- Introduction to Acrylic Production Process Flow
- Source： Hits：31 Date：2026-06-22
The scientific name of acrylic is polymethyl methacrylate (PMMA). The industrial mainstream is divided into two production routes: cast board and extruded board. In addition, there are acrylic pellets, pipes/rods, and bathroom integrated molding processes. The following will explain them in detail in modules.
1、 Basic Raw Material Description
1. Core raw materials
MMA monomer (methyl methacrylate, liquid transparent raw material, casting plate main material)
PMMA resin particles (solid particles for extrusion board and injection molding)
2. Functional additives
Initiator (benzoyl peroxide), UV anti UV agent, color paste, release agent, chain transfer agent, defoamer, toughening agent
2、 Full process flow of casting acrylic board (high transparency thick plate)
Cast plates are commonly used for thick plates, optical grade, fish tanks, displays, and handicrafts. They are produced intermittently in batches, with high molecular weight, 93% transparency, and low internal stress
Process 1: Pre polymerization pulping (core key)
MMA monomer is added to the stirring kettle to remove impurities that hinder the polymerization of raw materials;
Low speed heating at a constant temperature of 40-60 ℃ for pre polymerization, converting low viscosity monomers into viscous syrup (pre polymerization slurry);
Cool down to room temperature, add initiators, colorants, and UV resistant additives according to the formula, and stir evenly at high speed;
Vacuum defoaming: Negative pressure extracts bubbles from the slurry to avoid pinholes and white spots on the board.
Process 2: Mold Assembly (Glass Mold)
Select high polished tempered glass and thoroughly wipe it dust-free;
Assemble rubber sealing strips according to the thickness of the board, and the thickness of the sealing strips determines the thickness of the board;
Align the glass on both sides, lock and seal the fixture, and form a hollow cavity;
Tilt the mold and reserve injection and exhaust ports.
Process 3: Quantitative pouring and injection of materials
Inject the pre polymerized slurry after defoaming into the mold cavity at a constant speed, slowly exhaust the internal air, and seal the injection port.
Process 4: Segmented constant temperature polymerization curing (determines the quality of the board)
Low temperature water bath pre polymerization: The mold is sent to a 45~60 ℃ hot water tank for 12-24 hours of insulation, and polymerization occurs slowly to avoid rapid heating and internal stress and bubbles;
High temperature drying room curing: Raise the temperature to 85-95 ℃ and keep it warm for 4-8 hours to achieve a monomer conversion rate close to 100% and complete curing;
Gradient slow cooling to prevent thermal cracking, warping, and deformation of the board.
Process 5: Demoulding, Annealing to Relieve Stress
Open the fixture, separate the glass mold, and take out the entire acrylic substrate;
Annealing treatment: Bake at a constant temperature of 70-80 ℃ for 2-4 hours to release internal polymerization stress, and subsequent cutting and polishing are less likely to crack.
Process 6: Post processing, quality inspection, film coating packaging
Cut off the edge overflow and burrs;
Full inspection: transmittance, bubbles, scratches, thickness, color difference;
Double sided PE protective film for scratch resistance, cut into standard sizes, stacked and packaged for storage.
Characteristics of Casting Process
Can produce 1-300mm ultra thick sheets with high optical grade;
Long production cycle (1-3 days per batch) and high cost;
The thickness tolerance is slightly larger, suitable for high-end customized products.
3、 Continuous process flow for extruding acrylic sheets (large quantities of thin sheets)
Extrusion board is suitable for advertising thin sheets, light boxes, and vacuum forming. It is a fully automatic continuous production line with large output and high thickness accuracy
PMMA acrylic particles
Extruded acrylic sheet finished product
Process 1: Raw material drying pretreatment
PMMA particles are sent to a vacuum dryer and dried at 80-100 ℃ for 4-6 hours, with a moisture content controlled below 0.02%, to prevent melt foaming and surface fogging.
Process 2: Extrusion melting plasticization
Dry particles are fed into a single/twin-screw extruder;
Segmented temperature control of the barrel at 180-240 ℃, screw shearing and stirring, complete melting of particles into uniform PMMA melt;
The melt pump stabilizes the pressure and eliminates pressure fluctuations in the melt, ensuring uniform thickness of the plate surface.
Process 3: Die head casting molding
The high-temperature melt passes through a T-shaped flat die head to extrude continuous sheet-like melt, with precise control of the basic thickness of the die lip gap.
Process 4: Three roll calendering and shaping (core thickness setting)
The molten sheet enters three sets of high-precision polishing cooling rollers (roller temperature 40~60 ℃):
The thickness calibration of the upper, middle, and lower rollers can be controlled with a tolerance of ± 0.1mm;
Mirror polishing on the roller surface gives acrylic double-sided high gloss;
Synchronized water cooling for rapid shaping, preventing stretching and deformation.
Process 5: Traction, trimming, cooling and conveying
The tractor pulls the sheet at a constant speed, and the rotating blades on both sides cut off the burrs. The air-cooled roller conveyor is completely cooled and solidified.
Process 6: Film covering, fixed length cutting, winding/stacking
Double sided automatic protective film;
Servo cutting machine cuts according to the order size to a fixed length;
Thin plates can be rolled up, thick plates can be stacked, and automatic quality inspection and packaging are available.
Characteristics of Extrusion Process
Continuous high-speed production, suitable for 1-10mm thin plates, with low cost;
Uniform thickness, customizable length, good hot bending and vacuum forming performance;
Low molecular weight, weaker chemical resistance and polishing effect than cast plates.
4、 Production process of acrylic pellets (extrusion/injection molding raw materials)
Continuous polymerization in MMA polymerization reactor to produce block shaped PMMA;
Water cooling and crushing;
Double screw extrusion granulation, underwater cutting;
Dry screening, packaging, and produce transparent acrylic particles for supply to sheet metal, bathroom, and injection molding factories.
5、 Acrylic bathroom integrated molding process (bathtub, shower room)
Extrude acrylic thick plate substrate;
Heating and softening of the board in an oven (120-160 ℃);
Vacuum forming, fitting with molds to form bathtub and washbasin shapes;
Reinforced with fiberglass resin sprayed on the back;
Trimming, drilling, polishing, and assembling accessories.
6、 Core comparison between casting board and extrusion board process
table
Project Casting Acrylic Sheet Extrusion Acrylic Sheet
Raw material starting point MMA liquid monomer solid PMMA particles
Production method: Intermittent batch, 1 board, 1 mold, fully automatic continuous production line
Production cycle 1-3 days/batch, continuous output of several meters per minute
Suitable for thick plates with a thickness of 1-300mm and thin plates with a thickness of 1-10mm
Molecular chain with high molecular weight, toughness, chemical resistance, low molecular weight, easy to thermoform
Thickness tolerance ± 0.5~1mm ± 0.1mm, high precision
Extremely high transparency and optical properties, good ripple free performance, with slight water ripples
Representative uses include fish tanks, optical lenses, handicrafts, thick display boards, advertising light boxes, vacuum forming, signage, and thin decorative panels
7、 General Quality Control Points
Moisture control: Excessive moisture content generates bubbles and white mist;
Temperature curve: rapid heating, explosive board, high internal stress;
Defoaming process: The slurry/melt bubbles are directly scrapped;
Cleanliness: Dust causes black spots and pockmarks on the board surface;
Annealing treatment: unannealed sheets are prone to cracking during cutting and hot processing.
