Low Profile Additives for Zero-Shrinkage Molding

Advanced thermoplastic additives that eliminate mold shrinkage in compression molding and pultrusion. Essential for achieving Class-A automotive surfaces and precision-molded parts.

The Science of Dimensional Control

Lechi Low Profile Additives (LPA) are thermoplastic polymers that phase-separate during the curing process to counteract the natural volumetric shrinkage of unsaturated polyester resins. By carefully balancing the expansion of the thermoplastic phase against the contraction of the thermoset matrix, our additives enable molders to achieve zero or even negative shrinkage. This technology is critical for automotive body panels, electrical housings, and any application where surface waviness or sink marks are unacceptable. Our portfolio includes PS, PVAc, PMMA, and Saturated Polyester systems, each optimized for specific performance requirements.

Eliminates surface sink marks and fiber read-through
Enables Class-A automotive surface finish
Compatible with SMC, BMC, and pultrusion processes
Available in colorable and non-colorable grades
Improves impact resistance in some formulations

Quick Stats

Product Models:6
Chemistry:UPR

Application Fields

SMC/BMC

Precision Surface Technology

Controlled Phase Separation

Engineered molecular weight distribution ensures uniform additive dispersion and predictable shrinkage compensation across the entire part.

Surface Gloss Enhancement

PMMA and Saturated Polyester grades deliver mirror-like surface gloss without the need for in-mold coating or post-painting.

Mechanical Property Balance

High-impact PS grades maintain or improve toughness while delivering low-profile performance, ideal for automotive safety components.

Processing Compatibility

Manufacturing Process Compatibility

Our Low Shrinkage Additives series is meticulously formulated to integrate seamlessly into your existing manufacturing infrastructure, from high-precision molding to heavy-duty winding.

Filament Winding
Pultrusion
SMC/BMC Molding
RTM/Infusion
Viscosity
Optimized
Flow control
Gel Time
Adjustable
Work life
Shrinkage
Low Rate
Precision
Storage
3-6 Months
Shelf life

Low Shrinkage Additives Specifications

Complete technical data for our low shrinkage additives lineup. Select the model that best fits your industrial requirement.

ModelChemical TypeViscosity (mPa·s)Gel Time (min)Molding ProcessApplication FieldCharacteristics
LC-3801
General PS
9000-15000
Compression molding, Pultrusion
SMC/BMC
Plasticity, colorable
LC-3803
General PS
4000-6500
Compression molding, Pultrusion
SMC/BMC
Plasticity, colorable
LC-3814
High Impact PS
3500-5500
Compression molding, Pultrusion
SMC/BMC
High impact, colorable
LC-3892
Saturated Polyester
150-230
Compression molding, Pultrusion
SMC/BMC
High gloss, low viscosity, non-colorable
LC-3817
PVAc
4200-4800
Compression molding, Pultrusion
SMC/BMC
Low profile, high brightness, non-colorable
LC-3870
PMMA
2500-3200
Compression molding, Pultrusion
SMC/BMC
High gloss, weather resistance, water resistance
Brand Strength

Why Global Industry Leaders
Choose Lechi Composites

1

Quality Assurance

Every batch undergoes rigorous testing in our ISO-certified facilities to ensure consistent mechanical properties.

2

R&D Innovation

Our technical team continuously refines chemical formulations to meet evolving international standards.

3

Reliable Supply Chain

Global production capacity of 600,000 tons provides stability for your large-scale projects.

LECHI
20+
Years Excellence

"Global Quality.
Professional Service."

Request Quote & Samples for Low Shrinkage Additives

Fill out the form below to receive a factory-direct quote and request free technical samples for your composite manufacturing.

Minimum 10 characters. Be specific about your requirements for better assistance.
By submitting this form, you acknowledge that your information will be processed according to our privacy policy. We typically respond within 24 hours during business days.

Achieve Perfect Surface Finish

Work with our molding experts to optimize your LPA loading and cure cycle for zero-shrinkage, Class-A parts.