge to packaging, tailored to your OEB target, ATEX zone and GMP requirements. Request a no-obligation process consultation and receive a concrete proposal.

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Industrial vacuum cleaners

Industrial vacuum cleaners keep production areas dust-free, prevent cross-contamination and control the risk of combustible dust. Unlike an ordinary vacuum cleaner, they are built for continuous heavy use, fine and hazardous powders and strict hygiene and explosion requirements. For engineers, buyers and QA in pharma, chemical, food and the battery industry, the right industrial vacuum cleaner is an indispensable part of a safe and GMP-compliant process. HECHT supplies vacuum cleaners tuned to your dust, environment and classification.

Why an industrial vacuum cleaner

Dust that accumulates on floors, equipment and ledges causes three problems: it contaminates other products, it exposes operators and it can form an explosive dust-air mixture. An industrial vacuum cleaner removes that dust at source, with filtration and construction designed for fine and hazardous powders. It is therefore not a cleaning aid but a safety and quality instrument.

Selection criteria: what to look for

You choose the right cleaner based on the dust and the environment.

  • Type of dust — particle size, density, toxicity and combustibility
  • Filtration class — from standard to HEPA H14, depending on the OEB band
  • Drive — electric or compressed-air (venturi); in ATEX zones often compressed air
  • Collection volume — matched to the amount of dust and the desired emptying frequency
  • Cleanability — CIP/WIP and smooth 316L surfaces for pharma and food
  • Mobility — mobile for local use or fixed for central extraction

Filtration and the OEB band

Filtration determines whether the cleaner is suitable for hazardous substances. For highly active powders, HEPA final filtration (H13/H14) is necessary, often with a validated bag-in-bag-out (BIBO) discharge of the collected dust, so the operator is not exposed when emptying.

  • OEB 1–2 — standard to fine filtration suffices
  • OEB 3–4 — HEPA filtration with safe, closed dust discharge
  • OEB 5 — dual HEPA and validated BIBO, SMEPAC-verified

ATEX: vacuuming in explosion-prone zones

In zones with combustible dust or vapour, the vacuum cleaner must be ATEX-compliant. That means an earthed, antistatic design, spark-free components and often a compressed-air (venturi) drive without an electrical ignition source. The correct zone classification (for example zone 22 for dust) determines the required design. HECHT supplies ATEX vacuum cleaners with the accompanying documentation and zoning.

Hygienic cleaning in pharma and food

In GMP environments, the vacuum cleaner itself is a potential contamination source. That is why product-contact parts are made in 316L with smooth, seamless surfaces and no dead zones to EHEDG, and are CIP/WIP-cleanable. Per product or batch, the filter unit can be swapped to prevent cross-contamination.

Mobile or central system

For incidental cleaning or several workstations, a mobile unit suffices. For large areas, continuous dust generation or multiple extraction points, a central vacuum system is more efficient: one powerful vacuum source serves multiple connection points through a fixed pipe network. HECHT advises based on your layout, dust load and frequency of use.

Frequently asked questions about industrial vacuum cleaners

What distinguishes an industrial vacuum cleaner from an ordinary one?

Continuous heavy use, high-grade filtration up to HEPA, robust construction and suitability for fine, hazardous and combustible powders.

Which filtration do I need for pharmaceutical dust?

HEPA H13/H14 with a validated, closed dust discharge (BIBO), matched to the product's OEB band.

When do I need an ATEX vacuum cleaner?

As soon as you work in a zone with combustible dust or vapour; a compressed-air-driven, earthed design avoids electrical ignition sources.

Can I use the same cleaner for several products?

Yes, provided you swap the filter unit per product and apply CIP/WIP cleaning to prevent cross-contamination.

Mobile or central: which is better?

Mobile for incidental and local use; central for large areas, continuous dust generation or multiple extraction points.

Related guides

Tailored advice from HECHT

Looking for a vacuum cleaner that suits your dust, OEB band and environment? HECHT's specialists analyse your dust load, classification and layout and advise a mobile or central solution with the right filtration and ATEX design. Contact us for a cleaning analysis and a tailored proposal.

