How long does polyamide need to be conditioned? Determining and reviewing conditioning times
What determines the conditioning time of PA6 and PA66 parts, and how to review an existing process time before you change it.
The right conditioning time has two limits. It is too short if the part does not reach the required condition: dry PA6 and PA66 are less tough at room temperature and are more prone to brittle fracture under impact or assembly loads.
Once the required condition, including the safety margin, has been reliably reached, additional time generally brings the part no further benefit. Whether it does harm depends on the process. If the part is simply approaching equilibrium with a suitably chosen climate, its moisture content barely changes; at elevated process temperatures, however, post-mould shrinkage and warpage can increase with duration. If the moisture supply is above the target, the part can take up more moisture than intended, with consequences for dimensions and stiffness. In every case, the extra time ties up equipment, floor space and inventory.
In practice, this often raises a second question: is the time a plant has used for years actually the time needed? In our experience, many specifications were set once and not re-examined since. This article explains what the conditioning time depends on, how to determine it, and how to review and safeguard an existing process time. Why polyamide is moisture-conditioned in the first place and which processes exist is covered in our guide How to condition polyamide.
Contents · 10 sections
Conditioning time follows from five inputs — if one is missing, any number of hours is a guess
A conditioning time is not a material property but the result for a particular part under particular conditions. Anyone who quotes one has to state the following five inputs with it; if one is missing, the figure cannot be verified.
What determines the time and what you need to know
| Factor | How it affects the time | What you need to know |
|---|---|---|
| Material and compound | grade and additives change the uptake behaviour; fillers and flame retardants can shift both the target and the rate | manufacturer, exact grade designation, filler content, flame retardant, datasheet |
| Wall thickness and geometry | in the diffusion model, the time scales with the square of the thickness; ribs and thin sections shorten the path the water has to travel | relevant wall thicknesses, thick sections, function-critical features |
| Initial moisture content | freshly moulded parts contain little water; parts stored beforehand will already have taken up moisture — how much depends on storage time and climate | time and storage climate between moulding and conditioning |
| Target condition | the closer the target is to the equilibrium of the climate provided, the longer it takes — and disproportionately so | target value or property target with reference basis, tolerance, sampling location and time of testing |
| Process and process parameters | higher temperature accelerates uptake; the moisture supply determines which equilibrium can be reached | process, temperature, humidity, programme sequence |
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A sixth, often overlooked factor is loading. It determines whether the least favourable position in a load needs the same time as the most favourable one.
How to define a target condition — with a reference basis, sampling location and test method — is explained in the section Which moisture content is right of our guide. For the question of time, one principle is enough: the target follows from the part’s requirements, never from the time you would like it to take.
In the diffusion model, conditioning time scales with the square of wall thickness
Water enters the part by diffusion, from the surface inwards. As long as uptake continues, the outer layers are wetter than the core. Such moisture gradients have been measured in PA6 test specimens by X-ray computed tomography and compared with a diffusion calculation.
The effect of wall thickness on the time is not linear. ISO 62 evaluates water absorption with Fick’s model of a flat plate whose surfaces are held at constant conditions, and in this model thickness appears squared. Applied to two walls, the model gives the following: a snap-fit hook one third as thick as the base would reach the same point in about one ninth of the time. A wall twice as thick would need roughly four times as long.
ISO 1110 likewise sets the minimum times before the first weighing and between weighings of polyamide test specimens in proportion to the square of the specimen thickness. Real parts deviate from the model: edges, ribs and changing wall thicknesses, uneven initial moisture and conditions that change during the process — for example while the load heats up — all play a part. The direction of the effect remains the same.
The last stretch to equilibrium takes the longest
At moisture equilibrium, a part neither takes up nor releases water in a given climate; the value applies to that climate only. The second consequence of the model is less widely known: uptake slows down the closer it gets to this equilibrium. The first half of the possible water uptake is reached comparatively quickly, while the last few per cent take the longest.
Under ISO 1110:2019, accelerated conditioning of polyamide test specimens is considered complete when three consecutive weighings lie within 0.1 %. The standard equates this with at least 95 % of the equilibrium value, not with “complete”, and states that further conditioning has no noticeable effect on the properties of the specimens. So even the test laboratory does not wait for the last remainder of uptake.
Two practical consequences follow. If the target condition lies close to the equilibrium of the climate provided, every further step towards it becomes expensive, because the final steps take up a large share of the total time. A target that is justified by the function and lies below that equilibrium, on the other hand, can be reached considerably earlier. This is no licence to lower targets — but it explains why two specifications with similar-sounding targets can need very different times.
