What should be paid attention to in the process of processing and manufacturing thermoplastic acrylic resin?

The processing of thermoplastic acrylic resin needs to focus on three main points: temperature control, solvent selection and compatibility matching, while avoiding melt degradation and product defects to ensure processing efficiency and finished product quality.

1. Temperature control: avoid overheating degradation.

Temperature is a key parameter in the processing process, which directly affects the fluidity and stability of resin.

The processing temperature should strictly match the resin model, usually between 180-250℃, which is subject to the thermal stability data provided by the supplier.

Avoid excessive local temperature, such as screw retention area or nozzle blockage, otherwise it will lead to resin decomposition, bubbles, discoloration or mechanical properties degradation.

During the cooling stage, the cooling rate should be controlled, too fast may lead to stress concentration, cracking or deformation of the product; Too slow will affect production efficiency.

2. Selection of solvents and additives: ensure the balance between dissolution and performance.

Thermoplastic acrylic resin is often processed by solution method or melting method, and the choice of solvents and additives directly affects the processing process and the properties of finished products.

When processing the solution, it is necessary to choose solvents with good solubility and moderate volatilization rate (such as toluene and ethyl acetate) to avoid sticking or pinholes on the surface of the product caused by solvent residues.

When melting processing, if additives such as plasticizer and antioxidant need to be added, it is necessary to ensure their compatibility with resin to prevent the precipitation of additives from affecting appearance and weather resistance.

Avoid using strong polar or corrosive solvents, so as not to destroy the molecular structure of resin and reduce the strength of products.

3. Equipment and process parameters: Adapting resin fluidity

Adjust the equipment parameters according to the melting index (MI) of the resin to ensure the stability of the processing.

During injection molding or extrusion, the rotation speed and back pressure of the screw should match the fluidity of the resin: the rotation speed and back pressure of the resin with poor fluidity should be increased to ensure mold filling; For resins with good fluidity, the parameters should be lowered to prevent overflow.

Mold design should be smooth and exhaust well, so as to avoid the difficulty of demoulding products due to rough mold surface or the bubbles caused by poor exhaust.

Before processing, it is necessary to dry the resin (usually the moisture content should be lower than 0.1%) to avoid the evaporation of water at high temperature, which will lead to the appearance of silver lines or voids in the products.

4. Compatibility and blending processing: avoiding performance conflicts.

If it needs to be modified by blending with other plastics (such as PVC and ABS), it is necessary to focus on compatibility.

Priority should be given to selecting resin brands with verified compatibility, or adding compatibilizer (such as maleic anhydride graft) to prevent delamination of the blending system and affect the mechanical properties of the products.

When blending, the mixing ratio and dispersion uniformity of each component should be controlled to avoid processing difficulties or uneven performance of finished products caused by excessive local concentration.