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ATEX and explosion safety in powder processing

Dust explosions are an underestimated risk in the powder processing industry. A cloud of fine organic or metallic dust combined with an ignition source can trigger a devastating explosion within milliseconds. For engineers, buyers and QA managers in pharma, chemicals, food and the battery industry, ATEX-compliant process equipment is therefore not an option but a legal and operational necessity. HECHT supplies powder handling systems that build explosion safety into every design.

What ATEX means for your process

ATEX refers to two European directives: 2014/34/EU for equipment in explosive atmospheres and 1999/92/EC for the protection of workers. For powder processing companies this means all equipment in contact with combustible dust must be certified for the correct zone and explosion group. Non-compliant equipment leads to audit failures, insurance complications and, in the worst case, personal injury.

The core of ATEX compliance is breaking the explosion triangle: combustible dust, oxygen and an ignition source must never be present simultaneously in dangerous proportions.

Dust explosions: the mechanism

A dust explosion requires five elements, captured in the explosion pentagon:

  • Combustible dust — organic substances (sugar, starch, milk powder), metals (aluminium, lithium) or pharmaceutical APIs
  • Sufficiently fine particles — typically below 500 microns, with explosivity rising as particle size falls
  • Suspended dust cloud — a dispersion at a concentration above the lower explosion limit
  • Oxygen — from the ambient air
  • Ignition source — sparks, hot surfaces, static electricity or mechanical friction

Dust explosion characteristics are expressed in Kst value and Pmax. These determine the explosion class (St 1, St 2, St 3) and thereby the construction requirements.

Zoning: classifying ATEX zones

Zoning divides your installation according to the likelihood of an explosive dust atmosphere forming. Correct zone classification is the basis of the explosion protection document (EPD).

  • Zone 20 — dust cloud present continuously or for long periods, for example inside a mixer or silo
  • Zone 21 — present occasionally in normal operation, such as at filling and discharge points
  • Zone 22 — present rarely and briefly, typically in the immediate vicinity of equipment

HECHT equipment is available in category 1D, 2D and 3D versions, matched to the zone in which the equipment is installed.

Earthed design and static electricity

Static charging is one of the most common ignition sources in powder transport. Friction between powder and hose walls, or between powder and equipment surfaces, builds up charges that discharge as a spark. An earthed design prevents this.

HECHT consistently applies:

  • Continuous earthing — all conductive parts electrically bonded to an earth potential below 10⁶ ohm
  • Conductive or antistatic hoses and seals — to prevent charge build-up in flexible sections
  • Earthing control — monitoring systems that verify earthing continuity before a process starts

Explosion protection: preventing and controlling

ATEX recognises two strategies that HECHT combines: explosion prevention (avoiding ignition) and explosion protection (controlling the consequences). Where prevention cannot be fully guaranteed, constructive measures are applied.

  • Pressure-shock-resistant design — equipment built to withstand the full explosion pressure without failing
  • Explosion pressure relief — bursting discs that vent pressure in a controlled way to a safe area
  • Explosion suppression — fast-acting suppressant injection that smothers the explosion at its source
  • Decoupling — fast-closing valves that prevent an explosion propagating through pipework

Integration in dust-free and closed systems

Explosion safety and operator protection reinforce each other. A closed, dust-free process design not only limits operator exposure to powder but also reduces the chance of an explosive atmosphere outside the equipment. HECHT integrates ATEX compliance into vacuum transport, containment filling heads and dosing systems, so a single installation meets both safety and GMP requirements.

Inerting with nitrogen is a complementary measure: by bringing the oxygen content below the limit value, explosion becomes impossible regardless of dust concentration or ignition source.

Frequently asked questions about ATEX

When is ATEX equipment mandatory?

As soon as a combustible dust atmosphere can form in your process, ATEX applies. The zone classification determines the equipment category you need.

What is the difference between Kst and Pmax?

Kst indicates the rate of pressure rise and determines the explosion class; Pmax is the maximum explosion pressure. Both are needed to size protective measures.

Is earthing sufficient as protection?

Earthing prevents static ignition but does not cover all ignition sources. A complete ATEX concept combines prevention with constructive protection.

What is inerting?

Replacing oxygen with an inert gas such as nitrogen, making combustion impossible. This is especially relevant for lithium and reactive APIs.