PA6, PA66 and compounds: additives shift both the target and the rate
According to manufacturer information, unreinforced PA6 takes up more water than unreinforced PA66 in the same climate. It does not automatically follow that PA66 conditions faster or more slowly. Uptake capacity and uptake rate are different quantities: one describes how much water the material holds at equilibrium, the other how quickly it gets there.
Measurements on thin films of an unreinforced PA66 have shown that the diffusion coefficient rises with temperature and depends strongly on the water content above the glass transition temperature of the amorphous (disordered) regions. This is the temperature above which these regions are no longer hard and glassy but mobile; absorbed water lowers it. There is therefore no blanket rule that PA66 takes longer or shorter than PA6; it would depend on the grade, the climate and the target.
Glass fibres do not take up water themselves, but they count towards the mass. A moisture value referred to the whole part is therefore lower without the polymer matrix being any drier. Anyone who transfers a target value from an unreinforced to a reinforced grade can easily end up comparing two different quantities. Other additives, such as impact modifiers, also change the uptake behaviour.
Flame-retardant compounds can take longer — but this is not a rule
In our experience at Condisystems, certain flame-retardant polyamide compounds can need longer conditioning times than comparable grades without flame retardant. This does not apply to every flame retardant. For this article, we found no published study that directly compares the uptake rate of flame-retardant and non-flame-retardant polyamides.
Flame retardants are not a single substance. To our knowledge, very different systems are used in polyamide compounds — the finished blend of polymer, fibres and additives — including both halogenated and halogen-free systems, among them systems based on red phosphorus. The datasheet and the material designation show which system a grade contains: under ISO 1043-4, flame retardants are identified by “FR” and a code number.
What datasheets show about flame retardants and moisture — and what they do not
A datasheet comparison from a single manufacturer shows that a flame-retardant grade can have a lower equilibrium value in the standard atmosphere 23/50 (23 °C, 50 % relative humidity) than a comparable grade without flame retardant. Ultramid A3EG5 from BASF is a PA66 with 25 % glass fibre and no flame retardant (PA66-GF25; the 25 % is a mass fraction). For this grade, BASF gives an equilibrium moisture absorption in this atmosphere — listed in the datasheet as saturation — of 1.7 to 2.1 %. For the comparable grade with a flame retardant based on red phosphorus, Ultramid A3X2G5, it gives 1.4 to 1.7 %. Saturation in water at 23 °C is 5.7 to 6.3 % for both.
All of these are typical values, determined by a method similar to ISO 62. They refer to the whole material, including glass fibres and flame retardant, not to the polymer matrix. ISO 62 refers to the mass of the pre-dried test specimen; the datasheets do not state the exact basis. They are not values for parts.
The datasheets do not say whether the lower value is due to the flame retardant itself or to other differences in the formulation. They say nothing about the rate of uptake, and they apply to two grades from one manufacturer, not to flame retardants in general.
What this means for assessing the time
The widespread explanation that flame retardants form a barrier “within the molecular structure” is not established as a general statement and is no basis for planning. In practice, every assessment of conditioning time should start from the exact compound designation. The target value is set for the compound rather than carried over from the standard grade, and the conditioning time is determined on the flame-retardant part. If the compound changes — for example because of a change of supplier or a new fire-safety requirement — the existing time has to be reassessed.
Temperature, moisture supply and loading: how the process changes the conditioning time
A process changes the conditioning time through two levers: temperature, which sets the rate of diffusion, and the moisture supply, which determines which equilibrium can be reached. Studies on the PA6 and PA66 grades investigated have shown that higher temperature accelerates uptake considerably.
More heat is nevertheless not a free pass. Heat can trigger post-mould shrinkage in polyamide — annealing makes deliberate use of this. Whether and how strongly conditioning at elevated temperature has this effect depends on temperature, duration and grade; warpage, the heat resistance of the part and how evenly the load is heated also come into play. Which temperature a part can tolerate is a question for the material and the geometry, not for the equipment.
The moisture supply works differently: it sets the upper limit. The equilibrium depends on the relative humidity and the polyamide grade. If this equilibrium lies above the target condition, time has to limit the result; if it lies below, the part will not reach the target however long it is conditioned.
Loading plays a part in every process. Densely packed bulk loads, parts in the middle of a mesh pallet box or covered surfaces do not necessarily receive the same moisture and temperature as parts at the edge. When setting the time, what counts is therefore the least favourable position in a real load, not a sample part stored on its own.
