The four Types of Molded Pulp

The emergence of molded pulp as a preferred means of packaging and protecting products can be attributed to several factors including improved molding technologies, processes and equipment, and the increasing need for environmentally friendly and sustainable packaging. Molded pulp is a superbly formable material providing endless design possibilities. It is remarkably versatile, and the type of molded pulp best suited for your specific project will depend on the product to be packaged and protected.

The International Molded Fibre Association has identified four categories of molded pulp. Keiding is classified as a Type 1: Heavy-Wall manufacturer. The fundamental characteristics of all 4 types are as follows:

Type-1: Thick-Wall

Heavy-Wall products, also referred to as Thick-Wall, commonly have wall thicknesses of 3/16" – 1/2". The finished surface is moderately smooth, the opposite side coarse. Product definition is moderate since only one forming mold is used. Standard volumes range between 20,000 – 2,000,000 parts annually and typical applications include blocking, bracing, cushioning & support.

Type-2: Transfer Molded

Transfer Molded products, also referred to as Thin-Wall, usually have wall thicknesses of 1/16" to 3/16". Two forming molds are used, the first to form and the second to transfer; therefore both front and back surfaces are relatively smooth, and product accuracy and definition are good. High-speed transfer molding technology assures high-capacity, and typical applications include egg cartons, drink & fruit trays, electronics and other delicate items.

Type-3: Thermoformed Fiber

Thermoformed molded pulp products originate from "cure-in-the-mold" technology producing strong, well-defined and smooth-surfaced parts. Wall thicknesses typically range between 1/16" – 1/8". Once formed the pulp is captured in heated forming molds which press and further densify the molded pulp product. Parts are ejected from the heated molds in their finished state; no oven drying is needed. Uses are for those where high-definition and appearance are essential.

Type-4: Processed

Processed molded pulp products are those that have undergone a secondary procedure in addition to the core manufacturing process. Secondary processing might include dying, coating, printing, die-cutting, chemical additions, etc.