How is zoning determined?

Based on the likelihood and duration of an explosive atmosphere, recorded in the explosion protection document. HECHT advises on this together with your safety officer.

Related guides

Tailored advice from HECHT

Explosion safety starts with the process design, not with a bursting disc added afterwards. HECHT analyses your powder properties, zone classification and handling process and delivers an ATEX-compliant system that aligns with your GMP and operator protection requirements. Contact our engineers for a no-obligation risk analysis and a concept tailored to your installation.

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Sieving technology for powders

Screening technology separates powders and granules by particle size and removes unwanted foreign matter, lumps and oversize. It is an indispensable step for product quality: a screened powder flows better, doses more accurately and meets specification. For engineers, buyers and QA in pharma, chemical, food and the battery industry, the screening strategy determines purity, particle distribution and process reliability. HECHT supplies screening solutions tuned to your product, capacity and hygiene requirements.

What screening technology does

A screen passes powder over a tensioned mesh with a defined aperture. Particles smaller than the aperture fall through (the good fraction); larger particles, lumps and foreign matter are retained (the oversize). Through vibration, rotation or ultrasonic activation, the mesh stays open and throughput high. In this way, screening ensures a consistent particle distribution and a product free of contamination.

Main screen types

The choice depends on the separation goal, the capacity and the fineness.

  • Vibratory screen — circular vibration for general separation and control screening
  • Tumbler screen — gentle, horizontal motion for high precision and multiple fractions
  • Centrifugal screen — rotating rotor that pushes powder through a cylindrical mesh, high throughput
  • Control screen (safety screening) — fine screen that catches foreign matter just before packaging
  • Ultrasonic screen — ultrasonically activated mesh for very fine and sticky powders

Separating, control screening or de-lumping

Screening technology fulfils several roles, depending on where in the process the screen sits.

  • Classifying — splitting into multiple particle fractions to specification
  • Safety screening — final check for foreign matter before packaging
  • De-lumping — breaking up agglomerates and lumps into a free-flowing product
  • Separating — removing oversize, fibres or packaging residues

Capacity and fineness

A screen's throughput depends on the aperture, the screening area and the product properties. Fine apertures and sticky or moist powders lower capacity; ultrasonic activation then keeps the mesh open and restores throughput. HECHT dimensions the screen based on the required fineness, capacity and product properties, so you achieve both separation and throughput.

Dust-free screening and containment

Screening is an open process that releases a lot of dust without control. A closed screen design with sealed inlets and outlets, integrated into vacuum or screw conveying, keeps the dust inside. For highly active powders, the screen is built containment-compliant with split-butterfly valves and, depending on the OEB band, SMEPAC-verified enclosure to minimise operator exposure.

Hygienic design and ATEX

In pharma and food, screen and mesh are fully CIP/WIP-cleanable, in 316L with smooth surfaces and no dead zones to GMP and EHEDG. Quick-change screen decks speed up product changeovers and prevent cross-contamination. For combustible powders, the screen is earthed and built ATEX-compliant; for oxygen-sensitive battery powders, screening can take place under nitrogen.

Frequently asked questions about screening technology

What is the difference between classifying and safety screening?

Classifying splits a product into multiple particle fractions; safety screening is a final fine check that only catches foreign matter and oversize before packaging.

Which screen suits fine, sticky powders?

An ultrasonic screen keeps the fine mesh open and restores throughput with sticky or moist products.

How do I achieve high throughput in fine screening?

By combining sufficient screening area, the right motion (tumbler or centrifugal) and, where needed, ultrasonic activation.

Can I screen dust-free with highly active substances?

Yes, with a closed screen design, split-butterfly valves and SMEPAC-verified containment matched to the OEB band.

How fast can I change between products?

With quick-change screen decks and CIP/WIP cleaning, product changeovers are short and free of cross-contamination.

Related guides

Tailored advice from HECHT

Looking for a screening solution that separates, controls or de-lumps for your product and capacity? HECHT's specialists analyse your powder, fineness requirement and OEB band and design a screen that combines quality, throughput and dust-free operation. Contact us for a screening analysis and a tailored proposal.