What the process principles mean for the conditioning time
This overview considers process principles solely in terms of their effect on the conditioning time. The basic principle, selection criteria and limits of all processes are described in the section Which conditioning processes exist of our guide.
| Process principle | What determines the time | What to consider when setting the time |
|---|---|---|
| Unheated humid atmosphere | very high moisture supply at ambient temperature; process times are longer than with heated processes | ambient temperature varies with the building and the season; the time must also be sufficient at the lowest ambient temperature to be expected; used during storage or transport time |
| Heated steam or humid atmosphere (chamber, cabinet) | the rate rises with temperature; with container loads, the least well-reached part determines the time | set the time at the least favourable load position; assess the thermal load |
| Pressurised steam exposure (steam admitted to a closed vessel operated above ambient pressure) | high temperature and high moisture supply at the same time; with pure saturated steam, temperature rises with pressure | check heat resistance, warpage and surface; with short times, small variations carry relatively more weight |
| Vacuum-assisted processes | pressure reduction in a closed chamber, combined with steam | that the pressure reduction accelerates diffusion in polyamide has not been demonstrated; its effect on the conditioning time must be verified for each system and part |
| Water bath (parts immersed in cold or heated water) | water saturation lies well above equilibrium in the standard atmosphere; heated water accelerates uptake | if the target lies below water saturation, time has to limit the result and must be controlled precisely; parts come out wet, and water-soluble constituents can be leached out |
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The table describes process principles independently of any manufacturer, from the point of view of conditioning time. It contains no measurement results, no equipment data and no ranking. Process names used by equipment manufacturers are product designations and do not necessarily correspond to a row in this table.
For our own No-Energy process, our experience is as follows. In the regular process, it operates at nearly 100 % relative humidity, without additional heating and without active steam introduction, and the parts remain surface-dry and stain-free. Under particular conditions, such as rapid changes in temperature, condensation cannot be ruled out physically. Because the process is unheated, a shorter time here saves mainly equipment occupancy and floor space, hardly any energy.
Experience values are tied to their process. A time that has proven itself in a heated steam atmosphere says nothing about the same load without heating — and vice versa. Condisystems offers systems for saturated steam, vacuum, steam atmosphere and No-Energy conditioning; an overview is available under conditioning systems. What conditioning time a particular system needs for a particular part is not answered by an overview but by a trial.
A conditioning time set historically is not automatically the minimum time required
In many plants, the same conditioning specification has applied for years: one duration, one temperature, one humidity value, one process, one fixed sequence. It is followed reliably — but in our experience it is often no longer questioned. Typical possible origins of such specifications are:
- a time chosen generously as a precaution during start-up,
- experience with earlier moulds, machines or materials,
- a time carried over from a similar part,
- changes to material, mould, geometry or requirements without the specification being adjusted.
The list describes possible causes, not documented individual cases from customer projects. None of these origins makes a specification wrong. It only means that its duration is a decision, not proof of the shortest sufficient time. A review can therefore have three outcomes. The existing time may be appropriate or longer than necessary — or it may no longer be sufficient under today’s conditions, for example after a change to a flame-retardant compound or a thicker wall. The third outcome is valuable too.
What a validated reduction can achieve — and under what conditions
A shorter conditioning time is not an end in itself. Its benefit arises in production, and there it depends on the role conditioning plays in the material flow.
| Possible effect | Condition under which it occurs |
|---|---|
| More runs per system | Occupancy per batch falls. More parts pass through production, however, only if conditioning is the bottleneck and loading, unloading, cooling or transport do not become the new bottleneck |
| Shorter lead time | Parts are ready for assembly or dispatch sooner — unless they then wait for a fixed collection date anyway |
| Lower work-in-progress | At the same throughput, the inventory held in a process stage falls in proportion to its residence time, provided operation is steady. In the hypothetical worked example (36 → 20 hours, freely chosen figures), around 44 % fewer parts would, arithmetically, be in conditioning |
| Better planning | Shorter times that are reliably met fit more easily into shift and delivery schedules |
| Lower cost per batch | With heated processes, energy and occupancy costs can fall; with unheated processes, mainly the occupancy of equipment and floor space; an amount can only be derived from your own costs |
| Less additional equipment | Existing systems may be able to handle more parts — but only if the reduction has been validated and applies to all parts concerned |
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The hypothetical worked example, with freely chosen figures, shows how time and capacity relate to each other. A week has 168 hours; at 36 hours per run, around 4.7 runs fit in arithmetically, at 20 hours 8.4 — not 44 % more, but 1.8 times as many. This figure is an upper limit for the system alone, with continuous operation and no ancillary times. With loading and unloading, shift patterns and downstream processes, the actual gain is smaller, and for production as a whole it only arises where conditioning limits the pace.
