Pulp Molding Machine Pre-Compression Stage Cycle Time

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Solution Overview

Problem

Conventional pulp molding machines have low production efficiency due to long cycle times and a high risk of crushing pulp molding articles during the thermo-forming stage, and they often imprint mesh patterns on the products, leading to inefficient and structurally compromised packaging.

Innovation Solution

A pulp molding machine with a pre-compression stage to reduce water vapor content in the pulp before thermo-forming, using a multi-stage process with precise mold gaps and heating to enhance drying and prevent structural damage, and employing porous metal molds to improve surface smoothness and reduce mesh imprinting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single-stage thermo-forming process is used to drain water from wet pulp, then the production cycle time is long (about 160 seconds), but the structural integrity of the pulp molding article is maintained

Engineering Contradiction:

Improveproduction efficiencyVSAvoidcycle time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The single-stage thermo-forming process is divided into multiple stages: a first thermo-forming stage for initial water drainage, followed by a second thermo-forming stage for final drying. This segmentation allows each stage to be optimized independently, reducing the overall cycle time while maintaining product integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first thermo-forming stage performs preliminary water drainage before the second stage. By removing a significant portion of moisture in the initial stage, the subsequent drying stage requires less time, thereby reducing the total cycle time while preserving structural integrity.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If a larger compression force is applied during thermo-forming to reduce production time, then the production efficiency improves, but the structure of the pulp molding article is crushed

Engineering Contradiction:

Improveproduction efficiencyVSAvoidstructural integrity

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The compression force is applied dynamically in two distinct phases: a first compression force during the initial thermo-forming stage, and a second compression force during the final drying stage. This dynamic adjustment allows efficient water removal without crushing the pulp structure.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The compression parameters are changed between stages: higher compression force and temperature in the first stage for rapid water drainage, and adjusted parameters in the second stage for final drying. This parameter optimization achieves both high productivity and structural integrity.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If conventional aluminum molds with mesh are used for dredging and thermo-forming, then the molding process is simple, but the mesh needs frequent replacement and imprints traces on the product surface

Engineering Contradiction:

Improvemolding process simplicityVSAvoidsurface smoothness

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs porous molds that utilize capillary action and porosity for water drainage instead of traditional mesh structures. This eliminates mesh imprints on the product surface while maintaining effective water removal, thereby improving surface smoothness without complicating the molding process.

Inventive Principle:

Principle #31Porous materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The process significantly reduces production time, enhances the structural strength and smoothness of pulp molding articles, and improves overall production efficiency while preventing structural damage and mesh imprinting issues.

Implementation Method 1

a first pre-compression forming sub-stage to drain off water or vapor in advance from the wet pulp with high water content between a first upper mold and a first lower mold

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

a compression thermo-forming stage for preventing the crushing of the structure of the pulp molding article during the compression thermo-forming stage if a larger compression force and thermal is applied

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 3

the wet pulp is thermo-compressed by and between a second upper mold and a second lower mold

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9976262B2Pulp molding machine, pulp molding process and paper-shaped article made thereby

Publication Date: 2018.05.22 GOLDEN ARROW PRINTING

AI summary

A pulp molding machine, a pulp molding process and a paper-shaped article made thereby are provided. The pulp molding machine comprises a pulp-dredging stage, a first pre-compression forming sub-stage, a second pre-compression stage, a compression thermo-forming stage and an edge-cutting stage. The pulp molding process comprises the steps of a pulp-dredging step, a first pre-compression forming step, a second pre-compression forming step, a compression thermo-forming step and an edge-cutting step. The pulp molding machine the pulp molding process can drain off water or vapor from a wet pulp more efficiently and shorten the cycle time of the pulp molding process due to the extra pre-compression sub-stage. The paper-shaped article made thereby has a greater smoothness and structural strength than conventional paper-shaped product.