Liquid crystal polymer (LCP) is used in thin-wall parts such as fine-pitch connectors and coil bobbins. For a grade comparison, start with the exact Vectra or Zenite designation, then check shrinkage by flow direction and behavior after the planned reflow profile.
LCP Liquid Crystal Polymer: What Changes in the Mold?
Thermotropic LCP molecules retain a degree of order in the melt and align during injection. The molded part can therefore respond differently along and across the direction of flow.
Flow direction, gate location and converging melt fronts can affect shrinkage, flatness and strength. Identify the loading direction and functional dimensions before freezing the gate and tool layout.
For a supplier-grade comparison, consult the Celanese Vectra and Zenite material overview and request the current technical data sheet for the exact grade.
Vectra A130, Vectra E130i and Zenite 6130
| Property and test method | Vectra A130 | Vectra E130i | Zenite 6130 |
|---|---|---|---|
| Total filler content | 30% | 30% | 30% |
| Densité · ISO 1183 | 1,620 kg/m³ | 1,610 kg/m³ | 1,620 kg/m³ |
| Tensile modulus · ISO 527-2/1A, 1 mm/min | 15 000 MPa | 15 000 MPa | 13 000 MPa |
| HDT à 1,8 MPa · ISO 75-1/-2 | 235 °C | 276 °C | 268 °C |
| Retrait du moule, parallèle / normal · ISO 294-4 | 0.20% / 0.40% | 0.10% / 0.10% | 0.15% / 0.80% |
Source: Celanese short-term LCP properties guide. These are typical test results. Confirm the current grade sheet before specifying the material.
LCP, PPS and PEEK by Application Requirement
Choose the candidate grade against the assembly conditions. Compare equivalent test methods, and use samples to check dimensions after heat exposure. A resin family name alone gives little information about the molded part.
| Exigence relative aux pièces | Que faut-il comparer ? |
|---|---|
| Thin wall and long flow path | Fill trial, weld-line location and minimum section on the actual tool. |
| Exposition à la chaleur | HDT test load, service duration and dimensional change after the planned reflow profile. |
| Assembly fit | Directional shrinkage, flatness, creep and retention of inserts or terminals. |
Where LCP, PPS and PEEK Differ in a Buying Decision
- LCP : consider for a thin-wall electrical component where filling, terminal position and post-reflow fit drive the choice.
- P.P.S. : compare a named molding grade where the assembly calls for a different balance of chemical exposure, heat and geometry.
- PEEK : evaluate a named grade for the specified load and service environment; include the process and qualification cost in the comparison.
These are candidate-selection routes, not a universal ranking. Ask for the same part-level acceptance evidence from each proposed route.
Checks Before a Grade Substitution
- Use the actual wall section and flow length to judge fill.
- Compare directional shrinkage and flatness through the expected thermal profile.
- Ask for grade documentation and agree how the molded part will be inspected.
The table provides three named starting points, not interchangeable purchase specifications. Check the full grade suffix, color and current documentation before approving an alternative.
Mise en œuvre du LCP : paramètres de moulage par injection
| Process step | What to agree before sampling |
|---|---|
| Drying and handling | Confirm grade-specific drying, moisture control and residence-time instructions. |
| Filling | Review gate, venting and weld lines at the actual wall thickness. |
| Sample verification | Measure functional dimensions before and after the agreed thermal or conditioning cycle. |
Informations clés sur le traitement :
- Review weld-line location relative to contact loading, ribs and clip roots.
- Use the selected grade’s processing guide to set the starting conditions.
- Inspect the first samples and record the process window used to make them.
Principales applications du LCP
| Candidature | Validation des pièces |
|---|---|
| Fine-pitch connector | Check terminal position and housing flatness before and after reflow. |
| Coil bobbin | Review weld lines, winding load and the required electrical evidence. |
| Sensor or relay housing | Review dimensional stability, contact retention and grade-specific flammability documentation. |
Limites du LCP
- Orientation can affect dimensions and strength across the flow direction.
- A weld line near a terminal or clip can become a local weak point. Verify the molded part under its actual load.
- A material substitution can change fill, shrinkage and assembly fit. Recheck functional dimensions before release.
Classification des types LCP : I, II, III
Some references group thermotropic LCPs into Types I, II and III by polymer chemistry and thermal behavior. For sourcing, use the trade name, grade code and current supplier documentation.
| Selection input | Justificatifs à fournir |
|---|---|
| Grade identity | Trade name, exact grade designation and current data sheet. |
| Exposition à la chaleur | HDT test load, application duration and any grade-specific thermal rating. |
| Fit or appearance | Trial part from the proposed gate and tool layout with functional dimensions identified. |
Compare grades at the same HDT load and using comparable test specimens. Use a part trial to determine dimensional stability through the required thermal cycle.
Interpreting LCP Grade Data
Thermal and Electrical Acceptance for the Assembly
Separate continuous service temperature from the short reflow cycle and from HDT under a stated test load. For terminal housings, agree which positions and flatness dimensions are measured before and after the actual assembly thermal profile. Low moisture absorption alone does not establish the finished part’s dimensional acceptance.
Where electrical insulation or flame performance matters, identify the required test, part thickness and grade-specific documentation. The resin family name does not establish an approval for the assembled device.
For gate placement, wall transitions and weld-line review, use the Celanese Vectra design guide alongside the current grade sheet. Mark terminal retention loads and critical weld-line locations on the drawing before the tool layout is released.
Questions fréquemment posées
En quoi le LCP se distingue-t-il des autres plastiques techniques ?
Molecular orientation during filling can lead to different shrinkage and mechanical behavior in the flow and transverse directions. Inspect the dimensions that control terminal or mating-part fit.
Quelles sont les principales applications du LCP dans le domaine de l'électronique ?
Common applications include fine-pitch connectors, coil bobbins and related thin-wall electrical components. Request the relevant electrical, flammability and thermal evidence for the exact grade and part thickness.
En quoi le Vectra LCP se distingue-t-il du Zenite LCP ?
Vectra and Zenite are Celanese LCP product families. A130, E130i and 6130 in the table differ in HDT and directional shrinkage despite the same nominal filler level. Compare current grade sheets before specifying a substitute.
Le LCP peut-il être utilisé dans le domaine médical ?
Ask the supplier for the exact grade, declaration and test documentation applicable to the device, contact duration and intended use. Have the device team confirm whether any part-level validation is required.
Que doit comporter un appel d'offres pour le moulage par injection de LCP destiné à un connecteur à paroi mince ?
Veuillez fournir le boîtier et l'ensemble de bornes, les sections minimales des parois, les positions critiques des bornes, les contraintes relatives aux lignes de soudure, l'exposition au refusionnement, ainsi que la documentation requise concernant la résistance électrique ou au feu. Précisez la référence exacte du LCP lorsqu'une référence est homologuée. Demandez que le devis distingue clairement la vérification des matériaux, l’examen du remplissage et des points d’injection, la manipulation des inserts, l’inspection des échantillons et la validation de la production, plutôt que de traiter toutes les nuances de LCP comme interchangeables.
Request an LCP Grade or Molded-Part Review
Need resin? State the approved trade name and full grade code, color, required documents, sample quantity and expected usage. If the grade is not fixed, explain the application and the tests it must pass. Availability is confirmed for the requested specification.
Need finished components? Send the housing and mating-terminal drawings, minimum wall, annual quantity and thermal profile. Mark terminal positions, retention loads, cosmetic areas and any prohibited weld-line location.
Grade values are typical. Confirm the current supplier data sheet and validation requirements before placing an order.