Would you like to review an existing conditioning time? Send us an enquiry.
Test function-critical features specifically — the rest of the part remains part of the requirement
In many polyamide parts, the function depends on just a few features: snap-fit hooks, clips and snap-fit joints, thin flexing ribs, assembly and locking features. These features are often thinner-walled than the base and can therefore reach the required condition earlier under the same conditions. For a specific part, this is not automatically established; the way the feature is connected, its geometry and the process control all play a part.
In addition, the condition at the end of the process is not the condition at assembly: afterwards, excess surface moisture is released quickly, moisture evens out between the thin feature and the base, and it continues to be exchanged with the surroundings. What matters is the condition at the time the requirement applies.
Basing the conditioning time on these features rather than on the whole part can make sense — but only if all requirements for the whole part are still demonstrably met. The base does not become irrelevant just because it does not snap into place.
Other areas have requirements of their own: dimensional accuracy and dimensional stability, stiffness and strength, long-term and creep behaviour, ease of assembly, electrical or other application-specific properties. A critical feature may also be thick-walled itself — a bearing seat, a screw boss, a thick section; it is then not the fastest but the slowest part of the component. Customer drawings, technical specifications, material requirements and existing process approvals remain in force.
Which features need which test
| Feature | Typical requirement | Suitable evidence |
|---|---|---|
| Snap-fit hook, clip, latch | deflection reserve during joining, no fracture, no stress whitening | assembly trial, joining and release force, visual inspection for stress whitening |
| Thin flexing rib | repeated bending without cracking | bending test with the number of cycles required by the specification |
| Locking and assembly feature | function in the assembled state | assembly under production conditions, retention force |
| Base, housing | dimensional accuracy, warpage, stiffness | dimensional inspection after conditioning and after storage, comparison with reference parts |
| Bearing seat, screw boss, thick section | fit, retention force, dimensional stability | dimensional and functional testing; where appropriate, water content of a sample taken from this area, determined to ISO 15512 |
| Whole part | requirements of the customer specification, e.g. a moisture value with reference basis | measurement by the method defined in the specification |
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Moisture measurements and functional tests complement each other. Weighing shows the average across the part; water content determination to ISO 15512 shows the water content of a sample taken from it. Only the functional test shows whether a feature performs its function.
Reviewing and validating an existing conditioning time: an eight-step procedure
The following procedure describes how an existing process time is technically reviewed. It is a review method, not a set of instructions for shortening: at the end, the existing time can be confirmed, shortened or extended. Validation here means demonstrating with documented trials that the process reliably delivers the required result under production conditions.
Step 1: Record the existing specification and where it came from
Record all the parameters used for conditioning today: duration, temperature, humidity, process, loading and the time between moulding and conditioning. Where the specification came from is just as important. An internal rule of thumb can be reviewed internally; a validated process specification approved by the customer, or a requirement in a drawing or specification, is binding and can only be changed through an agreed change.
Step 2: Define the requirements for the whole part and the acceptance criteria
Establish which functions the part has to perform during assembly and in service, and which material and customer requirements are binding. These are turned into measurable acceptance criteria — before the first trial. Anyone who sets the criteria only after seeing the results runs the risk of fitting them to the desired outcome.
Step 3: Identify critical features, test locations and worst-case conditions
Identify the features that are sensitive to too little or too much moisture, and the locations where measurements or tests will be made. This includes the least favourable permissible conditions in production — and which conditions these are depends on the target. Freshly moulded parts contain little water and, depending on the storage climate, can already take up moisture before conditioning. If a minimum condition has to be reached, the driest permissible initial condition is therefore usually decisive — for example after the shortest storage time or in a dry storage climate. If a maximum value has to be met, a wetter initial condition can be less favourable.
What has to be considered, then, are the actual permissible ranges of initial moisture content, storage time and storage climate — not simply the longest storage time. Added to this are the densest loading and the least favourable position in the load. At the same time, record which requirements on the rest of the part are to be tested as well.
Step 4: Plan comparative trials with graded times
Several conditioning times are investigated under otherwise identical, documented conditions, with the existing time as the reference. How many steps make sense and where they lie depends on the part; there are no generally valid time steps. Sample size and evaluation are planned with quality assurance so that the result supports a decision.