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Containment filling heads: function, OEB classes and choice

Filling bags, drums, IBCs or reactors with powder is one of the most dust-sensitive steps in any production process. Every discharge releases fine dust that exposes operators, causes product loss and risks cross-contamination. Containment filling heads solve this at the source. For engineers, buyers and QA in pharma, chemicals, food and the battery industry, filling heads are the key to dust-free, controlled and GMP-compliant filling. HECHT designs filling heads that integrate seamlessly into your existing process.

What is a containment filling head?

A filling head is the connection between your dosing or transport system and the container being filled. A containment filling head adds enclosed dust control: the product flows within a sealed space from the outlet into the container without dust escaping to the surroundings. The difference from an open discharge point is fundamental: an open point accepts dust emission, a filling head eliminates it.

Filling heads are used in both small-scale manual filling and fully automated lines, and scale to OEB class and throughput.

How dust-free filling works technically

Dust-free filling relies on controlling displaced air. When powder flows into a container, an equal volume of air must flow out. That air carries dust with it. The filling head captures this air and filters the dust back into the process.

  • Sealed coupling — an inflatable or mechanical seal connects the container airtight
  • Return venting — displaced, dust-laden air is extracted and filtered
  • Negative pressure control — a slight vacuum in the fill zone keeps dust inside the system
  • Product guidance — a central fill pipe guides the powder gently into the container to limit turbulence

Containment levels and OEB classes

Not every product requires the same protection level. The Occupational Exposure Band (OEB) determines how strict the containment must be. HECHT supplies filling heads across the full spectrum.

  • OEB 1–2 — standard low-dust filling heads with return venting, suitable for food and non-critical chemicals
  • OEB 3–4 — enhanced containment with double sealing and integrated filtration
  • OEB 5 — high containment with split butterfly valves and wash-in-place, for HPAPI and highly active substances

Containment performance is verified to SMEPAC, giving you objectively measured exposure values for your QA file.

Applications by industry

Filling heads are used in virtually every powder processing sector, each with different priorities.

  • Pharma — high-containment filling of APIs and formulations under GMP, with demonstrable operator protection
  • Chemicals — dust-free filling of pigments, additives and reactive powders, often in an ATEX zone
  • Food — hygienic filling to EHEDG standards, with cleanable surfaces and avoidance of product residue
  • Battery — controlled filling of cathode and anode materials under inert atmosphere

Cleaning, GMP and EHEDG

For validated production, cleanability is as important as containment. A filling head that cannot be thoroughly cleaned poses a cross-contamination risk during product changeovers. HECHT designs filling heads with polished, crevice-free surfaces that meet GMP and EHEDG guidelines.

Depending on the application, the filling head is available with wash-in-place (WIP) or clean-in-place (CIP), so cleaning takes place without disassembly and with reproducible results. This shortens downtime between batches and supports your validation.

Integration into the process chain

A filling head never functions in isolation. Its performance depends on how it works with the dosing system, vacuum transport and downstream containers. HECHT supplies filling heads as part of an integrated handling concept in which dosing accuracy, transport capacity and containment are matched to each other.

This prevents bottlenecks: a filling head is only as good as the feed supplying it and the seal the container provides.

Frequently asked questions about filling heads

What is the difference between a filling head and an ordinary discharge point?

A discharge point is open and lets dust escape; a containment filling head seals the fill zone and filters displaced air, so no dust is released.

Up to which OEB class can HECHT fill?

Up to and including OEB 5, with split butterfly valves and WIP for highly active substances such as HPAPIs.

How is containment performance demonstrated?

Through SMEPAC tests that measure actual exposure concentration, usable as objective evidence in your QA file.

Are filling heads available ATEX-compliant?

Yes, in earthed and zone-certified versions for combustible powders and inert processes.

Can a filling head be fitted into an existing line?

Yes, HECHT designs the connection to your existing dosing and transport systems and to your container formats.

Related guides

Tailored advice from HECHT

The right filling head depends on your product, OEB class, container format and cleaning requirements. HECHT brings these factors together in a single validated design that protects operators, eliminates product loss and passes your audits. Contact us for an analysis of your filling process and a tailored filling head concept.

