What causes the surface of wood plastic products to turn white？

Wood plastic products, with their advantages of waterproofing, anti-corrosion, and environmental protection, are widely used in outdoor flooring, guardrails, decorative profiles, and other scenarios. However, many manufacturers often encounter problems such as whitening, white mist layer, and localized powdering on the surface of their products during production or end use, which not only affect the appearance and texture, but also seriously reduce the product’s weather resistance and service life. Most people only adjust raw materials, but ignore the core issues of equipment technology and production operations.

Beisu Machinery has been deeply involved in the research and manufacturing of wood plastic extrusion equipment for many years. Based on on-site debugging experience of wood plastic production lines, we have comprehensively identified the core reasons and improvement solutions for the whitening of the surface of wood plastic products.

The core fault reason for the whitening of the surface of wood plastic products

Unreasonable formula and raw material ratio

Formula issues are the most common root cause of wood plastic whitening. Some manufacturers choose low-quality small molecule lubricants and additives to reduce costs, which have poor compatibility with wood powder and plastic substrates. After production, they are prone to continuous migration to the surface of the product, forming a white precipitate layer. At the same time, if the proportion of wood powder added is too high and the raw materials are not dried thoroughly, residual water vapor will accelerate the penetration and precipitation of additives, coupled with changes in outdoor temperature and humidity, further exacerbating the surface whitening and flowering phenomenon.

Deviation control of extrusion process parameters

Wood plastic extrusion requires extremely high precision in temperature, pressure, and speed parameters. Unstable temperature control and fluctuating temperatures in various areas during the production process can lead to uneven plasticization of materials, resulting in localized areas of under plasticization and a matte white and rough texture on the surface of the finished product. In addition, excessive traction speed and tensile stress can cause plastic molecule orientation deformation, resulting in stress whitening on the surface of the product, especially at the edges and corners of the profile.

Production equipment configuration and matching issues

Insufficient device adaptability can also trigger batch whitening problems. Ordinary plastic extrusion equipment has not optimized the screw and die for the high filling characteristics of wood plastic, resulting in uneven material mixing, incomplete exhaust, residual air bubbles and voids inside the product, and a visually whitening effect after light refraction. The exclusive optimization of screw structure and exhaust system for the Beisu Machinery wood plastic production line can fully solve the problems of material mixing and insufficient exhaust, and reduce whitening defects from the equipment end.

Outdoor aging and environmental factors

Long term outdoor use of wood plastic products can cause UV radiation to damage the molecular structure of lignin and plastic, resulting in surface photooxidation and powdering, forming a uniform white frost like surface. If sufficient anti UV stabilizers and weather resistant additives are not added to the formula, or if there is no surface co extrusion protective structure, overall fading, whitening, powdering and aging problems may occur after short-term use.

Summary of fault rectification

In summary, the whitening of the surface of wood plastic products is mainly divided into two categories: production process defects and later environmental aging. Daily production needs to be improved from four dimensions: optimizing formula additives, stabilizing extrusion parameters, adapting specialized wood plastic extrusion equipment, and improving weather resistant formula system, which can significantly reduce the rates of whitening, powdering, and flower defects. As a professional manufacturer of extrusion equipment, Beisu Machinery can provide a complete set of technical support such as process debugging, parameter optimization, and equipment upgrades for wood plastic production lines.

FAQ

Q1: What is the reason why newly produced wood plastic products immediately turn white?

Mostly caused by the precipitation of additives, poor plasticization, or excessive tensile stress, priority can be given to adjusting the formula, extrusion temperature, and traction parameters to improve.

Q2: Is whitening after a period of outdoor use a quality issue?

Most likely, the aging problem is due to insufficient weather resistant additives and lack of UV protection, which is caused by inadequate formulation or equipment process protection.

Q3: How to quickly distinguish between additive whitening and stress whitening?

Additive whitening refers to the overall misty whitening that occurs repeatedly after wiping; Stress whitening is mostly concentrated at the corners, bending, and stretching positions.

Q4: Will equipment issues cause batches of wood plastic products to turn white?

Yes, ordinary extrusion equipment with insufficient mixing and exhaust capacity can cause sustained uneven plasticization, leading to batch appearance defects.

Q5: Does Beisu Machinery support wood plastic process debugging and rectification?

Support, providing a one-stop solution for equipment debugging and process optimization to address issues such as whitening, poor plasticization, and low output.

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