If you do not want to tie up your own equipment capacity for this, the conditioning of the trial parts can also be outsourced as contract conditioning, on a project basis and in all four processes. Results from a different system, however, initially apply only to that system and that process.
Step 5: Check the results against the acceptance criteria
Testing takes place at a defined point in time, ideally the time at which the requirement applies, often at assembly, because after the process the moisture evens out within the part and continues to be exchanged with the surroundings. Functional tests on the critical feature, dimensional checks on the base and moisture measurements are assessed together. What each measurement tells you is set out in the section How to verify successful conditioning of our guide.
Step 6: Safeguard process stability and robustness
A time that is sufficient once is not yet a production time. The result has to hold across material batches, the permissible variation in initial moisture content, changing loads and the variation of the equipment. The new time is therefore not set at the shortest step that passed, but with a justified margin above it.
Step 7: Validate the new process time and obtain approval
A shorter time only counts as suitable once it meets all requirements reproducibly and the necessary approvals are in place. Depending on the supply relationship, for example in the automotive supply chain, the customer has to be informed before the change is introduced or has to agree to it. Without this approval, the existing specification remains valid, even if the trials support a shorter time.
Step 8: Document, implement and monitor
The new time is laid down together with all parameters, the trial documentation and the acceptance criteria. The first production batches are tested more closely, and afterwards to the defined extent. If the material, supplier, mould, geometry or process changes, the time is reassessed — following the same logic that led to the review.
Checklist: documents you should have ready to review a conditioning time
- current specification with all parameters, and where it came from
- material with manufacturer, grade designation, fillers and flame retardant
- drawing with wall thicknesses and function-critical features
- binding customer and material requirements, existing process approvals
- acceptance criteria and test methods
- storage time and storage climate before conditioning
- loading, batch size and time available
- existing test results and known problems
How long will your parts need to be conditioned?
We can discuss with you how the conditioning time for your parts can be estimated from material and part data, which process is suitable and how an existing process time can be reviewed. How reliable an estimate can be depends on the information available; trials on the part and validation are often needed.
Conclusion: as long as necessary — and no longer than proven necessary
The conditioning time can only be set for a specific part, and it is only proven by testing the requirements on that part. Conditioning time scales with the square of wall thickness in the diffusion model, and uptake slows down as it approaches equilibrium. Even a change to the target, the wall or the compound can therefore shift the required time considerably.
An existing process time deserves the same scrutiny. It is a decision of its time, not proof of the shortest sufficient duration. Reviewing it can free up capacity and reduce lead time and inventory — or reveal that it is no longer sufficient under today’s conditions. Either result is only reliable with trials, evidence of robustness and approval; the new time is then set with a margin above the shortest step that passed.
Frequently asked questions
Does PA66 need different conditioning times from PA6?
A time determined for PA6 does not automatically apply to PA66, but in which direction and by how much it differs cannot be stated in general terms. Unreinforced PA6 takes up more water than unreinforced PA66 in the same climate; how quickly a grade reaches its target also depends on temperature and water content.
Why do thick-walled parts take disproportionately longer?
Because in the diffusion model the time scales with the square of the thickness: a flat plate twice as thick needs roughly four times as long to reach the same fraction of its final uptake. Real parts with ribs and varying wall thicknesses follow the model only approximately; the direction remains the same.
Do flame-retardant polyamides take longer?
In our experience, certain flame-retardant compounds can need longer conditioning times, but not every flame retardant does; there is no generally established cause. A datasheet comparison of two PA66-GF25 grades from the same manufacturer shows a lower equilibrium value in the standard atmosphere for the flame-retardant grade. The values refer to the whole material, not to the matrix, and whether this applies to flame retardants in general is an open question. In such a case, a target value carried over from the standard grade moves closer to the equilibrium. The conditioning time is therefore determined on the specific compound.
Does the whole part have to be fully conditioned?
Not necessarily — whether less is sufficient is decided by the requirements for the whole part. Function-critical features can reach their condition earlier than the base. Designing the process around these features is only permissible if all requirements for the whole part, including binding specifications, are still demonstrably met.
Can an existing conditioning time be shortened?
Possibly — if comparative trials show that a shorter time meets all requirements reproducibly and the necessary approvals are in place. A binding customer or material specification is not changed unilaterally; the trial results can, however, form the basis for agreeing a change with the customer. There is no guarantee that every time can be shortened.