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See also: complete guide to containment OEB 1 to 6

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Rotary valves for powder processing: operation, types and applications 2026

Anyone transporting powders, granulates or pellets via pneumatic systems will sooner or later encounter the dosing gate — also known as a rotary valve, rotary airlock or rotating valve. This compact device plays a crucial role in every powder processing installation: it provides controlled transfer of bulk goods between spaces of different pressure, without losing the airflow.

For process engineers and production managers in pharma, fine chemicals, food and battery production, choosing the right dosing gate directly affects process stability, production loss and installation safety.

How does a dosing gate work?

A dosing gate consists of a rotor with cells (vanes) that rotates within a cylindrical housing. The principle is simple but effective:

  1. Filling — material drops through the inlet into the rotor's cells
  2. Transport — the rotor turns and carries the material to the outlet
  3. Discharge — the material drops or is blown into the receiving system

Rotation speed determines dosing accuracy: slower = less material per unit of time. This makes the dosing gate suitable for both continuous processes and precise batch dosing.

Because the rotor seals off the space between the high- and low-pressure sides, the pressure difference remains intact. This is essential in pneumatic transport, where the transport air would otherwise escape via the material stream.

Types of dosing gates

Not every dosing gate is suitable for every application. The main variants:

Standard dosing gate (open rotor)

For dry, free-flowing materials without high hygiene requirements. Suitable for granulates, pellets and non-sticky powders in the chemical industry.

GMP dosing gate (hygienic design)

Fully cleanable (CIP/SIP), polished surfaces, no dead zones. Required for pharma, food and nutraceuticals. Complies with FDA and EHEDG standards.

ATEX dosing gate

For explosion-sensitive powders (St1–St3) in zones 20, 21 or 22. Fitted with an explosion-proof motor, grounding and spark-free materials. Mandatory for flammable powders such as fine metal dust, pigments or certain food products.

Containment dosing gate (closed system)

For products with a low exposure limit (OEL < 1 µg/m³). Equipped with a mechanical seal to fully prevent dust emission. Applicable to APIs, cytostatics and hormones.

High-temperature dosing gate

For hot gases, drying processes or high-temperature pneumatic transport. Housing and rotor are made of heat-resistant steel.

Applications by sector

Pharma and API production: Dosing gates are used for transferring active substances between dryer, mill and packaging. Containment versions with SMEPAC validation are standard for OEB 3–5 products.

Fine chemicals and ATEX environments: Pigments, catalysts and fine chemicals require ATEX compliance. The dosing gate acts as a pressure-resistant transition in the pneumatic transport system.

Food and nutraceuticals: Sugars, proteins, herbs and vitamins are hygienically transferred via GMP dosing gates with CIP capability. The installation complies with EHEDG and FDA standards.

Battery production: Lithium salts (LiPF6) and cathode material (NMC, LFP) are moisture- and oxygen-sensitive. The dosing gate is fitted with an inert gas seal and ATEX Zone 21 certification.

Plastics and polymer processing: Granulates and pellets are precisely dosed into extruders and mixing installations via dosing gates, with minimal particle damage.

What to consider when choosing a dosing gate?

Several parameters play a role in selecting a dosing gate: bulk density and flow properties of the material, desired throughput capacity (kg/h or m³/h), pressure difference across the gate (bar), ATEX requirement (zone and dust class), hygienic design (CIP/SIP), wear resistance for abrasive material and the required containment level (OEL class).

An incorrectly chosen dosing gate leads to wear, leakage, product loss or — in the worst case — a safety incident. Hecht Technology always advises based on product analysis and process parameters.

Hecht Technology: integrated dosing gate solutions

Hecht Technology supplies and integrates dosing gates as part of a complete powder handling system. From pneumatic transport to containment filtration: the dosing gate is matched to the product, the pressure difference and the safety requirements of your installation.

More information about dosing gates and rotary valves is available at hecht-technology.nl and hecht.eu.

Conclusion

A dosing gate is an indispensable link in every powder processing installation with pneumatic transport. The right version — GMP, ATEX or containment — determines the safety, accuracy and cleanability of your process. Choose based on product characteristics and process parameters, not on price alone.

Want to know more? Visit hecht-technology.nl or get in touch directly.

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