What information does Condisystems need for an initial estimate?
Essential information: the material with manufacturer and exact compound designation; a drawing or description of the part with the relevant wall thicknesses; the requirement for the part or the desired target condition; and, if available, the current conditioning time with process parameters. Quantities and batch sizes, the time available in production and existing test results are also helpful. You can send your enquiry using our enquiry form.
Sources
Supported technical statements in this article are based on the following sources. Definitions, model calculations and conclusions worded as assessments are not referenced separately. Statements identified as the experience of Condisystems are based on operating practice, not on a publication. The standards apply to test specimens and test methods, not to the industrial conditioning of a particular part.
- 1ISO 62:2008 — Plastics — Determination of water absorption. Full text consulted. Supports: the flat-plate diffusion model with the squared effect of thickness, and its limits; water saturation on immersion; leaching of water-soluble constituents.
- 2ISO 1110:2019 — Plastics — Polyamides — Accelerated conditioning of test specimens, edition 4 (confirmed in 2024; replaces ISO 1110:1995, technically revised according to the foreword, which names the polyamide symbol and the references as the main changes). Introduction, clauses 1–7 and Table 1 consulted in the published preview. Supports: storage at 70 °C and 62 % RH until at least 95 % of the equilibrium value, completion via weighings within 0.1 %, minimum times before the first weighing and between weighings in proportion to the square of the specimen thickness, no noticeable effect of longer conditioning on the properties, slow uptake at room temperature, scope (test specimens; not above 2 % by mass of extractables).
- 3ISO 15512:2019 — Plastics — Determination of water content. Supports: water content of finished parts as well, including by Karl Fischer titration (scope according to the ISO abstract).
- 4ISO 291:2008 — Plastics — Standard atmospheres for conditioning and testing. Title and scope according to the standards catalogue.
- 5ISO 1043-4:2021 — Plastics — Symbols and abbreviated terms — Part 4: Flame retardants. Supports: identification of flame retardants by “FR” and a code number (scope according to the standards catalogue).
- 6IAPWS R7-97(2012) — Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. Supports: coupling of pressure and temperature for saturated steam.
- 7Sambale AK, Stanko M, Emde J, Stommel M: Characterisation and FE Modelling of the Sorption and Swelling Behaviour of Polyamide 6 in Water. Polymers 2021, 13(9), 1480. doi:10.3390/polym13091480. Supports: diffusion in PA6, temperature dependence, concentration-dependent diffusion coefficient, lower toughness in the dry state.
- 8Sambale AK, Maisl M, Herrmann HG, Stommel M: Characterisation and Modelling of Moisture Gradients in Polyamide 6. Polymers 2021, 13(18), 3141. doi:10.3390/polym13183141. Supports: measured moisture gradients in PA6 test specimens; water content as an integral value.
- 9Broudin M, Le Gac P-Y, Le Saux V, Champy C, Robert G, Charrier P, Marco Y: Water diffusivity in PA66: Experimental characterization and modeling based on free volume theory. European Polymer Journal 67 (2015) 326–334. doi:10.1016/j.eurpolymj.2015.04.015. Supports: diffusion coefficient of PA66 dependent on temperature and water content, strongly so above the glass transition temperature; PA66 films were investigated.
- 10DuPont: Zytel® and Minlon® Nylon Resins — Molding Guide, (05/17) GNE-A11218-00-A1216 (manufacturer’s guide). Supports: factors governing the time to equilibrium; low moisture content of freshly moulded parts; different uptake of PA6 and PA66; moisture equalisation after conditioning; post-mould shrinkage through annealing; effect of additives; water saturation well above equilibrium at 50 % RH. Manufacturer information for its own grades.
- 11BASF: Product information Ultramid® A3EG5, issue 09/2026. Supports: moisture absorption at 23 °C / 50 % RH and water absorption in water at 23 °C (typical values, similar to ISO 62).
- 12BASF: Product information Ultramid® A3X2G5, issue 09/2026. Supports: flame retardant based on red phosphorus; moisture absorption at 23 °C / 50 % RH and water absorption in water at 23 °C (typical values, similar to ISO 62).
- 13Little JDC: A Proof for the Queuing Formula: L = λW. Operations Research 9(3) (1961) 383–387. doi:10.1287/opre.9.3.383. Supports: relationship between inventory, throughput and residence time.
- 14condisystems.com, accessed 22 October 2026: pages on conditioning systems (processes offered, No-Energy principle) and contract conditioning (scope of service). Manufacturer information.